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The future of recombinant host defense peptides

Abstract

The antimicrobial resistance crisis calls for the discovery and production of new antimicrobials. Host defense peptides (HDPs) are small proteins with potent antibacterial and immunomodulatory activities that are attractive for translational applications, with several already under clinical trials. Traditionally, antimicrobial peptides have been produced by chemical synthesis, which is expensive and requires the use of toxic reagents, hindering the large-scale development of HDPs. Alternatively, HDPs can be produced recombinantly to overcome these limitations. Their antimicrobial nature, however, can make them toxic to the hosts of recombinant production. In this review we explore the different strategies that are used to fine-tune their activities, bioengineer them, and optimize the recombinant production of HDPs in various cell factories.

Background

In 2019 alone, 1.27 million people died globally due to antimicrobial-resistant bacteria (ARB) [1]. At the current rate of resistance development, 10 million people will die by 2050 due to our inability to treat infections [1]. There is, therefore, a severe need to find suitable alternatives as effective as conventional antibiotics or that can be used in a combinatorial treatment [2].

One potential alternative is the use of host defense peptides (HDPs), which are a diverse and well-studied class of bioactive peptides (AMPs) that all multicellular organisms produce as a defense mechanism against pathogenic microbes [3, 4]. HDPs were discovered in the 1980s thanks to the keen eye of researchers that could not explain what they observed with their current understanding of immunity. For instance, Cecropia moth pupa that lacked antibodies or lymphocytes were still able to resist bacterial infections thanks to the action of cecropin [5]. Another example is the potent antimicrobial activity of rabbit neutrophils due to defensins [6] and the skin wound-healing abilities of an African clawed frog, thanks to secreted magainins [7]. Since then, the field of HDPs exploded and today there are more than 3000 known peptide sequences that come from all domains of life, including HDPs [8].

The characteristics that usually define HDPs are their short amino acidic sequences (between 12 and 50 amino acids) [4], a net positive charge [5], a certain degree of hydrophobicity [9] and a wide range of broad-spectrum biological activities [10]. Among these activities, HDPs have microbicidal (effective against bacteria, virus, and fungi) [11,12,13], antibiofilm [14, 15], and immunomodulatory activities [16,17,18]. Interestingly, it might be difficult for microorganisms to develop resistance against HDPs because of their multiple modes of action, which may ultimately lead to microbial death [3].

Their well-known characteristics make them amenable to engineering [19,20,21] (Fig. 1A, B), peptide repurposing, such as engineered venoms that can be modified to become non-toxic HDPs [22] (Fig. 1A), development of multidomain proteins based on the combination of different HDPs (Fig. 1B), de novo designs [9, 23] (Fig. 1C), or aid in the discovery of hidden peptides within larger protein structures [24] (Fig. 1D). All these new technologies yield an almost unlimited potential to modify known sequences or discover new peptides and modes of action.

Fig. 1
figure 1

Schematic figure showing several strategies that can be used to engineer antimicrobial peptides. A Rational modification of peptides to improve some of their features; B multidomain proteins based on the combination of different HDPs; C design new peptides based on their known properties; or D find encrypted peptides “buried” in known protein sequences

There are multiple ways to classify HDPs, considering their secondary structure or common ancestry, for example. In vertebrates, there are two major families of HDPs: cathelicidins and defensins [10]. The latter have a common β-sheet core stabilized by three disulphide bridges. Depending on how the cysteine residues link together, defensins are classified into α-, β-, and θ-defensins [10]. Instead, over one third of the cathelicidins are α-helical. Cathelicidins are produced as prepropeptides that need to be secreted and then cleaved by serine proteases [25]. However, there are other families, such as histatins, which are histidine rich HDPs from mammals’ saliva (Fig. 1D) [10, 24, 26].

Although some peptide-based antimicrobials are in advanced clinical trials, none of them has been granted regulatory approval [27]. There are many reasons, beyond the scope of this review, as to why that is the case, including potential toxicity, low stability, half-life, and a high production cost.

Together with the need to be safe and effective, one of the big questions that remains is how to produce them in large quantities in a sustainable way and with a competitive price. Besides, some strategies including chemical modifications and delivery vehicles are being studied to improve the properties of these peptides [28].

The first HDPs were isolated and purified from their natural sources, but this process is difficult and time-consuming, and results in low yields, making it difficult to scale up (Fig. 2). Most of the studies to date use chemically synthesized HDPs [29], and, by automated solid-phase peptide synthesis (SPPS) [29]. This strategy involves the repetitive binding of different amino acids to obtain the desired peptide sequence, which is bound to a resin support. Once the sequence is obtained, the peptide can be retrieved from the solid support with high purity via a cleavable linker.

Fig. 2
figure 2

Advantages and disadvantages of different recombinant expressions systems to produce HDPs [52, 108,109,110]. Only the most utilized systems are shown, as there are very few instances where mammalian cells have been used for recombinant HDP production, as it is probably too expensive and unnecessary in many cases. The bulk of the work with plant systems is based on transgenic plants to enhance their properties with genetic modifications, but not necessarily recombinant HDP production per se

Yet, in addition to the high production costs, one of the main problems of chemical synthesis is its environmental impact, due to the excessive use of organic solvents during the process [30]. Thus, it does not suit the needs of large-scale production [31]. Besides, chemical synthesis can be tricky for longer peptide sequences of more than 35 amino acid residues [32]. In this context, our goal in this review is to discuss the feasibility of recombinant HDP production as an alternative to chemical synthesis, considering several of the microbial cell factories that have been used so far, as well as various protein forms and strategies that lead to success in recombinant HDP production endeavors.

Cell factories for recombinant HDP production

As an alternative to chemical synthesis, technologies based on recombinant DNA have been explored for the biosynthesis of HDPs. The recombinant production of these peptides offers a more flexible, sustainable, scalable, and cost-effective production [31]. Many organisms can be used as hosts for recombinant HDP production, including plants, insect cells, mammalian cells, yeast, and bacterial cells [33]. However, choosing the optimal expression organism is critical to ensure proper protein yields, biological function, and final cost (Fig. 2).

Recombinant production in bacteria

The most extensively used host for recombinant expression of proteins and peptides are bacteria, as they are easy to manipulate, grow fast and use inexpensive media. Nevertheless, bacteria, have a limited ability to make disulphide-bonds, glycosylation, and other post translational modifications (PTMS) [34,35,36]. These limitations, however, might not be critical for HDP recombinant production [37]. In the absence of a strict need for PTMS, the heterologous expression in bacteria is a reasonable approach for their production with sufficient conformational and functional quality.

As it occurs for many other recombinant proteins, the most utilized bacterium for HDP production is E. coli (Table 1), since it has been widely studied as a recombinant host, with an extensive knowledge of its genetics, biochemistry, and physiology [38]. There are well-established protocols and a large catalogue of expression vectors, and besides, it grows fast. In addition, some HDPs have been successfully expressed in Lactococcus lactis (Table 1) and Bacillus subtilis. Although there are only few examples of HDPs produced in these LPS-free bacteria, they are appealing candidates considering their status as generally regarded as safe (GRAS). Most HDPs expressed in bacteria are produced with inducible expression systems yielding quantities that range between 2 and 600 mg/L [39].

Table 1 Recombinant expression of HDPs and the different cell hosts used to express them

Recombinant production in yeasts

Sometimes, the production of cysteine rich cationic HDPs fails in bacterial systems such as E. coli, due to an inefficient formation of disulphide bridges that leads to improper folding and lack of bioactivity [40]. Another concern when expressing HDPs in bacteria is their natural lethality towards the host [41]. Therefore, switching to eukaryotic cells can be a suitable alternative to overcome this challenge, allowing for the heterologous expression of HDPs. Yeasts are one of the simplest eukaryotic organisms [42] and offer a good compromise between the higher complexities of eukaryotic cells and the relatively simple and inexpensive recombinant production of prokaryotic systems (Fig. 2). Besides, they grow faster than typical mammalian recombinant hosts such as Chinese Hamster Ovary (CHO) or Human Embryonic Kidney (HEK293) cells. And yeasts are free from endotoxins and harmful human viruses and can secrete large amounts of heterologous recombinant proteins with little host cell protein secretion, which can simplify downstream purification (Fig. 2).

Exploiting all of these, a group from MIT [43] expressed apidaecin, an insect HDP, fused to human serum albumin (HSA) in the yeast Pichia pastoris. They obtained yields of more than 700 mg/L with no cell lysis and no debris removal steps required. However, because it is a fusion construct, downstream cleaving of the fusion tag was necessary. Fish [44], human [45] and fungal [46] peptides have also successfully been produced recombinantly in P. pastoris (Table 1), showing evidence that it can be a useful alternative to the most used expression system for recombinant production (E. coli). Saccharmoyces cerevisiae is another yeast-based system that has been used for the expression of HDPs [47, 48], albeit less than P. pastoris. The yields (mg/L) for HDPs expressed in yeast found in the relevant literature are highly variable [39], between less than 0.1 to up to 831 mg/L, suggesting the need to fine tune the expression system for each of the peptides.

