Figure 3.

The complex interplay of innate and adaptive immunity in FV infection. Virus sensing initiates IFN I responses, which stimulate and activate NK cells, CD8+ T cells and DCs. CD4+ and CD8+ T cell priming by FV-infected DCs is more efficient when complement-opsonized virus was taken up by the DCs, but IgG-opsonized virus inhibits T cell induction. Infected B cells can also initiate CD8+ T cell responses, which is also more efficient after infection with complement opsonized virus. The expression of APOBEC3 after virus sensing augments B cell/antibody responses, whereas the expression of Tetherin facilitates CD4+ and CD8+ T cell responses by enhancing antigen presentation. Effector CD8+ T cell responses can be suppressed by virus-activated NK cells, Tregs as well as gMDSCs.