Objective:To evaluate the expressions of three biomarkers combination of CD27, CD38 and human leucocyte antigen (HLA)-DR in the application of discrminating active tuberculosis (ATB) and latent tuberculosis infection (LTBI).Methods:Sixty cases of ATB and 44 cases of LTBI were enrolled from March 2021 to February 2022 in Huashan Hospital, Fudan University and Wuxi Fifth People′s Hospital. Freshly isolated peripheral blood mononuclear cells (PBMC) from patients were stimulated with 6 kDa early secretory antigenic target/culture filtrate protein 10 peptide pools. The expressions of CD27, CD38 and HLA-DR on Mycobacterium tuberculosis-specific CD4 + T lymphocytes were evaluated by polychromatic flow cytometry. Mann-Whitney U test was used for statistical analysis. The area under the receiver operator characteristic curve (AUROC) was used to evaluate the diagnostic value of biomarkers in discriminating ATB and LTBI. Results:The frequencies of CD27 -, CD38 +, HLA-DR +, CD27 -CD38 +, CD27 -HLA-DR + and CD38 + HLA-DR + in ATB group were all higher than those in LTBI group, and the differences were all statistically significant ( U=26.00, 451.00, 384.00, 8.00, 7.00 and 184.00, respectively, all P<0.001). The AUROC of CD27 -CD4 + interferon-γ(IFN-γ) + T lymphocytes was 0.71 with a cut-off value of 52.31%, with the sensitivity of 50.00% and specificity of 87.20%. The AUROC of CD38 + CD4 + IFN-γ + T lymphocytes was 0.82 with a cut-off value of 30.25%, with the sensitivity of 73.40% and specificity of 89.70%. The AUROC of HLA-DR + CD4 + IFN-γ + T lymphocytes was 0.85 with a cut-off value of 36.60%, with the sensitivity of 66.00% and specificity of 94.90%. The AUROC of CD27 -CD38 + CD4 + IFN-γ + T lymphocytes was 0.80 with a cut-off value of 8.82%, with the sensitivity of 90.60% and specificity of 61.50%. The AUROC of CD27 -HLA-DR + CD4 + IFN-γ + T lymphocytes was 0.83 with a cut-off value of 18.62%, with the sensitivity of 75.00% and specificity of 79.50%. The AUROC of CD38 + HLA-DR + CD4 + IFN-γ + T lymphocytes was 0.93 with a cut-off value of 22.35%, with the sensitivity of 79.70% and specificity of 100.00%. Conclusions:The expressions of CD27 -, CD38 + and HLA-DR + in Mycobacterium tuberculosis-specific CD4 + T lymphocytes are higher in ATB group compared to LTBI group. ATB and LTBI could be well discriminated by detecting the expressions of CD27, CD38 and HLA-DR on CD4 + IFN-γ + T lymphocytes with flow cytometry.

Objective:To investigate the role of glycoprotein A repetitions predominant (GARP) in the pathogenesis of tuberculosis through regulatory T cell (Treg), in order to provide new targets for the treatment of tuberculosis.Methods:Sixty patients with active pulmonary tuberculosis (ATB) admitted to Huashan Hospital, Fudan University and Wuxi Fifth People′s Hospital from January to September 2021 were included. And six individuals with latent tuberculosis infection (LTBI), and 16 healthy controls (HC) were recruited during the same period. Flow cytometry was performed to detect the proportion of Treg in the peripheral blood, and the expressions of GARP and transforming growth factor-β1 (TGF-β1) on Treg in different groups. Mann-Whitney U test was used for statistical analysis. Results:Among the 60 patients with ATB, 23 patients did not receive anti-tuberculosis drug therapy, 17 patients were treated for less than three months, ten patients were treated for three to less than six months, and ten patients were treated for greater than or equal to six months. The percentage of CD4 + CD25 + forkhead box protein 3 (Foxp3) + Treg in untreated ATB patients was 7.50%(5.67%, 9.00%), which was higher than that in HC (5.57%(5.03%, 6.09%)), and the difference was statistically significant ( U=95.00, P=0.010). The percentage of GARP expressing in CD4 + CD25 + Foxp3 + Treg in untreated ATB patients was 10.37%(7.79%, 12.90%), which was higher than that in LTBI (7.02%(5.15%, 8.81%)) and HC (5.33%(4.26%, 6.67%)), respectively, and the differences were both statistically significant ( U=31.00, P=0.040; U=36.00, P<0.001, respectively), while there was no significant difference between LTBI and HC ( U=25.00, P=0.095). The percentage of CD4 + CD25 + Foxp3 + Treg expressing TGF-β1 in untreated ATB patients was 7.13%(4.25%, 8.89%), which was higher than that in HC (3.59%(2.10%, 5.17%)), and the difference was statistically significant ( U=71.00, P=0.001). The expressions of GARP in CD4 + CD8 -CD25 + Foxp3 + Treg in patients with ATB treated for less than three months group, three to less than six months group and greater than or equal to six months group were 7.82%(3.94%, 13.17%), 6.92%(5.61%, 9.47%) and 7.26%(5.82%, 9.64%), respectively. The expressions of TGF-β1 in CD4 + CD8 -CD25 + Foxp3 + Treg in the above three treatment groups were 11.16%(7.91%, 15.23%), 8.66%(5.43%, 12.54%) and 7.82%(6.01%, 9.53%), respectively, and the expression of TGF-β1 in CD4 + CD8 -CD25 + Foxp3 + Treg in the patients with ATB treated for less than three months group was higher than that in the greater than or equal to six months group, the difference was statistically significant ( U=37.50, P=0.024). Conclusions:Foxp3/GARP/TGF-β1 pathway may be involved in the immune mechanism of Treg regulating the pathogenesis of tuberculosis, and GARP may be a new target for anti-tuberculosis therapy.

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.