Impaired expression of toll-like receptor 2 in nontuberculous mycobacterial lung disease

¹ Division of Pulmonary and Critical Care Medicine, Dept of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea

^* To whom correspondence should be addressed. E-mail: wjkoh{at}smc.samsung.co.kr.

	Abstract

The aims of our study were to investigate the expression of Toll-like receptor-2 (TLR2) on the peripheral blood monocytes from patients with NTM lung disease and from healthy controls, and to assess the responses of these monocytes to TLR2 agonists such as Mycobacterium avium and lipoteichoic acid (LTA).

We used the reverse transcriptase-polymerase chain reaction to analyze TLR2 mRNA expression in peripheral blood monocytes from 17 NTM patients and 10 healthy controls. We also determined the mRNA and protein secretion levels for the cytokines interleukin (IL)-12p40 and tumour necrosis factor (TNF)-.

After stimulation with M. avium or lipoteichoic acid, expression of TLR2 mRNA by peripheral blood monocytes was lower in NTM patients than in healthy controls. IL-12p40 and TNF- mRNA and cytokine secretion levels were also lower in patients than in healthy controls. Treatment with anti-TLR antibody decreased M. avium and lipoteichoic acid-induced IL-12p40 and TNF- production in healthy controls, but not in NTM patients.

Our results suggest that the downregulation of TLR2 and the resulting decreased production of IL-12p40 and TNF- following M. avium or lipoteichoic acid stimulation may contribute to host susceptibility to NTM lung disease.

This article has been cited by other articles:

				P. Sexton and A. C. Harrison Susceptibility to nontuberculous mycobacterial lung disease Eur. Respir. J., June 1, 2008; 31(6): 1322 - 1333. [Abstract] [Full Text] [PDF]