[Stimulation of humoral immunity to surface antigens of leukemia cells using interferon-containing sera].

C57BL/6 mice were immunized once with leukemic cells L 1210; (CBAXC57BL/6) F1 mice were immunized once with leukemic cells L 1210 and P-388. These animals were injected intraperitoneally for 8 days (including the day of immunization) with 0.4 ml each of allogeneic or syngeneic interferon-containing serum; as to control animals, they received the same amount of normal serum from the intact mice. The interferon-containing serum was obtained from the (CBAXC57BL/6) F1 mice 24 hours after the intraperitoneal injection of 2 mg of tilorone hydrochloride. Some of the samples of the interferon-containing serum were subjected to the 48-hour dialysis against the physiological saline. The interferon titer in the serum was 512-1500 units/ml. The sera from mice were tested in the microcytotoxic test against leukemic cells 9-10 days after the immunization. A distinct stimulation of the cytotoxic activity of the sera from mice given the interferon-containing serum was observed. Syngeneic interferon-containing serum caused a more marked immunity-stimulating effect than allogeneic serum.