TLR4 and TLR9 polymorphism: Probable role in susceptibility among the population of Bihar for Indian visceral leishmaniasis

Genetic variations in the host TLRs genes play an important role in susceptibility and/or resistance to visceral leishmaniasis by altering the host-pathogen interaction. In this study, we investigated the association between polymorphisms of TLR4 (Asp299Gly, Thr399Ile) and TLR-9 (T-1237C), with susceptibility to visceral leishmaniasis. A bi-directional PCR amplification of specific alleles technique was used to characterize the distribution of TLR4 (Asp299Gly and Thr399Ile) and TLR9 (T-1237C) polymorphisms. A total of 60 samples were randomly selected from confirmed visceral leishmaniasis patients and 24 endemic healthy volunteers. The samples were genotyped and allele frequencies were determined. We observed that TLR4 Asp299Gly and Thr399Ile genotypes were more frequent in visceral leishmaniasis patients (10% and 15% respectively) compared to controls (4.2% and 8.3% respectively). However, the differences were not significant in TLR4 Asp299Gly and Thr399Ile alleles and genotypes. In the case of TLR9, we observed the frequency of T1237C genotype was higher in visceral leishmaniasis patients (43.3%) than in healthy controls (33.3%). Statistically significant differences were observed in TLR9 T1237C alleles and genotypes. We concluded that TLR9 T1237C, but not TLR4, gene polymorphisms can be regarded as contributors to visceral leishmaniasis susceptibility among the Indian population of Bihar state.     

Interleukin-1 receptor antagonist gene polymorphism affects the progression of chronic renal failure

End-stage renal disease (ESRD) involves an inflammatory process. Interleukin-1 receptor antagonist (IL-1Ra) and interleukin-1beta gene polymorphisms affect susceptibility to the disease in several inflammatory diseases. We investigated whether these polymorphisms are involved in ESRD by genotyping DNA from 602 dialyzed patients and 433 controls with polymerase chain reaction and digestion with restriction endonuclease. Allele 2 of the IL-1Ra VNTR polymorphism was associated with ESRD (OR=1.46, 95% CI 1.19-1.78). We also found a strong association between this allele and recurrent peritonitis in peritoneal dialysis patients. Odds ratio for the risk allele was higher compared to entire ESRD group (OR=3.6, 95% CI 1.70-7.44). The homozygosity for the allele 2 was associated with disease progression, especially in patients with diabetic nephropathy and glomerulonephritis. For the patients from these two subgroups having 2.2 genotype, the mean time from disease onset to ESRD was 1.5 and 2.2 years, respectively, compared to 6.4 and 9.8 years for those with 1.1 genotype. The IL-1Ra allele 2 is associated with ESRD in our dialyzed patients. Our results demonstrate for the first time the association of the IL-1Ra allele 2 with faster progression to ESRD. If confirmed in other populations, it might be a predictor of faster disease progression.     

Association of angiotensinogen M235T gene polymorphism with end-stage renal disease risk: a meta-analysis

Association between angiotensinogen (AGT) M235T gene polymorphism and end-stage renal disease (ESRD) risk is still controversial. This meta-analysis was performed to evaluate the association of AGT M235T gene polymorphism with ESRD susceptibility. A predefined literature search and selection of eligible relevant studies were performed to collect data from electronic databases of PubMed, Embase and Cochrane Library. Sixteen literatures were identified for the analysis of association of AGT M235T gene polymorphism with ESRD risk. T allele and TT genotype were associated with ESRD susceptibility in Caucasians (T: OR = 1.13, 95 % CI: 1.02–1.25, P = 0.02; TT: OR = 1.22, 95 % CI: 1.03–1.45, P = 0.02). However, MM genotype might not play a protective role against ESRD risk in Caucasians. Furthermore, there was no a markedly positive association between AGT M235T gene polymorphism and ESRD susceptibility in overall populations, Asians and Africans. In conclusion, T allele or TT homozygote is associated with the onset of ESRD in Caucasians. However, more studies should be performed in the future.     

