FIG. 7.

The route of immunization does not account for the modulation of the peptide-specific T-cell priming for purified MalE and MalE delivered by SL3261*. (A) C57BL/6 mice (two per group) were i.p. immunized on days 0 and 21 with 100 μg of MalE in alum or with 10⁶ SL3261*pMalE or control SL3261* bacteria. Spleen cells from each group were pooled and were stimulated in vitro with the indicated Ag and tested for proliferation on day 4. (B and C). Mice were intravenously immunized with a single dose of 10⁶ SL3261*pMalE or control SL3261* bacteria. Three (B) and four (C) weeks later, spleen cells from individual mice (two per group) were recovered and tested for IFN-γ-producing cells by ELISPOT in response to the indicated antigenic stimulation. Each data point corresponds to the mean of the number of positive CD4⁺ T cells per spleen obtained in two individual mice.