Investigation of the cell composition and gene expression in the delayed-type hypersensitivity tuberculin skin test.

Dear Editor, The tuberculin skin test (TST) reagents have continuously improved, with the ESAT6-CFP10 (EC) test having recently been introduced, but are seldom based on the direction of the delayed-type hypersensitivity (DTH) mechanism. Previous studies only partially showed the infiltration and activation of immune cells and the production of cytokines of the skin induration[1,2], and lack the detailed measurements of cell proportions and gene expression in the DTH response. Therefore, in this study, we revealed the comprehensive characteristics of DTH by single-cell RNA sequencing (scRNA-seq) in the guinea pig tuberculosis (TB) model [Experimental Animal Welfare Ethics Committee, Beijing Tuberculosis and Thoracic Tumor Research Institute (2021-064)].