title: Expression of Mls determinants in mice exhibiting the severe combined immunodeficiency (scid) mutation or X-linked immunodeficiency (xid) defect.
abstract: While Ig+ B cells appear to be the principal cell type expressing immunogenic minor lymphocyte stimulatory (Mls) determinants, both T cells and B cells are capable of mediating deletion of developing Mls-reactive thymocytes. In addition, levels of mouse mammary tumor proviral transcripts are increased after B or T cell stimulation, and expression of functional Mls determinants is augmented by activation of B cells. These findings suggest Mls determinants are present on B and T lymphocytes, and that activation of B and T cells augments Mls expression. In the present study, we wished to determine whether B and T cells were required for expression of Mls determinants by examining mice with severe combined immunodeficiency (SCID) containing no detectable Ig+ B cells or TCR+ T cells, as well as animals that expressed the X-linked immunodeficiency (xid) defect and lacked a subset of mature B cells. We found Mlsa-reactive V beta 6hi T cells were deleted from thymi of male (CBA/NxAKR/J)F1 xid mice, and that spleen cells from these animals stimulated anti-Mlsa mixed lymphocyte responses by unprimed B10.BR spleen T cells. In addition, Mlsc-reactive V beta 3hi AKR/J thymocytes and spleen T cells were deleted in AKR/J----SCID bone marrow chimeras, and spleen cells from SCID mice stimulated proliferation by an Mlsc-specific T cell clone. These results demonstrate that both xid mice and SCID animals express Mls determinants that mediate deletion of developing, Mls-responsive thymocytes and stimulate proliferation of mature, Mls-reactive T cells. Hence, mature B cells and T cells are not essential for Mls expression.
authors.affiliation: Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
authors.forename: J L
authors.initials: JL
authors.lastname: Roberts
authors.forename: R
authors.initials: R
authors.lastname: Abe
authors.forename: E W
authors.initials: EW
authors.lastname: Shores
authors.forename: A
authors.initials: A
authors.lastname: Singer
mesh_terms: D000818:Animals; D008040:Genetic Linkage; D007153:Immunologic Deficiency Syndromes / Q000276:immunology*; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D016513:Mice, SCID / Q000276:immunology*; D016747:Minor Lymphocyte Stimulatory Antigens / Q000032:analysis*; D009154:Mutation; D011948:Receptors, Antigen, T-Cell / Q000032:analysis; D013601:T-Lymphocytes / Q000276:immunology; D014960:X Chromosome
chemical_list: D016747:Minor Lymphocyte Stimulatory Antigens; D011948:Receptors, Antigen, T-Cell