Natural killer cells in relation to Herpesvirus saimiri-induced disease course and manifestations in owl monkeys.

Infection of owl monkeys with Herpesvirus saimiri (HVS) results in disease courses ranging from chronic infections to fatal cancers. Malignant disease manifestations include the appearance of transformed T-cells, suppressor T-cells, and virus-carrying cells in the peripheral circulation. The reasons for the variability in disease course remain unknown. This study examined natural killer (NK) functions in relation to disease manifestations following HVS infection. The results from lymphocyte fractionation studies indicated that the owl monkey NK cell was of T-cell lineage and had receptors for the Fc fragment of IgG. Following virus infection, NK activity was enhanced in parallel with the appearance of transformed and suppressor cells in monkeys that developed malignant disease. Further studies on the relationship of these three disease characteristics indicated that they involved at least partially different T-cell subpopulations. The results further indicated that the different disease manifestations induced by HVS were polyclonal and at least partially independent events.