Recombinant production in fungi

The use of filamentous fungi for HDP production is still in its infancy. However, interest in their use is growing due to their successful application in the recombinant production of non-antimicrobial proteins, their ability to perform PTMS, scale-up ability, and inexpensiveness of culture. The fungal defensin plectasin, developed for the treatment of Gram-positive bacterial infections is produced recombinantly using Aspergillus oryzae as a high efficiency recombinant protein expression system, produced as a secreted product (Table 1) [49]. Another example is the recombinant production of a hybrid HDP of magainin II-cecropin B, successfully expressed in Cordyceps militaris with a yield of 3.86 mg/g of mycelium (Table 1) [50].

Recombinant production in insect cells

The first isolated HDP was cecropin (1980), an insect HDP [5]. Insect cell-based systems prove to be very valuable for the recombinant expression of HDPs. In general, the most prevalent systems are based on Drosophila melanogaster cell lines, although there is some work in mosquito and moth cells [51]. Two main approaches are used to express HDPs in insect systems, either by using a Baculovirus gene expression system [35], or by stably expressing a HDP by means of genome integration of the HDP-coding gene.

Even though they are more expensive than yeast and prokaryotic-based systems, they offer PTMS such as glycosylation that might aid the proper structure and bioactivity of HDPs [52], although it is not clear if PTMS are necessary in all instances, or at all, suggesting that their need (or their lack of) might require to be studied on a case-by-case basis. However, when the Baculovirus system is used, the lytic cycle of the virus can cause large amounts of recombinant peptide loss due to degradation [53]. Yields of HDPs produced in insect systems are less well documented than for yeast or bacterial systems, and range between 6 and 25 mg/L [39].

Forms of recombinant HDPs

In general, recombinant HDPs have been produced in 3 main forms (Table 1): soluble protein (secreted or intracellular), inclusion bodies (IBs) or as encapsulated soluble protein.

Soluble recombinant production

Many HDPs have been successfully obtained through recombinant production in different expression systems in a soluble form (Table 1) [54, 55]. In E. coli and L. lactis, HDPs are typically produced intracellularly and purified after cell disruption (Table 1). In contrast, when B. subtilis, yeast or fungi are used, the sequences of the proteins of interest are, mostly, designed to be secreted to the growth media (Table 1). However, in many other cases, especially when using bacterial expression systems, HDPs aggregate forming IBs, being necessary to solubilize these protein aggregates (Table 1), as detailed in “IBs as a source of soluble HDPs” section.

Besides aggregation, another issue of recombinant bacterial expression of HDPs is their potential lethality to the recombinant host due to their antibacterial nature [56, 57]. In addition, they are highly susceptible to proteolysis due to their small size and positive charge. To overcome all these problems, the most common strategy is to produce soluble HDPs with a fusion partner or to produce them as multidomain proteins, as described in detail in “Strategies to optimize HDP production” section.

Encapsulated soluble HDPs

Some groups have also been working on the development of HDP delivery systems to have a time-controlled release to improve bioavailability and to minimize toxicity and proteolytic degradation and, in consequence, increase stability, when administered in vivo [58]. Most of these studies, however, have been done using synthetic HDPs. For example, different HDPs have been encapsulated using polymeric lactic-co-glycolic acid (PLGA) nanoparticles, showing that the encapsulated peptide kept the antimicrobial activity and did not increase toxicity when compared to the naked peptide [59, 60]. Other studies using PLGA microspheres decorated with N-acetyl cysteine (NAC) for pulmonary drug delivery have shown to have a good potential both in vitro and in vivo [61]. Synthetic HDPs have been also nanoencapsulated in lipid-based nanoparticles. A peptide from the cathelicidin family was encapsulated in liposomes and the authors proved that the peptide kept its antimicrobial activity while showing a sustained release and a reduction in pro-inflammatory cytokines release when compared to the non-encapsulated peptide [62]. Another approach that has been studied is the use of Polyethylene glycol (PEG)-stabilized lipodisks to protect cationic peptides [63]. There is also a recent study that evaluated the encapsulated form of recombinant HDPs. Kaur and coauthors analyzed the PEGylated form of mouse alpha-defensin cryptdin-2 [64] and they observed a two-fold decrease in the antimicrobial activity when cryptidin-2 is conjugated to PEG. This effect could be attributed to a masking effect of PEG, and further studies are needed to evaluate the impact of PEGylation size and site, as previously described [64]. Going a step further, Drayton and coworkers have designed an enzyme-cleavable HDP-PEG system for the delivery of active HDPs, which is based on the release of the antimicrobial peptide at the site of infection after cleavage by a host enzyme [65]. Thus, although much remains to be done, the results obtained so far are promising when it comes to increase peptide stability and decrease some of the adverse effects.

Antimicrobial inclusion bodies

IBs are protein nanoparticles or aggregates whose formation has been widely described in E. coli [56, 57], but also in other microbial expression systems such as lactic acid bacteria [66,67,68,69,70] and yeast [70, 71]. These aggregates can be easily purified [72] and offer interesting features not available in a soluble form. IBs are an active biomaterial that has already been explored in several applications such as cancer [73], biocatalysis [74], tissue regeneration [75] and immunostimulation [76], as they are highly stable protein nanoparticles with slow-release properties [56, 57, 77]. Recently, two studies have proven that HDP-based IBs are biologically active against different pathogenic bacteria [20, 37]. In the first study, López-Cano et al. showed that human α-defensin 5 (HD5) and lingual antimicrobial peptide (LAP) IBs are highly active against MRSA and Pseudomonas aeruginosa, with antimicrobial activities comparable to the soluble counterpart [37]. The second study showed the antibiofilm properties of IB-decorated surfaces against a carbapenem resistant Klebsiella pneumoniae [20], adding to the evidence that antimicrobial IBs can be effectively used against AMR bacteria.

To maintain antimicrobial activity, constant administration of an antimicrobial that has a short half-life is required, as concentrations under minimum inhibitory concentrations (MIC) will probably happen during treatment, further increasing the appearance of AMRs. This is why a slow-release profile seems to be vital to maintain constant antimicrobial levels for long periods, to get an optimal therapeutic benefit, where HDP-based IBs are promising protein format for antimicrobial applications [37]. Therefore, antimicrobial IBs can be used as nanopills that display antibacterial activity against different AMR Gram-positive and Gram-negative strains. These HDP-releasing nanopills can also be used to decorate plastic surfaces to avoid biofilm formation by bacteria [20]. In addition, the IB format per se can be antimicrobial, as one study found, where non-antimicrobial proteins such as GFP and IFN-γ, when presented as IBs, achieved a significant reduction in bacterial loads [13].

IBs as a source of soluble HDPs

IBs can also be used as an alternative source to obtain soluble HDPs when recombinant proteins aggregate (Fig. 3). This is useful when the isolated soluble version of the HDP is required for specific applications, but most of the protein of interest forms aggregates. It is especially relevant when HDPs are produced in E. coli, since in many cases it is necessary to recover the protein of interest from the aggregated fraction (Table 1). A high percentage (around 34%) of the recombinant HDPs produced in E. coli are extracted from IBs (Table 1).

Fig. 3
figure 3

Mild solubilization of HDP produced as IB in prokaryotic systems such as E. coli [20]

In general terms, high concentrations of denaturing agents such as 6M GdnHCl or 8M urea are used to extract soluble protein from IBs. However, alternative protocols have been developed in the last years [78]. Since it has been widely proven that proteins embedded in these nanoparticles can still be functional, the soluble form of different proteins has also been extracted under mild, non-denaturing conditions [20, 66, 78,79,80]. Unlike denaturing protocols, this last strategy allows to obtain soluble protein from IBs without the need to use unfolding and refolding processes. Among these articles, some of them have already successfully tried this approach using IBs formed by antimicrobial proteins [20, 21, 37]. Indeed, solubilized IB proteins show antimicrobial activity against E. coli in a dose-dependent fashion against carbapenem-resistant K. pneumoniae embedded in biofilms [20]. However, it is important to point out that the selection of an optimal mild solubilizer is especially relevant when antimicrobial proteins are purified because recently it has been reported that they can impair the antimicrobial activity [81].

Strategies to optimize HDP production

Fusion tags

There is a wide range of fusion partners (fusion tags) that have been used, as a strategy to properly express HDPs in a soluble form (Table 1). These solubility enhancing domains assist with correct folding and promote the expression to the soluble fraction of the protein of interest. In addition to enhance HDP solubility, tags might also protect against proteolysis, which HDPs are prone to due to their small size [82]. Some widely used solubility tags that tend to yield high levels of HDPs in the cytoplasm of E. coli are GST, Trx, GFP, SUMO and Silk (Table 1, Fig. 4A) [43, 83,84,85,86,87,88]. Although they need to be studied empirically on a case to case basis, in general they considerably improve the solubility of many recombinant proteins [89].

