CONCLUSION: Temperature-sensitive mouse middle ear epithelial cells have been successfully established and characterized. OBJECTIVE: Temperature-sensitive middle ear epithelial cell lines are essential for pathophysiologic studies of otitis media. They are useful for studying the pathogen-host interaction, receptor identification, signal transduction, cytokine/mucin production and cellular responses, especially for cell proliferation and differentiation. The purpose of this study was to establish a large T-antigen [simian virus 40 A-gene (SV40)] mutant-immortalized mouse middle ear epithelial cell line for otitis media studies. MATERIAL AND METHODS: Primary culture of middle ear epithelial cells was established from the middle ear mucosa of an Immortomouse. The cells were transduced by a temperature-sensitive large T-antigen mutant and cultured for >50 passages. The expression of mRNA transcripts and proteins for epithelial cells was characterized by reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry. The temperature-sensitive properties of cells cultured at 33 degree C and 39 degree C were evaluated using 3H-thymidine incorporation, Trypan blue exclusion and peroxisome proliferator-activated receptor-gamma activity. RESULTS: Immortalized middle ear epithelial cells demonstrated a cobblestone-like monolayer culture. The cells expressed mucosal cell markers such as mucins, keratins and collagens. They proliferated at 33 degree C when the SV40 antigen was active and differentiated at 39 degree C when the SV40 antigen was inactive.
CONCLUSION: Temperature-sensitive mouse middle ear epithelial cells have been successfully established and characterized. OBJECTIVE: Temperature-sensitive middle ear epithelial cell lines are essential for pathophysiologic studies of otitis media. They are useful for studying the pathogen-host interaction, receptor identification, signal transduction, cytokine/mucin production and cellular responses, especially for cell proliferation and differentiation. The purpose of this study was to establish a large T-antigen [simian virus 40 A-gene (SV40)] mutant-immortalized mouse middle ear epithelial cell line for otitis media studies. MATERIAL AND METHODS: Primary culture of middle ear epithelial cells was established from the middle ear mucosa of an Immortomouse. The cells were transduced by a temperature-sensitive large T-antigen mutant and cultured for >50 passages. The expression of mRNA transcripts and proteins for epithelial cells was characterized by reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry. The temperature-sensitive properties of cells cultured at 33 degree C and 39 degree C were evaluated using 3H-thymidine incorporation, Trypan blue exclusion and peroxisome proliferator-activated receptor-gamma activity. RESULTS: Immortalized middle ear epithelial cells demonstrated a cobblestone-like monolayer culture. The cells expressed mucosal cell markers such as mucins, keratins and collagens. They proliferated at 33 degree C when the SV40 antigen was active and differentiated at 39 degree C when the SV40 antigen was inactive.