TLR9 -1486T/C and 2848C/T SNPs Are Associated with Human Cytomegalovirus Infection in Infants

Toll-like receptor 9 (TLR9) recognizes non-methylated viral CpG-containing DNA and serves as a pattern recognition receptor that signals the presence of human cytomegalovirus (HCMV). Here, we present the genotype distribution of single-nucleotide polymorphisms (SNPs) of the TLR9 gene in infants and the relationship between TLR9 polymorphisms and HCMV infection. Four polymorphisms (-1237T/C, rs5743836; -1486T/C, rs187084; 1174G/A, rs352139; and 2848C/T, rs352140) in the TLR9 gene were genotyped in 72 infants with symptomatic HCMV infection and 70 healthy individuals. SNP genotyping was performed by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Digested fragments were separated and identified by capillary electrophoresis. The HCMV DNA copy number was measured by a quantitative real-time PCR assay. We found an increased frequency of heterozygous genotypes TLR9 -1486T/C and 2848C/T in infants with HCMV infection compared with uninfected cases. Heterozygous variants of these two SNPs increased the risk of HCMV disease in children (P = 0.044 and P = 0.029, respectively). In infants with a mutation present in at least one allele of -1486T/C and 2848C/T SNPs, a trend towards increased risk of cytomegaly was confirmed after Bonferroni’s correction for multiple testing (Pc = 0.063). The rs352139 GG genotype showed a significantly reduced relative risk for HCMV infection (Pc = 0.006). In contrast, the -1237T/C SNP was not related to viral infection. We found no evidence for linkage disequilibrium with the four examined TLR9 SNPs. The findings suggest that the TLR9 -1486T/C and 2848C/T polymorphisms could be a genetic risk factor for the development of HCMV disease.     

Association of interleukin (IL)-4 intron-3 and IL-6 −174 G/C gene polymorphism with susceptibility to end-stage renal disease

Earlier studies suggest that end-stage renal disease (ESRD) is associated with inflammatory state and have become a major cause of morbidity and mortality worldwide. This study speculated the role of interleukins (IL)-2, -4, and -6 cytokines gene polymorphism with risk of susceptibility to ESRD. Polymorphism in IL-2 (−330 T/G, polymerase chain reaction [PCR]-restriction fragment length polymorphism), IL-4 (intron-3, variable number of tandem repeat, variable number tandem repeats analysis), and IL-6 (-174 G/C, amplification refractory mutation system, i.e. ARMS-PCR) were genotyped in 193 ESRD patients and 180 controls. Significant difference was observed in genotype frequencies of IL-4 and IL-6 between ESRD patients and control group (p < 0.001 and p = 0.032, respectively). Patients had higher frequency of homozygous B2B2 genotype (IL-4) than controls (62.7% vs 46.7) and GG genotype of IL-6 (73.1% vs 60.6%). The genotypic frequencies of IL-2 were comparable in patients and controls (p = 0.102). Significant association of IL-4 was also observed in patients with glomerulonephritis (p = 0.001). Combination of low IL-4 and high IL-6 genotypes were significantly associated with ESRD showing the highest risk, i.e. >threefolds risk (odds ratio=3.48, 95%CI=1.88–6.42; p < 0.001) among the four possible combinations taking high IL-4 and low IL-6 as reference. Our study suggests that polymorphism in IL-4 and IL-6 may be associated with susceptibility to ESRD. Further, combined analysis implicated a higher risk in ESRD patients with low IL-4 and high IL-6 producing genotypes. This study provided the basis for defined anti-inflammatory approaches to limit renal disease progression.     

Interleukin-1beta and receptor antagonist (IL-1Ra) gene polymorphisms and the prediction of the risk of end-stage renal disease.

Cytokines play an important role in the pathogenesis of kidney disease and its progression to end-stage renal disease (ESRD). Inflammation is regulated by the genes of the interleukin 1 (IL-1) gene cluster. Therefore, it was hypothesized that a polymorphism in this gene cluster may be associated with the risk of ESRD. Polymorphisms in the IL-1 gene cluster were examined in a cohort of 222 ESRD patients and 206 controls of similar ethnicity. These individuals were genotyped for IL-1 beta (promoter -511 and exon-5 +3953) genes and a variable number of tandem repeats (VNTR) in the IL-1 receptor antagonist gene (IL-1Ra). There was significant difference in genotype frequencies between ESRD patients and control group for IL-1beta (promoter region and exon-5) and IL-1Ra gene polymorphism (p < 0.001, 0.006 and < 0.001, respectively). A significant difference was observed in IL-1Ra for 1/1 (410/410) and 1/2 (410/240) genotypes, and the risk for ESRD was higher in those carrying the 1/1 genotype (p = 0.014, OR = 1.692, and p < 0.001, OR = 0.163). Also identified was a novel, rare allele of a single copy of 86 bp in ESRD patients as compared with the controls. The haplotype 'T-E2-1' frequency distribution between patients and controls revealed greater than threefold risk (p = 0.001, OR = 3.572, 95% CI = 1.589-8.032). Genetic linkage between the IL-1beta promoter region and exon-5 and between the IL-1beta promoter and IL-1Ra of IL-1 gene demonstrated a strong association among the variants in controls (D' = 0.42, p < 0.001, and D' = 0.39, p=0.001). Thus, the three polymorphisms within the IL-1 cluster are associated with ESRD. This finding is perhaps one of the strongest associations between genotype and ESRD reported, and it suggests that the IL-1 gene cluster affects the risk of development of ESRD.     

