FIG. 1.

(A) Lung leukocytes were isolated from mice that were either left untreated (Ctrl) or were treated (anti-CD4) with anti-CD4 Ab GK1.5 followed by C. neoformans infection for 2 weeks. Cells were stained with CD45 Ab and CD4 Ab (RM4-5) and were analyzed by flow cytometry. Treatment of mice with anti-CD4 MAb resulted in >98% CD4⁺ T-cell depletion, confirming the efficacy of antibody depletion. (B) Leukocytes were isolated from mice at weeks 2 and 3 postinfection as described in Materials and Methods, and total leukocytes were counted with a hemocytometer. Anti-CD4 Ab-treated mice had a significant reduction in total leukocyte numbers compared to the untreated group. Data are representative of two independent experiments. n ≥ 6 mice/group/time point. **, P < 0.005; *, P < 0.05.