title: alpha beta T cell regulation and CD40 ligand dependence in murine systemic autoimmunity.
abstract: To explore the mechanisms by which alpha beta T cells and gamma delta T cells regulate systemic autoimmunity, lupus-prone mice were rendered deficient in CD40 ligand and/or alpha beta T cells by intercrossing CD40L -/- and TCR-alpha -/- knockouts, generating CD40L-intact or -deficient (CD40L+ or CD40L-), alpha beta T cell-intact or -deficient (alpha beta+ or alpha beta-) MRL-lpr/lpr animals. As expected, CD40L+ alpha beta+ mice developed high titer autoantibodies along with severe renal and cutaneous disease. CD40L+ alpha beta- animals developed lower levels of autoantibodies, accompanied by less severe or delayed renal and cutaneous disease. CD40L- alpha beta+ mice developed even lower titers of autoantibodies and less severe renal disease yet developed cutaneous lesions indistinguishable from those of CD40L+ alpha beta+ disease. Most surprisingly, CD40L- alpha beta- animals developed higher levels of some autoantibodies than did CD40L- alpha beta+ mice and developed renal disease similar in severity to CD40L+ alpha beta- counterparts; however, they failed to develop skin disease. Thus, disruption of CD40L and alpha beta T cells provides a novel dissection of the physiology and pathology of murine lupus; while these data confirm previous findings demonstrating a role for CD40L-dependent, alpha beta T cell-dependent mechanisms in autoantibody production and renal disease in murine lupus, they also: 1) establish that alpha beta T cells may drive autoimmune skin disease by a CD40L-independent mechanism; 2) identify a role for CD40L in non-alpha beta T cell-dependent autoantibody production and autoimmune skin disease; and 3) suggest a role for alpha beta T cells in the down-regulation of autoimmunity driven by other T cells. Thus, both alpha beta and non-alpha beta T cells, such as gamma delta T cells, regulate systemic autoimmunity by CD40L-dependent and -independent mechanisms.
authors.affiliation: Section of Rheumatology, Yale University School of Medicine, New Haven, CT 06510, USA.
authors.forename: S L
authors.initials: SL
authors.lastname: Peng
authors.forename: J M
authors.initials: JM
authors.lastname: McNiff
authors.forename: M P
authors.initials: MP
authors.lastname: Madaio
authors.forename: J
authors.initials: J
authors.lastname: Ma
authors.forename: M J
authors.initials: MJ
authors.lastname: Owen
authors.forename: R A
authors.initials: RA
authors.lastname: Flavell
authors.forename: A C
authors.initials: AC
authors.lastname: Hayday
authors.forename: J
authors.initials: J
authors.lastname: Craft
mesh_terms: D000818:Animals; D001323:Autoantibodies / Q000096:biosynthesis; D001327:Autoimmune Diseases / Q000276:immunology* / Q000378:metabolism; D019013:CD40 Antigens / Q000235:genetics / Q000502:physiology*; D023201:CD40 Ligand; D007105:Immune Complex Diseases / Q000276:immunology / Q000378:metabolism; D007674:Kidney Diseases / Q000235:genetics / Q000276:immunology; D008024:Ligands; D008231:Lymphopenia / Q000235:genetics / Q000276:immunology; D008562:Membrane Glycoproteins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D051379:Mice; D019463:Mice, Inbred MRL lpr; D008817:Mice, Mutant Strains; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology*; D012871:Skin Diseases / Q000235:genetics / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism*
chemical_list: D001323:Autoantibodies; D019013:CD40 Antigens; D008024:Ligands; D008562:Membrane Glycoproteins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D023201:CD40 Ligand