Pro- and anti-inflammatory cytokines gene polymorphisms and Helicobacter pylori infection: interactions influence outcome

The aim of this study was to evaluate whether there was any correlation between Helicobacter pylori-associated diseases and (1) H. pylori virulence genes or (2) IL-1B, IL-1RN, IFN-G, TNF-A, IL-10 genetic polymorphisms. Patients with non-cardia gastric cancer (NCGC, n=129) or benign gastroduodenal diseases (n=792) were studied. IL-1RN intron 2 VNTR polymorphism (PCR), IL-1B -31 C/T (RFLP), the SNPs of IFN-G (+874 A/T), TNF-A (-1031 C/T, -857 C/T, -376 A/G, -308 A/G, -238 A/G), IL-10 (-1082 A/G, -819 C/T, -592 A/C) (Taqman chemistry) were studied. cagA, s1 and m1 vacA, were PCR amplified. Duodenal ulcer was more frequent in TNF-A -857 TT and in IL-1RN 1,2 subjects. TNF-A -857 TT genotype was also correlated with gastric ulcer. IL-10 -819 TT genotype was associated with intestinal metaplasia and NCGC. Antral inflammation was associated with TNF-A -1031 TT, while corpus activity with IL-10 -819 CC. H. pylori infection was associated with TNF-A -308 AG genotype, while IFN-G +874 AA genotype was associated with cagA. In conclusion, among host genetic factors contributing to H. pylori disease outcome, IFN-G +874 AA genotype favors cagA positive infections, TNF-A -857 TT duodenal ulcer while IL-10 -819 TT intestinal metaplasia and NCGC.     

Associations between the IL-4 -590 T allele and Plasmodium falciparum infection prevalence in asymptomatic Fulani of Mali

In this study, we compared the genotype and allele frequencies of the IL-10 -1087 A/G and IL-4 -590 C/T single nucleotide polymorphisms in asymptomatic subjects of two sympatric ethnic tribes differing in susceptibility to malaria, the Fulani and the Dogon in Mali. The genotype data was correlated with ethnicity and malariometric indexes. A statistically significant inter-ethnic difference in allele and genotype frequency for both loci was noted (P<0.0001). Within the Fulani, the prevalence of Plasmodium falciparum infection, as detected by both microscopy and PCR, was associated with the IL-4 -590 T allele (P=0.005 and P=0.0005, respectively), whereas, no such associations were seen in the Dogon. Inter-ethnic differences in spleen rates, higher in the Fulani than the Dogon, were seen between T carriers (TT and CT) of both groups (P<0.0001). Parasite densities and number of concurrent clones did not vary between IL-4 genotypes within any of the studied groups. These results suggest an association between the IL-4 -590 T allele and P. falciparum prevalence within the Fulani but not the Dogon. No associations between IL-10 genotypes and studied malariometric indexes were observed in any of the two communities.     

The lL-8 and IL-13 gene polymorphisms in inflammatory bowel disease and colorectal cancer

Inflammatory bowel diseases (IBD) and colorectal cancer (CRC) are disorders that originate from immune disturbances. In our study, we evaluated the association between the -251 T/A interleukin (IL)-8 and the -1112 C/T IL-13 polymorphisms, the risk of IBD, and CRC development. Genotypes were determined by PCR-restriction fragment length polymorphism in 191 patients with CRC, 150 subjects with IBD, and 205 healthy controls. We found an association between CRC and the presence of the -251 TA genotype and A allele of the IL-8 gene (odds ratios [ORs] 2.28 and 1.65). A similar relationship was observed between these polymorphic variants and ulcerative colitis (OR 2.05 for the -251 TA genotype and OR 1.47 for the -251 A allele) as well as Crohn's disease (ORs 3.11 and 1.56, respectively). Our research also revealed that the CT and TT genotypes of the IL-13 -1112 C/T polymorphism may be connected with a higher risk of CRC (ORs 2.28 and 1.65). The same genotypes affected the susceptibility of IBD (ORs 2.26 and 3.72). Our data showed that the IL-8 -251 T/A and IL-13 -1112 C/T polymorphisms might be associated with the IBD and CRC occurrence and might be used as predictive factors of these diseases in a Polish population.     

