IL-4-secreting CD40L⁺ MAIT cells support antibody production 

in the peripheral blood of Heonch-Schönlein purpura patients

In this research, we assessed peripheral blood from children who were diagnosed with HSP (Heonch-Schönlein purpura) by single-cell RNA sequencing to explore the different phenotypes of T cells that may contribute to the pathogenesis of HSP.

We found that the percentage of MAIT (mucosal associated invariant T) cells was sharply decreased in HSP patients. Genes and proteins related to T cell activation and effector were up-regulated in HSP MAIT cells. In addition, HSP MAIT cells displayed a Th2-like profile with an increased ability of producing IL-4 and IL-5. We also demonstrated that IL-4 was correlated with IgA levels in the serum of HSP patients. Furthermore, CD40L was up-regulated in HSP MAIT cells, and these CD40L⁺ MAIT cells showed an increased ability to produce IL-4 and to enhance IgA production from B cells.

Our research indicated that MAIT cells in HSP patients exhibit an activated and Th2-like phenotype. The enhanced IL-4 production and CD40L expression of MAIT cells could take part in the pathogenesis of HSP. Our research ”IL-4-secreting CD40L⁺ MAIT cells support antibody production in the peripheral blood of Heonch-Schönlein purpura patients” was published on Inflammation Research in January 2024.