Internalization of interleukin 1 (IL 1) correlates with IL 1-induced IL 2 receptor expression and IL 2 secretion of EL4 thymoma cells

The cytokine interleukin 1 (IL 1) plays an important role in the induction of IL 2 secretion and high-affinity IL 2 receptor (IL 2R) expression by T cells. The events that follow binding of IL 1 to IL 1R, however, are still unknown. In this study we describe two variants of the murine thymoma EL4 (5D3 and D6/76) that express comparable numbers of cell surface IL 1 receptors and bind IL 1 with the same affinity, but show distinct IL 1-dependent IL 2 secretion and IL 2R expression. In the presence of the tumor promoter phorbol 12-myristate 13-acetate IL 1 augments IL 2 secretion and IL 2R expression of EL4 5D3 but not of EL4 D6/76 cells. Comparison of the internalization of IL 1 by both clones revealed that EL4 D6/76 was unable to transport cell surface-bound IL 1 to the cytoplasm. These findings suggest that internalization of receptor-bound IL 1 is required for the action of this cytokine.     

Lack of association between polymorphisms of the IL18R1 and IL18RAP genes and cardiovascular risk: the MORGAM Project

Background

Interleukin-18 is a pro-inflammatory cytokine suspected to be associated with atherosclerosis and its complications. We had previously shown that one single nucleotide polymorphism (SNP) of the IL18 gene was associated with cardiovascular disease (CVD) through an interaction with smoking. As a further step for elucidating the contribution of the IL-18 pathway to the etiology of CVD, we here investigated the association between the genetic variability of two IL-18 receptor genes, IL18R1 and IL18RAP, with the risk of developing CVD.

Methods

Eleven tagging SNPs, 5 in IL18R1 and 6 in IL18RAP, characterizing the haplotypic variability of the corresponding genes; were genotyped in 5 European prospective CVD cohorts including 1416 cases and 1772 non-cases, as part of the MORGAM project. Both single-locus and haplotypes analyses were carried out to investigate the association of these SNPs with CVD.

Results

We did not find any significant differences in allele, genotype and haplotype frequencies between cases and non-cases for either of the two genes. Moreover, the search for interactions between SNPs located in different genes, including 5 IL18 SNPs previously studied in the MORGAM project, and between SNPs and environmental factors remained unfruitful.

Conclusion

Our analysis suggests that the variability of IL18R1 and IL18RAP genes are unlikely to contribute to modulate the risk of CVD.     

The structure and evolution of immunoglobulin kappa chain constant region genes in the genus Rattus

We have cloned and sequenced the C-kappa (Ck) genes from seven species and subspecies of rats which have diverged over the past few million years in Australia. Comparisons of these sequences with each other and the Ck genes of the laboratory rat, Rattus norvegicus, indicate noncoding regions have accumulated fewer mutations than adjacent coding sequences, and amino acid replacing nucleotide substitutions in the coding regions have accumulated at a rate at least as great as silent changes. Exactly the opposite of both of these findings is observed when comparisons are made between Ck or other genes from more distantly related species, indicating that these features may be characteristic of Ck short-term evolutionary gene divergence. Changes in the coding regions of these genes result in a non-random distribution of amino acid substitutions on the three-dimensional alpha-carbon backbone of the Ck domain in the most serologically distinct forms of Ck. While phylogenetic relationships inferred from the Ck nucleotide sequences are in general agreement with those derived from other data, considerable differences are seen in rates of accumulation of Ck gene nucleotide substitutions vs rates of accumulation of enzyme polymorphisms.     

