Abstract
Idiopathic dilated cardiomyopathy (IDC) is one of the major causes of death in humans and has been linked to Coxsackievirus B (CVB) infection. The aim of this study was to analyze phenotypes of heart-infiltrating immune cells in patients suffering from myocarditis and IDC associated with CVB infections. We found that the myocardium of these patients was infiltrated by CD4(+) and CD8(+) T lymphocytes as well as macrophages. Evidence of CVB3/4 infections was also found. In the majority of patients, the T-cell receptor repertoire (TCR) of the infiltrating lymphocytes was restricted, with a polyclonal expansion of the Vbeta7 gene family. We also found that human leukocyte antigen (HLA) class II alleles associated with susceptibility to type 1 diabetes (HLA-DR4 and HLA-DQA1*04/05/06 alleles) were remarkably infrequent in IDC patients (p < 0.005), thus suggesting that they might confer protection against IDC. Finally, mRNA for interleukin-1beta, interferon-gamma, and tumor necrosis factor-alpha was detected in the cardiac specimens, although at a lower level compared with specimens from hearts without signs of viral infections. We conclude that CVB infection of the human myocardium is associated with a selective, yet polyclonal activation of different T-cell subsets in genetically susceptible individuals. This immune response may play a critical role in modulating disease progression after viral infections.
MeSH terms
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Adolescent
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Adult
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Aged
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Animals
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CD4-Positive T-Lymphocytes / immunology*
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CD8-Positive T-Lymphocytes / immunology*
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Cardiomyopathy, Dilated / etiology
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Cardiomyopathy, Dilated / immunology*
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Cardiomyopathy, Dilated / virology
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Child
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Chlorocebus aethiops
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Complementarity Determining Regions / genetics
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Cytokines / biosynthesis
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Cytokines / genetics
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DNA, Viral / isolation & purification
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Diabetes Mellitus, Type 1 / genetics
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Enterovirus B, Human / pathogenicity*
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Enterovirus Infections / complications
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Enterovirus Infections / immunology*
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Enterovirus Infections / virology
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Female
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Gene Expression Profiling
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Gene Frequency
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Gene Rearrangement, T-Lymphocyte
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Genes, T-Cell Receptor alpha
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Genes, T-Cell Receptor beta
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Genetic Predisposition to Disease
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HLA-DQ Antigens / genetics
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HLA-DQ alpha-Chains
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HLA-DQ beta-Chains
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HLA-DR Antigens / genetics
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HLA-DR4 Antigen / genetics
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HLA-DRB1 Chains
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Humans
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Lymphocyte Activation
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Macrophages / immunology
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Male
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Middle Aged
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Myocarditis / etiology
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Myocarditis / immunology*
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Myocarditis / virology
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Myocardium / immunology*
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Myocardium / metabolism
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RNA, Messenger / analysis
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Receptors, Antigen, T-Cell, alpha-beta / analysis*
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T-Lymphocyte Subsets / immunology*
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Vero Cells / virology
Substances
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Complementarity Determining Regions
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Cytokines
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DNA, Viral
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HLA-DQ Antigens
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HLA-DQ alpha-Chains
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HLA-DQ beta-Chains
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HLA-DQA1 antigen
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HLA-DQB1 antigen
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HLA-DR Antigens
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HLA-DR4 Antigen
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HLA-DRB1 Chains
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RNA, Messenger
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Receptors, Antigen, T-Cell, alpha-beta