Genetic link between gut microbiota, immune cells, and rheumatoid arthritis: Mechanism of action of CD28 proteins

The gut microbiota serves a crucial function in modulating the immune responses of the host, as well as in managing inflammation within the body. In this particular study, the researchers sought to delve deeper into the specific mechanisms through which CD28 interacts with the gut microbiota and influences the functionality of immune cells. The study collected intestinal microbial samples from RA patients and healthy controls, analyzed microbial composition by high-throughput sequencing, and detected CD28 expression in T cells in combination with cellular immunology methods. At the same time, the effects of CD28 deletion on intestinal microbiota changes and inflammatory responses were evaluated using animal models. The findings from this study revealed a notable distinction in the gut microbiota profiles of individuals diagnosed with rheumatoid arthritis (RA) when compared to those of healthy control subjects. Specifically, the abundance of certain microbial species was observed to have a negative correlation with the expression levels of CD28, highlighting a complex interaction between the gut microbiome and the immune regulatory mechanisms involved in RA. Furthermore, experiments conducted on mice lacking CD28 demonstrated considerable alterations in their gut microbiota composition. These Cd28-deficient mice exhibited elevated levels of inflammatory markers, indicating an interplay between CD28 and the regulation of both the microbiota and the immune response.