Translocated microbiome composition determines immunological outcome in treated HIV infection

Area of Science:

• Immunology
• Microbiology
• Virology

Background:

• The microbiome's role in HIV disease is recognized, but mechanisms linking microbial changes to disease progression are unclear.
• Antiretroviral therapy (ART) impacts the gut microbiome, but its influence on immune recovery requires further elucidation.

Purpose of the Study:

• To investigate dynamic changes in microbial translocation and their impact on immune recovery during combination antiretroviral therapy (cART) for HIV.
• To identify specific microbial pathways influencing CD4 T cell restoration and systemic immune homeostasis.

Main Methods:

• Longitudinal analysis of microbial constituents and host immune responses in HIV patients initiating cART.
• Systems biology approach to identify microbial genera ratios associated with immune changes.
• Analysis of multiple HIV cohorts to generalize findings.

Main Results:

• Rapid, dynamic shifts in translocated microbial products were observed post-cART initiation.
• A distinct pathway involving the Serratia bacterial genus abundance ratio correlated with immune recovery.
• High Serratia abundance was linked to increased CD4 T cells, pro-inflammatory cytokines, and mucosal healing.
• Subsequent decreases in Serratia and inflammation facilitated T cell homeostasis and Th1/Th2 signature restoration.

Conclusions:

• Changes in translocated microbial species composition significantly influence systemic inflammation and CD4 T cell recovery in treated HIV infection.
• The ratio of specific bacterial genera, such as Serratia, plays a critical role in modulating immune responses during HIV treatment.
• Findings suggest a generalized principle linking microbial translocation dynamics to immune reconstitution in HIV.