Xin Li, Ph.D.

Xin Li, Ph.D., is an Assistant Professor (tenure-track) in the Departments of Pediatrics and Immunology at UT Southwestern Medical Center.  His research focuses on host–microbiota interactions in both health and disease. Using innovative techniques in microbiology and immunology, and multiple model organisms (bacteria, fungi, mice, and humans), his research aims to investigate the fundamental mechanisms by which gut commensal bacteria and fungi regulate local and systemic inflammatory immune responses.

For his Ph.D., Dr. Li studied the role of Tpl2, a host serine-threonine kinase, in modulating T regulatory and Th17 cell function, identifying a potential therapeutic target for autoimmune disorders. During his postdoctoral training at Weill Cornell Medical College, he focused on the impact of gut commensal fungi on host immune responses. His recent work revealed that fungal sensing by tissue-resident CX3CR1+ mononuclear cells in the gut can influence distal allergic airway disease, with specific immune cells transmitting signals to the lungs, initiating early mechanistic studies for gut-lung immune crosstalk (Li et al., Cell Host and Microbe, 2018; Leonardi, Li et al., Science, 2018). In a recent study (Li et al., Nature, 2022), Dr. Li demonstrated the significance of microbial strain diversity in driving inflammatory immunity. Dr. Li identified a key pore-forming toxin (candidalysin) that mediates niche-specific inflammatory immunity. In 2023, he joined the faculty at UT Southwestern in the Departments of Pediatrics and Immunology. Dr. Li and his team continue their work studying host and microbial interactions and tissue immunity using multiple model organisms.

His new research directions involve:

i) Identifying novel host factors involved in bacterial and fungal sensing to regulate inflammatory diseases.
ii) Identifying new microbial factors involved in bacterial and fungal sensing to regulate inflammatory diseases. These factors may include toxins, RNAs, etc.
iii) Utilizing fungi as a model system, genetic engineering of microbial effectors to understand how a microbe dictates protective immunity, and pathogenic immunity at tissue barriers.

Contact: xin.li@utsouthwestern.edu