title: Induction of CD4 T cell changes in murine AIDS is dependent on costimulation and involves a dysregulation of homeostasis.
abstract: Strong CD4 T cell activation and proliferation are seen in susceptible mice infected with the murine retroviral inoculum, LP-BM5, which produces an immunodeficiency syndrome called murine AIDS (MAIDS). We developed a short term adoptive transfer model of MAIDS to examine the requirements for the CD4 T cell response. Naive CD4 T cells from uninfected donors responded quickly after adoptive transfer into MAIDS-infected hosts, becoming activated and proliferating within several days. Using blocking mAbs to costimulatory ligands and CD4 T cells deficient in expression of their receptors, we found that the CD4 T cell response requires CD28:B7.1/B7.2 interactions, but not CTLA4 or CD40-CD40 ligand interactions. Naive CD4 T cells did not respond in H-2M-deficient mice with MAIDS, suggesting that disease requires recognition of self peptide-MHC complexes. The self MHC-dependent division and accumulation of large numbers of CD4 T cells suggest that MAIDS involves a disruption of the balance of homeostatic signals. Supporting this hypothesis, CD4 T cells from mice with MAIDS failed to regulate the homeostatic division of naive CD4 T cells in a cotransfer model. Thus, a combination of up-regulation of costimulatory ligands and disruption of homeostatic control may be responsible for CD4 lymphoproliferation in MAIDS.
authors.affiliation: Department of Biology, University of California at San Diego, La Jolla, CA 92093, USA.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Yen
authors.forename: Nancy
authors.initials: N
authors.lastname: Lepak
authors.forename: Susan L
authors.initials: SL
authors.lastname: Swain
mesh_terms: D000069594:Abatacept; D019264:Adoptive Transfer; D000818:Animals; D019138:Antibodies, Blocking / Q000008:administration & dosage; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D015703:Antigens, CD / Q000276:immunology / Q000378:metabolism; D000943:Antigens, Differentiation / Q000276:immunology / Q000378:metabolism; D001324:Autoantigens / Q000276:immunology / Q000378:metabolism; D018122:B7-1 Antigen / Q000276:immunology / Q000378:metabolism; D051940:B7-2 Antigen; D001896:Boron Compounds / Q000378:metabolism; D018106:CD28 Antigens / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000637:transplantation; D019013:CD40 Antigens / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D023201:CD40 Ligand / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D060908:CTLA-4 Antigen; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000378:metabolism; D000949:Histocompatibility Antigens Class II / Q000276:immunology / Q000378:metabolism; D006706:Homeostasis / Q000235:genetics / Q000276:immunology*; D007106:Immune Sera / Q000008:administration & dosage; D018796:Immunoconjugates; D007274:Injections, Intraperitoneal; D007700:Kinetics; D008213:Lymphocyte Activation / Q000235:genetics; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D018345:Mice, Knockout; D008819:Mice, Nude; D016513:Mice, SCID; D008822:Mice, Transgenic; D016183:Murine Acquired Immunodeficiency Syndrome / Q000235:genetics / Q000276:immunology* / Q000378:metabolism
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D019138:Antibodies, Blocking; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D001324:Autoantigens; D018122:B7-1 Antigen; D051940:B7-2 Antigen; D001896:Boron Compounds; D018106:CD28 Antigens; D019013:CD40 Antigens; D060908:CTLA-4 Antigen; C497965:Cd86 protein, mouse; C556707:Ctla4 protein, mouse; D018984:Epitopes, T-Lymphocyte; D005456:Fluorescent Dyes; D000949:Histocompatibility Antigens Class II; D007106:Immune Sera; D018796:Immunoconjugates; D008562:Membrane Glycoproteins; D023201:CD40 Ligand; D000069594:Abatacept