IMMUNOLOGY2026™ Conference Recordings For Attendees-Environmental dysregulation of MAIT cells in obesity

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Video Summary

The talk explored how obesity affects unconventional T cells, especially MAIT cells and Vδ2 γδ T cells, which are important for protection against infections and vaccine responses. The speaker emphasized that obesity is a chronic, progressive disease associated with increased risk of bacterial, viral, fungal, and parasitic infections, along with higher hospitalization and mortality.<br /><br />Using a large human cohort across the life course, the team found that obesity is associated with reduced numbers and impaired function of these cells in blood and adipose tissue. MAIT cells in obesity showed reduced IFN-γ production, increased IL-17 production, and loss of killing capacity. In children, MAIT-derived IL-17 was linked to insulin resistance. Mechanistically, obesity reduced glutamine availability and uptake, which disrupted MYC signaling, glycolysis, protein synthesis, and overall MAIT cell function.<br /><br />A similar pattern was seen in Vδ2 γδ T cells. These cells were reduced in obesity and showed weaker IFN-γ, TNF, and granzyme B responses. Their dysfunction was linked to impaired amino acid sensing through CD98/LAMTOR5 and reduced mTORC1 activity, leading to defective biosynthesis and effector function.<br /><br />Importantly, bariatric surgery reversed many of these defects, restoring nutrient-sensing pathways and T-cell function. The overall conclusion was that obesity-driven changes in nutrient availability impair unconventional T-cell immunity, and that treating obesity can restore immune competence.

Meta Tag

Date April 17, 2026 10:42 AM - 11:15 AM

Room Ballroom

Session Major Symposium D: Obesity, Environment, and Immunity, Sponsored by Eli Lilly and Company

Speaker Andrew Hogan

Track Cellular Adhesion, Migration, and Inflammation (CAM)

Year 2026

Keywords

obesity

MAIT cells

Vδ2 γδ T cells

immune dysfunction

nutrient sensing

bariatric surgery

vaccine responses

April 17, 2026 10:42 AM - 11:15 AM

Ballroom

Major Symposium D: Obesity, Environment, and Immunity, Sponsored by Eli Lilly and Company

Andrew Hogan

Cellular Adhesion, Migration, and Inflammation (CAM)

2026