Identification and characterization of rat T cell subpopulations expressing T cell receptors alpha/beta and gamma/delta.
Peripheral lymphoid organs of the rat were investigated for the presence of lymphocytes that expressed the pan-T cell markers CD5 and OX-52 but not the T cell receptor (TcR) alpha/beta. Two such populations were identified: 2% to 4% of lymphocytes in adult spleen, lymph nodes and peripheral blood are CD5+ TcR alpha/beta- and express the OX-52 antigen at the same density as TcR alpha/beta+ T-cells. About 90% of these cells are CD8+. A second population is CD5-, CD8+ and OX-52low. Radioimmunoprecipitation from digitonin lysates of surface-labeled cells with an anti-CD3 antiserum showed that the CD5+, but not the CD5- population of TcR alpha/beta- cells expresses a CD3-associated disulfide-linked cell surface molecule of about 100 kDa apparent mol. mass. Upon reduction, one major band, migrating with 48 kDa was observed. A band of the same size was obtained with an anti-human delta chain peptide antiserum, indicating that the CD3-associated non-TcR alpha/beta molecule is the rat TcR gamma/delta. Functional assays showed that most, if not all natural killer (NK) cell activity is present in the CD5(-)-OX-52low population. Reactivity to foreign major histocompatibility complex (MHC) antigens in mixed lymphocyte reaction was exclusively found in TcR alpha/beta+ splenic T cells. It is concluded that rat gamma/delta T cells in the spleen do not contain a high frequency of cells with specificity for foreign MHC antigens. The seeding of the periphery with alpha/beta and the presumptive gamma/delta T cells was followed from birth. Most prominently in the spleen, alpha/beta T cells reached adult levels much later than gamma/delta T cells. Taken together, these findings demonstrate the expression of the TcR gamma/delta on a minor population of peripheral rat T cells with the predominant phenotype CD4-CD8+ that has no NK cell activity when freshly isolated and does not contain a high frequency of alloreactive cells.
Lawetzky
A
A
Genzentrum der Ludwig-Maximilians-Universität München, Martinsried, FRG.
Tiefenthaler
G
G
Kubo
R
R
Hünig
T
T
D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D017252:CD3 Complex; D016827:CD8 Antigens; D003602:Cytotoxicity, Immunologic; D007113:Immunity, Innate; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology; D008198:Lymph Nodes / Q000166:cytology; D011233:Precipitin Tests; D051381:Rats; D011919:Rats, Inbred Strains; D011948:Receptors, Antigen, T-Cell / Q000032:analysis / Q000648:ultrastructure*; D013154:Spleen / Q000166:cytology; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000276:immunology*
D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D016827:CD8 Antigens; D011948:Receptors, Antigen, T-Cell