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Abstract Background To investigate whether the toll-like receptor 2 polymorphisms could influence susceptibility to pulmonary TB, its phenotypes, and blood lymphocyte subsets. Methods A total of 368 subjects, including 184 patients with pulmonary TB and 184 healthy controls, were examined for TLR2 polymorphisms over locus -100 (microsatellite guanine-thymine repeats), -16934 (T>A), -15607 (A>G), -196 to -174 (insertion>deletion), and 1350 (T>C). Eighty-six TB patients were examined to determine the peripheral blood lymphocyte subpopulations. Results We newly identified an association between the haplotype [A-G-(insertion)-T] and susceptibility to pulmonary TB (p = 0.006, false discovery rate q = 0.072). TB patients with systemic symptoms had a lower -196 to -174 deletion/deletion genotype frequency than those without systemic symptoms (5.7% vs. 17.7%; p = 0.01). TB patients with the deletion/deletion genotype had higher blood NK cell counts than those carrying the insertion allele (526 vs. 243.5 cells/μl, p = 0.009). TB patients with pleuritis had a higher 1350 CC genotype frequency than those without pleuritis (12.5% vs. 2.1%; p = 0.004). TB patients with the 1350 CC genotype had higher blood NK cell counts than those carrying the T allele (641 vs. 250 cells/μl, p = 0.004). TB patients carrying homozygous short alleles for GT repeats had higher blood NK cell counts than those carrying one or no short allele (641 vs. 250 cells/μl, p = 0.004). Conclusions TLR2 genetic polymorphisms influence susceptibility to pulmonary TB. TLR2 variants play a role in the development of TB phenotypes, probably by controlling the expansion of NK cells.

We hypothesized that epigenetics is a link between smoking/allergen exposures and the development of Asthma and chronic obstructive pulmonary disease (ACO). A total of 75 of 228 COPD patients were identified as ACO, which was independently associated with increased exacerbations. Microarray analysis identified 404 differentially methylated loci (DML) in ACO patients, and 6575 DML in those with rapid lung function decline in a discovery cohort. In the validation cohort, ACO patients had hypermethylated PDE9A (+ 30,088)/ZNF323 (− 296), and hypomethylated SEPT8 (− 47) genes as compared with either pure COPD patients or healthy non-smokers. Hypermethylated TIGIT (− 173) gene and hypomethylated CYSLTR1 (+ 348)/CCDC88C (+ 125,722)/ADORA2B (+ 1339) were associated with severe airflow limitation, while hypomethylated IFRD1 (− 515) gene with frequent exacerbation in all the COPD patients. Hypermethylated ZNF323 (− 296) / MPV17L (+ 194) and hypomethylated PTPRN2 (+ 10,000) genes were associated with rapid lung function decline. In vitro cigarette smoke extract and ovalbumin concurrent exposure resulted in specific DNA methylation changes of the MPV17L / ZNF323 genes, while 5-aza-2′-deoxycytidine treatment reversed promoter hypermethylation-mediated MPV17L under-expression accompanied with reduced apoptosis and decreased generation of reactive oxygen species. Aberrant DNA methylations may constitute a determinant for ACO, and provide a biomarker of airflow limitation, exacerbation, and lung function decline. [ABSTRACT FROM AUTHOR]

The aim of this study is to determine the roles of global histone acetylation (Ac)/methylation (me), their modifying enzymes, and gene-specific histone enrichment in active pulmonary tuberculosis (TB) disease. Global histone H3K27me3, H3K27me2, H3K9me3, H3K9Ac, and H3K14Ac expressions, and their modifying enzyme expressions, including KDM1A, KDM6B, EZH2, HDAC1, and HDAC2, were assessed in blood leukocytes from 81 patients with active pulmonary TB disease and 44 matched healthy subjects (HS). TLR2 , TNF-α , IFN-γ , and IL12B -specific histone enrichment of peripheral blood mononuclear cells was measured by chromatin immunoprecipitation method. We found that Global H3K14Ac was decreased and H3K27me2 was increased in TB patients as compared with that in HS. TB patients with low H3K14Ac had lower one-year survival. Global H3K27me3 was increased in TB patients with high bacterial burden, or systemic symptoms as compared with that in those without the attribute or HS. HDAC1 gene/protein expressions were increased in TB patients as compared with that in HS, whereas KDM6B gene/protein expressions were decreased. Global H3K27me2, HDAC1 and KDM6B protein expressions were all reversed to normal after 6-month anti-TB treatment. TNF-α/IL12B promoter-specific H3K14Ac and TNF-α/IL12B/IFN-γ promoter-specific H3K27me2 enrichment were all decreased in 10 TB patients as compared with that in 10 HS. Among them, IL12B -specific H3K27me2 enrichment was reversed to normal after treatment, while the other 4 remained depressed. In conclusions, H3K14 hypoacetylation and H3K27 hypermethylation play a role in the development of active pulmonary TB disease or its clinical phenotypes, probably through up-regulation of HDAC1 and down-regulation of KDM6B, respectively., Competing Interests: None.

Lipopolysaccharide (LPS) induces acute lung injury (ALI) via Toll-like receptor 4 (TLR4)-mediated MAPK activation. The lipid A fraction of LPS is considered to be the active moiety, but whether the lipid A-TLR4 interaction accounts completely for ALI-associated MAPK activation in vivo has not been determined. The lipid A fraction of LPS induces a discrete MAPK activation pattern in murine ALI. Mice (C57BL/6J, C3H/HeJ) were treated with intratracheal instillations of purified lipid A or LPS (10, 30, and 100 microg per mouse) or vehicle. ALI was assessed by histology. Chromogenic myeloperoxidase (MPO) activity was measured in lung homogenates. MAPK expression was quantified by immunoblotting. In vitro ERK inhibitor studies using thioglycollate-elicited macrophages were also performed. MPO increased in a dose- and time-responsive fashion. Notably, MPO was 2.4-fold greater after lipid A compared with LPS and vehicle at 6 h after instillation (lipid A, 0.88 +/- 0.25 vs. LPS, 0.37 +/- 0.21 optical density units.min(-1).mg(-1); P < 0.05). However, ALI scores were comparable at 6 and 24 h between LPS and lipid A. MPO was also comparable in vehicle-treated or C3H/HeJ mice treated with LPS or lipid A at 6 and 24 h. Phospho-ERK activation was pronounced at 6 and 24 h after lipid A but not LPS treatment. In vitro studies confirmed the relationship between phospho-ERK activation and cytokine expression in macrophage stimulated with either LPS or lipid A. Compared with whole LPS, the lipid A fraction is associated with amplified whole lung MPO and ERK activation 6 h after intratracheal instillation in mice.