Enumeration of immune interferon-producing cells induced by allogeneic stimulation.

We succeeded in enumerating interferon-producing cells induced by allogeneic stimulation, and proved that they were indeed T lymphocytes. The peak level of these cells in spleen was attained on day 5 after immunication, was maintained for about 2 days, and declined thereafter. Titers of interferon produced in vitro by sensitized spleen cells were maximum on day 7. This suggests that the maturation of immune interferon-producing cells follows cell proliferation after antigen stimulation.