WNV-induced leukocyte migration in the brain of WT and db / db mice. qRT-PCR was conducted on RNA extracted from mock- and WNV-infected brains from WT and db/db mice at indicated time points to determine fold-change in (A) CD45, (B) CD4, (C) CD8 and (D) CD11b gene expression. Changes in the levels of each gene were first normalized to the β-actin gene and then the fold-change in WNV-infected brain was calculated in comparison to corresponding mock-infected brain. Data represents the mean ± SEM, representing two independent experiments (n = 7 per group). *P <0.05. SEM, standard error of mean.