The expression of a tissue-specific self-peptide is required for allo-recognition.
We have compared the functional properties of I-Ad expressed on different cell types. Specifically, we have transfected I-A alpha d and I-A beta d cDNA into a panel of T cell thymomas of various phenotypes. Excellent class II surface expression was achieved in all T cell tumors, equivalent in level to that found on the B cell lymphoma A20. Interestingly, however, two allo-I-Ad-specific Thy differed in their recognition of the transfected tumor cells: whereas the 42H11 T cell hybridoma (THy) was stimulated very efficiently by all transfectants, the RK38.2.2 Thy did not react to any of them. Both THy responded equally well to I-Ad on A20 B lymphoma cells. Purified macrophages isolated from various sources were also differentially recognized by the two THy, although there was only a quantitative difference in stimulation. Taken together, these results are best interpreted to show that the TCR of the RK38.2.2 THy is specific for I-Ad in the context of a B cell-specific determinant, possibly a self-peptide that is naturally associated with Ia. A cross-reactive molecule could be expressed by macrophages and COS-1 cells, but not by T cells.
Molina
I J
IJ
Department of Pathology, Tufts University School of Medicine, Boston, MA 02111.
Huber
B T
BT
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology*; D000943:Antigens, Differentiation / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D006183:H-2 Antigens / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000276:immunology*; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D016169:Lymphocyte Function-Associated Antigen-1; D008264:Macrophages / Q000502:physiology; D008285:Major Histocompatibility Complex; D051379:Mice; D008815:Mice, Inbred Strains; D016028:Receptors, Leukocyte-Adhesion / Q000032:analysis; D013601:T-Lymphocytes / Q000276:immunology*; D014162:Transfection; D014407:Tumor Cells, Cultured
D000943:Antigens, Differentiation; D006183:H-2 Antigens; D000949:Histocompatibility Antigens Class II; D007376:Interleukin-2; D016169:Lymphocyte Function-Associated Antigen-1; D016028:Receptors, Leukocyte-Adhesion