Tissue localization and biochemical characteristics of a new thymic antigen recognized by a monoclonal thymocytotoxic autoantibody from New Zealand black mice.
Naturally occurring thymocytotoxic autoantibodies (NTA) have been described in both humans and mice with SLE. To define further the role of anti-thymic autoantibodies in murine lupus, we studied the cellular and molecular specificity of a spontaneous monoclonal NTA, designated TC-17, derived from a 4-mo-old New Zealand Black mouse. TC-17, an IgM autoantibody, has been shown previously to be unreactive with Lyt-1, Lyt-2, and L3T4 (T helper) antigens. We have shown further that it is also unreactive with Thy-1. TC-17 recognizes a new thymic antigen that appears to mark a distinct subpopulation of cortisol-sensitive cortical thymocytes. The antigen consists of a single glycoprotein chain with an apparent m.w. of 88,000. TC-17 shows reduced binding to thymocytes treated with tunicamycin, indicating either that glycosylation of TC-17 antigen is necessary for TC-17 to bind to it or that glycosylation is required for expression of the antigen on the cell surface. TC-17 uniquely reacts with two of 17 murine lymphoid tumor cell lines of intermediate cellular maturity. The thymocytotoxic activity of TC-17 is absorbed by single cell suspensions of murine stomach, small intestine, large intestine, kidney, and thymus. Moreover, the specific binding of TC-17 to gut tissue of normal and germfree mice can be demonstrated by indirect immunofluorescence, suggesting antigenic cross-reactions between thymic and gut tissue. TC-17 reacts with rat thymocytes as well as it does with murine cells, indicating moderate evolutionary conservation of the TC-17 antigen. The expression of this glycoprotein by a discrete thymocyte subset may prove to be a valuable probe for the study of murine T cell differentiation.
D000042:Absorption; D000818:Animals; D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis*; D000961:Antilymphocyte Serum; D001323:Autoantibodies; D002460:Cell Line; D005455:Fluorescent Antibody Technique; D006651:Histocytochemistry; D007152:Immunologic Capping; D051379:Mice; D008810:Mice, Inbred C57BL; D008814:Mice, Inbred NZB / Q000276:immunology*; D051381:Rats; D011919:Rats, Inbred Strains; D013045:Species Specificity; D013950:Thymus Gland / Q000276:immunology*; D013953:Thymus Neoplasms / Q000276:immunology; D014018:Tissue Distribution; D014415:Tunicamycin / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D000961:Antilymphocyte Serum; D001323:Autoantibodies; D014415:Tunicamycin