An analysis of the peritonitis in acute murine reovirus infection.

Reovirus 3 replicates in the mesothelial cells of the peritoneal cavity of infected neonatal Prince Henry mice. As virus replication becomes evident in these cells lymphocytes, polymorphonuclear leucocytes and especially mononuclear phagocytes increase in number in the peritoneal exudate and often surround the exfoliated and degenerating infected mesothelial cells. These events are accompanied by a polymorphonuclear leucocytosis, a lymphopenia and a transient monocytosis which reverses to a monocytopenia as virus replication appears in a variety of organs. Although in the peritoneal cavity the majority of exuded monocytes ingest virions and cellular debris a small proportion supports replication of reovirus 3. Polymorphonuclear leucocytes, on the other hand, did not exhibit evidence of reovirus replication.