The underlying mechanisms by which HIV perturbs intestinal epithelial junctions remain unclear, and the impact of opportunistic viral pathogens in the gut has not been fully appreciated. GUID:?52D9E789-A234-4B5A-AAE6-BBB5F79E17F4 S3 Fig: Verification of the epithelial origin of HCoEpiC. Mock-infected cells at passage 3 (A) and inoculated with CMV VR1814 at a MOI of 1 1.0 (B). HCoEpiC expressed cytokeratin, an epithelial cell marker (green) but not vimentin, a mesenchymal cell marker (C, green). Nuclei were counterstained with DAPI. Scale bars: 20 m.(TIF) ppat.1006202.s003.tif (3.3M) GUID:?E747FF43-2FA5-472B-8795-FF6984B0F3EA Data Availability StatementAll relevant data are within the paper and its Supporting Information files. Abstract Although invasive cytomegalovirus (CMV) disease is uncommon in the era of antiretroviral therapy (ART), asymptomatic CMV coinfection is nearly ubiquitous in HIV infected individuals. While microbial translocation and gut epithelial barrier dysfunction may promote persistent immune activation in treated HIV infection, potentially contributing to morbidity and mortality, it has been unclear whether CMV replication in individuals with LH-RH, human no symptoms of CMV disease might play a role in this process. We hypothesized that persistent CMV replication in the intestinal epithelium of HIV/CMV-coinfected individuals impairs gut epithelial barrier function. Using a combination of state-of-the-art hybridization technology (RNAscope) and immunohistochemistry, we detected CMV DNA and proteins and evidence of intestinal damage in rectosigmoid samples from CMV-positive individuals with both untreated and ART-suppressed HIV infection. Two different model systems, primary human intestinal cells differentiated to form polarized monolayers and a humanized mouse model of human gut, together demonstrated that intestinal epithelial cells are fully permissive to CMV replication. Independent of HIV, CMV disrupted tight junctions of polarized intestinal cells, significantly reducing transepithelial electrical resistance, a measure of monolayer integrity, and enhancing transepithelial permeability. The PROK1 effect of CMV infection on the intestinal epithelium is mediated, at least in part, by the CMV-induced proinflammatory cytokine IL-6. Furthermore, letermovir, a novel anti-CMV drug, dampened the effects of CMV on the epithelium. Together, our data strongly suggest that CMV can disrupt epithelial junctions, leading to bacterial translocation and chronic inflammation in the gut and that CMV could serve as a target for therapeutic intervention to prevent or treat gut epithelial barrier dysfunction during HIV infection. Author summary Intestinal epithelial barrier dysfunction is a well-known consequence of HIV infection that persists in spite of ART. The underlying mechanisms by which HIV perturbs intestinal epithelial junctions remain unclear, and the LH-RH, human impact of opportunistic viral pathogens in the gut has not been fully appreciated. HIV-infected individuals are almost universally coinfected with CMV. While ART has resulted in a dramatic decline in the occurrence of end-organ CMV diseases, CMV remains an independent contributor to systemic inflammation in HIV-infected people. In our analysis of rectosigmoid biopsies from CMV/HIV-coinfected individuals, we found active CMV replication associated with intestinal damage in the gut of ART-suppressed HIV-infected individuals with no symptoms of CMV disease. We demonstrated that CMV productively infects intestinal epithelial cells and, independent of HIV, disrupts their tight junctions and compromises epithelial barrier function. Furthermore, the CMV-induced proinflammatory cytokine IL-6 is a key factor in this process, and attenuation of CMV replication by letermovir, LH-RH, human a new anti-CMV agent currently in clinical development, was sufficient to prevent CMV-induced loss of epithelial integrity. Our data highlight the role of CMV as a cofactor in intestinal epithelial barrier dysfunction in asymptomatic HIV an infection and recommend a novel treatment technique to prevent intestinal epithelial hurdle dysfunction and irritation in HIV an infection. Introduction Immune system activation and intestinal epithelial hurdle dysfunction are main hallmarks of HIV an infection that persist regardless of powerful mixture antiretroviral therapy (Artwork) [1C6]. The hurdle properties of mucosal intestinal epithelium are preserved with a monolayer of columnar.