Tumor rejection by in vivo administration of anti-CD25 (interleukin-2 receptor alpha) monoclonal antibody.
Immune regulation has been shown to be involved in the progressive growth of some murine tumors. In this study, we demonstrated that a single in vivo administration of an amount less than 0.125 mg of anti-CD25 interleukin 2 receptor alpha monoclonal antibody (mAb; PC61) caused the regression of tumors that grew progressively in syngeneic mice. The tumors used were five leukemias, a myeloma, and two sarcomas derived from four different inbred mouse strains. Anti-CD25 mAb (PC61) showed an effect in six of the eight tumors. Administration of anti-CD25 mAb (PC61) caused a reduction in the number of CD4+ CD25+ cells in the peripheral lymphoid tissues. The findings suggested that CD4+ CD25+ immunoregulatory cells were involved in the growth of those tumors. Kinetic analysis showed that the administration of anti-CD25 mAb (PC61) later than day 2 after tumor inoculation caused no tumor regression, irrespective of depletion of CD4+ CD25+ immunoregulatory cells. Two leukemias, on which the PC61-treatment had no effect, seemed to be incapable of eliciting effective rejection responses in the recipient mice because of low or no antigenicity.
Onizuka
S
S
Department of Parasitology and Immunology, Okayama University Medical School, Japan.
Tawara
I
I
Shimizu
J
J
Sakaguchi
S
S
Fujita
T
T
Nakayama
E
E
D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D005260:Female; D005354:Fibrosarcoma / Q000139:chemically induced / Q000276:immunology / Q000628:therapy*; D005434:Flow Cytometry; D007942:Leukemia, Experimental / Q000276:immunology / Q000628:therapy*; D007953:Leukemia, Radiation-Induced / Q000276:immunology / Q000628:therapy*; D008198:Lymph Nodes / Q000276:immunology*; D008212:Lymphocyte Depletion; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009101:Multiple Myeloma / Q000276:immunology / Q000628:therapy*; D015375:Receptors, Interleukin-2 / Q000276:immunology*
D000911:Antibodies, Monoclonal; D015375:Receptors, Interleukin-2