The mucosal expression pattern of interferon-ε in rhesus macaques

The expression of INF-epsilon in multiple mucosal tissues of rhesus macaques. Type I IFNs play an important role in innate and adaptive immunity against viral infections. A novel type I IFN, namely IFN-epsilon, which can protect against vaginal transmission of HSV2 and Chlamydia muridarum bacterial infection, has been described in mice and humans. Nevertheless, the principle cell type and the expression pattern of IFN-epsilon in tissues remain uncertain. In addition, the expression of IFN-epsilon in Indian rhesus macaques (Macaca mulatta) has not been reported. Here, we analyzed IFN-epsilon expression in multiple mucosal sites of uninfected or SIV-infected Indian rhesus macaques using IHCS. We report for the first time the detection of IFN-epsilon expression in situ in the lung, foreskin, vaginal, cervical, and small and large intestinal mucosae of rhesus macaques. We found that the expression of IFN-epsilon was exclusive to the epithelial cells in all of the aforementioned mucosal tissues. Furthermore, the macaque IFN-epsilon sequence in this study revealed that macaque IFN-epsilon is highly conserved among human and other nonhuman primates. Lastly, SIV rectal infection did not significantly alter the expression of IFN-epsilon in rectal mucosae. Together, these findings indicate that IFN-epsilon may function as the first line of defense against the invasion of mucosal pathogens. Further studies should be conducted to examine IFN-epsilon protection against gastrointestinal as well as respiratory infections.