Expression of Toll-Like Receptor 2 and Toll-Like Receptor 4 in Cholesteatoma

One of the hallmarks of aural cholesteatoma is chronic and recurrent infection. Initiation and perpetuationof the inflammatory response of cholesteatoma may result from an exaggerated host defense reaction of the cholesteatomaepithelium. However, the role of innate immune system in cholesteatoma has not been fully elucidated. Toll-likereceptors (TLRs) are a part of the innate immune system involved in the response to microbial pathogen. TLRs appear torespond to pathogens and induce NF-κB activation. TLR 2 and TLR 4 seem to be related to the initiation of immune responsesagainst gram negative and positive bacteria. We have investigated the expression of TLR 2, and 4 in the normal external auditorycanal skin and cholesteatoma. Subjects and Method：A real time RT-PCR was performed to determine and quantify the expressionof TLR 2 and 4 mRNA. Immunohistochemical staining was performed for 17 cases of cholesteatoma and 8 cases of normalauditory canal skin to demonstrate the distribution of TLR 2 and 4. Results：All cholestatoma and normal external auditory canalskin expressed both TLR 2 and 4 mRNA. The mRNA of TLR 2 and 4 were expressed significantly higher in cholesteatoma thanin the normal external auditory canal skin (p