IMMUNOLOGY2025™ Conference Recordings-Mucosal-associated invariant T (MAIT) cells mediate IFN-I dependent immunosuppression in UV light-exposed skin: Implications for lupus photosensitivity

Mucosal-associated invariant T (MAIT) cells mediate IFN-I dependent immunosuppression in UV light-exposed skin: Implications for lupus photosensitivity - Grace Crossland

Back to course

Video Transcription

Video Summary

The talk examined how mucosal-associated invariant T (MAIT) cells respond to UV light in skin. MAIT cells are innate-like T cells found in barrier tissues and can be activated by microbial antigens or cytokines such as type 1 interferon. Because UV exposure strongly induces type 1 interferon, the speaker hypothesized that UV would expand skin MAIT cells. In healthy mice, chronic low-dose UVB increased MAIT cells in skin, and this expansion required interferon signaling. UV also drove regulatory T cell (Treg) expansion, but this response was lost in MAIT-deficient mice, suggesting MAIT cells help initiate a UV-induced immunosuppressive pathway. In lupus-prone mice, both MAIT and Treg expansion failed after UV, while cytotoxic CD8 T cells increased instead. However, expanding MAIT cells topically with their antigen restored the Treg/CD8 balance and reduced CD8 activation. The findings suggest MAIT cells may be important regulators of UV responses and potential targets in photosensitive lupus.

Keywords

MAIT cells

UVB exposure

type 1 interferon

regulatory T cells

photosensitive lupus