Depletion of CCR2⁺ cells enhanced viral loads in tissues and the severity of acute RRV infection.

<p>WT or CCR2-DTR C57BL/6 mice were inoculated in the left rear footpad with 1,000 PFU of RRV-T48 or RRV-T48-nsP1^6M. At days -1 and +2 relative to infection, mice were i.p. administered DT. 1 h prior to virus infection, Ly6C^hi monocytes were adoptively transferred into a subset of CCR2-DTR mice. At 5 dpi, viral RNA levels in (A) skeletal muscle tissue and (B) contralateral ankle tissue were quantified by qRT-PCR. (C) At 5 dpi, infectious virus in the serum was quantified by plaque assay. (D) The percent starting body weight was determined daily (n = 6–17 mice/group). Data are pooled from three independent experiments. <i>P</i> values were determined by one-way ANOVA with a Tukey’s multiple comparison test (A-C) and a repeated measures two-way ANOVA with a Bonferroni’s multiple comparison test (D). *, <i>P</i> <0.05; **, <i>P</i> < 0.01; ***, <i>P</i> < 0.001.