Figure 2

Fine specificity of the M2e-MAP induced Ab response. A. MAb 14C2-S1-4, which was used in all assays for quantification of serum Ab titers, was tested in ELISA against M2e-MAP Gd40 (squares), Cys-M2e (triangles) and HeLa-M2 (circles) as described in the method section, using the same reagents and incubation times for each assay. The mean OD (± SEM) above background of six replicates at each Ab dilution are shown. The three sigmoidal titration curves have similar EC50 values (-9.3 vs G40d, -9.5 vs Cys-M2e, -9.2 vs HeLa-M2). To further demonstrate the similarity between the three titration curves, OD values measured against HeLa-M2 were multiplied by 1.65 to generated the stipulated curve. A representative assay is shown. B. Pooled plasma samples (5 mice/group), obtained 3 wks after second (left column) and third (right column) immunization, were tested by ELISA for M2e-MAP- (squares), M2e(pep)- (triangles) and M2e(pep-nat)-specific (circles) Ab titers as described in the method section. The mice had been immunized with 3 μg M2e-MAP G40d and adjuvants by i.n. or s.c. routes as indicated below the x axis. Each symbol shows the mean serum Ab concentration determined in each sample by 2–3 independent assays. Data from a single vaccination experiment are shown. C. The fraction of M2e(pep-nat)-specific Abs is expressed as percent of the M2e(pep)-specific Ab concentration within each sample. Each dot indicates the % of anti-M2e(pep-nat) per group of 3–5 mice immunized by one of the protocols indicated below the x axis. In most groups, samples from secondary and tertiary responses were tested, and the mean % of these is shown. Horizontal bars indicate the geometric means within a vaccination protocol. Data from 12 independent vaccination experiments are shown. Groups immunized by different protocols did not differ significantly (ANOVA) with regards to percentage of anti-M2e(pep-nat)-specific Abs.