No apoptotic deaths and different levels of inductions of inflammatory cytokines in alveolar macrophages infected with influenza viruses.
Influenza viruses are reported to infect mainly the respiratory tract epithelium of hosts. Our studies in a pig model show that influenza A viruses infect alveolar macrophages that constitutively reside in the respiratory tract, without causing apoptosis. Tumor necrosis factor alpha was the inflammatory cytokine most highly induced in these macrophages. In vivo, alveolar macrophages infected with human H3N2 influenza virus showed greater expression of tumor necrosis factor alpha than did alveolar macrophages infected with human H1N1 influenza virus. Induction of specific inflammatory cytokine such as TNF-alpha is a polygenic trait that involves the HA and NA genes. Markedly elevated expression of tumor necrosis factor alpha may be responsible for the high mortality rate caused by H3N2 influenza virus infection in elderly patients.
Seo
Sang Heui
SH
Laboratory of Immunology, Division of Preventive Medicine, College of Veterinary Medicine, Chungnam National University, Daejeon 305-764, South Korea. seos@cnu.ac.kr
Webby
Richard
R
Webster
Robert G
RG
D000818:Animals; D017209:Apoptosis; D002478:Cells, Cultured; D016207:Cytokines / Q000032:analysis / Q000096:biosynthesis*; D004195:Disease Models, Animal; D009980:Influenza A virus / Q000235:genetics / Q000472:pathogenicity*; D009981:Influenza B virus / Q000472:pathogenicity*; D016676:Macrophages, Alveolar / Q000276:immunology* / Q000473:pathology / Q000821:virology; D009976:Orthomyxoviridae Infections / Q000097:blood / Q000276:immunology*; D012137:Respiratory System / Q000276:immunology*; D013552:Swine; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000096:biosynthesis
D016207:Cytokines; D014409:Tumor Necrosis Factor-alpha