ABSTRACT
Patients affected by pulmonary tuberculosis (PTB) manifest deficiencies in innate cellular immunity. The Tim3/Galectin-9 axis is an important regulator of Th1 cell immunity, leading to Th1 cell apoptosis. Herein, thisstudy aims to clarify the underlying roles of the Tim-3/Galectin-9 axis in T-cell immunity in PTB. Peripheralblood mononuclear cells (PBMCs) were extracted from subjects with and without PTB to examine theexpression of CD4, CD8, CD25, and Tim-3 under the stimulation of Mycobacterium tuberculosis (MTB) andpurified protein derivative (PPD). In addition, the expression of Tim-3 and Galectin-9 in PBMCs was determined. The Tim-3/Galectin-9 axis in the PBMCs was activated or blocked to detect the secreted levels of IFNc, TNF-a, IL-2, and IL-22. MTB stimulation increased the expression of CD4, CD8, CD25, Tim-3, andGalectin-9 in PBMCs. The blockade of Tim-3/Galectin-9 axis resulted in reduced secretion of IFN-c, TNF-a,IL-2, and IL-22 from T-cells. Moreover, Tim-3?CD4?T, Tim-3?CD8?, and Tim-3?CD25?T cells exhibited agreater ability to inhibit the replication of MTB in macrophages. Taken conjointly, the blockade of Tim-3/Galectin-9 axis inhibits the secretion of inflammatory cytokines in T-cells to regulate the T-cell immunity inPTB.