Figure 5.

The hematopoietic cell compartment is required to respond to type I IFN and produce IL-18 to activate IFN-γ production during HSV-2 infection. (A) WT and Ifnar^−/− mice were lethally irradiated and reconstituted with either WT or Ifnar^−/− bone marrow. Mice were allowed to reconstitute for 6–8 wk, and peripheral blood was assessed for reconstitution by examining the frequency of cells expressing CD45.1 or CD45.2. (B) Mice were then infected with 5 × 10⁴ pfu HSV-2 ivag. On days 1–3 p.i., vaginal lavages were examined for IFN-γ content (n = 3; repeated once with similar results). (C) WT and Il18^−/− mice were lethally irradiated and reconstituted with either WT or Il18^−/− bone marrow. 6–8 wk after reconstitution, mice were examined for CD45.1 and CD45.2 expression. (D) Mice were then infected with 10⁴ pfu HSV-2 ivag. On days 1–3 p.i., vaginal lavages were examined for IFN-γ (n = 7). Data in B and D are displayed as mean ± SEM and were analyzed using two-way ANOVA: ****, P < 0.0001.