Aim: The aim of this study was to explore whether the circulating frequency and function of myeloid-derived suppressor cells (MDSCs) are altered in patients with acute coronary syndrome (ACS). Methods: The frequency of MDSCs in peripheral blood was determined by flow cytometry, and mRNA expression in purified MDSCs was analyzed by real-time reverse transcription polymerase chain reaction (RT-PCR). The suppressive function of MDSCs isolated from different groups was also determined. The plasma levels of certain cytokines were determined using Bio-Plex Pro™ Human Cytokine Assays. Results: The frequency of circulating CD14⁺HLA-DR^-/low MDSCs; arginase-1 (Arg-1) expression; and plasma levels of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and IL-33 were markedly increased in ACS patients compared to stable angina (SA) or control patients. Furthermore, MDSCs from ACS patients were more potent suppressors of T-cell proliferation and IFN-γ production than those from the SA or control groups at ratios of 1:4 and 1:2; this effect was partially mediated by Arg-1. In addition, the frequency of MDSCs was positively correlated with plasma levels of IL-6, IL-33, and TNF-α. Conclusions: We observed an increased frequency and suppressive function of MDSCs in ACS patients, a result that may provide insights into the mechanisms involved in ACS.

Objective. To investigate the role of CD4+CD25+ T cells (Tregs) in protecting fine particulate matter (PM-) induced inflammatory responses, and its potential mechanisms. Methods. Human umbilical vein endothelial cells (HUVECs) were treated with graded concentrations (2, 5, 10, 20, and 40 µg/cm2) of suspension of fine particles for 24h. For coculture experiment, HUVECs were incubated alone, with CD4+CD25− T cells (Teff), or with Tregs in the presence of anti-CD3 monoclonal antibodies for 48 hours, and then were stimulated with or without suspension of fine particles for 24 hours. The expression of adhesion molecules and inflammatory cytokines was examined. Results. Adhesion molecules, including vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1), and inflammatory cytokines, such as interleukin (IL-) 6 and IL-8, were increased in a concentration-dependent manner. Moreover, the adhesion of human acute monocytic leukemia cells (THP-1) to endothelial cells was increased and NF-κB activity was upregulated in HUVECs after treatment with fine particles. However, after Tregs treatment, fine particles-induced inflammatory responses and NF-κB activation were significantly alleviated. Transwell experiments showed that Treg-mediated suppression of HUVECs inflammatory responses impaired by fine particles required cell contact and soluble factors. Conclusions. Tregs could attenuate fine particles-induced inflammatory responses and NF-κB activation in HUVECs.

Protein disulfide isomerase (PDI) and PDI-like proteins are members of the thioredoxin superfamily. They contain thioredoxin-like domains and catalyze the physiological oxidation, reduction and isomerization of protein disulfide bonds, which are involved in cell function and development in prokaryotes and eukaryotes. In this study, EtPDIL, a novel PDI-like gene of Eimeria tenella, was cloned using rapid amplification of cDNA ends (RACE) according to the expressed sequence tag (EST). The EtPDIL cDNA contained 1129 nucleotides encoding 216 amino acids. The deduced EtPDIL protein belonged to thioredoxin-like superfamily and had a single predicted thioredoxin domain with a non-classical thioredoxin-like motif (SXXC). BLAST analysis showed that the EtPDIL protein was 55–59% identical to PDI-like proteins of other apicomplexan parasites. The transcript and protein levels of EtPDIL at different development stages were investigated by real-time quantitative PCR and western blot. The messenger RNA and protein levels of EtPDIL were higher in sporulated oocysts than in unsporulated oocysts, sporozoites or merozoites. Protein expression was barely detectable in unsporulated oocysts. Western blots showed that rabbit antiserum against recombinant EtPDIL recognized only a native 24 kDa protein from parasites. Immunolocalization with EtPDIL antibody showed that EtPDIL had a disperse distribution in the cytoplasm of whole sporozoites and merozoites. After sporozoites were incubated in complete medium, EtPDIL protein concentrated at the anterior of the sporozoites and appeared on the surface of parasites. Specific staining was more intense and mainly located on the parasite surface after merozoites released from mature schizonts invaded DF-1 cells. After development of parasites in DF-1 cells, staining intensified in trophozoites, immature schizonts and mature schizonts. Antibody inhibition of EtPDIL function reduced the ability of E. tenella to invade DF-1 cells. These results suggested that EtPDIL might be involved in sporulation in external environments and in host cell adhesion, invasion and development of E. tenella.

