title: Attenuation of experimental autoimmune myocarditis by blocking T cell activation through 4-1BB pathway.
abstract: 4-1BB, a member of the tumor necrosis factor receptor (TNFR) family, binds the 4-1BB ligand (4-1BBL), works as a costimulatory molecule, and regulates T cell-mediated immune responses. Although inflammation is an essential pathological feature of myocarditis, the role of 4-1BB in experimental autoimmune myocarditis (EAM) remains unclear. Lewis rats were immunized on day 0 with purified porcine cardiac myosin to establish EAM. 4-1BB-immunoglobulin (4-1BBIg) was administered intraperitoneally (n=6) a total of 9 times (3 times per week). Rats were killed on day 21 to study effects of 4-1BB/4-1BBL pathway blockade. For controls, isotype-matched human IgG was administered in other EAM rats (n=6). Histologic and echocardiographic examination showed development of EAM attenuated by 4-1BBIg. Suppression of mRNA expression for IL-1alpha, IL-1beta, IL-4, IL-6, and TNF-alpha was noted in the heart tissue treated with 4-1BBIg. Treatment with 4-1BBIg reduced production of Th1-type cytokines, and inhibited T cell proliferation in vitro. In the 4-1BB signaling pathway in splenocytes, 4-1BBIg suppressed JNK, p38, and IkappaB activity but not that of ERK1/2. Blockade of T cell activation through the 4-1BB/4-1BBL pathway regulates development of EAM; therefore, 4-1BB may be an effective target for treating myocarditis.
authors.affiliation: Department of Cardiovascular Medicine Tokyo Medical and Dental University 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Haga
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Suzuki
authors.forename: Hisanori
authors.initials: H
authors.lastname: Kosuge
authors.forename: Masahito
authors.initials: M
authors.lastname: Ogawa
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Saiki
authors.forename: Go
authors.initials: G
authors.lastname: Haraguchi
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Maejima
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Isobe
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Uede
mesh_terms: D053330:4-1BB Ligand / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D001327:Autoimmune Diseases / Q000201:enzymology / Q000276:immunology* / Q000473:pathology / Q000517:prevention & control*; D049109:Cell Proliferation / Q000187:drug effects; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D051550:I-kappa B Kinase / Q000378:metabolism; D007150:Immunohistochemistry; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology*; D008297:Male; D009205:Myocarditis / Q000201:enzymology / Q000276:immunology* / Q000473:pathology / Q000517:prevention & control*; D009206:Myocardium / Q000201:enzymology / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011917:Rats, Inbred Lew; D034421:Sus scrofa; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D018417:Th1 Cells / Q000378:metabolism; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9 / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D053330:4-1BB Ligand; D016207:Cytokines; D012333:RNA, Messenger; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9; D051550:I-kappa B Kinase; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases