Differences of gene expression profiles of different subpopulations of exhausted T cells in patients with active pulmonary tuberculosis / 中华传染病杂志

ABSTRACT

Objective:To explore the differences of gene expression profiles of precursors of exhausted T cells (Tpex) and terminal exhausted T cells (Tex) in the peripheral blood of patients with active pulmonary tuberculosis (ATB).Methods:Twenty-five cases of ATB, 13 cases of latent tuberculosis infection (LTBI) and 10 health controls were enrolled from January 2021 to October 2022 in the Fifth People′s Hospital of Wuxi. The proportions of Tpex and Tex in the peripheral blood mononuclear cells (PBMCs) of the three groups were detected by flowcytometry. PBMCs of ATB were separated into Tpex and Tex by fluorescence-activated cell sorting. RNA-sequencing was performed and up-regulated and down-regulated genes were screended. Differently expressed genes were analyzed by gene set enrichment analysis of gene ontology (GO) to find regulatory pathways affecting cell metabolism and function. Wilcoxon matched-pairs signed rank test, Kruskal-Wallis test and Dunn multiple comparsion test were used for statistical analysis.Results:The proportion of Tpex in ATB group was 2.86%(1.74%), which was lower than 7.93%(6.16%) of Tex, and the difference was statistically significant ( Z=-3.91, P<0.001). The proportions of Tpex and Tex in LTBI group were 9.47%(6.26%) and 7.43%(5.48%), respectively, and the difference was not statistically significant ( Z=-0.93, P=0.345). The proportions of Tpex and Tex in healthy control group were 8.42%(2.69%) and 6.49%(5.14%), respectively, with no statistical significance ( Z=-1.36, P=0.170). There was statistical difference of the proportion of Tpex among the three groups ( H=21.93, P<0.001), and the proportion of Tpex in ATB group was lower than those in LTBI and heathy control groups, and the differences were both statistically significant ( Z=4.16, P<0.001 and Z=3.34, P=0.003, respectively), while the proportions of Tex in these three groups were not statistically different ( H=2.17, P=0.338). Compared with Tex, the gene expressions of memory markers, such as B-cell lymphoma 2 of Tpex were up-regulated, and the gene expressions of exhausted markers, such as lymphocyte activation gene 3 were down-regulated. In terms of cellular metabolism, the gene expressions of mitochondrial protein complex, mitochondrial matrix and oxidative phosphorylation of Tpex were up-regulated, and the gene expressions of glycolysis were down-regulated. The gene expressions of pyruvate metabolism in Tex were up-regulated, and the gene expressions of CD4 + T lymphocyte activation and differentiation and glycolytic process in Tpex were down-regulated. Conclusions:Tpex in ATB express more characteristics of memory cells and less features of exhausted markers compared with Tex, and the function of mitochondria of Tpex preserves well.