Expression of non-MHC-restricted T cell antigen-binding molecules by thymic lymphocytes.
Heterologous antisera which recognize non-major histocompatibility complex (MHC)-restricted T cell antigen-binding molecules (TABM) were used to characterize the expression and structure of TABM on thymic lymphocytes. Approximately 70% of thymocytes express membrane molecules bound by anti-TABM antibodies (mTABM). Antibody activity for thymocyte TABM could be removed by adsorption to splenic T cells, but not by adsorption to splenic B cells. Similarly, adsorption of the antiserum to thymocytes or splenic T cells removed antibody activity to a purified TABM whereas adsorption with B cells had no effect. Radioiodinated thymic and splenic T cell mTABM were resolved by 2D-polyacrylamide gel electrophoresis and when reduced, both populations of mTABM migrated primarily as Mr 23,000 proteins with an isoelectric point range of 6.8-7.8. Multimers of this protein were also observed at Mr 85-97,000 and 130-150,000 on both thymocytes and splenic T cells. These data indicate that MHC-unrestricted antigen-binding molecules are expressed by a majority of thymocytes and these thymic TABM are structurally and antigenically similar to mTABM on peripheral cells. This suggests an ontogenic relationship between thymic TABM and peripheral TABM.
Rellahan
B L
BL
Department of Pathology, University of Connecticut Health Center, Farmington 06032.
Cone
R E
RE
D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D001665:Binding Sites; D002454:Cell Differentiation; D000939:Epitopes / Q000032:analysis; D008565:Membrane Proteins / Q000032:analysis; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D010641:Phenotype; D013154:Spleen; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology* / Q000502:physiology; D013950:Thymus Gland / Q000276:immunology*
D000945:Antigens, Differentiation, T-Lymphocyte; D000939:Epitopes; D008565:Membrane Proteins