Cellular regulation of immune interferon production

Spleen cells obtained from mice injected 24–72 h previously with a T-cell mitogen were poor producers of immune interferon (IFNγ) when restimulated with the same mitogen in vitro. The reduced response appeared to be due to a suppressor cell population, since virgin spleen cells also gave a reduced response when cultured with the cells from injected mice. Through the use of different concentrations of monoclonal anti-Thy-1 antibody, the mitogen-induced suppressor cell population was shown to contain a relatively high density of the Thy-1 antigen. The IFN-producing cell population contained a relatively low density of the Thy-1 antigen, and either evolved from cells with a high density of Thy-1 antigen or required such cells as helpers in production of IFNγ.A model is proposed according to which the induction of T cells in mice for IFNγ production then involves a cell population with a relatively high density of Thy-1 antigen. The induced cells appear to evolve into IFN-producing cells of low density of Thy-1 antigen. IFN production by the cells with low density of Thy-1 antigen is suppressed or regulated by another stimulated cell population that, like the virgin T cells, possesses a high density of Thy-1 antigen. The IFN-producing cells with low density of Thy-1 antigen appear to represent a small portion of the total T-cell population.