Two major effector mechanisms for the antiviral effects of T cells are the production of IFNc and perforin mediated cytolysis [49] . We therefore adoptively transferred immune splenocytes from IFNc-/-or perforin-/-mice into persistently infected RAG1-/-mice and determined their capacity to clear intestinal MNV infection. Immune splenocytes from IFNc-/-mice were as effective as those from WT mice ( Figure 7B and 7C) . However, immune splenocytes from perforin-/-mice were less effective at clearing MNV infection from the duodenum/jejunum (p = 0.0003, Figure 7C ) or distal ileum (p = 0.0075, Figure 7B ) than cells from either WT or IFNc-/-mice, but more effective compared to transfer of non-immune cells in duodenum/jejunum (p = 0.0086) or distal ileum (p = 0.0001). Thus, while perforin was critical for efficient clearance of MNV infection from the intestine, it was not the only relevant effector mechanism.