Figure 4: Microglia accumulate at sites of infection in the CNS in a STING-independent manner.

(a,b) RNA from brain stem of WT and Sting^gt/gt mice infected for 6 days with either HSV-1 (1 × 10⁶ PFU per eye) or media alone (UT) were analysed by RT–qPCR for levels of Iba1 and gB mRNA. The data were normalized to β-actin and are presented as (means ± s.e.m.) fold induction relative to the WT UT. n=3–5 per group. (c,d) Single cells isolated from brain stems of WT and Sting^gt/gt mice infected for 6 days with HSV-1 were analysed by flow cytometry for expression of (c) Iba-1 or (d) CD45 staining of CD11b⁺ sub-gated cells. Data from representative mice from each group is shown together with median fluorescence intensity (MFI) ±s.d. n=6 per group (e) as control for CD45^hi staining, CD45 staining of CD11b⁺ sub-gated splenocytes was performed on a non-infected mouse. (f) Tissue sections of brain stems from WT and Sting^gt/gt mice infected for 6 days with HSV-1 or media alone (UT) were stained with an antibody against Iba1, n=4–5 per group, Scale bar, 20 μm.