Figure 1.

WNV infection induces leukocyte infiltration in the CNS. Adult, female B6 mice were inoculated SC with diluent (mock) or 10³ PFU of WNV in the left rear footpad. At various times post-inoculation, two mock-inoculated and four WNV-inoculated mice were sacrificed and perfused with perfusion buffer. CNS mononuclear cells were collected, and flow cytometry was performed for various cell markers. Representative scatter plots and gating for flow cytometry are shown for leukocytes isolated from brains of (A) a mock-inoculated mouse and (B) a WNV-inoculated mouse. (C) Numbers of CD45⁺ cells are reported per brain. Each data point represents an individual mouse, and solid horizontal lines represent the geometric means. Open symbols indicate mice that showed clinical signs of disease during acute illness. Two independent studies were performed for 1, 2, 4, 8 and 12 wpi, and these data were analyzed by Mann-Whitney U tests with P values indicated by: 0.001 < ** ≤0.01.