Fig. 4
figure 4

Different strategies allow the successful production of HDPs, which might otherwise be refractory to recombinant production. A A fusion partner that mimics the peptide precursor structure, but that must be removed downstream, B self-cleavable tags such as inteins, C specificity-targeting tags and D a multi-domain HDP combined or not with antimicrobial proteins and other non-antimicrobial domains

An interesting approach is the use of the N-terminal domain of spider silk as a fusion tag, which has been proven to yield up to 8 times more soluble protein compared to other frequently used expression tags and allows the expression of otherwise difficult to express peptides and proteins, such as the HDP precursor of LL-37 (hCAP18) [90]. Alternatively, acidic peptides can also be used, since they offer a charge-charge interaction that neutralizes the potential bactericidal effect of HDPs, avoiding the death of the host microorganism [91].

However, in many cases, there is a need to remove the carrier protein to isolate the peptide of interest. And often, removing the fusion partner requires expensive enzymatic cleavage or toxic reagents, such as cyanogen bromide or enterokinase hydrolysis [92, 93].

To overcome tag removal hurdles, self-cleaving tags (Fig. 4B), such as inteins can be used. Inteins are protein segments that can cut themselves from their precursors and re-join the flanking regions, also known as protein splicing [94]. This system has been used to express a cathelicidin, using B. subtilis as a host, allowing to purify the HDP by affinity chromatography and self-cleave in one step [95]. Self-cleaving tags, therefore, enable purification and cleavage in a single step, saving time, labor and reducing cost, but have an inherent risk of incomplete or uncontrolled cleavage [96].

Multidomain HDPs

Some researchers have explored the use of fusion partners that add other functions that go beyond just helping to fold and express the recombinant HDPs. An example of this are cationic elastin-like polypeptides (ELP), that have successfully been used to purify a fusion hybrid of cecropin A and D without the need of chromatography [97]. ELP tags allow to form reversible spherical aggregates that allow to precipitate the fused HDPs under certain temperature conditions, in a process called inverse transition cycling, thus simplifying downstream processing, in addition to allowing HDP expression.

A different example, that shows how fusion partners might add new features to HDPs, is the broad-spectrum plant defensin HDP C6, which can be fused to a peptide pheromone (cCF10) to add specificity to the original HDP. The cCF10 pheromone domain is species-specific and binds to the bacterial membrane of Enterococcus faecalis with high affinity, an appealing addition to the original antimicrobial activity that allows for the precise killing of E. faecalis while avoiding potential off-target killing of beneficial microorganisms found in the host microbiome, which is what most the conventional antibiotics do [98]. This type of multidomain approach is also known as specifically targeted antimicrobial peptides (STAMPs) [99]. Many combinations of killing and targeting domains can be tried, where wild-type, rationally enhanced or artificial sequences can be used [100,101,102,103]. In all cases, these hybrid antimicrobials show improved antimicrobial activity, selectivity, and kinetics against their specific targets [87, 98]. Nonetheless, there still are inevitable bactericidal effects on other bacteria.

The use of additional HDPs as fusion partners of other HDPs represents a unique strategy for the generation of recombinant multidomain HDPs (Fig. 5D), without the need for a carrier protein that needs to be removed downstream. For example, the pore-forming HD5 has been fused to an enzyme that hydrolyses bacterial membrane phospholipids, such as human XII-A secreted phospholipase A2 (sPLA2), generating a multidomain antimicrobial protein that can be successfully expressed recombinantly, and that attacks bacteria by using two completely different mechanisms [20]. This broad-spectrum multidomain construct, named JAMF1, was effective against several antibiotic resistant bacterial strains such as quinolone and carbapenem resistant K. pneumoniae (Fig. 5D). Similarly, in an effort to develop a vaccine against glyceraldehyde-3-phosphate dehydrogenase (GAPDH), an enzyme involved in the virulence of Mycoplasma bovis, different bovine HDPs were fused to GAPDH to boost the immune response against GAPDH (i.e. BMAP28, TAP and indolicidin) [104]. Interestingly, when HDPs are linked to enzymes, such as in the construct JAMF1 or GAPDH-HDP chimeras, both the enzyme and the HDP seem to keep the activities of the individual components, namely catalytic, antimicrobial, and immune-modulatory activities [21, 104].

Fig. 5
figure 5

The boundless possibilities of multidomain HDPs. There is a vast range of domains to choose from for each domain we might want to add to our chimeric HDP constructs, each one adding new functionalities, that might not necessarily be related to host defense (i.e. target specificity)

Mutlidomain HDP fragment-stitching

Like the multidomain approach, segments (but not the full active sequence) of an HDP can be stitched together in a hybrid molecule that is a mix of the parental peptides, a process we named HDP fragment-stitching. Fragments of peptides such as the human cathelicidin LL-37, CM4 from a Chinese domestic silk moth and TP5, a fragment of the thymus hormone, have been used in one study to create hybrid antimicrobial that works against enterotoxic E. coli [105]. Fragment-stitching might be useful to remove undesired activities from a parental peptide, such as the hemolytic activity of LL-37, while generating new HDPs.

Synergy of recombinant HDPs and antibiotics

The performance of antibiotics against some antimicrobial resistant (AMR) bacteria or in bacterial living resistant forms such as biofilms could be improved by their combination with other drugs. Numerous studies have assessed this principle by using synthetic HDPs [106] and antibiotics, demonstrating a clear synergy and beneficial effects on infection treatment. The main advantage of this strategy is to reduce the dose of each drug and consequently the possible toxic effects and eventually combine different mechanisms to control bacterial survival along with the emergence of bacterial resistances. In the context of recombinant HDPs, not many studies have been carried out. However, if synthetic HDPs can synergize with antibiotics, so should their recombinant version. To explore this, researchers tested the synergy of mouse β-defensin 3 (rMBD3) with different antibiotics against bacterial and yeast drug-resistant strains in vitro [107]. Interestingly, they found that the anti-methicillin-resistant S. aureus (MRSA) activity of rMBD3 in combination with ampicillin was synergistic, but it was not effective against methicillin sensible S. aureus [107]. Combinations of rMBD3 with itraconazole, amphotericin or 5-fluorocytosine were synergistic against two tested Candida albicans strains. These results support the potential of recombinant HDP to improve the activities of conventional antibiotics [107] and suggest that the same mechanism that makes bacteria resistant to a certain antibiotic might make them more vulnerable to combinatorial treatments.

Conclusions

HDPs hold promise as new candidates to combat antibiotic-resistant pathogens. There is a clear need for new potent HDP candidates and the means to produce them efficiently and at a low-cost. Research on different expression systems will effectively accelerate our ability to increase production yields, peptide structure and bioactivity and provide access to engineered microbial cell factories that work universally well for most HDPs. But the optimal expression systems are only one part of the equation.

New recombinant HDP forms, such as IBs and encapsulated HDPs, are also worth considering. They offer properties that the soluble form does not provide, including higher stability, a slower release profile, reduced HDP toxicity or on-site activation. Besides, IBs should be exploited as both a new antimicrobial HDP format and as a treasure trove of bioactive, functional, and soluble HDPs.

Finally, strategies to optimize HDP production, such as fusion tags and multidomain HDPs, open the door to designing newly added functionalities, such as the precise killing of a pathogen, while avoiding off-target effects on probiotic bacteria. Moreover, a well-crafted tag strategy not only increases the uses of a recombinant HDP but also should allow for its production without the need of downstream tag removal. Collectively, finely-tuned recombinant approaches show promise for much-needed sustainable, inexpensive, and larger-scale production of antimicrobial peptides as well as other peptide therapeutics and in turn, allow these molecules to enter clinical practice.

Availability of data and materials

The datasets supporting the review are referenced throughout the article.

Abbreviations

ARB:

Antimicrobial resistant bacteria

AMP:

Antimicrobial peptide

HDP:

Host-defense peptide

SPPS:

Solid-phase peptide synthesis

PTMS:

Post-translational modifications

GRAS:

Generally Recognized as Safe

CHO:

Chinese Hamster Ovary

HSA:

Human serum albumin

AMR:

Antimicrobial resistance

rMBD:

Recombinant mouse beta defensin

MRSA:

Methicillin resistant S. aureus

IB:

Inclusion bodies

HD5:

Human alpha defensin 5

CAP:

Cysteine rich acidic peptide

MIC:

Minimal inhibitory concentration

PLGA:

Poly(lactic-co-glycolic acid)

NAC:

N-Acetyl cysteine

PEG:

Polyethylene glycol

hCAP:

Human cathelicidin antimicrobial protein

ELP:

Elastin-like polypeptides

cCF10:

Cell-associated pheromone peptide

STAMPS:

Specifically targeted antimicrobial peptides

sPLA2 :

Secreted phospholipase A2

GAPDH:

Glyceraldehyde 3-phosphate dehydrogenase

References

  1. Antimicrobial Resistance Collaborators. Global burden of bacterial antimicrobial resistance in 2019: a systematic analysis. Lancet. 2022;399:629–55.

