Fig. 4.

Anti-CD8 mAb promotes the proliferation of CD4⁺ KJ1-26⁺ cells. BALB/c mice were injected with 2.5 × 10⁶ CD4⁺ KJ1-26⁺ cells and, on the same day, treated with either OVA alone or, OVA and anti-CD4 mAb plus isotype control or, with OVA and the anti-CD4/anti-CD8 mAb cocktail. An additional group was left without further treatment. From day 0 through day 3 post-treatment, three mice from each group were fed BrdU in the drinking water. An additional three mice from each group were fed BrdU from day 3 through 6 post-treatment. After three days of BrdU treatment splenocytes were isolated from all mice and the total number of CD4⁺ KJ1-26⁺ cells that were BrdU⁺ (panel a) was determined for each mouse by FACS. Data shown are mean ± SEM for each group and are representative of 2 experiments. * indicates statistical significance to 0.01–0.05. *** indicates statistical significance to 0.0001–0.0009. The Student t test was used to determine statistical significance. n = 3 per group. Panels b through e show the FACS profiles of CD4⁺ KJ1-26⁺ cells from the groups that were primed with OVA alone for three days or left untreated. Panel b shows the dot plot of splenocytes labeled with anti-CD4 mAb plus KJ1-26. The CD4⁺ KJ1-26⁺ cells are those indicated in the upper right hand box. Panels c through e show histograms of CD4⁺ KJ1-26⁺ cells only from untreated (panel c) and treated (panels d and e) mice co-labeled for either the presence of BrdU (panels c and d), or isotype control for BrdU (panel e), and the percentage of CD4⁺ KJ1-26⁺ cells expressing BrdU determined by FACS. Data shown are mean ± SEM for each group and are representative of 2 experiments. n = 3 per group.