TNF and scrub typhus: To investigate the expression of these cytokines in MAIT cells, we incubated PBMCs from 23 patients with scrub typhus and 14 HCs for 4 hours in the presence of PMA and IM; then the expressions of IFN-γ, IL-17A, TNF-α in the MAIT cell populations were examined at the single-cell level by intracellular flow cytometry (Fig 2A).