    Article  Google Scholar 

  2. Lázár V, Martins A, Spohn R, Daruka L, Grézal G, Fekete G, et al. Antibiotic-resistant bacteria show widespread collateral sensitivity to antimicrobial peptides. Nat Microbiol. 2018;3:718–31.

    Article  Google Scholar 

  3. Zasloff M. Antimicrobial peptides of multicellular organisms. Nature. 2002;415:389–95.

    Article  CAS  Google Scholar 

  4. Hancock REW, Sahl HG. Antimicrobial and host-defense peptides as new anti-infective therapeutic strategies. Nat Biotechnol. 2006;24:1551–7.

    Article  CAS  Google Scholar 

  5. Steiner H, Hultmark D, Engström A, Bennich H, Boman HG. Sequence and specificity of two antibacterial proteins involved in insect immunity. Nature. 1981;292:246–8.

    Article  CAS  Google Scholar 

  6. Lehrer RI, Szklarek D, Ganz T, Selsted ME. Correlation of binding of rabbit granulocyte peptides to Candida albicans with candidacidal activity. Infect Immun. 1985;49:207–11.

    Article  CAS  Google Scholar 

  7. Zasloff M. Antimicrobial peptides of multicellular organisms: my perspective. Adv Exp Med Biol. 2019;1117:3–6.

    Article  CAS  Google Scholar 

  8. Wang G, Li X, Wang Z. APD3: the antimicrobial peptide database as a tool for research and education. Nucleic Acids Res. 2016;44:D1087–93.

    Article  CAS  Google Scholar 

  9. Torrent M, Valle J, Nogués MV, Boix E, Andreu D. The generation of antimicrobial peptide activity: a trade-off between charge and aggregation? Angew Chem Int Ed Engl. 2011;50:10686–9.

    Article  CAS  Google Scholar 

  10. Mookherjee N, Anderson MA, Haagsman HP, Davidson DJ. Antimicrobial host defence peptides: functions and clinical potential. Nat Rev Drug Discov. 2020;19:311–32.

    Article  CAS  Google Scholar 

  11. Cândido ES, Cardoso MH, Chan LY, Torres MDT, Oshiro KGN, Porto WF, et al. Short cationic peptide derived from archaea with dual antibacterial properties and anti-infective potential. ACS Infect Dis. 2019;5:1081–6.

    Article  Google Scholar 

  12. Dassanayake RP, Falkenberg SM, Register KB, Samorodnitsky D, Nicholson EM, Reinhardt TA. Antimicrobial activity of bovine NK-lysin-derived peptides on Mycoplasma bovis. PLoS ONE. 2018;13:1–17.

    Article  Google Scholar 

  13. Carratalá JV, Brouillette E, Serna N, Sánchez-Chardi A, Sánchez JM, Villaverde A, et al. In vivo bactericidal efficacy of GWH1 antimicrobial peptide displayed on protein nanoparticles, a potential alternative to antibiotics. Pharmaceutics. 2020;12:1217.

    Article  Google Scholar 

  14. Mishra B, Wang G. Individual and combined effects of engineered peptides and antibiotics on Pseudomonas aeruginosa biofilms. Pharmaceuticals. 2017;10:58.

    Article  Google Scholar 

  15. De La Fuente-Núñez C, Cardoso MH, De Souza CE, Franco OL, Hancock REW. Synthetic antibiofilm peptides. Biochim Biophys Acta Biomembr. 2016;1858:1061–9.

    Article  Google Scholar 

  16. Freitas CG, Lima SMF, Freire MS, Cantuária APC, Júnior NGO, Santos TS, et al. An immunomodulatory peptide confers protection in an experimental candidemia murine model. Antimicrob Agents Chemother. 2017;61: e02518-16.

    Article  Google Scholar 

  17. van Harten R, van Woudenbergh E, van Dijk A, Haagsman H. Cathelicidins: immunomodulatory antimicrobials. Vaccines. 2018;6:63.

    Article  Google Scholar 

  18. Hancock REW, Haney EF, Gill EE. The immunology of host defence peptides: beyond antimicrobial activity. Nat Rev Immunol. 2016;16:321–34.

    Article  CAS  Google Scholar 

  19. Sandín D, Valle J, Chaves-Arquero B, Prats-Ejarque G, Larrosa MN, González-López JJ, et al. Rationally modified antimicrobial peptides from the N-terminal domain of human RNase 3 show exceptional serum stability. J Med Chem. 2021;64:11472–82.

    Article  Google Scholar 

  20. Roca-Pinilla R, López-Cano A, Saubi C, Garcia-Fruitós E, Arís A. A new generation of recombinant polypeptides combines multiple protein domains for effective antimicrobial activity. Microb Cell Fact. 2020;19:1–7.

    Article  Google Scholar 

  21. Roca-Pinilla R, Holani R, López-Cano A, Saubi C, Baltà-Foix R, Cobo ER, et al. Sequence edition of single domains modulates the final immune and antimicrobial potential of a new generation of multidomain recombinant proteins. Sci Rep. 2021;11:23798.

    Article  CAS  Google Scholar 

  22. Silva ON, Torres MDT, Cao J, Alves ESF, Rodrigues LV, Resende JM, et al. Repurposing a peptide toxin from wasp venom into antiinfectives with dual antimicrobial and immunomodulatory properties. Proc Natl Acad Sci USA. 2020;117:26936–45.

    Article  CAS  Google Scholar 

  23. De Santis E, Alkassem H, Lamarre B, Faruqui N, Bella A, Noble JE, et al. Antimicrobial peptide capsids of de novo design. Nat Commun. 2017;8:2263.

    Article  Google Scholar 

  24. Torres MDT, Melo MCR, Crescenzi O, Notomista E, de la Fuente-Nunez C. Mining for encrypted peptide antibiotics in the human proteome. Nat Biomed Eng. 2022;6:67–75.

    Article  Google Scholar 

  25. Gudmundsson GH, Agerberth B, Odeberg J, Bergman T, Olsson B, Salcedo R. The human gene FALL39 and processing of the cathelin precursor to the antibacterial peptide LL-37 in granulocytes. Eur J Biochem. 1996;238:325–32.

    Article  CAS  Google Scholar 

  26. Cesaro A, Torres MDT, Gaglione R, Dell’Olmo E, Di Girolamo R, Bosso A, et al. Synthetic antibiotic derived from sequences encrypted in a protein from human plasma. ACS Nano. 2022;16(2):1880–95.

    Article  CAS  Google Scholar 

  27. Haney EF, Straus SK, Hancock REW. Reassessing the host defense peptide landscape. Front Chem. 2019;7:43.

    Article  CAS  Google Scholar 

  28. Drayton M, Kizhakkedathu JN, Straus SK. Towards robust delivery of antimicrobial peptides to combat bacterial resistance. Molecules. 2020;25:3048.

    Article  CAS  Google Scholar 

  29. Münzker L, Oddo A, Hansen PR. Chemical synthesis of antimicrobial peptides. Methods Mol Biol. 2017. https://doi.org/10.1007/978-1-4939-6737-7_3.

    Article  Google Scholar 

  30. da Costa JP, Cova M, Ferreira R, Vitorino R. Antimicrobial peptides: an alternative for innovative medicines? Appl Microbiol Biotechnol. 2015;99:2023–40.

    Article  Google Scholar 

  31. Wibowo D, Zhao C-X. Recent achievements and perspectives for large-scale recombinant production of antimicrobial peptides. Appl Microbiol Biotechnol. 2019;103:659–71.

    Article  CAS  Google Scholar 

  32. Latham PW. Therapeutic peptides revisited. Nat Biotechnol. 1999;17:755–7.

    Article  CAS  Google Scholar 

  33. Sampaio de Oliveira KB, Leite ML, Rodrigues GR, Duque HM, da Costa RA, Cunha VA, et al. Strategies for recombinant production of antimicrobial peptides with pharmacological potential. Expert Rev Clin Pharmacol. 2020;13:367–90.

    Article  CAS  Google Scholar 

  34. Kaur J, Kumar A, Kaur J. Strategies for optimization of heterologous protein expression in E. coli: roadblocks and reinforcements. Int J Biol Macromol. 2018;106:803–22.

    Article  CAS  Google Scholar 

  35. Parachin NS, Mulder KC, Viana AAB, Dias SC, Franco OL. Expression systems for heterologous production of antimicrobial peptides. Peptides. 2012;38:446–56.

