Target cells for interferon production in human leukocytes stimulated by sendai virus

Whole leukocytes, mononuclear cells, polymorphonuclear cells (PMN), MONOCYTES, PURIFIED LYMPHOCYTES, AND T (rosette-forming cells, RFC) and non-T (nonrosette-forming cells, nonRFC) lymphocytes isolated from the human peripheral blood were stimulated by Sendai virus, respectively, and examined for interferon production in their culture fluids. High levels of interferon were produced by mononuclear cells, but not by PMN. Removal of monocytes from the mononuclear cell population did not affect at all the levels of interferon produced, although it strongly suppressed interferon induction by polyinosinic-polycytidylic acid (poly IC) and mitogenic response to phytohemagglutinin (PHA) of the lymphocytes. Purified monocytes and T lymphocytes were unresponsive to the virus. In contrast, a population of purified non-T lymphocytes produced high levels of interferon. Addition of monocytes to the interferon-producing non-T lymphocytes did not affect the levels of interferon produced. No detectable levels of interferon were produced in the mixture of T lymphocytes and monocytes. It is concluded that non-T lymphocytes may be a major target for interferon induction of human leukocytes by Sendai virus.