Differential cytostatic effect of interferon on murine BALB/c B- and T-cell tumors.
The cytostatic effect of murine interferon (IFN) on several BALB/c-derived B- and T-cell tumor cells was examined. After incubation for 1 h in vitro with 1000 U of IFN, followed by intraperitoneal inoculation, tumor formation was not decreased in the case of B cell tumors or Lyt-1+2- or Lyt-1+2+3+ T cells tumors. Under the same conditions, the onset of tumor formation for Lyt-2+3+ T-cell tumors was delayed and the final incidence decreased. When the effect of IFN on cell multiplication in vitro was examined, Lyt-2+3+ T-tumor cells were found to be more sensitive to the cytostatic effect of IFN than Lyt-1+2+3+ T-tumor cells. This shows that the sensitivity of lymphocyte-derived tumor cells to the cytostatic effect of IFN is influenced by the type of differentiation of the cells.