Bacterial Infections in Patients Living with HIV.

Pneumonia, as well as other types of acute and chronic lung injuries, remain the leading causes of death in individuals living with HIV. Individuals with HIV who are on antiretroviral therapy continue to have a greater risk for pneumonia, including bacterial and mycobacterial infections. Alveolar macrophages and lung epithelial cells constitute the first line of host defense against invading pathogens. The predisposition of individuals living with HIV to infections despite ante-retroviral therapy is mechanistically related to HIV pro-viruses integrating into host cells, including airway epithelial cells and alveolar macrophages. Alveolar macrophages harbor latent HIV even when individuals appear to have complete suppression on ART. In parallel, pneumonia can irreversibly impair lung function in HIV-infected individuals. Cells that Macrophages exposed to HIV or HIV-related proteins have been shown to secrete exosomes that contain miRNAs. These exosomes can regulate several innate and acquired immune functions by stimulating cytokine production and inflammatory responses. Furthermore, these secreted exosomal miRNAs can shuttle between cells, causing cellular dysfunction in the case of epithelial cells; they disrupt lung epithelial barrier dysfunction, which leads to a predisposition to bacterial infections. We discuss the common bacterial infections that occur in patients living with HIV and provide mechanistic insights into how the intercellular communication of miRNAs results in cellular dysfunction.