Neutrophil Lifespan: HIV-Associated Intestinal Inflammation

White blood cells
White blood cells

Gastrointestinal (GI) mucosal damage and immune dysfunction drive chronic inflammation and microbial translocation in HIV infection; which predict and likely contribute to non-infectious comorbidities and mortality. Although long-term antiretroviral therapy (ART) partially restores mucosal damage; a degree of mucosal immune dysfunction and inflammation persists and is with morbidities and mortality.

The increased survival of white blood cells called neutrophils is with alterations in the intestinal microbiome of HIV-infected individuals; according to a study published April 11 in the open-access journal PLOS Pathogens by Nichole Klatt of the University of Miami, and colleagues. Moreover, the findings suggest that Lactobacillus bacteria; which are commonly in probiotics, may reduce neutrophil lifespan, and could an effective therapeutic strategy to reduce intestinal inflammation in HIV-infected individuals.

Quantifying the neutrophils

In the new study, Klatt and colleagues addressed this gap in knowledge by quantifying neutrophils in relation; to other white blood cells in the gastrointestinal tissues of HIV-infected individuals receiving treatment. The findings show that neutrophils in the gastrointestinal tract of HIV-infected individuals have a longer lifespan. Therefore, increased neutrophil lifespan may contribute to neutrophil accumulation in colorectal biopsy tissue; potentially implicating neutrophil lifespan as a new therapeutic target for intestinal inflammation in HIV infection.

The results also suggest that different bacteria that naturally reside in the gastrointestinal tract can alter neutrophil lifespan and that changes in the relative abundances of these bacteria in HIV infection may contribute to increased neutrophil lifespan. Specifically, Lactobacillus species uniquely decrease neutrophil survival and neutrophil frequency; which could have important therapeutic implications for reducing neutrophil-driven inflammation in HIV and other chronic inflammatory conditions.

Implicate neutrophil lifespan

These data were so striking because they clearly implicate neutrophil lifespan; as a potential target to reduce intestinal inflammation in HIV infection. “Neutrophil lifespan is increased in many different chronic diseases, and strategies targeting neutrophil lifespan are being investigated to reduce neutrophil-driven inflammation. However, this connection had not previously been investigated in the context of HIV infection.”

“They think one of the most exciting and interesting findings was that Lactobacillus species can override neutrophil survival signals; reduce neutrophil lifespan and numbers,” states first author Tiffany Hensley-McBain. “Overall, they believe these data have important and widespread implications for discovering new therapeutics for neutrophil-driven inflammation; is not only HIV infection, but many chronic inflammatory diseases.”