Macrophage inflammatory proteins in cytomegalovirus-related inner ear injury

Abstract

Objective Inner ear inflammation triggered by CMV infection may play a role in CMV-related auditory pathogenesis. The purpose of the study was to determine if a virally encoded macrophage inflammatory protein played a role in CMV-related hearing loss. Design Mutagenesis was performed with deletion of a guinea pig CMV macrophage inflammatory protein. Intracochlear inoculations were performed on three groups of animals (n = 18). Group 1 received sterile viral media, Group 2 received wild-type CMV virus, and Group 3 received “knockout” (KO) virus with a deleted immunomodulation gene. Baseline and postinoculation ABRs were obtained. ELISA and PCR were performed and temporal bones examined. Subjects Eighteen guinea pigs. Results The KO group had significantly better hearing than the WT group. There were no significant differences between the KO and sham groups. The WT group had significant hearing loss at all frequencies. Inflammation and fibrosis were noted in the WT temporal bones only. Conclusions Virally encoded macrophage inflammatory proteins appear to play a significant role in CMV-related hearing loss.