Related Experiment Videos
Temporal sequence of viral antigen expression in the cochlea induced by cytomegalovirus
E M Keithley1, P Sharp, N K Woolf
1Division of Head and Neck Surgery, University of California San Diego Medical Center.
Abstract:
Injection of guinea-pig cytomegalovirus into seronegative guinea pig cochleas results in viral labyrinthitis. The location of infected cells 1-8 days following inoculation was examined using an immunohistochemical assay for viral antigens. Mesothelial cells below the basilar membrane and those lining the scala tympani, especially below the osseous spiral lamina, were the first cells to express antigen. This occurred 2 days following inoculation. Infection then spread rapidly toward the brain and through the perilymphatic duct to involve inflammatory cells, mesothelial cells of Reissner's membrane, spiral ganglion cells, and the vestibular ganglion cells. In any one cochlea, more mesothelial cells and inflammatory cells expressed viral antigen than any other cell type. It seems then, that there is a differential susceptibility to viral infection and antigen expression in the various cell types of the cochlea. Typical cytomegalic inclusions were common in mesothelial cells. However, many cells labelled for viral antigens did not contain inclusions. The identification of viral antigens then, is a more sensitive technique for demonstrating infection than is the location of cytomegalic inclusion cells.
Insights
Guinea-pig cytomegalovirus causes cochlear inflammation. Mesothelial and inflammatory cells are initially infected, with infection spreading rapidly throughout the cochlea, highlighting differential cell susceptibility.
Area of Science:
- Virology
- Otolaryngology
- Immunohistochemistry
Background:
- Guinea-pig cytomegalovirus (GPCMV) infection can lead to viral labyrinthitis.
- Understanding the cellular tropism and spread of GPCMV within the cochlea is crucial for developing therapeutic strategies.
Purpose of the Study:
- To investigate the temporal and spatial progression of GPCMV infection in the guinea pig cochlea.
- To identify the specific cell types susceptible to GPCMV infection and antigen expression.
Main Methods:
- Intracochlear inoculation of GPCMV in seronegative guinea pigs.
- Immunohistochemical analysis to detect viral antigens at various time points post-inoculation (1-8 days).
Main Results:
- Viral antigen expression was first detected in mesothelial cells of the scala tympani and below the basilar membrane at 2 days post-inoculation.
- Infection rapidly spread to involve inflammatory cells, Reissner's membrane, spiral ganglion, and vestibular ganglion cells.
- Mesothelial and inflammatory cells showed the highest prevalence of viral antigen expression, indicating differential cellular susceptibility.
Conclusions:
- Mesothelial cells are an early and significant site of GPCMV infection in the cochlea.
- Immunohistochemical detection of viral antigens is a more sensitive method for identifying infection than observing cytomegalic inclusions.