Insufficient perforin expression in CD8+ T cells in response to hemagglutinin from avian influenza (H5N1) virus.
Hypercytokinemia has been considered to be responsible for hemophagocytosis and multiorgan failure in severe human cases of H5N1 viral infection. In this study, we show a recombinant hemagglutinin (H5) from a H5N1 virus may suppress the perforin expression and reduce cytotoxicity of human CD8+ T cells to kill H5-bearing cells. The persistence of H5-presenting cells provides sustained stimulation and leads to a marked lymphoproliferation and IFN-gamma hyperproduction. We propose the IFN-gamma hyperproduction may explain macrophage overactivation and subsequent hypercytokinemia and hemophagocytosis in severe human cases of avian influenza.
Department of Internal Medicine, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei, Taiwan. hsmaids@hotmail.com
Szu-Min
SM
Hsieh
Shan-Chwen
SC
Chang
D000328:Adult; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D049109:Cell Proliferation; D003602:Cytotoxicity, Immunologic; D003713:Dendritic Cells / Q000276:immunology; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000276:immunology*; D006801:Humans; D066298:In Vitro Techniques; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage; D007371:Interferon-gamma / Q000096:biosynthesis; D007700:Kinetics; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D011994:Recombinant Proteins / Q000276:immunology
D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007252:Influenza Vaccines; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D011994:Recombinant Proteins; C109963:hemagglutinin, avian influenza A virus; D054353:Perforin; D007371:Interferon-gamma