Influenza A virus infects macrophages and stimulates release of tumor necrosis factor-alpha.
The clinical picture of influenza A virus infections indicates that release of tumor necrosis factor-alpha (TNF-alpha) may be involved. In the present study we exposed the murine macrophage line PU5-1.8 to influenza A virus and observed a productive infection which was followed by subsequent cell death. Infection of macrophages was accompanied by TNF-alpha mRNA accumulation and TNF-alpha release. TNF-alpha production could only be induced by live virus whereas interferon release was also stimulated by inactivated virus. When virus-infected macrophages were exposed to low amounts of lipopolysaccharide (LPS; 1-10 ng/ml) TNF-alpha production was strongly potentiated. These data show that low LPS concentrations could readily trigger a high TNF-alpha release from influenza-A-virus-infected macrophages which could, at least partially, explain the serious complications of combined influenza A virus and bacterial infections.
Hinder
F
F
Institute of Immunology, Philipps University, Marburg, FRG.
Schmidt
A
A
Gong
J H
JH
Bender
A
A
Sprenger
H
H
Nain
M
M
Gemsa
D
D
D000818:Animals; D002460:Cell Line; D009980:Influenza A virus / Q000472:pathogenicity*; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000378:metabolism / Q000382:microbiology*; D009976:Orthomyxoviridae Infections / Q000503:physiopathology; D012333:RNA, Messenger / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D008070:Lipopolysaccharides; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha