Evidence for the existence of distinct heterogeneity among the peripheral CD4-CD8- T cells from MRL-lpr/lpr mice based on the expression of the J11d marker, activation requirements, and functional properties.
Autoimmune-susceptible, MRL-lpr/lpr (lpr) mice develop a profound lymphadenopathy resulting from the accumulation of CD4-CD8- (double-negative, DN) cells in peripheral lymphoid organs. The source and the mechanism of this abnormal accumulation of cells is still unknown. Recently, we reported that a significant number (approximately 35%) of the CD4-CD8- cells expressed J11d, a marker expressed by immature thymocytes but not by mature functional peripheral T cells. In the present study, we investigated the phenotype, growth requirements, and functional properties of purified J11d+ and J11d- subpopulations. Using the mAb, F23.1, which recognizes a TCR determinant encoded by the V beta 8 gene family, it was observed that approximately 30% of the J11d+ and J11d- DN cells expressed this determinant. Further studies on the thymus revealed that J11d+ DN cells from lpr thymus also contained F23.1+ cells (approximately 25%), whereas, similar cells from normal MRL(-)+/+mice were all F23.1-, consistent with earlier reports in other normal strains. Further phenotypic studies revealed that the peripheral J11d+ and J11d- cells from lpr mice were similar in expressing CD3, Ly-5 (B220), and Ly-24 (Pgp-1) determinants. When stimulated with phorbol myristic acetate (PMA) and recombinant IL-2 (rIL-2), only J11d- cells but not J11d+ cells responded by proliferation. However, in the presence of calcium ionophore (A23187) and PMA, both J11d+ and J11d- subpopulations proliferated by producing and responding to endogenous IL-2 but not IL-4. The lymph node T cells from 1-month-old MRL-lpr/lpr mice responded strongly when stimulated with PMA + rIL-4 or PMA + rIL-6. In contrast both J11d+ and J11d- subpopulations failed to respond when similarly stimulated. The J11d+ but not J11d- cells demonstrated spontaneous cytotoxic activity against the NK-sensitive YAC-1 tumor targets. The J11d- cells did not exhibit cytotoxic potential in spite of culture with PMA + rIL-2. Even after repeated culture in vitro with PMA + A23187 or PMA + rIL-2, both J11d+ and J11d- subpopulations failed to express the mature phenotype bearing CD4 and/or CD8 antigens. The present study demonstrates the expansion of unique J11d+, alpha beta-TCR+, DN T cells with cytotoxic potential in lpr mice and further suggests the existence of phenotypic and functional heterogeneity among the abnormal lpr DN cells.
Kakkanaiah
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VN
Department of Biology, Virginia Polytechnic Institute and State University, Blacksburg 24061.
Nagarkatti
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M
Nagarkatti
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PS
D000818:Animals; D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D000950:Antigens, Ly / Q000032:analysis; D001327:Autoimmune Diseases / Q000276:immunology*; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens; D000001:Calcimycin / Q000494:pharmacology; D002454:Cell Differentiation; D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D007376:Interleukin-2 / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D008213:Lymphocyte Activation; D051379:Mice; D008817:Mice, Mutant Strains; D011948:Receptors, Antigen, T-Cell / Q000032:analysis; D016693:Receptors, Antigen, T-Cell, alpha-beta; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly; D015704:CD4 Antigens; D016827:CD8 Antigens; D007376:Interleukin-2; D015850:Interleukin-6; D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta; D015375:Receptors, Interleukin-2; D015847:Interleukin-4; D000001:Calcimycin; D013755:Tetradecanoylphorbol Acetate