Knowledge Bank

Mucosal Associated Invariant T (MAIT) cells are a unique subset of T cells that bridge the innate and adaptive immune systems. Unlike conventional T cells, MAIT cells recognize specific microbial metabolites presented by an MHC-related protein 1 (MR1) (Toubal et al. 2019). Our research team previously developed a method to expand human MAIT (h MAIT) cells in vitro using immunomagnetic selection and stimulation with MR1-coated microspheres loaded with the potent agonist 5-OP-RU. Rhesus macaques (RM) are crucial animal models in translational research due to their immunobiological similarity to humans. While RM MAIT cells are similar to h MAIT cells (Rahman et al. 2020), limited studies have been conducted on their functionality due to challenges during in vitro expansion. This study aimed to adapt our previous method to expand RM MAIT cells in vitro for further investigation. Our findings demonstrate that RM MAIT cells can respond to microspheres coated with antigen-loaded species-specific MR1, similar to human MAIT cells. However, RM MAIT cells require additional costimulatory signals compared to their human counterparts for significant in vitro expansion. We were able to develop a method to expand RM MAIT cells in vitro. These results provide a foundation for further exploration of these important innate-like T cells in this critical animal model, potentially advancing our understanding of MAIT cell biology and its implications in translational research.