Figure 5. An E2 K200R mutation or deletion of MARCO allows for enhanced viremia and more rapid viral dissemination.

(A) WT C57BL/6 mice were inoculated in the left footpad with 1,000 PFU of the indicated virus. At 24 hpi, infectious virus in the ipsilateral left ankle, contralateral right ankle, and serum were quantified by focus formation assay (CHIKV) or plaque assay (ONNV). Mean ± SD. N = 5–10, two experiments. Mann-Whitney test; **p<0.01, ****p<0.0001. (B) WT or MARCO^-/- C57BL/6 mice were inoculated as in (A) with CHIKV or CHIKV E2 K200R. At 24 hpi, infectious virus in the ipsilateral left ankle, contralateral right ankle, right quadriceps, and serum were quantified by focus formation assay. Mean ± SD. N = 9, two experiments. Kruskal-Wallis or One-way ANOVA; **p<0.01, ***p<0.001, ****p<0.0001.