The role of Themis in development of type 2 diabetes

Type 2 diabetes (T2D) is a complex metabolic disorder driven by chronic inflammation and immune dysregulation, particularly within adipose tissue. This study investigates the role of the T cell-specific protein Themis in modulating immune-metabolic interactions that contribute to T2D pathogenesis. Using high-fat diet (HFD)-induced obesity models, we demonstrate that Themis -deficient (KO) mice exhibit accelerated weight gain, glucose intolerance, and insulin resistance compared to wild-type (WT) controls. These metabolic abnormalities are linked to functional alterations in the CD8⁺ T cell compartment, including site-specific clonal expansion and reshaping of the T cell receptor (TCR) repertoire within adipose tissue, suggesting antigen-driven activation. Additionally, Themis deficiency leads to significant shifts in gut microbiome composition, characterized by reduced diversity and increased abundance of Firmicutes , particularly Clostridium species. However, fecal microbiota transplantation from Themis KO mice into germ-free WT hosts failed to recapitulate the full T2D phenotype, underscoring the dominant role of intrinsic immune dysfunction over microbial dysbiosis. These findings highlight a synergistic interplay between adaptive immunity and the microbiome in shaping metabolic outcomes and suggest that T cells play a central role in responses that influence T2D progression. Our data advocate for a more integrated approach to T2D research, incorporating genetic, immunological, and microbial factors.