title: Regulation of natural killer cell activity by anti-I-region monoclonal antibodies.
abstract: The effects of a monoclonal antibody directed against immune response gene products on mouse NK activity were examined. In vivo administration of an anti-I-Ak antibody to C3H/He (H-2k) mice modulated their peritoneal cell (PC) and spleen cell (SC) natural killer (NK) activity against YAC-1 lymphoma target cells in vitro. No such effect was observed when BALB/c (H-2d) mice were treated with this antibody. Administration of anti-I-Ak antibody to mice before and after infection with Toxoplasma or treatment with poly(I:C) leads to suppression of NK activity in comparison to NK activity of mice infected with Toxoplasma or injected with poly(I:C) alone. A similar treatment regimen with M5/114 antibody which reacts with I-Ab, I-Ad, I-Ed, and I-Ek molecules resulted in decreased NK activity in B10.D2 (H-2d) but not in B10.BR (H-2k) mice. Serum and cell culture supernatant interferon (IFN) concentrations were not altered as a result of anti-I-Ak treatment. Removal of adherent cells did not restore NK activity of anti-I-Ak-treated Toxoplasma-infected mice to levels obtained with mice infected with Toxoplasma. In contrast, depletion of Ly 2.1+ cells from nylon-wool nonadherent SC of mice treated with anti-I-Ak antibody, before and after infection with Toxoplasma, resulted in restoration of NK activity to the same level as that observed in Toxoplasma-infected mice.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D002448:Cell Adhesion; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D007372:Interferons / Q000097:blood; D007694:Killer Cells, Natural / Q000276:immunology*; D008285:Major Histocompatibility Complex; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D014123:Toxoplasmosis / Q000097:blood
chemical_list: D000911:Antibodies, Monoclonal; D000949:Histocompatibility Antigens Class II; D007372:Interferons