Role of Th1 and Th17 cells in the development and complexity of coronary artery disease: comparison analysis by the methods of flow cytometry and SYNTAX score.

BACKGROUND: There have been few reports on the relationship between the expression of the CD4⁺ T cells producing interferon-γ (Th1)/interleukin-17 (Th17) and degree of atherosclerosis. Thus, we analyzed Th1 and Th17 cell frequencies in patients with noncardiac chest pain (control), stable angina (SA), and acute myocardial infarction (AMI), and compared the complexity of the coronary artery with the SYNTAX score. PATIENTS AND METHODS: This study included 124 patients with a complaint of chest pain who underwent coronary angiography (control: 30 patients, SA: 47 patients, AMI: 47 patients). Peripheral blood was sampled during coronary angiography. Mononuclear cells from patients were stimulated for 4 h ex vivo. After staining with specific antibodies and fluorescence, the frequencies of Th1 and Th17 cells were measured by flow cytometry. The SYNTAX score was calculated by coronary angiography and a web-based calculator. RESULTS: There was no significant difference in the baseline characteristics, except the higher frequencies of hypertension in SA patients (76.1%) and smoking in AMI patients (53.3%). Patients with SA showed a significantly higher frequency of Th1 cells (21.56±9.57%) compared with controls (14.84±8.58%) and patients with AMI (9.04±7.02%) (P<0.001). The frequency of Th17 cells also increased in SA patients (control: 1.90±1.05%, SA: 2.96±1.42%, AMI: 1.32±0.92%, P<0.001). The SYNTAX score was significantly higher in SA patients (SA: 21.51±11.67, AMI: 15.36±8.84, P=0.006) and correlated with the frequencies of Th1 and Th17 cells (r=0.359, P=0.001; r=0.248, P=0.031; respectively). CONCLUSION: Th1 and Th17 cells were related to the development of SA, but not AMI. They could be a useful marker for the complexity of atherosclerosis in coronary artery disease.

PRR5, a novel component of mTOR complex 2, regulates platelet-derived growth factor receptor beta expression and signaling.

The protein kinase mammalian target of rapamycin (mTOR) plays an important role in the coordinate regulation of cellular responses to nutritional and growth factor conditions. mTOR achieves these roles through interacting with raptor and rictor to form two distinct protein complexes, mTORC1 and mTORC2. Previous studies have been focused on mTORC1 to elucidate the central roles of the complex in mediating nutritional and growth factor signals to the protein synthesis machinery. Functions of mTORC2, relative to mTORC1, have remained little understood. Here we report identification of a novel component of mTORC2 named PRR5 (PRoline-Rich protein 5), a protein encoded by a gene located on a chromosomal region frequently deleted during breast and colorectal carcinogenesis (Johnstone, C. N., Castellvi-Bel, S., Chang, L. M., Sung, R. K., Bowser, M. J., Pique, J. M., Castells, A., and Rustgi, A. K. (2005) Genomics 85, 338-351). PRR5 interacts with rictor, but not raptor, and the interaction is independent of mTOR and not disturbed under conditions that disrupt the mTOR-rictor interaction. PRR5, unlike Sin1, another component of mTORC2, is not important for the mTOR-rictor interaction and mTOR activity toward Akt phosphorylation. Despite no significant effect of PRR5 on mTORC2-mediated Akt phosphorylation, PRR5 silencing inhibits Akt and S6K1 phosphorylation and reduces cell proliferation rates, a result consistent with PRR5 roles in cell growth and tumorigenesis. The inhibition of Akt and S6K1 phosphorylation by PRR5 knock down correlates with reduction in the expression level of platelet-derived growth factor receptor beta (PDGFRbeta). PRR5 silencing impairs PDGF-stimulated phosphorylation of S6K1 and Akt but moderately reduces epidermal growth factor- and insulin-stimulated phosphorylation. These findings propose a potential role of mTORC2 in the cross-talk with the cellular machinery that regulates PDGFRbeta expression and signaling.