    Article  CAS  Google Scholar 

  36. Deng T, Ge H, He H, Liu Y, Zhai C, Feng L, et al. The heterologous expression strategies of antimicrobial peptides in microbial systems. Protein Expr Purif. 2017;140:52–9.

    Article  CAS  Google Scholar 

  37. López-Cano A, Martínez-Miguel M, Guasch J, Ratera I, Arís A, Garcia-Fruitós E. Exploring the impact of the recombinant Escherichia coli strain on defensins antimicrobial activity: BL21 versus Origami strain. Microb Cell Fact. 2022;21:77.

    Article  Google Scholar 

  38. Sørensen HP, Mortensen KK. Advanced genetic strategies for recombinant protein expression in Escherichia coli. J Biotechnol. 2005;115:113–28.

    Article  Google Scholar 

  39. Deo S, Turton KL, Kainth T, Kumar A, Wieden H-J. Strategies for improving antimicrobial peptide production. Biotechnol Adv. 2022;59: 107968.

    Article  CAS  Google Scholar 

  40. Kuddus MDR, Rumi F, Tsutsumi M, Takahashi R, Yamano M, Kamiya M, et al. Expression, purification and characterization of the recombinant cysteine-rich antimicrobial peptide snakin-1 in Pichia pastoris. Protein Expr Purif. 2016;122:15–22.

    Article  CAS  Google Scholar 

  41. Bommarius B, Jenssen H, Elliott M, Kindrachuk J, Pasupuleti M, Gieren H, et al. Cost-effective expression and purification of antimicrobial and host defense peptides in Escherichia coli. Peptides. 2010;31:1957–65.

    Article  CAS  Google Scholar 

  42. Yong E. Yeast suggests speedy start for multicellular life. Nature. 2012. https://doi.org/10.1038/nature.2012.9810.

    Article  Google Scholar 

  43. Cao J, de la Fuente-Nunez C, Ou RW, Torres MDT, Pande SG, Sinskey AJ, et al. Yeast-based synthetic biology platform for antimicrobial peptide production. ACS Synth Biol. 2018;7:896–902.

    Article  CAS  Google Scholar 

  44. Tai H-M, You M-F, Lin C-H, Tsai T-Y, Pan C-Y, Chen J-Y. Scale-up production of and dietary supplementation with the recombinant antimicrobial peptide tilapia piscidin 4 to improve growth performance in Gallus gallus domesticus. PLoS ONE. 2021;16: e0253661.

    Article  CAS  Google Scholar 

  45. Zhang X, Jiang A, Qi B, Yu H, Xiong Y, Zhou G, et al. Secretion expression of human neutrophil peptide 1 (HNP1) in Pichia pastoris and its functional analysis against antibiotic-resistant Helicobacter pylori. Appl Microbiol Biotechnol. 2018;102:4817–27.

    Article  CAS  Google Scholar 

  46. Liang X, Jiang H, Si X, Xin Q, Meng D, Chen P, et al. Boosting expression level of plectasin in recombinant Pichia pastoris via 2A self-processing peptide assembly. Appl Microbiol Biotechnol. 2022;106(9–10):3669–78.

    Article  CAS  Google Scholar 

  47. Thyab Gddoa Al-sahlany S, Altemimi A, Al-Manhel A, Niamah A, Lakhssassi N, Ibrahim S. Purification of bioactive peptide with antimicrobial properties produced by Saccharomyces cerevisiae. Foods. 2020;9:324.

    Article  Google Scholar 

  48. Xia L, Liu Z, Ma J, Sun S, Yang J, Zhang F. Expression, purification and characterization of cecropin antibacterial peptide from Bombyx mori in Saccharomyces cerevisiae. Protein Expr Purif. 2013;90:47–54.

    Article  CAS  Google Scholar 

  49. Mygind PH, Fischer RL, Schnorr KM, Hansen MT, Sönksen CP, Ludvigsen S, et al. Plectasin is a peptide antibiotic with therapeutic potential from a saprophytic fungus. Nature. 2005;437:975–80.

    Article  CAS  Google Scholar 

  50. Zhang M, Shan Y, Gao H, Wang B, Liu X, Dong Y, et al. Expression of a recombinant hybrid antimicrobial peptide magainin II-cecropin B in the mycelium of the medicinal fungus Cordyceps militaris and its validation in mice. Microb Cell Fact. 2018;17:18.

    Article  Google Scholar 

  51. Carballar-Lejarazú R, Rodríguez MH, de la Cruz H-H, Ramos-Castañeda J, Possani LD, Zurita-Ortega M, et al. Recombinant scorpine: a multifunctional antimicrobial peptide with activity against different pathogens. Cell Mol Life Sci. 2008;65:3081–92.

    Article  Google Scholar 

  52. Zitzmann J, Weidner T, Czermak P. Optimized expression of the antimicrobial protein Gloverin from Galleria mellonella using stably transformed Drosophila melanogaster S2 cells. Cytotechnology. 2017;69:371–89.

    Article  CAS  Google Scholar 

  53. Hu Y. Baculovirus as a highly efficient expression vector in insect and mammalian cells. Acta Pharmacol Sin. 2005;26:405–16.

    Article  CAS  Google Scholar 

  54. Ingham AB, Moore RJ. Recombinant production of antimicrobial peptides in heterologous microbial systems. Biotechnol Appl Biochem. 2007;47:1–9.

    Article  CAS  Google Scholar 

  55. Li Y, Chen Z. RAPD: a database of recombinantly-produced antimicrobial peptides. FEMS Microbiol Lett. 2008;289:126–9.

    Article  CAS  Google Scholar 

  56. Rinas U, Garcia-Fruitós E, Corchero JL, Vázquez E, Seras-Franzoso J, Villaverde A. Bacterial inclusion bodies: discovering their better half. Trends Biochem Sci. 2017;42:726–37.

    Article  CAS  Google Scholar 

  57. de Marco A, Ferrer-Miralles N, Garcia-Fruitós E, Mitraki A, Peternel S, Rinas U, et al. Bacterial inclusion bodies are industrially exploitable amyloids. FEMS Microbiol Rev. 2019;43:53–72.

    Article  Google Scholar 

  58. van Gent ME, Ali M, Nibbering PH, Kłodzińska SN. Current advances in lipid and polymeric antimicrobial peptide delivery systems and coatings for the prevention and treatment of bacterial infections. Pharmaceutics. 2021;13:1840.

    Article  Google Scholar 

  59. Sharma A, Vaghasiya K, Ray E, Verma RK. Nano-encapsulated HHC10 host defense peptide (HDP) reduces the growth of Escherichia coli via multimodal mechanisms. Artif Cells Nanomed Biotechnol. 2018;46:S156–65.

    Article  CAS  Google Scholar 

  60. Sharma A, Vaghasiya K, Ray E, Gupta P, Kumar Singh A, Datta Gupta U, et al. Mycobactericidal activity of some micro-encapsulated synthetic host defense peptides (HDP) by expediting the permeation of antibiotic: a new paradigm of drug delivery for tuberculosis. Int J Pharm. 2019;558:231–41.

    Article  CAS  Google Scholar 

  61. Sharma A, Vaghasiya K, Gupta P, Singh AK, Gupta UD, Verma RK. Dynamic mucus penetrating microspheres for efficient pulmonary delivery and enhanced efficacy of host defence peptide (HDP) in experimental tuberculosis. J Control Release. 2020;324:17–33.

    Article  CAS  Google Scholar 

  62. Javia A, Misra A, Thakkar H. Liposomes encapsulating novel antimicrobial peptide Omiganan: characterization and its pharmacodynamic evaluation in atopic dermatitis and psoriasis mice model. Int J Pharm. 2022;624: 122045.

    Article  CAS  Google Scholar 

  63. Reijmar K, Edwards K, Andersson K, Agmo HV. Characterizing and controlling the loading and release of cationic amphiphilic peptides onto and from PEG-stabilized lipodisks. Langmuir. 2016;32:12091–9.

    Article  CAS  Google Scholar 

  64. Kaur N, Dilawari R, Kaur A, Sahni G, Rishi P. Recombinant expression, purification and PEGylation of Paneth cell peptide (cryptdin-2) with value added attributes against Staphylococcus aureus. Sci Rep. 2020;10:12164.

    Article  CAS  Google Scholar 

  65. Drayton M, Alford MA, Pletzer D, Haney EF, Machado Y, Luo HD, et al. Enzymatically releasable polyethylene glycol—host defense peptide conjugates with improved activity and biocompatibility. J Control Release. 2021;339:220–31.

    Article  CAS  Google Scholar 

  66. Gifre-Renom L, Baltà-Foix R, Arís A, Garcia-Fruitós E. Nondenaturing solubilization of inclusion bodies from lactic acid bacteria. In: Insoluble proteins 2022. New York: Humana; 2022. p. 389–400.

