Figure 5

Assessment of the green fluorescent protein (GFP) ⁺ brain infiltrate in Theiler's murine encephalomyelitis virus (TMEV)-infected LysM:eGFP mice. Flow cytometric analysis of brain-infiltrating leukocytes (BILs) collected at 18 hpi from LysM:eGFP reporter mice (Lys:GFP) and from wild-type littermates (wt) (C) revealed the presence of distinct GFP^hi and GFP^mid populations in the reporter mice (B). Further characterization of CD11b, Gr1, and 1A8 staining showed that the GFP^hi population was composed of CD11b⁺⁺⁺Gr1⁺1A8⁺ neutrophils, the GFP^mid population was composed of CD11b⁺⁺Gr1⁺1A8^- inflammatory monocytes, and the GFP^neg population contained CD11b⁺Gr1^-1A8^- microglia (resident macrophages). (D-I) are derived from the gated populations in (B). These findings confirm our other observations and indicate the presence of both neutrophils and inflammatory monocytes in the brain at 18 hpi. Results are representative of more than 10 mice.