Expression of inhibitory regulators of innate immunity in patients with active tuberculosis

• Main Authors: Dana C. Blok, Liesbeth M. Kager, Arie J. Hoogendijk, Ivar O. Lede, Wahid Rahman, Rumana Afroz, Paul Bresser, Jaring S. van der Zee, Aniruddha Ghose, Caroline E. Visser, Menno D. de Jong, Abu Shahed Md Zahed, Md Anwar Husain, Khan Mashrequl Alam, Pravat Chandra Barua, Mahtabuddin Hassan, Ahmed Hossain, Md Abu Tayab, Rene Lutter, Nick Day, Arjen M. Dondorp, Alex F. de Vos, Cornelis van 't Veer, Tom van der Poll
• Other Authors: Academic Medical Centre, University of Amsterdam
• Format: Article
• Published: 2018
• Subjects: Medicine
• Online Access: https://repository.li.mahidol.ac.th/handle/123456789/36216
• Institution: Mahidol University

© 2015 Blok et al.; licensee BioMed Central. Background: Tuberculosis (TB) is an important cause of morbidity and mortality worldwide. Toll-like-receptors (TLRs) are important for the recognition of the causative agent Mycobacterium tuberculosis. Negative regulation of TLRs is necessary to control deleterious inflammatory damage, but could provide a means of immune evasion by M. tuberculosis as well. Methods: To obtain insight in the extent of expression of inhibitory regulators of immunity in patients with active TB, peripheral-blood-mononuclear-cells (PBMCs) and plasma were obtained from 54 TB patients and 29 healthy blood donors from Chittagong, Bangladesh. Bilateral alveolar macrophages were obtained from an infected versus a contralateral normal lung segment of 9 patients. Statistical analyses were performed using Mann-Whitney U and Wilcoxon matched pairs testing. Correlations were calculated using the Spearman rho test. Results: PBMCs harvested from TB patients demonstrated increased mRNA expression of IL-1-receptor-associated-kinase-M, suppressor-of-cytokine-signalling-3 and Toll-interacting-protein. Flow cytometry revealed enhanced expression of IL-1-receptor-like-1 (ST2) on lymphocytes. Plasma soluble ST2 was elevated in patients with TB and correlated with established TB biomarkers, most strongly with soluble interleukin-2 receptor subunit aα and interleukin-8. Alveolar macrophage mRNA expression of negative TLR regulators did not differ between the infected and contralateral lung side. Conclusion: These results show enhanced expression of distinct negative regulators of innate immunity in PBMCs of patients with TB and identify plasma soluble ST2 as a potential novel biomarker for TB disease activity.