Significance of the Notch Signaling Pathway in Modulating the Differentiation of Main T-Lymphocytes Populations in Patients with Infiltrative Pulmonary Tuberculosis

Abstract

The objective: to evaluate the modulating effect of the Notch signaling pathway on differentiation of Th1 and Th2 lymphocytes in vitro in patients with infiltrative pulmonary tuberculosis.Subjects and Methods. 14 new patients with infiltrative pulmonary tuberculosis were enrolled in the study. Mononuclear leukocytes were isolated from blood by gradient centrifugation. Only Mycobacterium tuberculosis antigens in the form of the CFP10-ESAT6 protein or together with Y-secretase inhibitor DAPT (5 μМ/l or 10 μМ/l) were added to the incubation medium. Cells were cultured for 72 h in a complete nutrient medium with 5% CO2 at 37°C. Counts of Th1 and Th2 lymphocytes were determined by flow cytometry by evaluating the expression of CD4 receptor and intracellular transcription factors T-bet and GATA-3.Results. Cell stimulation with the CFP10-ESAT6 protein was accompanied by increasing number of Th1 and Th2 lymphocytes only in patients with pulmonary tuberculosis resistant to isoniazid + rifampicin. Adding DAPT at the concentration of 10 μМ/L to the incubation medium in these patients led to the growing number of Th1 lymphocytes and decrease in Th2 lymphocytes. In pulmonary tuberculosis patients who were susceptible to isoniazid + rifampicin, only decrease in the number of Th2-lymphocytes was regeistered. In all groups of subjects, suppression of the Notch signaling pathway led increase in the Th1/Th2 index versus Th1/Th2 stimulated with CFP10-ESAT6 antigens.