Effect of co-incubation with cytomegalovirus on growth of interleukin 2-dependent lymphocytes.

We have tested the ability of human cytomegalovirus (CMV) to interfere with the interleukin-2 (IL-2)-dependent proliferation of T lymphocytes in long-term tissue culture. The results indicate that CMV was able to establish an apparently abortive infection in approximately 40% of such cells, although productive viral replication could not be detected, and was able to impede cellular proliferation almost completely. The addition of high concentrations of exogenous IL-2 to cultures of CMV co-incubated cells was not readily able to overcome the anti-proliferation inhibitory effect induced by this virus. Exposure to CMV led to an approximate 50% decrease in the number of cells which expressed Tac Ag, or IL-2 receptor, at the cell surface.