NK1.1+ CD4+ T cells lose NK1.1 expression upon in vitro activation.
NK1.1+ CD4+ T cells produce IL-4 promptly in vivo upon injection of anti-CD3 and may play a role in initiating Th2 cell-mediated immunity. To characterize their in vitro activation properties, NK1.1+ CD4+ T cells were obtained in high purity from spleens of normal C57BL/6 mice, where they represent 2 to 5% of CD4+ T cells, or from MHC-class II I-Ab gene knockout mice, where they constitute 42% of CD4+ T cells. Activation of NK1.1+ CD4+ T cells from either source with plate-bound anti-CD3 resulted in loss of expression of NK1.1 as determined both by flow cytometric analysis and by reverse transcriptase-PCR analysis. A portion of these cells also lost CD4 expression. Both the CD4+ and CD4- activated cells retained the over-representation of V beta8 and V alpha14 chains and expressed the intermediate levels of the TCR-CD3 complex that is characteristic of resting NK1.1+ CD4+ T cells. The anti-NK1.1 mAb used for cell sorting was not the cause of NK1.1 or CD4 disappearance, since the sorted cells remain both NK1.1+ and CD4+ when cultured in the absence of anti-CD3 or in the presence of anti-CD3 and cyclosporin A. Furthermore, NK1.1+ CD4+ T cells that were not treated with anti-NK1.1 Ab also lost NK1.1 expression after activation. Populations of activated CD4+ and CD4- cells (derived from NK1.1+ CD4+ T cells) produced both IL-4 and IFN-gamma upon restimulation with plate-bound anti-CD3.
Chen
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Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Huang
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Paul
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D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000950:Antigens, Ly; D000954:Antigens, Surface / Q000276:immunology*; D017252:CD3 Complex / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002454:Cell Differentiation; D002478:Cells, Cultured; D006224:Cricetinae; D005434:Flow Cytometry; D006801:Humans; D037181:Lectins, C-Type; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D055651:NK Cell Lectin-Like Receptor Subfamily B; D011971:Receptors, Immunologic / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000950:Antigens, Ly; D000954:Antigens, Surface; D017252:CD3 Complex; C527203:KLRB1 protein, human; C527211:Klrb1c protein, mouse; D037181:Lectins, C-Type; D055651:NK Cell Lectin-Like Receptor Subfamily B; D011971:Receptors, Immunologic