title: Bystander target cell lysis and cytokine production by dengue virus-specific human CD4(+) cytotoxic T-lymphocyte clones.
abstract: Dengue hemorrhagic fever, the severe form of dengue virus infection, is believed to be an immunopathological response to a secondary infection with a heterologous serotype of dengue virus. Dengue virus capsid protein-specific CD4(+) cytotoxic T-lymphocyte (CTL) clones were shown to be capable of mediating bystander lysis of non-antigen-presenting target cells. After activation by anti-CD3 or in the presence of unlabeled antigen-presenting target cells, these clones could lyse both Jurkat cells and HepG2 cells as bystander targets. Lysis of HepG2 cells suggests a potential role for CD4(+) CTL in the liver involvement observed during dengue virus infection. Three CD4(+) CTL clones were demonstrated to lyse cognate, antigen-presenting target cells by a mechanism that primarily involves perforin, while bystander lysis occurred through Fas/Fas ligand interactions. In contrast, one clone used a Fas/Fas ligand mechanism to lyse both cognate and bystander targets. Cytokine production by the CTL clones was also examined. In response to stimulation with D2 antigen, CD4(+) T-cell clones produced gamma interferon, tumor necrosis factor alpha (TNF-alpha) and TNF-beta. The data suggest that CD4(+) CTL clones may contribute to the immunopathology observed upon secondary dengue virus infections through direct cytolysis and/or cytokine production.
authors: Center for Infectious Disease and Vaccine Research, University of Massachusetts Medical Center, Worcester, Massachusetts 01655, USA.
authors: S J
authors: SJ
authors: Gagnon
authors: F A
authors: FA
authors: Ennis
authors: A L
authors: AL
authors: Rothman
mesh_terms: D017951:Antigen Presentation / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D003716:Dengue Virus / Q000276:immunology*; D053222:Fas Ligand Protein; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis*; D008213:Lymphocyte Activation / Q000276:immunology; D008233:Lymphotoxin-alpha / Q000096:biosynthesis*; D008562:Membrane Glycoproteins / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*; D019014:fas Receptor / Q000276:immunology
chemical_list: C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008233:Lymphotoxin-alpha; D008562:Membrane Glycoproteins; D014409:Tumor Necrosis Factor-alpha; D019014:fas Receptor; D007371:Interferon-gamma