title: Analysis of CD3 antigen expression in patients with ataxia-telangiectasia.
abstract: The expression of CD3 molecules by the lymphocytes of five patients with ataxia-telangiectasia was examined using the murine monoclonal antibody OKT3. By immunofluorescent staining, fewer of the patients' peripheral blood mononuclear cells and purified T cells expressed CD3 compared with normals. The proliferative response of the patients' cells to OKT3 was also less than normal. However, the mononuclear cells from all five patients produced IL-2 after OKT3 stimulation; in four patients IL-2 was normal, while one patient produced greater than normal levels. While the expression of cellular IL-2 receptors and the release of these receptors into culture supernatants was generally less in ataxia-telangiectasia patients, the levels of receptor expression were not significantly less than normal. As analysed by sodium dodecyl sulphate polyacrylamide gel electrophoresis, the CD3 molecules from ataxia-telangiectasia patients' lymphocytes were no different from those of normal individuals. These results suggest that patients with ataxia-telangiectasia have structurally normal CD3 molecules which may be used to activate cells normally for some but not all T cell functions.
mesh_terms: D000293:Adolescent; D000328:Adult; D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology*; D001260:Ataxia Telangiectasia / Q000276:immunology*; D002648:Child; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis / Q000276:immunology; D008213:Lymphocyte Activation; D008297:Male; D010835:Phytohemagglutinins / Q000494:pharmacology; D011971:Receptors, Immunologic / Q000032:analysis; D015375:Receptors, Interleukin-2; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D007376:Interleukin-2; D010835:Phytohemagglutinins; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2