The cytomegalic inclusion cell and disease. II. Social behaviour in vitro.

Upon primary cytomegalovirus infection, previously healthy individuals acutely reject the mass of virus-infected cells, by adequate cellular and humoral defence mechanisms. By contrast, the immunologically immature or compromised host, while still able to neutralize extracellular virus, will tolerate the persistence of the allenated population of cytomegalovirus-converted cells. The micropathology of cytomegalovirus-infected monolayers, however, runs a different course, due to the absence of any immune effector in the in vitro systems. In cultured monolayers of fibroblasts, the infected cells are selected out and aggregate engulfing one another to form giant multinucleated structures.