title: Distinct memory CD4+ T-cell subsets mediate immune recognition of Epstein Barr virus nuclear antigen 1 in healthy virus carriers.
abstract: CD4+ T cells, specific for transforming latent infection with the Epstein Barr virus (EBV), consistently recognize the nuclear antigen 1 of EBV (EBNA1). EBNA1-specific effector CD4+ T cells are primarily T-helper 1 (TH1) polarized. Here we show that most healthy EBV carriers have such IFN-secreting EBNA1-specific CD4+ T cells at a frequency of 0.03% of circulating CD4+ T cells. In addition, healthy carriers have a large pool of CD4+ T cells that proliferated in response to EBNA1 and consisted of distinct memory-cell subsets. Despite continuous antigen presence due to persistent EBV infection, half of the proliferating EBNA1-specific CD4+ T cells belonged to the central-memory compartment (TCM). The remaining EBNA1-specific CD4+ T cells displayed an effector-memory phenotype (TEM), of which a minority rapidly secreted IFN upon stimulation with EBNA1. Based on chemokine receptor analysis, all EBNA1-specific TCM CD4+ T cells were TH1 committed. Our results suggest that protective immune control of chronic infections, like EBV, includes a substantial reservoir of TCM CD4+ TH1 precursors, which continuously fuels TH1-polarized effector cells.
authors.affiliation: Laboratory of Viral Immunobiology, Christopher H. Browne Center for Immunology and Immune Diseases, The Rockefeller University, New York, NY 10021, USA.
authors.forename: Kevin N
authors.initials: KN
authors.lastname: Heller
authors.forename: Jenica
authors.initials: J
authors.lastname: Upshaw
authors.forename: Beza
authors.initials: B
authors.lastname: Seyoum
authors.forename: Henry
authors.initials: H
authors.lastname: Zebroski
authors.forename: Christian
authors.initials: C
authors.lastname: Münz
mesh_terms: D000956:Antigens, Viral / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D019309:Epstein-Barr Virus Nuclear Antigens / Q000276:immunology*; D006801:Humans; D007156:Immunologic Memory; D007372:Interferons / Q000378:metabolism; D037182:T-Cell Antigen Receptor Specificity; D016176:T-Lymphocyte Subsets / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology
chemical_list: D000956:Antigens, Viral; D019309:Epstein-Barr Virus Nuclear Antigens; D007372:Interferons