Figure 7.

T cell activation and trafficking after WNV infection. (A) Mock or WNV-infected splenocytes from wild-type, C1q^−/−, C4^−/−, fD^−/−, and fB^−/− mice on day 8 were harvested and stimulated ex vivo. Cells were stained for CD4 or CD8 and intracellular IFNγ and analyzed by flow cytometry. Data are an average of at least three independent experiments and reflect 6–10 mice per group. Asterisks indicate differences from mock infected that are statistically significant (*P < 0.05; **P < 0.005). (B) Representative flow cytometry profiles showing intracellular IFNγ staining of splenic CD8⁺ T cells after WNV infection in wild-type or complement-deficient mice. The percentage of double-positive cells is indicated in the top right corner. (C) Brains were harvested from WNV-infected wild-type, C1q^−/−, C4^−/−, and fB^−/− mice on day 9. Leukocytes were isolated by percoll gradient centrifugation and double-stained for CD3 and CD4 or CD8. The total number of brain infiltrating CD4⁺ or CD8⁺ T cells was determined by multiplying the total number of leukocytes from three pooled brains by the percentage of double-positive cells as measured by flow cytometry. Data are an average of at least three independent experiments and reflect at least five groups of three mice. Asterisks indicate differences from wild type that are statistically significant (*P < 0.05; **P < 0.005). (D) Representative flow cytometry profiles showing CD3⁺CD8⁺ T cells in the brain after WNV infection in wild-type or complement-deficient mice.