Immunology

New research suggests that gut microorganisms do not merely influence immune cell function, but also support the production of immune cells that form the first line of defense against infection. By understanding the mechanisms responsible for maintaining and replacing immune cells, researchers hope to one day develop targeted therapies to support and boost immune function in humans.

Study investigators from the Regenerative Medicine Institute at Cedars-Sinai collaborated with the Mount Sinai School of Medicine and lead institution - the California Institute of Technology.

Previous research studies have evaluated the influence of gut microbes on the function of immune cells, but little had been known about their influence on the production of immune cells, a process known as hematopoiesis.

In this study, published in the journal Cell Host & Microbe, investigators found that mice lacking gut microbes were defective in immune cell production. Immune cell populations have to be maintained and replaced to ensure enough immune cells are available to fight infection. Consequently, the investigators noted that mice lacking gut microbes were more susceptible to bacterial infections.

"This work provides important clues about the role of gut microbes in supporting a healthy immune system that is capable of providing efficient protection from infection," said Helen Goodridge, PhD, collaborating author, assistant professor in the Department of Biomedical Sciences and a research scientist in the Regenerative Medicine Institute. "We now have a clearer understanding of how gut microbes influence immune cell production, which has implications for immune defense against infection."