Fig 3.

CD8 T cells are important in the exaggerated inflammatory response in the absence of regulatory T cells (T_regs). The cellular infiltrate in the inflamed ear was analysed at day 3 and 8 after challenge by flow cytometry in T_reg-depleted mice as well as in non-depleted control mice. (a) Absolute number (#) of CD8 T cells/ear; (b) absolute number (#) of CD4 T cells/ear; (c) to deplete both CD4 and CD8 T cells, a rat anti-mouse CD4 and a rat anti-mouse CD8 monoclonal antibody (mAb) were administered either at day −6 (one day prior to sensitization) or day 2 (at peak of the response) in groups previously depleted for T_regs. Ear-swelling response was measured 8 days post-challenge and the response after depletion of T cells at either days −6 or 2 in T_reg-depleted mice was compared to a group only depleted for T_regs. (d) To investigate the effect of selective depletion of CD8 T cells, a rat anti-mouse CD8 mAb was administered at peak of the inflammatory response at day 2 after challenge in a T_reg-depleted group. Ear-swelling response was followed 8 days after challenge and compared to a T_reg-depleted group as well as a group depleted for neither T_regs nor CD8 T cells. Data are depicted as mean ± standard error of the mean. *P < 0·05, **P < 0·01 and ***P < 0·001, n = 5/group.