Gene expression in tonsil and oral epithelia

To study characteristics of the orapharyngeal epithelia which may influence susceptibility or resistance to HIV, we performed microarray analysis of the tonsil and gingival epithelium.Tonsil epithelium has been implicated in HIV pathogenesis, but its role in oral transmission remains controversial. We performed microarray analysis of Laser Capture Microdissected tonsil and gingival epithelium. Our data revealed that genes related to immune functions such as antibody production and antigen processing were increasingly expressed in tonsil compared to the epithelium of another oro-pharyngeal site, gingival epithelium. Importantly, tonsil epithelium highly expressed genes associated with HIV entrapment and/or transmission, including the HIV co-receptor CXCR4 and the potential HIV binding molecules, FcRIII, complement receptor 2, and various complement components. This increased expression of molecules involved in viral recognition, binding and entry may favor virus-epithelium interaction in an environment with reduced innate anti-viral mechanisms. Specifically, secretory leukocyte protease inhibitor, an innate molecule with anti-HIV activity, was minimal in the tonsil epithelium, in contrast to oral mucosa. Collectively, our data suggest that increased expression of molecules associated with HIV binding and entry coupled with decreased innate anti-viral factors may render the tonsil a potential site for oral transmission.

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Moutsopoulos NM, Nares S, Nikitakis N, Rangel Z, Wen J, Munson P, Sauk J, Wahl SM