FIG. 7.

Depletion of CD4⁺ T cells significantly reduces TS-specific antibodies and IFN-γ-secreting CD4⁺ and CD8⁺ T cells induced by immunization with p154/13. BALB/c mice were treated for three consecutive days with anti-CD4, anti-CD8, or rat-IgG. One and 22 days later, these mice were immunized i.m. with 100 μg of p154/13. In parallel, control mice received 100 μg of pcDNA3. (A) Fourteen days after the last immunization, blood samples were collected and the sera were assayed for the presence of antibodies to recombinant TS-cat by ELISA The results represent the mean values obtained from four mice ± the standard deviations (SD). (B) Pooled spleen cells obtained from two mice immunized with p154/13 and treated with anti-CD4, anti-CD8, or rat-IgG were expanded for 6 days in the presence of irradiated A20J-TS cells. The expanded cells were restimulated in the presence of A20J-pcDNA3, A20J-TS, A20J cells, or A20J cells coated with 1 μM peptide TS_359-367 (A20J-TS_359-367). IFN-γ was estimated in supernatants collected after 18 h. Results are expressed as the average of triplicate cultures ± SD.