B-tropic FV protected 129P2 Apobec3 KO mice from pathogenic NB-tropic FV challenge.

(A) Infection schedule. 129P2 Apobec3 KO mice were infected with B-tropic FV (FV-B) or mock (DMEM). At 28 dpi, the mice were challenged with NB-tropic FV (FV-NB) and evaluated for infection levels by flow cytometry 7 days later. (B) Gating strategy for FV+ cells. BM cells and splenocytes (not shown) were incubated with an FV Glyco-Gag-specific IgG2b antibody, MAb 34, then stained with a goat anti-mouse IgG2b antibody conjugated to APC. Representative flow plots demonstrating the gating strategy for MAb 34+ cells are shown. Cellular infection levels at 7 days post-challenge are shown for (C) BM and (D) Splenocytes. Ter119+ erythroblasts, CD11b+ myeloid cells and/or CD19+ B cells were gated from the live population. Plasma samples were analyzed for (E) Infectious viremia based on a focal infectivity assay in Mus dunni cells and (F) plasma viral load based on viral RNA copies detected by quantitative RT-PCR. Black bars represent the mean, and each dot corresponds to an individual mouse. Flow cytometry and plasma viral load data were analyzed using a 2-tailed Student’s t test. Infectious viremia data were analyzed using a 2-tailed Mann-Whitney U test. Data were considered statistically significant with p<0.05. Data are representative of two independent experiments.