title: Effect of recombinant interleukin 2 (R-IL2) on in vivo growth of murine myeloma X5563.
abstract: The present study deals with the effect of recombinant interleukin 2 (R-IL2) on in vivo growth of murine myeloma X5563. Administration of R-IL2 (5 X 10(4) J.U./mouse per day) s. c. starting 1 day after X5563 inoculation i.d. had a marginal effect on the growth of X5563, and all the mice repeatedly given R-IL2 from day 1 to day 17 died. However, daily administration of R-IL2 starting 7 days after the tumor inoculation was highly effective and significantly lengthened survival time compared with the control mice injected with vehicle alone. About 50% of the treated mice were completely cured, and survived for more than a month after the therapy ceased. In a representative experiment, where the growth of X5563 was slow because of the small number of inoculated tumor cells, all the mice (n = 6) given R-IL2 from day 11 to day 23 showed complete cure of the established X5563 solid tumor. These mice showed in vivo protective immunity and in vitro cytotoxic T cell responses to X5563 tumor antigens. Histologically, a large number of macrophages and lymphocytes had infiltrated the area around the necrotic X5563 tumor mass in the mice which had received R-IL2 therapy. These results suggest that repeated injections of R-IL2 at the local site after tumor development can augment antitumor immunological responses and subsequently induce tumor regression.
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000276:immunology; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D004274:DNA, Recombinant; D005260:Female; D007110:Immunity, Active; D007111:Immunity, Cellular; D007376:Interleukin-2 / Q000627:therapeutic use*; D051379:Mice; D008809:Mice, Inbred C3H; D009101:Multiple Myeloma / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000951:Antigens, Neoplasm; D004274:DNA, Recombinant; D007376:Interleukin-2