Evaluation of IL17A expression and of IL17A,IL17F and IL23R gene polymorphisms in Brazilian individuals with periodontitis

The IL23/Th17 axis plays an important role in the pathogenesis of cell-mediated tissue damage caused either by autoimmunity or immune responses against bacterial infection. Single nucleotide polymorphisms in the IL17A, IL17F and IL23R genes have been associated with several inflammatory diseases. However, these polymorphisms have not yet been studied in periodontitis. The aim of present study was to evaluate the expression of IL17A and occurrence of the IL17A (rs2275913), IL17F (rs763780) and IL23R (rs11209026) gene polymorphisms in different clinical forms or severity of periodontitis in a sample of Brazilian individuals. Peripheral blood was obtained from 30 non-smoker individuals and analyzed by flow cytometry to determine IL-17 expression. Genomic DNA was obtained from oral swabs in 180 individuals and analyzed by Real-time PCR. The study group was composed by individuals without periodontitis (control), with aggressive periodontitis (AP) and with chronic periodontitis (CP). Higher frequency of IL17A+CD4+ T cells was observed in control group. The A+ genotype from IL17A (rs2275913) was associated with lack of disease. No association was found considering the IL17F and IL23R polymorphisms. Our data suggest that IL17A and the presence of IL17A (rs2275913) A allele are associated with the absence of periodontal disease.     

重组人IL1-Ra与TGF-β1共转染软骨细胞的基因表达

目的：探讨重组人IL1-Ra与TGF-β1基因转染软骨细胞的表达情况。方法：体外分离培养兔关节软骨细胞，然后用构建的IL1-Ra与TGF-β1质粒通过脂质体介导下共转染软骨细胞，通过荧光显微镜观察转基因的表达和荧光定量PCR检测其表达。结果：荧光显微镜观察有绿色荧光蛋白表达，荧光定量PCR鉴定证实转染的软骨细胞中转基因得到表达。结论：IL1-Ra与TGF-β1基因共转染软骨细胞可以获得表达，为基因治疗骨关节炎的研究提供基础。     

Chromosome 5q candidate genes in coeliac disease: genetic variation at IL4, IL5, IL9, IL13, IL17B and NR3C1

Genetic predisposition to coeliac disease (CD) is determined primarily by alleles at the HLA-DQB locus, and evidence exists implicating other major histocompatibility complex-linked genes (6p21) and the CTLA4 locus on chromosome 2q33. In addition, extensive family studies have provided strong, reproducible evidence for a susceptibility locus on chromosome 5q (CELIAC2). However, the gene responsible has not been identified. We have assayed genetic variation at the IL4, IL5, IL9, IL13, IL17B and NR3C1 (GR) loci, all of which are present on chromosome 5q and have potential or demonstrated involvement in autoimmune and/or inflammatory disease, in a sample of 409 CD cases and 355 controls. Thirteen single nucleotide polymorphisms were chosen on the basis of functional relevance, prior disease association and, where possible, prior knowledge of the haplotype variation present in European populations. There were no statistically significant allele or haplotype frequency differences between cases and controls. Therefore, these results provide no evidence that these loci are associated with CD in this sample population.     

Epistatic effect of IL1A and IL4RA genes on the risk of atopy

BACKGROUND: Several studies have demonstrated a linkage or association of the atopic phenotype with T-cell cytokine genes involved in the regulation of the TH1/TH2 balance (eg, IL4, IL13, and their common receptor, IL4RA). We have recently shown that polymorphism of the pro-inflammatory cytokine IL1A gene is strongly associated with atopy. OBJECTIVE: We now examined whether the polymorphisms of IL1A (G/T at +4845) and IL4RA (T/C at +22446) would show an epistatic effect on the risk of atopy. METHODS: Skin prick tests and gene polymorphism analyses were performed in a population-based sample of asthmatic and nonasthmatic subjects. RESULTS: Our results showed that in the nonasthmatic group the previously described elevated risk of atopy in noncarriers of allele T of IL1A (ie, having the genotype GG) was restricted to individuals who were also noncarriers of allele C of IL4RA (genotype TT). This finding applies to the general population of Finland, where 3.3% of adults are asthmatic. CONCLUSION: These data suggest that the IL1A and IL4RA genes show an epistatic effect on the risk of atopy.     

