title: Expression of CD45R0 (UCHL1) by CD4+ and CD8+ T cells as a sign of in vivo activation in infectious mononucleosis.
abstract: CD45R0 (UCHL1), a member of leucocyte common antigen family, is expressed largely on previously activated or memory T cells. We examined CD45R0 expression of T cell subpopulations in patients with Epstein-Barr virus (EBV) induced infectious mononucleosis (IMN) as a sign of in vivo activation. Consistent with the notion that activated CD8+ T cells expand in acute IMN; the majority of CD8+ T cells in patients with acute IMN expressed CD45R0 to the similar extent to HLA-DR expression. Most CD4+ T cells in these patients also demonstrated marked expression of CD45R0 as well as HLA-DR antigens, compared with age-matched controls. Expression of CD45R0 by CD4+ T cells in patients with acute IMN was more notable than their HLA-DR expression. While predominant CD8+ T cells resulted in decreased percentages of CD4+ T cells, CD4+ T cells expressing CD45R0 were shown to be significantly elevated in absolute number. The results suggest that both CD4+ and CD8+ T cells may be activated by stimulation with EBV infection. The appearance of two T cell subpopulations expressing CD45R0 in acute IMN implies their immunoregulatory roles in the control of EBV-infected cells.
authors.affiliation: Department of Paediatrics, School of Medicine, Kanazawa University, Ishikawa, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Miyawaki
authors.forename: Y
authors.initials: Y
authors.lastname: Kasahara
authors.forename: H
authors.initials: H
authors.lastname: Kanegane
authors.forename: K
authors.initials: K
authors.lastname: Ohta
authors.forename: T
authors.initials: T
authors.lastname: Yokoi
authors.forename: A
authors.initials: A
authors.lastname: Yachie
authors.forename: N
authors.initials: N
authors.lastname: Taniguchi
mesh_terms: D015703:Antigens, CD / Q000096:biosynthesis*; D000943:Antigens, Differentiation / Q000096:biosynthesis*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D005434:Flow Cytometry; D006684:HLA-DR Antigens / Q000096:biosynthesis; D006649:Histocompatibility Antigens / Q000096:biosynthesis*; D006801:Humans; D007223:Infant; D007244:Infectious Mononucleosis / Q000276:immunology*; D017493:Leukocyte Common Antigens; D008213:Lymphocyte Activation / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D013997:Time Factors
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D006684:HLA-DR Antigens; D006649:Histocompatibility Antigens; D017493:Leukocyte Common Antigens