□ Overview
○ Expert : Professor Su-Hyung Park (KAIST Graduate School of Medical Science)
○ Date : May 3, 2024 (Friday), 14:00 - 18:00
○ Venue : IBS Headquarters, Room C239
□ Lecture Topic
Roles of virtual memory T cells in chronic inflammatory disease
Su-Hyung Park
Graduate School of Medical Science and Engineering, KAIST, Republic of Korea
Virtual memory T (TVM) cells are a T-cell subtype that exhibit a memory phenotype without prior exposure to a foreign antigen. Although several recent studies suggest that TVM cells exertanti-viral and anti-bacterial function, pathogenic roles of TVM cells causing inflammatory diseases have not been studied. Here, we identified a novel CD8+ T-cell subset (CD44s-hiCD49dloCD8+Tcells), which is originated from TVM cells and can cause a chronic inflammatory disease, alopecia areata(AA). In the skin of alopecic mice, we detected a distinct TVM-cell subpopulation characterized by superior expression of CD44 and features of tissue residency, which was transcriptionally, phenotypically, and functionally distinct from conventional CD8+TVM cells. Mechanistically, this cell population could be induced from conventional TVM cells by IL-12, IL-15, and IL-18 stimulation. Moreover, the pathological activity of CD44s-hi CD49dlo CD8+ T cells was mediated by NKG2D-depedent innate-like cytotoxicity against target cells, which was further augmented by IL-15 stimulation and triggered the onset of disease. Collectively, our results suggest a new immunological mechanism through which TVM cells can cause chronic inflammatory disease by innate-like cytotoxicity.