title: Defective expression of HLA class I antigens: a case of the bare lymphocyte without immunodeficiency.
abstract: A case of the bare lymphocyte without apparent immunodeficiency was observed in a 33-year-old woman who had no history of severe infections but suffered from sino-bronchial disease. No HLA-A and -B antigens (class I antigens) were detected at the cell surface of lymphocytes, granulocytes, and platelets, but they were expressed, although at a reduced level, on the cultured B lymphoid cell line. T lymphocytes were normal in number and in the relative proportion of T4/T8 and responded to mitogens but not to PPD and candida. HLA-DR antigens (class II antigens) were present on B lymphocytes and showed intermediate MLR-stimulatory capacity, which made it possible to deduce the patient's HLA genotype. She was found to be homozygous at consanguinity for HLA-A, -B, and -DR antigens. The numbers of B lymphocytes, immunoglobulins, and complements were all in the normal range; there was, however, a low level of IgM. Two-dimensional gel analysis of class I antigens revealed the presence of normally expressed beta-2 microglobulins (B2M) and an apparently single set of class I heavy chains, allowing us to consider two alternative cellular mechanisms in this defect; the presence of one abnormal class I structural gene and the regulatory mechanism that acted in cis were suggested.
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal; D001402:B-Lymphocytes / Q000276:immunology; D001792:Blood Platelets / Q000276:immunology; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D005260:Female; D006098:Granulocytes / Q000276:immunology; D006680:HLA Antigens / Q000032:analysis* / Q000276:immunology; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006801:Humans; D007124:Immunoenzyme Techniques; D007153:Immunologic Deficiency Syndromes / Q000276:immunology; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology*; D008297:Male; D010375:Pedigree; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D006680:HLA Antigens; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II