title: Novel immunoregulatory B cell pathways revealed by lpr-+ mixed chimeras.
abstract: lpr, a murine mutation of the Fas apoptosis receptor, causes lymphadenopathy and autoantibody production, with lymphadenopathy primarily due to a population of CD4-CD8-B220+ T cells. Previous in vivo experiments, in which lpr and normal bone marrow cells were coinfused into lpr hosts, have demonstrated that only T cells of lpr origin accumulated abnormally and only B cells of lpr origin produced autoantibodies. Moreover, in these chimeras, B cells of normal origin were unable to respond to conventional, T cell-dependent exogenous Ag. To address the role of lpr B cells in regulation of lpr autoimmunity, we have prepared lpr-+ mixed chimeras and selectively eliminated lpr B cells using allele-specific, mAb treatment, thus allowing normal B cells to develop in an environment with lpr T cells. From these data, we arrived at four major conclusions: 1) Compared with control-treated chimeric mice, lpr B cell-depleted mice had greatly reduced total lymph node cell counts; 2) the T cells were derived equally from normal and lpr donors, and the percentage of lpr-derived CD4-CD8- T cells was greatly reduced; 3) despite the presence of the remaining lpr T cells, no autoantibodies were produced by the normal derived B cells; and 4) lpr T cells without lpr B cells were unable to prevent a normal B cell response to conventional Ag. These data demonstrate that B cells can play a critical and expansive regulatory role, not only for T cells, but for other B cells as well.
authors.affiliation: Department of Medicine, University of Florida, Gainesville 32610, USA.
authors.forename: E S
authors.initials: ES
authors.lastname: Sobel
authors.forename: V N
authors.initials: VN
authors.lastname: Kakkanaiah
authors.forename: J
authors.initials: J
authors.lastname: Schiffenbauer
authors.forename: E A
authors.initials: EA
authors.lastname: Reap
authors.forename: P L
authors.initials: PL
authors.lastname: Cohen
authors.forename: R A
authors.initials: RA
authors.lastname: Eisenberg
mesh_terms: D000818:Animals; D000917:Antibody Formation / Q000235:genetics; D001323:Autoantibodies / Q000096:biosynthesis; D016175:B-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D015704:CD4 Antigens; D016827:CD8 Antigens; D002465:Cell Movement / Q000235:genetics / Q000276:immunology; D015536:Down-Regulation / Q000235:genetics / Q000276:immunology; D006801:Humans; D007126:Immunoglobulin Allotypes / Q000235:genetics; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008206:Lymphatic Diseases / Q000235:genetics / Q000276:immunology / Q000473:pathology; D008211:Lymphocyte Cooperation / Q000235:genetics; D008212:Lymphocyte Depletion; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D019463:Mice, Inbred MRL lpr; D011828:Radiation Chimera / Q000235:genetics / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000473:pathology; D005719:gamma-Globulins / Q000276:immunology
chemical_list: D001323:Autoantibodies; D015704:CD4 Antigens; D016827:CD8 Antigens; D007126:Immunoglobulin Allotypes; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D005719:gamma-Globulins