Subsets of thymopoietic rat thymocytes defined by expression of the CD2 antigen and the MRC OX-22 determinant of the leukocyte-common antigen CD45.
The MRC OX-22 monoclonal antibody recognizes a restricted determinant of the rat leukocyte-common antigen (L-CA, CD45), which is expressed on most peripheral T cells and all B cells. In contrast only 2%-3% of thymocytes are OX-22+ and these are now shown to be mostly of the immature CD4-CD8- (double-negative, DN), phenotype with very few of the mature phenotype cells being OX-22+. Analysis of immunoperoxidase sections suggests that the DN OX-22+ cells are located in the cortex. Among the DN cells about 60% are OX-22+ and a similar percentage are positive for CD2 antigen. Double staining showed that OX-22+CD2-, OX-22+CD2+, and OX-22-CD2+ populations can be defined and that these three sets account for approximately 95% of the DN cells. Measurement of the thymopoietic activity of DN subsets showed that OX-22+CD2- and OX-22+CD2+ cells have regenerative capacity whilst OX-22-CD2+ cells do not.
Law
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DA
Medical Research Council Cellular Immunology Unit, Sir William Dunn School of Pathology, Oxford GB.
Spruyt
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LL
Paterson
D J
DJ
Williams
A F
AF
D000367:Age Factors; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000943:Antigens, Differentiation / Q000032:analysis*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D018801:CD2 Antigens; D002453:Cell Cycle; D000939:Epitopes; D005434:Flow Cytometry; D006410:Hematopoiesis; D006649:Histocompatibility Antigens / Q000032:analysis*; D017493:Leukocyte Common Antigens; D051381:Rats; D011971:Receptors, Immunologic / Q000032:analysis*; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology*
D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D000945:Antigens, Differentiation, T-Lymphocyte; D018801:CD2 Antigens; D000939:Epitopes; D006649:Histocompatibility Antigens; D011971:Receptors, Immunologic; D017493:Leukocyte Common Antigens