CPH1和EFG1基因在游离态及生物膜态白念珠菌的表达差异

目的 检测游离态及不同时期生物膜态白念珠菌转录因子CPH1和EFG1的表达,探讨其在生物膜形成过程中的作用.方法 应用激光共聚焦显微镜观察白念珠菌质控株ATCC90028和临床分离株14215于聚乙烯片上黏附生长24 h后的生物膜形态.分别提取6株白念珠菌临床分离株13860、13874、14127、14371、14215、14533和质控株ATCC90028游离态以及早期(聚乙烯片上黏附生长4h)、中期(聚乙烯片上黏附生长12h)、晚期(聚乙烯片上黏附生长24 h)生物膜态的总RNA,应用荧光定量PCR测定其CPH1和EFG1基因的表达.结果 聚乙烯片上黏附生长24 h后,激光共聚焦显微镜下可见质控株ATCC90028多为单层的孢子细胞黏附;白念珠菌临床分离株14215形成菌丝态为主,具有三维结构的生物膜.相对于游离态,白念珠菌质控株ATCC90028在生物膜形成的早中晚期转录因子CPH1和EFG1表达均下调.临床分离株转录因子CPH1在游离态、生物膜形成的早中晚期时表达差异均无统计学意义(均P＜0.05).而与游离态相比,临床分离株转录因子EFG1基因的相对表达量在生物膜形成早期及中期均上调[0.141(0.029 ～ 0.212)、0.252(0.103 ～ 0.943)比0.077(0.018 ～ 0.113),均P＜0.05],在生物膜形成晚期则无明显改变(P＞0.05),相对表达量为0.091(0.024 ～ 0.354).结论 转录因子EFG1在白念珠菌临床分离株生物膜形成过程中有重要的调控作用.     

No evidence of association between functional polymorphisms located within IL6R and IL6ST genes and systemic sclerosis

Systemic sclerosis (SSc) is a complex autoimmune disease which genetic component has not been yet completely understood. IL6 encodes a cytokine with a crucial role in the development of autoimmunity and fibrosis and its actions mainly are controlled by IL-6 receptor (IL-6R). We aimed to investigate whether the functional genetic variants rs8192284 and rs2228044 previously associated with several autoimmune diseases, located within the IL-6 receptor (IL-6R) subunits IL6R and IL6ST genes, respectively, are involved in the susceptibility to SSc and/or its major clinical subphenotypes. A Spanish cohort including 1013 SSc patients and 1375 controls was genotyped using the TaqMan? allelic discrimination technology. SSc patients were subdivided according to the major clinical forms, autoantibody status and presence of fibrotic lung affection. Our data showed no influence of the selected variants in global SSc susceptibility (rs8192284: P?=?0.67, odds ratios (OR)?=?0.98; rs2228044: P?=?0.99, OR?=?1.00). Similarly, the clinical/autoantibody subphenotype analyses did not yielded significant results. Our data suggest that the analyzed polymorphisms may not play a significant role in the SSc susceptibility.     

Haplotype structure of inflammatory cytokines genes (IL1B, IL6 and TNF/LTA) in US Caucasians and African Americans

The major inflammatory cytokines interleukin(IL)1beta, IL6 and tumor necrosis factor alpha (TNFalpha) play a crucial role in infection, inflammation and stress responses. Previously, three coding genes were resequenced, identifying promoter polymorphisms that were used in association studies of neurodegenerative diseases, metabolic disorders and cancer. These studies have produced intriguing but inconsistent results, potentially because the known functional variants: IL1B-511 C>T, IL6-174 G>C and TNF-308 G>A provided an incomplete picture of the total functional diversity at these genes. Therefore, we created marker panels for IL1B, IL6 and TNF/LTA that included the known functional marker but also other markers evenly spaced and with sufficient density to identify haplotype block structure and to maximize haplotype diversity. A total of 26 markers were genotyped in 96 US Caucasians and 96 African Americans. In both populations, a single block with little evidence of historical recombination was observed in IL1B, IL6 and TNF/LTA. For each gene, haplotypes captured the information content of each functional locus, even if that locus was not genotyped, and presumably haplotypes would capture the signal from unknown functional loci whose alleles are of moderate abundance. This study demonstrates the utility of using gene haplotype maps and marker panels as tools for linkage studies on related phenotypes.     

