Abstract:

Objective: To investigate the expression level of liver kinase B1 (LKB1) gene in peripheral blood mononuclear cells (PBMCs) of Mycobacterium tuberculosis (MTB)-infected individuals and its correlation with interferon-γ (IFN-γ) levels. Methods: In this prospective study conducted between March and June 2024, we enrolled 23 patients with active pulmonary tuberculosis (PTB) hospitalized at Xi’an Chest Hospital, 20 individuals with latent tuberculosis infection (LTBI) diagnosed in the outpatient department of Xijing Hospital of Air Force Medical University, and 20 healthy individuals undergoing routine check-ups at the same hospital as the healthy control group. Peripheral blood samples were collected from all participants, and PBMCs were isolated. The mRNA expression levels of LKB1 and IFN-γ were compared across the three groups. The association between LKB1 expression and IFN-γ levels was assessed using correlation analysis. Results: (1) The relative expression levels of LKB1 in the PTB, LTBI, and healthy control groups were 0.529 (0.304, 0.964), 1.326 (1.064, 1.591), and 0.949 (0.732, 1.396), respectively. Statistically significant differences were observed among the three groups (H=23.707, P<0.01). LKB1 mRNA expression was markedly reduced in the PTB group compared with the healthy controls (H=2.560, P=0.031), while the LTBI group demonstrated a significantly elevated expression compared with the PTB group (H=-4.857, P<0.01). (2) In patients with PTB, the relative expression level of LKB1 mRNA in peripheral blood was inversely correlated with IFN-γ levels following stimulation with ESAT-6 antigen (r=-0.647, P=0.001) and CFP-10 antigen (r=-0.435, P=0.038). Conclusion: LKB1 expression is significantly downregulated in PBMCs of patients with active PTB and is inversely associated with IFN-γ levels, suggesting a potential role for LKB1 in modulating immune responses during MTB infection.

Key words: Mycobacterium tuberculosis, Infection, Liver kinase B1, Gene expression, Interferon-gamma