FIG 2.

Treg depletion in IL-2 Ab Cx-treated mice results in a loss of protection against CHIKV-induced pathology. WT or DEREG mice (n = 4 per group) were treated with IL-2 Ab Cx for 3 days (−5, −4, and −3 dpi) followed by DT administration for 2 days to deplete Tregs. Following depletion, mice were infected s.c. with 10⁶ PFU CHIKV-SGP011. (A) Representative scatter plot showing peripheral Treg population from DEREG animals with or without IL-2 Ab Cx treatment, followed by DT or no DT treatment. Numbers in scatter plots indicate the Treg population percentage within total CD4⁺ T cells. Data are means and SD. Statistical analysis was done using one-tailed unpaired t test. **, P = 0.001 (WT+DT versus DEREG+IL-2 Ab Cx+DT); ***, P < 0.0001 (DEREG+IL-2 Ab Cx+DT versus DEREG+IL-2 Ab Cx). (B) Joint swelling of mice was measured from 0 to 12 dpi following CHIKV infection after IL-2 Ab Cx and DT treatment. Data are means ± SD. Statistical analysis was done using a two-tailed unpaired t test comparing DEREG+IL-2 Ab Cx+DT and DEREG+IL-2 Ab Cx. ***, P = 0.0007 (6 dpi), <0.0001 (7 dpi), <0.0001 (8 dpi), 0.0004 (9 dpi), 0.0003 (10 dpi), <0.0001 (11 dpi), or 0.0001 (12 dpi).