title: Epstein-Barr virus-specific T-cell cytotoxicity is mediated through the perforin pathway in patients with lymphoproliferative disorders after allogeneic bone marrow transplantation.
abstract: The in vivo cytotoxic mechanism of Epstein--Barr virus (EBV)-specific cytotoxic lymphocytes was examined in a patient who suffered with EBV-associated lymphoproliferative disease (LPD) after bone marrow transplantation (BMT). His peripheral CD8+ T-cell count was significantly increased and >70% of these cells were EBV-specific by fluorescence-activated cell sorter (FACS) analysis for interferon-gamma production. Intracellular perforin expression was markedly increased in CD8+ T cells by FACS analysis. The lymphocytes from this patient had cytotoxic activity against autologous EBV+ lymphoblastoid cell lines which were completely inhibited by concanamycin A, an inhibitor of perforin, and a anti-human leucocyte antigen (HLA)-class I monoclonal antibody. These results suggest that the cytotoxicity was mediated by the perforin, in an HLA-class I-restricted manner. We performed serial intracellular perforin analyses in another patient who also showed endogenous expansion of EBV-specific CD8+ T cells that coincided with an increased EBV-DNA load. Perforin expression in the CD8+ and CD4+ T cells paralleled the EBV-specific CD8+ T cells and EBV-DNA load, which also suggests that perforin mediates EBV-specific cytolysis in vivo and is responsible for effective immunosurveillance against EBV reactivation after BMT. Evaluation of host immunity against EBV by determining perforin expression in lymphocytes and EBV-specific lymphocytes along with quantification of EBV-DNA may be useful for predicting the clinical course of patients with EBV-associated LPD after BMT.
authors.affiliation: The Department of Pediatrics/Developmental Pediatrics, Nagoya University School of Medicine, Japan. ayami@med.nagoya-u.ac.jp
authors.forename: Ayami
authors.initials: A
authors.lastname: Yoshimi
authors.forename: Ikuya
authors.initials: I
authors.lastname: Tsuge
authors.forename: Hiroe
authors.initials: H
authors.lastname: Namizaki
authors.forename: Yo
authors.initials: Y
authors.lastname: Hoshino
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kimura
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Watanabe
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Kuzushima
authors.forename: Seiji
authors.initials: S
authors.lastname: Kojima
mesh_terms: D015415:Biomarkers / Q000097:blood; D016026:Bone Marrow Transplantation / Q000009:adverse effects*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002675:Child, Preschool; D003602:Cytotoxicity, Immunologic; D004279:DNA, Viral / Q000032:analysis; D020031:Epstein-Barr Virus Infections / Q000276:immunology* / Q000821:virology; D004854:Herpesvirus 4, Human / Q000302:isolation & purification; D006801:Humans; D016867:Immunocompromised Host; D007223:Infant; D008232:Lymphoproliferative Disorders / Q000276:immunology* / Q000821:virology; D008297:Male; D008562:Membrane Glycoproteins / Q000097:blood / Q000276:immunology*; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D019562:Viral Load
chemical_list: D015415:Biomarkers; D004279:DNA, Viral; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D054353:Perforin