Alanine-threonine polymorphism of Helicobacter pylori RpoB is correlated with differential induction of interleukin-8 in MKN45 cells.

Geographical differences in the genetic diversity of Helicobacter pylori isolates were examined by analyzing rpoB sequences. An extremely high level of allelic diversity among H. pylori strains was found. The rpoB sequences of Asian and non-Asian (North and South American, European, and South African) strains were found to differ. An amino acid polymorphism (alanine and threonine RpoB types) was found at the 497th residue by deduced amino acid analysis. RpoB with a threonine residue (RpoB(Thr)) was uniquely present in East Asian countries, and two-thirds of the H. pylori isolate population in this region was RpoB(Thr); however, this type was rare or absent in Western countries, where RpoB(Ala) predominated. RpoB(Thr) strains induced a much larger amount of interleukin-8, a chemokine that plays an important role in chronic inflammation, than RpoB(Ala) strains in cultured MKN45 cells.

Application of RNA polymerase beta-subunit gene (rpoB) sequences for the molecular differentiation of Legionella species.

The nucleotide sequences of the partial rpoB gene were determined from 38 Legionella species, including 15 serogroups of Legionella pneumophila. These sequences were then used to infer the phylogenetic relationships among the Legionella species in order to establish a molecular differentiation method appropriate for them. The sequences (300 bp) and the phylogenetic tree of rpoB were compared to those from analyses using 16S rRNA gene and mip sequences. The trees inferred from these three gene sequences revealed significant differences. This sequence incongruence between the rpoB tree and the other trees might have originated from the high frequency of synonymous base substitutions and/or from horizontal gene transfer among the Legionella species. The nucleotide variation of rpoB enabled more evident differentiation among the Legionella species than was achievable by the 16S rRNA gene and even by mip in some cases. Two subspecies of L. pneumophila (L. pneumophila subsp. pneumophila and subsp. fraseri) were clearly distinguished by rpoB but not by 16S rRNA gene and mip analysis. One hundred and five strains isolated from patient tissues and environments in Korea and Japan could be identified by comparison of rpoB sequence similarity and phylogenetic trees. These results suggest that the partial sequences of rpoB determined in this study might be applicable to the molecular differentiation of Legionella species.

Population genetic structure of Legionella pneumophila inferred from RNA polymerase gene (rpoB) and DotA gene (dotA) sequences.

The population structure of Legionella pneumophila was studied by using partial RNA polymerase gene (rpoB) and DotA gene (dotA) sequences. Trees inferred from rpoB sequences showed that two subspecies of L. pneumophila, Legionella pneumophila subsp. pneumophila and Legionella pneumophila subsp. fraseri, were clearly separated genetically. In both rpoB and dotA trees, 79 Korean isolates used in this study constituted six clonal populations, four of which (designated subgroups P-I to P-IV) were identified in L. pneumophila subsp. pneumophila and two of which (designated subgroups F-I and F-II) were identified in L. pneumophila subsp. fraseri. Although the relationships among subgroups were not identical, such subgrouping was congruent between the rpoB and dotA trees. Type strains of several serogroups did not belong to any subgroup, presumably because isolates similar to these strains were not present among our local sample of the population. There was evidence that horizontal gene transfer or recombination had occurred within L. pneumophila. Contrary to the phylogeny from rpoB and the taxonomic context, subgroups P-III and P-IV of L. pneumophila subsp. pneumophila proved to be closely related to those of L. pneumophila subsp. fraseri or showed a distinct clustering in the dotA tree. It can be inferred that dotA of subgroups P-III and P-IV has been transferred horizontally from other subspecies. The diverse distribution of serogroup 1 strains through the gene trees suggests that surface antigen-coding genes that determine serogroup can be exchanged. Thus, it can be inferred that genetic recombination has been important in the evolution of L. pneumophila.