The precocious lines of Eimeria spp. have unique phenotypes. However, the genetic basis of the precocious phenotype is still poorly understood. The identification of Eimeria genes controlling the precocious phenotype is of immense importance in the fight against coccidiosis. In the present study, a novel gene of Eimeria maxima was cloned using rapid amplification of cDNA ends (RACE) based on the expressed sequence tag (EST). Homologous genes were also found in Eimeria tenella and Eimeria acervulina. Alignment of the amino acid sequences from E. tenella, E. maxima, and E. acervulina showed 80-86 % identity, demonstrating a conserved protein in different Eimeria spp. This gene, designated Eimeria-conserved protein (ECP), contained 235 amino acids with a predicted molecular mass of 25.4 kDa and had 100 % identity with one annotated protein from E. maxima (Emax_0517). Real-time PCR and Western blot analysis revealed that the expression of ECP at mRNA and protein level in E. tenella is developmentally regulated. Messenger RNA levels from the ECP gene were higher in sporozoites than in other developmental stages (unsporulated oocysts, sporulated oocysts, and second-generation merozoites). Expression of ECP protein was detected in unsporulated oocysts, increased in abundance in sporulated oocysts, and was most prominent in sporozoites. Thereafter, the level of the ECP protein decreased, and no ECP-specific protein was detected in second-generation merozoites. Immunostaining with anti-rECP indicated that ECP is highly concentrated in both refractile bodies (RB) of free sporozoites, but is located at the apical end of the sporozoites after invasion of DF-1 cells. The specific staining of the ECP protein becomes more intense in trophozoites and immature first-generation schizonts, but decreases in mature first-generation schizonts. Inhibition of the function of ECP using specific antibodies reduced the ability of E. tenella sporozoites to invade host cells. Compared with the parent strain, both mRNA and protein expression levels in the sporulated oocyst were downregulated in the precocious line of E. tenella. These results suggest that ECP may be involved in invasion and development of the first-generation merogony stage of E. tenella. Findings of downregulation of ECP mRNA and protein expression in the precocious line enrich the study of the precocious phenotype of Eimeria.

No abstract

This study investigated the relationship between IL-33/ST2 signal pathway gene polymorphisms and myocardial infarction (MI) in Han Chinese. A case-control association analysis was performed on a total of 490 MI patients (MI group) and 929 normal subjects (NC group). Sequenom Mass Array and Taqman genotyping technique were used to analyze the tag single nucleotide polymorphisms (SNPs) in the genes encoding IL-33, ST2, and IL-1RaP (rs11792633, rs1041973 and rs4624606). The results showed that the frequencies of rs4624606 genotypes AA, TT, AT were 0.031, 0.647, 0.322 in MI group and 0.026, 0.712, 0.263 in NC group, and the allele frequencies of A and T were 0.192, 0.808 in MI group and 0.157, 0.843 in NC group. There were significant differences in rs4624606 genotypes and allele frequencies between MI group and NC group (P<0.05). For rs11792633, the allele frequencies of C and T were 0.45, 0.55 in MI group and 0.454, 0.546 in NC group with no significant differences found between the two groups. Compared with genotype CC+TC, rs11792633 genotype TT had an increased risk of hypertension (P<0.05). However, there were no significant differences in the frequencies of rs11792633 genotypes between the two groups. No significant differences were noted in the frequencies of rs1041973 genotype and allele between the two groups. Logistic regression analysis showed that rs4624606 genotypes AT and AA+AT were both significantly associated with MI (AT: OR=1.325, P=0.029, 95% CI=1.03-1.705; AA+AT: OR=1.316, P=0.028, 95% CI=1.03-1.681) after factors such as age, gender, smoking, drinking, body mass index (BMI), triglyceride (TG) and cholesterol were adjusted. Those carrying rs4624606 genotype AT or AA+AT had an increased risk of MI. No associations were found between the polymorphisms of the other two loci with MI. It was concluded that, in the IL33/ST2 signal pathway, the A allele of rs4624606 polymorphism of IL-1RaP gene is a potential independent risk factor for MI, and the genotypes AA+AT and AT are associated with the incidence of MI.

Regulatory T cells (Tregs) play a pivotal role in the pathological development of hypertension. Helios, a transcription factor from the Ikaros family, was recently reported to be a bona fide marker for natural Tregs or activated Tregs with suppression function, however, little has been known about its role in hypertension. This study was aimed to find whether Helios+ Tregs really play a vital role in hypertension. A total of 60 hypertension patients, and 46 normotension subjects were enrolled in this study. Frequencies of different Tregs subsets in peripheral blood were measured by flow cytometry. Plasma cytokine level was determined by ELISA. The mRNA expression of Foxp3 and Helios in purified CD4+ T cells was detected by RT-PCR. Proportion of CD4+Foxp3+Helios+ Tregs was decreased significantly in patients with hypertension (62.52%±1.18% vs. 71.89%±1.03%, P<0.01), and it was correlated with plasma level of IL-10 positively (a=0.505, P<0.05) and plasma level of IFN-gamma negatively (r=-0.551, P<0.05). The mRNA expression of Foxp3 (7.23±1.00 vs. 10.58±0.54, P<0.05) and Helios (8.47±0.95 vs. 15.52±2.0, P<0.05) was decreased in CD4+ T cells from patients with hypertension. Helios+ Tregs were decreased in patients with hypertension and may play a protective role in hypertension progression.

Regulatory T cells (Tregs) play an essential role in acute coronary syndrome (ACS). However, there is debate about which Treg subsets are truly critical to ACS. Helios, a transcription factor, was recently reported to be a bona fide marker for natural Tregs or activated Tregs with a suppression function, but little is known about its role in ACS. We therefore examined Helios+ Tregs in patients with ACS, patients with stable angina, and control subjects. 73 patients with ACS, 30 patients with stable angina, and 48 control subjects were enrolled. The frequencies and estimated absolute numbers of different Treg subsets in peripheral blood were measured by flow cytometry. Plasma cytokine level was measured by ELISA. The mRNA expression of Foxp3 and Helios in purified CD4+ T cells was determined by RT-PCR. Helios+ Tregs was decreased significantly in patients with ACS. The frequency and estimated absolute numbers of CD4+Foxp3+Helios+ Tregs were negatively correlated with IL-6 and positively correlated with circulating level of TGF-beta1 and HDL-C. The mRNA expression of Foxp3 and Helios was decreased in CD4+ T cells from patients with ACS. In summary, Helios+ Tregs was downregulated in patients with ACS and may play a role in ACS.