Murine cytomegalovirus replication in salivary glands is controlled by both perforin and granzymes during acute infection

The course of mouse cytomegalovirus (MCMV) infection was compared between wild-type and mutant C57BL/6 (B6) mice deficient in either RAG-2, perforin, granzyme A, granzyme B or combinations thereof at two time points post infection (p.i.). At day 15 p.i., virus titers were similarly elevated in salivary glands of all mutant, but not wild-type B6 mice and undetectable in lung and spleen tissues of any of the mouse strains. Significant pathological alterations were only seen in salivary glands and spleen from RAG2(-/-), but not in those from other mice whereas few inflammatory foci were observed in lung tissues of all mice except B6. At day 30 p.i., elevated virus titers were observed only in salivary glands, lung and spleen from RAG2(-/-), but in none of the other mice, and were accompanied by extended pathological alterations in all three organs. The data extend previous reports on the critical role of NK/CD8⁺ T cells in the early control of MCMV infection by showing that both perforin and granzymes A/B contribute to viral elimination in salivary glands; however, neither of the three molecules alone seem to be indispensable for the final central of infection.