Intestinal Microbiota Dysbiosis Promotes Mucosal Barrier Damage and Immune Injury in HIV-Infected Patients

Figure 2

HIV infection induces intestinal mucosal barrier damage and immune cell dysfunction, which aggravates the inflammatory response. HIV infection induces damage to the intestinal mucosal barrier and causes microbial translocation. LPS of the translocated bacteria promotes the survival of neutrophils and the activation of pro-inflammatory macrophages and DCs by activating NF-κB through the TLR4 signaling pathway. Activated macrophages increase the survival of mucosal neutrophils and inhibit the function of NK cells by expressing IL-1β, TNF-α, and TGFβ. Activated DCs interact with T cells through CD40/CD40L and secrete cytokines, such as IL-23, IL-1β, and IL-10, to further promote the activation of T cells and aggravate the inflammatory response. Δ42PD1⁺ Vδ2 cells homing to the gut results in small intestinal inflammatory damage by activating the TLR4 signal pathway. The frequencies of Vδ1⁺ cells producing IFNγ, TNF-α, and MIP-1β were significantly increased in HIV-infected patients.