Vi-er-respiratory infection is often associated with acute otitis media suggesting that some respiratory virus compromise host defenses. We have shown that chinchillas inoculated intranasally with influenza A virus (INF) have subsequent de

No abstract

Depressed chemotactic activity of polymorphonuclear leukocytes (PMNL) infected with influenza virus could be due to changes occurring at the plasma membrane. The present study examined the effect of unopsonized influenza virus on chemotaxis, adherence, receptor binding, shape change, membrane fluidity, and release of specific granules from PMNL. Chemotactic activity of PMNL under-agarose to the chemoattractants, zymosan-activated serum ( ZAS ) and N-formyl-methionyl-leucyl- phenylalanine (fMLP), and adherence of PMNL to a plastic surface were markedly decreased in virus-treated cells as compared to control cells. The binding of fMLP to the PMNL was increased in virus-treated cells compared with control cells. Exposure of cells to virus, ZAS , or fMLP caused 35%-50% of the cells to become bipolar in shape, whereas less than 5% of the cells exposed to buffer became bipolar. Influenza virus did not alter membrane fluidity as measured by electron spin resonance spectroscopy with the probe 5-doxyl stearate. Virus-treated PMNL stimulated with FMLP or Staphylococcus aureus exhibited a marked decrease in the amount of lactoferrin released into phagosomes, onto the cells' outer membrane, and into the extracellular medium as compared to control cells. The possible relationship between inhibition of lysosomal enzyme degranulation and decreased chemotactic activity and adherence of PMNL is discussed.

Various reports have indicated that infection of polymorphonuclear leukocytes (PMNL) with influenza virus causes depression of their metabolic and chemotactic responses, but the effect the PMNL has on the life cycle of influenza virus has not been well defined. The studies reported here were undertaken to determine whether influenza virus could replicate within PMNL. Virus-infected and uninfected PMNL were labeled with