Fig. 1
Lack of immune response after oral application with recombinant B. subtilis spores in mice. a Schematic representation of tapA operon carrying E. granulosus immunogenic peptide EgTrp fused in frame at the 3’end of tasA. tapA, anchoring and assembly protein; sipW, signal peptidase and tasA, main protein matrix. The amino acid region corresponding to the immunogenic peptide is indicated. For simplicity of the figures, TasA-(102-207)EgTrp is named as (102-207)EgTrp. Diagram not to scale. b Schematic schedule for the oral application of recombinant B. subtilis spores in mice. Three groups of six animals each were orally provided with (i) saline solution (placebo), spores of B. subtilis tasA/sinR and (iii) spores of B. subtilis (102-207)EgTrp. The animals were orally applied with 5 × 1010 CFU per dose on days 1, 21, 42. Feces were collected daily from days 1–6 and on days 20, 41 and 50. Quantification of a daily number of spores in feces of mice of the indicated groups after day 1 (c) and on days 20, 41 and 50 (d) post-oral application. All data are represented as mean ± SEM. The local intestinal humoral immune response, fecal sIgA (e) and serological IgA (f) were obtained by indirect ELISA coated with biofilm extract of B. subtilis (102-207)EgTrp, biofilm extract of B. subtilis tasA/sinR, recombinant H6-EgTrp or recombinant H6-mCherry. The tested animal groups are indicated