Therapeutic efficacy of repeated cycles of local IL-2 injections in mice carrying slowly growing tumour grafts.
Local IL-2 administration prior to transplantation of murine sarcoma virus (MSV Harvey)-induced tumour MSVT2 provided a model of slowly growing tumours suitable for long-term investigation of the therapeutic efficacy of repeated IL-2 injection cycles. Challenge of mice with the dose of sarcoma cells, which was lethal for 20/20 untreated control recipients, revealed that 8/20 IL-2-pretreated mice were protected by the local IL-2 treatment and survival indefinitely. Nine out of twenty IL-2-pretreated mice died during the same time period as the control mice, i.e., during 36 days, and 3/20 IL-2 pretreated mice were tumour-negative until day 60, when incipient tumours arose. The three late tumours were used as a model to investigate the therapeutic efficacy of the new cycles of repeated local IL-2 administration. It was found that no resistance to IL-2 immunotherapy was induced by pretreatment of the late tumours and that the tumours were repeatedly susceptible to local IL-2 treatment. Spleen cells of the tumour-bearing mice, which were not cytotoxic for MSVT2 tumour cells in vitro, could be made cytotoxic by addition of exogenous IL-2.
Símová
J
J
Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Praha.
Bubeník
J
J
Indrová
M
M
Bubeníková
D
D
Jandlová
T
T
D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D004334:Drug Administration Schedule; D007279:Injections, Subcutaneous; D007376:Interleukin-2 / Q000008:administration & dosage / Q000627:therapeutic use*; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008980:Moloney murine sarcoma virus; D009368:Neoplasm Transplantation; D012192:Retroviridae Infections / Q000276:immunology / Q000628:therapy; D012513:Sarcoma, Experimental / Q000276:immunology / Q000628:therapy*; D013154:Spleen / Q000276:immunology; D014412:Tumor Virus Infections / Q000276:immunology / Q000628:therapy
D000970:Antineoplastic Agents; D007376:Interleukin-2