We also observed that spleens from infected IPS-1 2/2 mice exhibited significantly increased numbers of CD8+ T cells in comparison to those from infected wild type mice, whereas the expansion of splenic CD4+ T cells in wild type and IPS-1 2/2 mice were not different (Fig 7D) . The spleens from WNV-infected IPS-1 2/2 mice showed significantly higher numbers (3.9-fold; p,0.05) of WNV-specific CD8+ T cells producing IFNc.