PLoS Pathogens (Apr 2015)

Murine CMV-induced hearing loss is associated with inner ear inflammation and loss of spiral ganglia neurons.

  • Russell D Bradford,
  • Young-Gun Yoo,
  • Mijo Golemac,
  • Ester Pernjak Pugel,
  • Stipan Jonjic,
  • William J Britt

DOI
https://doi.org/10.1371/journal.ppat.1004774
Journal volume & issue
Vol. 11, no. 4
p. e1004774

Abstract

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Congenital human cytomegalovirus (HCMV) occurs in 0.5-1% of live births and approximately 10% of infected infants develop hearing loss. The mechanism(s) of hearing loss remain unknown. We developed a murine model of CMV induced hearing loss in which murine cytomegalovirus (MCMV) infection of newborn mice leads to hematogenous spread of virus to the inner ear, induction of inflammatory responses, and hearing loss. Characteristics of the hearing loss described in infants with congenital HCMV infection were observed including, delayed onset, progressive hearing loss, and unilateral hearing loss in this model and, these characteristics were viral inoculum dependent. Viral antigens were present in the inner ear as were CD(3+) mononuclear cells in the spiral ganglion and stria vascularis. Spiral ganglion neuron density was decreased after infection, thus providing a mechanism for hearing loss. The lack of significant inner ear histopathology and persistence of inflammation in cochlea of mice with hearing loss raised the possibility that inflammation was a major component of the mechanism(s) of hearing loss in MCMV infected mice.