Interferon production in mixed cultures of murine leukocytes and syngeneic L1210 leukemia cells.

Spleen cells from DBA/2 mice did not proliferate, but released interferon (IFN) when cultured in the presence of mitomycin C-treated syngeneic L1210 leukemia cells apparently free from mycoplasma and common non-oncogenic viral infections. IFN titers reached a plateau after 18 h of culture. The biological activity of this IFN was stable at pH 2 and could be inactivated by antibody raised against alpha and beta-IFN. Removal of phagocytes from the spleen cell suspensions caused a decrease in IFN production. By contrast, suspensions depleted in Thy 1.2-positive cells had an enhanced capacity to produce IFN in response to the L1210 cells.