title: Roles of programmed death-1 (PD-1)/PD-1 ligands pathway in the development of murine acute myocarditis caused by coxsackievirus B3.
abstract: OBJECTIVE
  This study was designed to investigate the roles of programmed death-1 (PD-1) and PD-1 ligands (PD-L) in the development of murine acute myocarditis caused by Coxsackievirus B3. PD-1/PD-L belong to the CD28/B7 superfamily, and the PD-1/PD-L pathway is known to transduce a negative immunoregulatory signal that antagonizes the T-cell receptor-CD28 signal and inhibits T-cell activation.
  
  
  METHODS
  We first analyzed the expression of PD-L1/PD-L2 on cardiac myocytes in vivo and in vitro. Second, we examined the effects of in vivo treatment with an anti-PD-1, PD-L1, or PD-L2 monoclonal antibodies on the development of myocardial inflammation in C3H/He mice infected with Coxsackievirus B3. Third, to investigate the effects of anti-PD-1 monoclonal antibody treatment on the activation of the infiltrating cells, we examined the expression of interleukin (IL)-2, interferon (IFN)-gamma, CD40 ligand (CD40L), Fas ligand (FasL), and perforin as activation markers in mouse hearts by a semiquantitative PCR method.
  
  
  RESULTS
  PD-L1 was markedly induced on cardiac myocytes with acute myocarditis. In vivo anti-PD-1 or -PD-L1 blocking monoclonal antibody treatment increased the myocardial inflammation whereas anti-PD-1 stimulating monoclonal antibody treatment decreased the myocardial inflammation, and anti-PD-L2 monoclonal antibody treatment had no effect. Anti-PD-1 monoclonal antibody treatment significantly increased the expression of IFN-gamma, FasL, CD40L, perforin, and Coxsackievirus B3 genomes in myocardial tissue.
  
  
  CONCLUSIONS
  Our findings strongly suggest that the PD-1/PD-L1 pathway played a pivotal role in suppressing myocardial inflammation and raise the possibility of immunotherapy by stimulating the PD-1/PD-L1 pathway to prevent myocardial damage in viral myocarditis.
authors: Department of Cardiovascular Medicine, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Tokyo 113-8655, Japan. sekoyosh-tky@umin.ac.jp
authors: Yoshinori
authors: Y
authors: Seko
authors: Hideo
authors: H
authors: Yagita
authors: Ko
authors: K
authors: Okumura
authors: Miyuki
authors: M
authors: Azuma
authors: Ryozo
authors: R
authors: Nagai
mesh_terms: D000208:Acute Disease; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D000937:Antigen-Antibody Reactions; D000943:Antigens, Differentiation / Q000032:analysis / Q000502:physiology*; D017209:Apoptosis; D018122:B7-1 Antigen / Q000032:analysis / Q000378:metabolism; D060890:B7-H1 Antigen; D015415:Biomarkers / Q000032:analysis; D023201:CD40 Ligand / Q000235:genetics; D002478:Cells, Cultured; D003384:Coxsackievirus Infections / Q000276:immunology / Q000378:metabolism*; D029822:Enterovirus B, Human; D053222:Fas Ligand Protein / Q000235:genetics; D005260:Female; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000235:genetics; D007376:Interleukin-2 / Q000235:genetics; D008024:Ligands; D008213:Lymphocyte Activation; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008809:Mice, Inbred C3H; D008856:Microscopy, Fluorescence; D009205:Myocarditis / Q000276:immunology / Q000378:metabolism / Q000821:virology*; D010455:Peptides / Q000032:analysis / Q000378:metabolism; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins / Q000235:genetics; D061027:Programmed Cell Death 1 Ligand 2 Protein; D061026:Programmed Cell Death 1 Receptor; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D018122:B7-1 Antigen; D060890:B7-H1 Antigen; D015415:Biomarkers; C498919:Cd274 protein, mouse; D053222:Fas Ligand Protein; D007376:Interleukin-2; D008024:Ligands; D008562:Membrane Glycoproteins; C556977:PDCD1LG2 protein, human; C491383:Pdcd1 protein, mouse; C556978:Pdcd1lg2 protein, mouse; D010455:Peptides; D052899:Pore Forming Cytotoxic Proteins; D061027:Programmed Cell Death 1 Ligand 2 Protein; D061026:Programmed Cell Death 1 Receptor; D012333:RNA, Messenger; D054353:Perforin; D023201:CD40 Ligand; D007371:Interferon-gamma