title: In vivo effects of GK1.5 (anti-L3T4a) monoclonal antibody on induction and expression of delayed-type hypersensitivity.
abstract: The in vivo effects of monoclonal GK1.5 antibody, directed against the L3T4a determinant expressed on Class II-restricted T cells, on the induction and expression of murine delayed-type hypersensitivity (DTH) responses were examined. Development and expression of both hapten (2,4-dinitrofluorobenzene and 2,4,6-trinitrochlorobenzene)- and protein antigen poly(Glu60Ala30Tyr10)-specific DTH are significantly inhibited by injection of monoclonal anti-L3T4a antibody. The inhibitory effects of anti-L3T4a were most pronounced when administered during the afferent (induction) phase of the DTH response, leading to the functional inhibition of the generation of both polyclonal lymph node T-proliferative cells (Tprlf) and DTH effector cells (TDH). The in vivo inhibitory effect is apparently unrelated to preferential induction of suppressor T cells as GK1.5 inhibited DTH induction in cyclophosphamide-treated as well as normal recipients. L3T4a expression on the various T-cell subsets involved in DTH induction and elicitation was also examined. The data show that three functionally distinct, antigen-specific T-cell subsets, Tprlf, TDH, and Th cells involved in DTH induction, bear the Lyt 1+2-, L3T4+ phenotype. Possible mechanisms where in vivo injection of anti-L3T4a inhibits Class II-restricted T-cell subsets involved in DTH induction and expression, including immune depletion and inhibition of T-cell-receptor/ligand interactions, are discussed.
authors.forename: S D
authors.initials: SD
authors.lastname: Miller
authors.forename: M K
authors.initials: MK
authors.lastname: Jenkins
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000950:Antigens, Ly / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology; D003520:Cyclophosphamide / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects; D018800:Thy-1 Antigens; D014301:Trinitrobenzenes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000950:Antigens, Ly; D000954:Antigens, Surface; D000949:Histocompatibility Antigens Class II; D018800:Thy-1 Antigens; D014301:Trinitrobenzenes; D003520:Cyclophosphamide