Influenza A virus infection of human Schwann cells in vitro.

OBJECTIVES

Sudden sensorineural hearing loss, vestibular neuronitis, vocal fold paralysis and Bell's palsy have been associated with a viral etiology, due to the infection of nerve cells. The goal of this research was to ascertain whether Schwann cells can support infection with human influenza A virus and thereby represent a plausible alternative site for virus-host interaction. Viral infection of Schwann cells may lead to secretion of inflammatory mediators, leukocyte recruitment, demyelination and nerve damage.

MATERIAL AND

METHODS

Cultured human Schwann cells were exposed to human influenza A virus. Infection was assayed at various times post-inoculation (0, 24, 48 and 72 h) using light microscopy, immunocytochemistry and influenza A virus-specific reverse transcriptase polymerase chain reaction (RT-PCR). A group of unexposed cells served as controls.

RESULTS

Following exposure to the virus, vacuolization, cellular expansion and detachment from the dish were seen as early as 24 h post-inoculation. The exposed cells demonstrated positive immunocytochemical staining for influenza A virus antigen at 24, 48 and 72 h. Using RT-PCR, a sharp rise in influenza A virus-specific mRNA was detected.

CONCLUSIONS

Human Schwann cells can be infected with human influenza A virus. Further studies will assess the inflammatory response in this model.