Figure 4

Effect of LPS removal procedure on T cell stimulation. A. Equal amounts of proteins: Four proteins were treated with LPS removal beads. Whole blood of 3 healthy donors was stimulated with 5 μg/ml of treated or non-treated protein preparations. After fixation and permeabilization, leukocytes were stained with antibodies against CD4, CD40L, and IFN-γ. The stained cells were measured by FACS. CD4+ T cells were gated electronically. Frequencies of double-positive T cells stimulated with treated preparations were related to frequencies obtained after stimulation with untreated proteins. The latter frequencies were standardized (set to 100%). B. Equal volumes: The results of the experiment given in A. are displayed considering equal volumes of treated and untreated protein preparations, respectively. Representative results from 3 of 8 individuals tested.