Figure 6.
West Nile virus infection is uniformly fatal in CCR5 knockout mice. (A) Time course of viral clearance from spleen. Virus was quantified in the spleens of the indicated strains of surviving mice at the indicated times by focus formation assay. Mock-infected mice were analyzed on day 7 of the experiment. (B) Time course of viral clearance from brain. Virus was quantified in the brain of the indicated strains of mice at the indicated times by focus formation assay. Data were pooled from three to four experiments with three to five mice at each time point indicated and are presented as the mean ± SEM. *, P < 0.02 for the indicated comparison by Student's t test. N/A, not applicable, because all infected CCR5−/− die by day 13. (C) Kaplan-Meier analysis of survival of WNV-infected mice. Results shown are pooled data from three independent experiments for CCR5+/+ mice (n = 50 total mice) and CCR5−/− mice (n = 34), and two independent experiments for CCR1−/− mice (n = 30) and CX3CR1−/− mice (n = 32). Similar results were obtained for both wild-type C57BL6/J and C57BL/6NTac control mice; however, only the C57BL6/J results are shown (CCR5+/+). (D) Kaplan-Meier analysis of survival of adoptive transfer mice. WT → KO, transfer of splenocytes from WNV-infected CCR5+/+ mice into WNV-infected CCR5−/− mice; KO → KO, transfer of splenocytes from WNV-infected CCR5−/− mice to WNV-infected CCR5−/− mice. The following control groups were included that did not undergo adoptive transfer: Mock, mock-infected CCR5+/+mice; CCR5+/+, WNV-infected CCR5+/+ mice; and CCR5−/−, WNV-infected CCR5−/− mice. Data represent a single experiment with 10 mice in each group.