FIG 6.

Anti-CD137 MAb-mediated clearance of CHIKV RNA in the spleen is abolished in mice lacking T cells. Four-week-old WT (A to L) or TCRβδ^−/− C57BL/6 (M) mice were inoculated with 10³ FFU of CHIKV-LR. At 2 dpi, 400 μg of agonistic anti-CD137 MAb or isotype-control MAb in combination with anti-NK1.1 depleting MAb or depletion-isotype-control MAb (A and B), anti-CD8α depleting MAb or depletion-isotype-control MAb (C and D), anti-CD4 depleting MAb or depletion-isotype-control MAb (E and F), anti-CD8α and anti-CD4 depleting MAbs or depletion-isotype-control MAbs (G and H), anti-CD8α, anti-CD4, and anti-NK1.1 depleting MAbs or depletion-isotype-control MAbs (I and J), or anti-Ly6G depleting or depletion-isotype-control MAb (K and L) was administered via the i.p. route. All depleting and depletion-isotype-control MAbs were administered every 4 days, except for anti-Ly6G and isotype-control MAbs, which were administered every 2 days. Spleens were harvested at 14 dpi, and viral RNA from tissue homogenates was measured by qRT-PCR. Data were pooled from two or three experiments. Each symbol represents an individual mouse, and bars indicate median values. *, P < 0.05; ***, P < 0.001; ****, P < 0.0001; n.s., not significant, Mann-Whitney test. Representative flow cytometry dot plots confirming cell depletions are shown (A, C, E, G, I, and K). The numbers within the flow cytometry plots refer to the percentage of cells in the gated (boxed or circled) areas.