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Neuraminidase activity is not the cause of influenza virus-induced neutrophil dysfunction
Abstract:
Influenza viruses have been shown to decrease the ability of polymorphonuclear leukocytes (PMN) to respond to a variety of stimuli. This study was done to determine if viral neuraminidase was responsible for decreased PMN function. Treatment of human PMN with purified neuraminidases from influenza virus, Vibrio cholerae, or Clostridium perfringens did not significantly affect the ability of human PMN to respond to stimulation. Occasional virus preparations that lacked the ability to depress PMN function did not differ in neuraminidase activity from viruses capable of causing depression. These results demonstrate that neuraminidase activity is not the cause of influenza virus-induced PMN dysfunction.
Insights
Influenza viruses impair polymorphonuclear leukocyte (PMN) function. This study found that viral neuraminidase is not responsible for this decreased PMN response, indicating other viral factors are involved.
Area of Science:
- Immunology
- Virology
Background:
- Influenza viruses are known to suppress polymorphonuclear leukocyte (PMN) function.
- The specific viral component responsible for this immunosuppression remains unclear.
Purpose of the Study:
- To investigate whether viral neuraminidase is the cause of influenza-induced PMN dysfunction.
Main Methods:
- Human PMNs were treated with purified neuraminidases from various sources (influenza virus, Vibrio cholerae, Clostridium perfringens).
- PMN function was assessed by their response to stimulation after treatment.
- Neuraminidase activity of influenza virus preparations was correlated with their ability to depress PMN function.
Main Results:
- Treatment of human PMNs with purified neuraminidases did not significantly impair their function.
- No significant difference in neuraminidase activity was observed between influenza virus preparations that did and did not depress PMN function.
Conclusions:
- Viral neuraminidase activity is not the cause of influenza virus-induced PMN dysfunction.
- Other viral factors likely mediate the observed decrease in PMN function during influenza infection.