title: T helper cells change their Lyt-1,2 phenotype during an immune response.
abstract: Evidence is presented that T helper cells change their Lyt-1,2 phenotype, from Lyt-1+2- to Lyt-1-2+, during a secondary response. In a secondary adoptive transfer the Lyt phenotype of carrier-primed T cells was established before and after secondary challenge using monoclonal antibodies and both positive and negative selection in the fluorescence-activated cell sorter. In a carrier-primed donor, the T helper cells were Lyt-1+2- whereas 3 days after boosting the majority were Lyt-2+, and resistant to treatment with anti-Lyt-1 and complement. Parking experiments in lethally irradiated recipients confirmed that Lyt-2+ T helper cells were generated from Lyt-2- precursors. In a primary response, both Lyt-2- and Lyt-2+ T helper cells were present 4 to 20 days after immunization. Therefore T helper cells do not exhibit invariant expression of the Lyt-1,2 alloantigens.
mesh_terms: D000818:Animals; D000921:Antibody-Producing Cells / Q000276:immunology; D000950:Antigens, Ly / Q000235:genetics / Q000276:immunology*; D002352:Carrier Proteins / Q000276:immunology; D002469:Cell Separation; D004136:Dinitrobenzenes / Q000276:immunology; D006801:Humans; D007106:Immune Sera / Q000494:pharmacology; D007117:Immunization, Secondary; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D010641:Phenotype; D011828:Radiation Chimera; D013601:T-Lymphocytes / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D005719:gamma-Globulins / Q000276:immunology
chemical_list: D000950:Antigens, Ly; D002352:Carrier Proteins; D004136:Dinitrobenzenes; D007106:Immune Sera; D005719:gamma-Globulins