Effect of in vivo depletion of CD4⁺ or CD8⁺ lymphocytes on survival in A20-inoculated mice.

(A) HSP70. (B) GP96. CD4⁺ or CD8⁺ lymphocytes were depleted by intravenous injection of anti-CD4 or anti-CD8 2 days before HSP immunization, as described in “Materials and methods.” (A) Immunized with PBS (○), 40 μg HSP70 derived from A20 cells (■), 40 μg HSP70 derived from A20 cells in CD4⁺T-cell–depleted mice (■), and 40μg HSP70 derived from A20 cells in CD8⁺ T-cell–depleted mice (▴). (B) Immunized with PBS (○), 5 μg GP96 derived from A20 cells (■), 5 μg GP96 derived from A20 cells in CD4⁺ T-cell–depleted mice (▪), and 5 μg GP96 derived from A20 cells in CD8⁺ T-cell–depleted mice (▴). Depletion of CD4⁺ or CD8⁺lymphocytes in vivo completely abrogated the survival efficacy of both HSP70 (A) and GP96 (B) immunization. *P < .01 versus PBS, CD4⁺ T-cell–depleted or CD8⁺ T-cell–depleted mice, Wilcoxon test. There were 5 mice in each group. Data are representative of 3 separate experiments.