    Chapter  Google Scholar 

  67. López-Cano A, Bach A, López-Serrano S, Aragon V, Blanch M, Pastor JJ, et al. Potential of oral nanoparticles containing cytokines as intestinal mucosal immunostimulants in pigs: a pilot study. Animals. 2022;12:1075.

    Article  Google Scholar 

  68. Cano-Garrido O, Sánchez-Chardi A, Parés S, Giró I, Tatkiewicz WI, Ferrer-Miralles N, et al. Functional protein-based nanomaterial produced in microorganisms recognized as safe: a new platform for biotechnology. Acta Biomater. 2016;43:230–9.

    Article  CAS  Google Scholar 

  69. Gifre-Renom L, Ugarte-Berzal E, Martens E, Boon L, Cano-Garrido O, Martínez-Núñez E, et al. Recombinant protein-based nanoparticles: elucidating their inflammatory effects in vivo and their potential as a new therapeutic format. Pharmaceutics. 2020;12:450.

    Article  CAS  Google Scholar 

  70. Villaverde A, Corchero JL, Seras-Fanzoso J, Garcia-Fruitós E. Functional protein aggregates: just the tip of the iceberg. Nanomedicine. 2015;10:2881–91.

    Article  CAS  Google Scholar 

  71. Rueda F, Gasser B, Sánchez-Chardi A, Roldán M, Villegas S, Puxbaum V, et al. Functional inclusion bodies produced in the yeast Pichia pastoris. Microb Cell Fact. 2016;15:166.

    Article  Google Scholar 

  72. Seras-Franzoso J, Cano-Garrido O, Peternel S, Arís A, Garcia-Fruitós E. Purification of inclusion bodies produced in bacteria and yeast. Methods Mol Biol. 2022;2406:401–16.

    Article  Google Scholar 

  73. Pesarrodona M, Jauset T, Díaz-Riascos ZV, Sánchez-Chardi A, Beaulieu M, Seras-Franzoso J, et al. Targeting antitumoral proteins to breast cancer by local administration of functional inclusion bodies. Adv Sci. 2019;6:1900849.

    Article  CAS  Google Scholar 

  74. Hrabárová E, Achbergerová L, Nahálka J. Insoluble protein applications: the use of bacterial inclusion bodies as biocatalysts. New York: Humana Press; 2015. p. 411–22. https://doi.org/10.1007/978-1-4939-2205-5_24.

    Book  Google Scholar 

  75. Seras-Franzoso J, Peebo K, García-Fruitós E, Vázquez E, Rinas U, Villaverde A. Improving protein delivery of fibroblast growth factor-2 from bacterial inclusion bodies used as cell culture substrates. Acta Biomater. 2014;10:1354–9.

    Article  CAS  Google Scholar 

  76. Torrealba D, Parra D, Seras-Franzoso J, Vallejos-Vidal E, Yero D, Gibert I, et al. Nanostructured recombinant cytokines: a highly stable alternative to short-lived prophylactics. Biomaterials. 2016;107:102–14.

    Article  CAS  Google Scholar 

  77. Gifre-Renom L, Seras-Franzoso J, Rafael D, Andrade F, Cano-Garrido O, Martinez-Trucharte F, et al. The biological potential hidden in inclusion bodies. Pharmaceutics. 2020;12:157.

    Article  CAS  Google Scholar 

  78. Singhvi P, Saneja A, Srichandan S, Panda AK. Bacterial inclusion bodies: a treasure trove of bioactive proteins. Trends Biotechnol. 2020;38:474–86.

    Article  CAS  Google Scholar 

  79. Gifre-Renom L, Cano-Garrido O, Fàbregas F, Roca-Pinilla R, Seras-Franzoso J, Ferrer-Miralles N, et al. A new approach to obtain pure and active proteins from Lactococcus lactis protein aggregates. Sci Rep. 2018;8:1–10.

    Article  CAS  Google Scholar 

  80. Singhvi P, Saneja A, Ahuja R, Panda AK. Solubilization and refolding of variety of inclusion body proteins using a novel formulation. Int J Biol Macromol. 2021;193:2352–64.

    Article  CAS  Google Scholar 

  81. López-Cano A, Sicilia P, Gaja C, Arís A, Garcia-Fruitós E. Quality comparison of recombinant soluble proteins and proteins solubilized from bacterial inclusion bodies. N Biotechnol. 2022;72:58–63.

    Article  Google Scholar 

  82. Li Y. Carrier proteins for fusion expression of antimicrobial peptides in Escherichia coli. Biotechnol Appl Biochem. 2009;54:1–9.

    Article  CAS  Google Scholar 

  83. Baker RT. Protein expression using ubiquitin fusion and cleavage. Curr Opin Biotechnol. 1996;7:541–6.

    Article  CAS  Google Scholar 

  84. Hammarström M, Hellgren N, van den Berg S, Berglund H, Härd T. Rapid screening for improved solubility of small human proteins produced as fusion proteins in Escherichia coli. Protein Sci. 2009;11:313–21.

    Article  Google Scholar 

  85. Dyson MR, Shadbolt SP, Vincent KJ, Perera RL, McCafferty J. Production of soluble mammalian proteins in Escherichia coli: identification of protein features that correlate with successful expression. BMC Biotechnol. 2004;4:32.

    Article  Google Scholar 

  86. Satakarni M, Curtis R. Production of recombinant peptides as fusions with SUMO. Protein Expr Purif. 2011;78:113–9.

    Article  CAS  Google Scholar 

  87. Wang M, Zheng K, Lin J, Huang M, Ma Y, Li S, et al. Rapid and efficient production of cecropin A antibacterial peptide in Escherichia coli by fusion with a self-aggregating protein. BMC Biotechnol. 2018;18:62.

    Article  CAS  Google Scholar 

  88. Sinha R, Shukla P. Antimicrobial peptides: recent insights on biotechnological interventions and future perspectives. Protein Pept Lett. 2019;26:79–87.

    Article  CAS  Google Scholar 

  89. van Ham TJ, Esposito A, Kumita JR, Hsu STD, Kaminski Schierle GS, Kaminski CF, et al. Towards multiparametric fluorescent imaging of amyloid formation: studies of a YFP model of α-synuclein aggregation. J Mol Biol. 2010;395:627–42.

    Article  Google Scholar 

  90. Kronqvist N, Sarr M, Lindqvist A, Nordling K, Otikovs M, Venturi L, et al. Efficient protein production inspired by how spiders make silk. Nat Commun. 2017;8:15504.

    Article  CAS  Google Scholar 

  91. Kim SC, Jang SA, Sung BH, Kim JM, Lim KJ, Shin JR, et al. Method for the mass expression of an antimicrobial peptide by co-expression of a basic antimicrobial peptide and an acidic peptide using a translational coupling system. US: Korea Advanced Inst Sci & Tech OP—KR 20070141932.

  92. Lee JH, Minn I, Park CB, Kim SC. Acidic peptide-mediated expression of the antimicrobial peptide buforin II as tandem repeats in Escherichia coli. Protein Expr Purif. 1998;12:53–60.

    Article  CAS  Google Scholar 

  93. Srinivasulu B, Syvitski R, Seo JK, Mattatall NR, Knickle LC, Douglas SE. Expression, purification and structural characterization of recombinant hepcidin, an antimicrobial peptide identified in Japanese flounder, Paralichthys olivaceus. Protein Expr Purif. 2008;61:36–44.

    Article  CAS  Google Scholar 

  94. Perler FB, Davis EO, Dean GE, Gimble FS, Jack WE, Neff N, et al. Protein splicing elements: inteins and exteins—a definition of terms and recommended nomenclature. Nucleic Acids Res. 1994;22:1125–7.

    Article  CAS  Google Scholar 

  95. He Q, Fu A, Li T. Expression and one-step purification of the antimicrobial peptide cathelicidin-BF using the intein system in Bacillus subtilis. J Ind Microbiol Biotechnol. 2015;42:647–53.

    Article  CAS  Google Scholar 

  96. Li Y. Self-cleaving fusion tags for recombinant protein production. Biotechnol Lett. 2011;33:869–81.

    Article  CAS  Google Scholar 

  97. Yang K, Su Y, Li J, Sun J, Yang Y. Expression and purification of the antimicrobial peptide cecropin AD by fusion with cationic elastin-like polypeptides. Protein Expr Purif. 2012;85:200–3.

    Article  CAS  Google Scholar 

  98. Xu L, Shao C, Li G, Shan A, Chou S, Wang J, et al. Conversion of broad-spectrum antimicrobial peptides into species-specific antimicrobials capable of precisely targeting pathogenic bacteria. Sci Rep. 2020;10:944.

    Article  CAS  Google Scholar 

  99. Sarma P, Mahendiratta S, Prakash A, Medhi B. Specifically targeted antimicrobial peptides: a new and promising avenue in selective antimicrobial therapy. Indian J Pharmacol. 2018;50:1.

