title: Antigen-driven expansion and contraction of CD8+-activated T cells in primary EBV infection.
abstract: The origin of the increased numbers of CD8+ atypical lymphocytes, expressing activated markers such as HLA-DR or CD45RO, in the peripheral blood of patients with infectious mononucleosis (IM) has been debated. Using a recently developed assay to detect intracellular accumulation of IFN-gamma in EBV-reactive T cells by FACS, we have demonstrated that 34-54% of HLA-DR+/CD8+ and 34-60% of CD45RO+/CD8+ T cells in the PBMCs of febrile patients suffering from IM are EBV-specific. The EBV-specific CD8+ T cell counts in the PBMCs of four febrile patients suffering from IM ranged between 2,260 and 8,200/microl, decreasing to 5.1% and 7.9% of the counts in the first samples over 10 days in two donors. The decline of CD8+ T cell subpopulations, namely HLA-DR+, CD45RO+, and EBV-specific T cells, was in parallel with the drop in the EBV genome load. These data indicate that the Ag-driven expansion of CD8+ T cells and subsequent contraction with the Ag decline in vivo in humans is effective for clearing virus-infected cells with minimal disturbance of the homeostasis of the immune system.
authors.affiliation: Laboratory of Viral Oncology, Aichi Cancer Center Research Institute, Nagoya, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Hoshino
authors.forename: T
authors.initials: T
authors.lastname: Morishima
authors.forename: H
authors.initials: H
authors.lastname: Kimura
authors.forename: K
authors.initials: K
authors.lastname: Nishikawa
authors.forename: T
authors.initials: T
authors.lastname: Tsurumi
authors.forename: K
authors.initials: K
authors.lastname: Kuzushima
mesh_terms: D000956:Antigens, Viral / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000821:virology*; D002469:Cell Separation; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D016679:Genome, Viral; D006684:HLA-DR Antigens / Q000276:immunology; D004854:Herpesvirus 4, Human / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D007244:Infectious Mononucleosis / Q000276:immunology / Q000821:virology; D007371:Interferon-gamma / Q000096:biosynthesis; D017493:Leukocyte Common Antigens / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology*; D019562:Viral Load
chemical_list: D000956:Antigens, Viral; D018984:Epitopes, T-Lymphocyte; D006684:HLA-DR Antigens; D015395:Histocompatibility Antigens Class I; D007371:Interferon-gamma; D017493:Leukocyte Common Antigens