Evaluation of IL18 and IL18R1 polymorphisms: genetic susceptibility to knee osteoarthritis

We examined single-nucleotide polymorphisms (SNPs) in IL18 and IL18/R1 genes and knee OA. IL18 rs1946518 wild-type allele was more frequently observed in cases (P = 0.04). Haplotype 1 was more frequently observed in cases (P = 0.04). Genetic variation in the promoter region of IL18, but not IL18R1, may be associated with OA.     

Differential gene expression of neonatal and adult DRG neurons correlates with the differential sensitization of TRPV1 responses to nerve growth factor

Cultures of neonatal and adult dorsal root ganglion (DRG) neurons are commonly used in in vitro models to study the ion channels and signaling events associated with peripheral sensation under various conditions. Differential responsiveness between neonatal and adult DRG neurons to physiological or pathological stimuli suggests potential differences in their gene expression profiles. We performed a microarray analysis of cultured adult and neonatal rat DRG neurons, which revealed distinct gene expression profiles especially of ion channels and signaling molecules at the genomic level. For example, Ca²⁺-stimulated adenylyl cyclase (AC) isoforms AC3 and AC8, PKCδ and CaMKIIα, the voltage-gated sodium channel β1 and β4, and potassium channels K_v1.1, K_v3.2, K_v4.1, K_v9.1, K_v9.3, K_ir3.4, K_ir7.1, K_2P1.1/TWIK-1 had significantly higher mRNA expression in adult rat DRG neurons, while Ca²⁺-inhibited AC5 and AC6, sodium channel Na_v1.3 α subunit, potassium channels K_ir6.1, K_2P10.1/TREK-2, calcium channel Ca_v2.2 α1 subunit, and its auxiliary subunits β1 and β3 were conversely down regulated in adult neurons. Importantly, higher adult neuron expression of ERK1/2, PI3K/P110α, but not of TRPV1 and TrkA, was found and confirmed by PCR and western blot. These latter findings are consistent with the key role of ERK and PI3K signaling in sensitization of TRPV1 by NGF and may explain our previously published observation that adult, but not neonatal, rat DRG neurons are sensitized by NGF.     

Variation in the IL1B, TNF and IL6 genes and individual susceptibility to prosthetic joint infection

ABSTRACT: BACKGROUND: Prosthetic joint infection (PJI) is an important failure mechanism of total joint arthroplasty (TJA). Here we examine whether the particular genetic variants can lead to increased susceptibility to PJI development. RESULTS: We conducted a genetic-association study to determine whether PJI could be associated with functional cytokine gene polymorphisms (CGP) influencing on innate immunity response. A case-control design was utilized and previously published criteria for PJI were included to distinguish between cases and control subjects with/without TJA. Six single nucleotide polymorphisms (SNPs) located in the genes for interleukin-1beta (SNP: IL1B-511, +3962), tumour necrosis factor alpha (TNF-308, -238) and interleukin-6 (IL6-174, nt565) were genotyped in 303 Caucasian (Czech) patients with TJA (89 with PJI / 214 without PJI), and 168 unrelated healthy Czech individuals without TJA. The results showed that carriers of the less common IL1B511*T allele were overrepresented in the group of TJA patients with PJI (69%) in comparison with those that did not develop PJI (51%, p=0.006, pcorr=0.037) and with healthy controls (55%, p=0.04, pcorr=N.S.). There was no significant difference in the distribution of the remaining five investigated CGPs and their haplotypes between groups. CONCLUSION: A functional variant of the gene encoding for IL-1beta was preliminarily nominated as a genetic factor contributing to the susceptibility to PJI. Our results should be independently replicated; studies on the functional relevance of IL1B gene variants in PJI are also needed.