    Article  Google Scholar 

  100. Xi D, Teng D, Wang X, Mao R, Yang Y, Xiang W, et al. Design, expression and characterization of the hybrid antimicrobial peptide LHP7, connected by a flexible linker, against Staphylococcus and Streptococcus. Process Biochem. 2013;48:453–61.

    Article  CAS  Google Scholar 

  101. He J, Yarbrough DK, Kreth J, Anderson MH, Shi W, Eckert R. Systematic approach to optimizing specifically targeted antimicrobial peptides against Streptococcus mutans. Antimicrob Agents Chemother. 2010;54:2143–51.

    Article  CAS  Google Scholar 

  102. He J, Anderson MH, Shi W, Eckert R. Design and activity of a ‘dual-targeted’ antimicrobial peptide. Int J Antimicrob Agents. 2009;33:532–7.

    Article  CAS  Google Scholar 

  103. Eckert R, Qi F, Yarbrough DK, He J, Anderson MH, Shi W. Adding selectivity to antimicrobial peptides: rational design of a multidomain peptide against Pseudomonas spp. Antimicrob Agents Chemother. 2006;50:1480–8.

    Article  CAS  Google Scholar 

  104. van der Merwe J, Prysliak T, Gerdts V, Perez-Casal J. Protein chimeras containing the Mycoplasma bovis GAPDH protein and bovine host-defence peptides retain the properties of the individual components. Microb Pathog. 2011;50:269–77.

    Article  Google Scholar 

  105. Cheng J, Ahmat M, Guo H, Wei X, Zhang L, Cheng Q, et al. Expression, purification and characterization of a novel hybrid peptide CLP with excellent antibacterial activity. Molecules. 2021;26:7142.

    Article  CAS  Google Scholar 

  106. Li J, Fernández-Millán P, Boix E. Synergism between host defence peptides and antibiotics against bacterial infections. Curr Top Med Chem. 2020;20:1238–63.

    Article  CAS  Google Scholar 

  107. Jiang Y, Yi X, Li M, Wang T, Qi T, She X. Antimicrobial activities of recombinant mouse β-defensin 3 and its synergy with antibiotics. J Mater Sci Mater Med. 2012;23:1723–8.

    Article  CAS  Google Scholar 

  108. Behrendt R, White P, Offer J. Advances in Fmoc solid-phase peptide synthesis. J Pept Sci. 2016;22:4–27.

    Article  CAS  Google Scholar 

  109. Yi T, Sun S, Huang Y, Chen Y. Prokaryotic expression and mechanism of action of aα-helical antimicrobial peptide A20L using fusion tags. BMC Biotechnol. 2015;15:1–10.

    Article  Google Scholar 

  110. Meng D-M, Zhao J-F, Ling X, Dai H-X, Guo Y-J, Gao X-F, et al. Recombinant expression, purification and antimicrobial activity of a novel antimicrobial peptide PaDef in Pichia pastoris. Protein Expr Purif. 2017;130:90–9.

    Article  CAS  Google Scholar 

  111. Zhou X, Wang Y, Pan Y, Li W. Nisin-controlled extracellular production of apidaecin in Lactococcus lactis. Appl Microbiol Biotechnol. 2008;78:947–53.

    Article  CAS  Google Scholar 

  112. Stambuk F, Ojeda C, Machado Matos G, Rosa RD, Mercado L, Schmitt P. Big defensin from the scallop Argopecten purpuratus ApBD1 is an antimicrobial peptide which entraps bacteria through nanonets formation. Fish Shellfish Immunol. 2021;119:456–61.

    Article  CAS  Google Scholar 

  113. Gong T, Du J, Li S-W, Huang H, Qi X-L. Identification and functional analysis of a defensin CcDef2 from Coridius chinensis. Int J Mol Sci. 2022;23:2789.

    Article  CAS  Google Scholar 

  114. Popa C, Shi X, Ruiz T, Ferrer P, Coca M. Biotechnological production of the cell penetrating antifungal PAF102 peptide in Pichia pastoris. Front Microbiol. 2019;10:1472.

    Article  Google Scholar 

  115. Panteleev PV, Bolosov IA, Kalashnikov AÀ, Kokryakov VN, Shamova OV, Emelianova AA, et al. combined antibacterial effects of goat cathelicidins with different mechanisms of action. Front Microbiol. 2018;9:2983.

    Article  Google Scholar 

  116. Al Kashgry NAT, Abulreesh HH, El-Sheikh IA, Almaroai YA, Salem R, Mohamed I, et al. Utilization of a recombinant defensin from Maize (Zea mays L.) as a potential antimicrobial peptide. AMB Express. 2020;10:208.

    Article  CAS  Google Scholar 

  117. Li Z-J, Zhang Z-X, Xu Y, Shi T-Q, Ye C, Sun X-M, et al. CRISPR-based construction of a BL21 (DE3)-derived variant strain library to rapidly improve recombinant protein production. ACS Synth Biol. 2022;11:343–52.

    Article  CAS  Google Scholar 

  118. Hao X, Chi H, Tang X, Xing J, Sheng X, Zhan W. The functions of β-defensin in flounder (Paralichthys olivaceus): antibiosis, chemotaxis and modulation of phagocytosis. Biology. 2021;10:1247.

    Article  CAS  Google Scholar 

  119. Ishida H, Nguyen LT, Gopal R, Aizawa T, Vogel HJ. Overexpression of antimicrobial, anticancer, and transmembrane peptides in Escherichia coli through a calmodulin-peptide fusion system. J Am Chem Soc. 2016;138:11318–26.

    Article  CAS  Google Scholar 

  120. Yang N, Teng D, Mao R, Hao Y, Wang X, Wang Z, et al. A recombinant fungal defensin-like peptide-P2 combats multidrug-resistant Staphylococcus aureus and biofilms. Appl Microbiol Biotechnol. 2019;103:5193–213.

    Article  CAS  Google Scholar 

  121. Acosta S, Quintanilla L, Alonso M, Aparicio C, Rodríguez-Cabello JC. Recombinant AMP/polypeptide self-assembled monolayers with synergistic antimicrobial properties for bacterial strains of medical relevance. ACS Biomater Sci Eng. 2019;5:4708–16.

    Article  CAS  Google Scholar 

  122. Xie Q, Wang Y, Zhang M, Wu S, Wei W, Xiao W, et al. Recombinant HNP-1 produced by Escherichia coli triggers bacterial apoptosis and exhibits antibacterial activity against drug-resistant bacteria. Microbiol Spectr. 2022;10: e00860-21.

    Article  Google Scholar 

  123. Wang A, Wang S, Shen M, Chen F, Zou Z, Ran X, et al. High level expression and purification of bioactive human α-defensin 5 mature peptide in Pichia pastoris. Appl Microbiol Biotechnol. 2009;84:877–84.

    Article  CAS  Google Scholar 

  124. Čipáková I, Hostinová E, Gašperı́k J, Velebný V. High-level expression and purification of a recombinant hBD-1 fused to LMM protein in Escherichia coli protein. Expr Purif. 2004;37:207–12.

    Article  Google Scholar 

  125. Maiti S, Patro S, Purohit S, Jain S, Senapati S, Dey N. Effective control of Salmonella infections by employing combinations of recombinant antimicrobial human β-defensins hBD-1 and hBD-2. Antimicrob Agents Chemother. 2014;58:6896–903.

    Article  Google Scholar 

  126. Cipakova I, Hostinova E. Production of the human-beta-defensin using Saccharomyces cerevisiae as a host. Protein Pept Lett. 2005;12:551–4.

    Article  CAS  Google Scholar 

  127. Lin Q, Xie K, Chen D, Yu B, Mao X, Yu J, et al. Expression and functional characterization of a novel antimicrobial peptide: human beta-defensin 118. Biomed Res Int. 2020. https://doi.org/10.1155/2020/1395304.

    Article  Google Scholar 

  128. Xu Z, Peng L, Zhong Z, Fang X, Cen P. High-level expression of a soluble functional antimicrobial peptide, human β-defensin 2, in Escherichia coli. Biotechnol Prog. 2006;22:382–6.

    Article  CAS  Google Scholar 

  129. Peng L, Xu Z, Fang X, Wang F, Yang S, Cen P. Preferential codons enhancing the expression level of human beta-defensin-2 in recombinant Escherichia coli. Protein Pept Lett. 2004;11:339–44.

    Article  CAS  Google Scholar 

  130. Vargues T, Morrison G, Seo E, Clarke D, Fielder H, Bennani J, et al. Efficient production of human β-defensin 2 (HBD2) in Escherichia coli. Protein Pept Lett. 2009;16:668–76.

    Article  CAS  Google Scholar 

  131. Wang F, Fang X, Xu Z, Peng L, Cen P. Fusion expression of human beta-defensin-2 from multiple joined genes in Escherichia coli. Prep Biochem Biotechnol. 2004;34:215–25.

