Antigen presentation by hapten-specific B lymphocytes. I. Role of surface immunoglobulin receptors.
The present study examines the ability of hapten-specific murine splenic B lymphocytes to present hapten-proteins to carrier-specific T cell hybridomas. BALB/cB cells specific for 2,4,6-trinitrophenyl (TNP) were isolated from spleens of immune mice by elution from TNP-gelatin-coated dishes. Such cells presented the TNP-modified terpolymer, GL phi, at concentrations as low as 0.1 microgram/ml, to a GL phi-specific, I-Ed-restricted, interleukin 2-producing T cell hybridoma. In contrast, the same B lymphocytes required 1,000-fold higher concentrations of unmodified GL phi to stimulate the same T cell hybridoma. The presentation of low concentrations of TNP-GL phi by TNP-specific B lymphocytes was significantly or completely blocked by anti-Ig antibody or TNP-proteins, indicating that surface Ig receptors were critically involved in this phenomenon. Finally, binding of TNP-proteins did not alter the ability of the B cells to present unrelated, unhaptenated proteins or to stimulate alloreactive T cells. These results suggest that surface Ig receptors serve to focus antigens onto specific B lymphocytes and that such cells are highly efficient at presenting linked antigenic determinants to T cells. The implications of these findings for the mechanisms of physiologic, histocompatibility-restricted T-B collaboration are discussed.
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D001666:Binding Sites, Antibody; D000939:Epitopes / Q000276:immunology; D006241:Haptens / Q000276:immunology*; D006649:Histocompatibility Antigens / Q000235:genetics; D000949:Histocompatibility Antigens Class II; D051379:Mice; D008807:Mice, Inbred BALB C; D010455:Peptides / Q000276:immunology; D011108:Polymers; D011817:Rabbits; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism* / Q000502:physiology*; D014301:Trinitrobenzenes / Q000276:immunology
D000939:Epitopes; D006241:Haptens; D006649:Histocompatibility Antigens; D000949:Histocompatibility Antigens Class II; C024138:I-E-antigen; D010455:Peptides; D011108:Polymers; D011947:Receptors, Antigen, B-Cell; D014301:Trinitrobenzenes; C020749:GAT