title: Impaired expression of Toll-like receptor 2 in nontuberculous mycobacterial lung disease.
abstract: The aims of the present study were to investigate the expression of Toll-like receptor (TLR)2 on the peripheral blood monocytes of patients with nontuberculous mycobacterial (NTM) lung disease and healthy controls, and to assess the responses of these monocytes to TLR2 agonists such as Mycobacterium avium and lipoteichoic acid (LTA). Reverse transcriptase-PCR was used to analyse TLR2 mRNA expression in peripheral blood monocytes from 17 NTM patients and 10 healthy controls. mRNA and protein secretion levels were also determined for the cytokines interleukin (IL)-12 p40 and tumour necrosis factor (TNF)-alpha. Expression of TLR2 mRNA by peripheral blood monocytes after stimulation with M. avium or LTA was lower in NTM patients than in healthy controls. IL-12 p40 and TNF-alpha mRNA and cytokine secretion levels were also lower in patients than in healthy controls. Treatment with anti-TLR antibody decreased M. avium- and LTA-induced IL-12 p40 and TNF-alpha production in healthy controls, but not in NTM patients. The present results suggest that the downregulation of Toll-like receptor 2 and the resulting decreased production of interleukin-12 p40 and tumour necrosis factor-alpha following Mycobacterium avium or lipoteichoic acid stimulation may contribute to host susceptibility to nontuberculous mycobacterial lung disease.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Centre, Sungkyunkwan University School of Medicine, Gangnam-Gu, Seoul, Korea.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Ryu
authors.forename: E J
authors.initials: EJ
authors.lastname: Kim
authors.forename: S-H
authors.initials: SH
authors.lastname: Lee
authors.forename: S Y
authors.initials: SY
authors.lastname: Kim
authors.forename: G Y
authors.initials: GY
authors.lastname: Suh
authors.forename: M P
authors.initials: MP
authors.lastname: Chung
authors.forename: H
authors.initials: H
authors.lastname: Kim
authors.forename: O J
authors.initials: OJ
authors.lastname: Kwon
authors.forename: W-J
authors.initials: WJ
authors.lastname: Koh
mesh_terms: D016207:Cytokines / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D020022:Genetic Predisposition to Disease; D006801:Humans; D053762:Interleukin-12 Subunit p40 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000378:metabolism; D008171:Lung Diseases / Q000378:metabolism* / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000378:metabolism; D009164:Mycobacterium Infections / Q000378:metabolism* / Q000382:microbiology*; D009162:Mycobacterium avium / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D013682:Teichoic Acids / Q000378:metabolism; D013997:Time Factors; D051195:Toll-Like Receptor 2 / Q000096:biosynthesis*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D016207:Cytokines; D053762:Interleukin-12 Subunit p40; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D013682:Teichoic Acids; D051195:Toll-Like Receptor 2; D014409:Tumor Necrosis Factor-alpha; C009900:lipoteichoic acid