    Article  Google Scholar 

  132. Huang L, Wang J, Zhong Z, Peng L, Chen H, Xu Z, et al. Production of bioactive human β-defensin-3 in Escherichia coli by soluble fusion expression. Biotechnol Lett. 2006;28:627–32.

    Article  CAS  Google Scholar 

  133. Xu Z, Zhong Z, Huang L, Peng L, Wang F, Cen P. High-level production of bioactive human beta-defensin-4 in Escherichia coli by soluble fusion expression. Appl Microbiol Biotechnol. 2006;72:471–9.

    Article  CAS  Google Scholar 

  134. Wang A, Su Y, Wang S, Shen M, Chen F, Chen M, et al. High efficiency preparation of bioactive human α-defensin 6 in Escherichia coli Origami(DE3)pLysS by soluble fusion expression. Appl Microbiol Biotechnol. 2010;87:1935–42.

    Article  CAS  Google Scholar 

  135. Huang L, Ching CB, Jiang R, Leong SSJ. Production of bioactive human beta-defensin 5 and 6 in Escherichia coli by soluble fusion expression. Protein Expr Purif. 2008;61:168–74.

    Article  CAS  Google Scholar 

  136. Liu H, Diao H, Hou J, Yu H, Wen H. Soluble expression and purification of human β-defensin DEFB136 in Escherichia coli and identification of its bioactivity. Protein Expr Purif. 2021;188: 105968.

    Article  CAS  Google Scholar 

  137. Dai J, Ou W, Yu G, Ai Q, Zhang W, Mai K, et al. The antimicrobial peptide cecropin AD supplement alleviated soybean meal-induced intestinal inflammation, barrier damage, and microbial dysbiosis in juvenile turbot, Scophthalmus maximus. Front Mar Sci. 2020;7: 584482.

    Article  Google Scholar 

  138. Reichhart J-M, Petit I, Legrain M, Dimarcq J-L, Keppi E, Lecocq J-P, et al. Expression and secretion in yeast of active insect defensin, an inducible antibacterial peptide from the fleshfly Phormia terranovae. Invertebr Reprod Dev. 1992;21:15–24.

    Article  CAS  Google Scholar 

  139. Perez-Perez DA, Villanueva-Ramirez TDJ, Hernandez-Pedraza AE, Casillas-Vega NG, Gonzalez-Barranco P, Zarate X. The small metal-binding protein SmbP simplifies the recombinant expression and purification of the antimicrobial peptide LL-37. Antibiotics. 2021;10:1271.

    Article  CAS  Google Scholar 

  140. Lin C-H, Pan Y-C, Liu F-W, Chen C-Y. Prokaryotic expression and action mechanism of antimicrobial LsGRP1C recombinant protein containing a fusion partner of small ubiquitin-like modifier. Appl Microbiol Biotechnol. 2017;101:8129–38.

    Article  CAS  Google Scholar 

  141. Hu J, Li S, Lv Q, Miao M, Li X, Li F. Characterization of the dual functions of LvCrustinVII from Litopenaeus vannamei as antimicrobial peptide and opsonin. Mar Drugs. 2022;20:157.

    Article  CAS  Google Scholar 

  142. Li J, Islam S, Guo P, Hu X, Dong W. Isolation of antimicrobial genes from Oryza rufipogon Griff by using a Bacillus subtilis expression system with potential antimicrobial activities. Int J Mol Sci. 2020;21:8722.

    Article  CAS  Google Scholar 

  143. Xu J, Zhong F, Zhang Y, Zhang J, Huo S, Lin H, et al. Construction of Bacillus subtilis strain engineered for expression of porcine β-defensin-2/cecropin P1 fusion antimicrobial peptides and its growth-promoting effect and antimicrobial activity. Asian-Australas J Anim Sci. 2016;30:576–84.

    Article  Google Scholar 

  144. Haught C, Davis GD, Subramanian R, Jackson KW, Harrison RG. Recombinant production and purification of novel antisense antimicrobial peptide in Escherichia coli. Biotechnol Bioeng. 1998;57:55–61.

    Article  CAS  Google Scholar 

  145. Sun B, Wibowo D, Sainsbury F, Zhao C-X. Design and production of a novel antimicrobial fusion protein in Escherichia coli. Appl Microbiol Biotechnol. 2018;102:8763–72.

    Article  CAS  Google Scholar 

  146. Trueman HE, Sriskantha A, Qu Y, Rapson TD, Sutherland TD. Modification of honeybee silk by the addition of antimicrobial agents. ACS Omega. 2017;2:4456–63.

    Article  CAS  Google Scholar 

  147. Zhang L, Li X, Wei D, Wang J, Shan A, Li Z. Expression of plectasin in Bacillus subtilis using SUMO technology by a maltose-inducible vector. J Ind Microbiol Biotechnol. 2015;42:1369–76.

    Article  CAS  Google Scholar 

  148. Zhang K, Lian S, Shen X, Zhao X, Zhao W, Li C. Recombinant porcine beta defensin 2 alleviates inflammatory responses induced by Escherichia coli in IPEC-J2 cells. Int J Biol Macromol. 2022;208:890–900.

    Article  CAS  Google Scholar 

  149. Shalovylo YI, Yusypovych YM, Hrunyk NI, Roman II, Zaika VK, Krynytskyy HT, et al. Seed-derived defensins from Scots pine: structural and functional features. Planta. 2021;254:129.

    Article  CAS  Google Scholar 

  150. Gaglione R, Dell’Olmo E, Bosso A, Chino M, Pane K, Ascione F, et al. Novel human bioactive peptides identified in apolipoprotein B: evaluation of their therapeutic potential. Biochem Pharmacol. 2017;130:34–50.

    Article  CAS  Google Scholar 

  151. Wang T, Wang Z, Mi J, Wang W, Li K, Qi X, et al. Recombinant avian β-defensin produced by food-grade Lactococcus as a novel and potent immunological enhancer adjuvant for avian vaccine. Probiotics Antimicrob Proteins. 2021;13:1833–46.

    Article  CAS  Google Scholar 

  152. Thomas DS, Manoharan C, Rasalkar S, Mishra RK, Gopalapillai R. Recombinant expression of sericin-cecropin fusion protein and its functional activity. Biotechnol Lett. 2020;42:1673–82.

    Article  CAS  Google Scholar 

  153. Orrapin S, Intorasoot A, Roytrakul S, Dechsupa N, Kantapan J, Onphat Y, et al. A novel recombinant javanicin with dual antifungal and anti-proliferative activities. Sci Rep. 2019;9:18417.

    Article  CAS  Google Scholar 

  154. Almasia NI, Molinari MP, Maroniche GA, Nahirñak V, Barrios Barón MP, Taboga OA, et al. Successful production of the potato antimicrobial peptide Snakin-1 in baculovirus-infected insect cells and development of specific antibodies. BMC Biotechnol. 2017;17:75.

    Article  CAS  Google Scholar 

  155. Zhang L, Li G, Zhan N, Sun T, Cheng B, Li Y, et al. Expression of a Pseudomonas aeruginosa-targeted antimicrobial peptide T9W in Bacillus subtilis using a maltose-inducible vector. Process Biochem. 2019;81:22–7.

    Article  CAS  Google Scholar 

  156. Tanhaeian A, Azghandi M, Mousavi Z, Javadmanesh A. Expression of thanatin in HEK293 cells and investigation of its antibacterial effects on some human pathogens. Protein Pept Lett. 2019;27:41–7.

    Article  Google Scholar 

  157. Luan C, Zhang HW, Song DG, Xie YG, Feng J, Wang YZ. Expressing antimicrobial peptide cathelicidin-BF in Bacillus subtilis using SUMO technology. Appl Microbiol Biotechnol. 2014;98:3651–8.

    Article  CAS  Google Scholar 

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Acknowledgements

Figures were created with BioRender.com.

Funding

This work was funded by Ministerio de Ciencia, Innovación y Universidades Grant (PID2019-107298RB-C21/AEI/10.13039/501100011033) to AA and EG-F and by Marató de TV3 foundation (201812-30-31-32-33) to EG-F. The authors are also indebted to CERCA Programme (Generalitat de Catalunya) and European Social Fund for supporting our research. RRP was supported by internal funding from Children’s Medical Research Institute.

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RRP, AA and EGF conceived and designed the manuscript. RRP, AA and EGF performed the bibliographic research, conceptualized, and drafted the manuscript. LL outlined the structure and reviewed the manuscript. All authors read and approved the final manuscript.

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Correspondence to Anna Arís or Elena Garcia-Fruitós.

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Roca-Pinilla, R., Lisowski, L., Arís, A. et al. The future of recombinant host defense peptides. Microb Cell Fact 21, 267 (2022). https://doi.org/10.1186/s12934-022-01991-2

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