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 w ild-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 infe ction (p.i.). At day 15 p.i., virus titers were similarly elevated in saliv ary glands of all mutant, but not wild-type B6 mice and undetectable in lun g and spleen tissues of any of the mouse strains. Significant pathological alterations were only seen in salivary glands and spleen from RAG2(-/-), bu t 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 titer s were observed only in salivary glands, lung and spleen from RAG2(-/-), bu t in none of the other mice, and were accompanied by extended pathological alterations in all three organs. The data extend previous reports on the cr itical 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 eliminatio n in salivary glands; however, neither of the three molecules alone seem to be indispensable for the final control of infection.