Cytokine single nucleotide polymorphisms in Iranian patients with pulmonary tuberculosis

BACKGROUND: Several genes coding for different cytokines may affect host susceptibility to tuberculosis. METHODS: In the present study, the allele and genotype frequencies of a number polymorphic genes coding for cytokines or cytokine receptors were investigated in Iranian patients with pulmonary tuberculosis (PTB). RESULTS: From the IL-1 cluster, a positive, significant difference was found at position -889, where the T/T genotype was over represented in PTB patients (p = 0.01); a positive, significant increase was found in the IL1R PstI 1970 C/C genotype, where the C allele was over represented in the PTB patients (p = 0.01). A significant negative association at codon 10 TGF-beta, T allele, was shown in our patients and the C allele and C/C genotype were over represented in the PTB patients (P<0.005). For TNF-alpha at position -238, we found a negative association for the G/A genotype and a positive association for the G/G genotype (p = 0.0009). Significant negative associations at position -590 IL-4, T allele and the T/T genotype were shown in our patients (p = 0.0007); also, the C allele and T/C genotype were significantly increased in our patients (P<0.05). With IL-6 at -174, G/G increased and G/C decreased significantly in the patients (P<0.005). CONCLUSION: Pro-inflammatory cytokines such as TNF-alpha and TGF-beta seem to be decreased, and IL-6 increased in PTB patients.     

Cytokine gene polymorphisms are associated with risk of urinary bladder cancer and recurrence after BCG immunotherapy

The association of interleukin-1β (IL-1B) -511C?>?T and IL-1 receptor antagonist (IL-1RN) VNTR, transforming growth factor-β (TGF-B1) +28C?>?T and interferon-γ (IFN-G)?+?874T>A polymorphisms with bladder cancer (CaB) susceptibility and risk of recurrence in Bacillus Calmette–Guérin (BCG)-treated patients was analyzed in 287 controls and 213 CaB patients (73 BCG treated). Increased risk was observed with the IL-1RN*2 allele (odds ratio (OR) 5.01) and the IFN-G +874 A allele (OR 1.78). TGF-B TT and IFN-G +874 A carriers were associated with reduced (hazard ratio (HR) 0.37) and enhanced (HR 2.24) risk of recurrence after BCG immunotherapy, respectively. The study suggests that cytokine gene variants may modulate CaB susceptibility and risk of recurrence after BCG immunotherapy.     

Association between polymorphisms in the promoter region of interleukin-10 and susceptibility to inflammatory bowel disease

The aim of this study was to assess the association of polymorphisms in the promoter region of the IL-10 gene with the risk of inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC). Fifteen studies (3,693 cases and 4,574 controls) were included in a meta-analysis of association between IL-10 ?1082G/A, ?819C/T and ?592C/A polymorphisms, and IBD, CD and UC using allele contrast and the recessive, dominant, and additive models. Hardy–Weinberg equilibrium was confirmed for each study. Heterogeneity and study quality were investigated using stratification analyses and sensitivity analyses. Polymorphism ?1082G/A showed significant association with CD, with odds ratios (ORs) for the GG + GA genotype and GG versus AA genotype of 1.278 (1.004–1.627) and 1.238 (1.027–1.492) in all subjects. Significant associations were found in the Caucasian subgroup using the allele contrast, dominant, and additive models. C-allele carriers of the ?819C/T polymorphism were at increased risk of IBD (OR 1.093, 95 % CI 1.004–1.190). Association with the ?819C/T polymorphism was also found in Caucasians with CD (C vs. T: OR 1.104, 95 % CI 1.010–1.206; CC + CT vs. TT: OR 1.328, 95 % CI 1.006–1.754; CC vs. TT: OR 1.339, 95 % CI 1.008–1.778), and with UC (CC vs. CT + TT: OR 1.188, 95 % CI 1.019–1.385). No significant association was found between the ?592C/A polymorphism and IBD, CD or UC. In conclusion, the meta-analysis demonstrated clear association between the IL-10 polymorphisms ?1082G/A and ?819C/T and the risk of IBD.     

Interleukin-1β and receptor antagonist (IL-1Ra) gene polymorphisms and the prediction of the risk of end-stage renal disease

Abstract

Cytokines play an important role in the pathogenesis of kidney disease and its progression to end-stage renal disease (ESRD). Inflammation is regulated by the genes of the interleukin 1 (IL-1) gene cluster. Therefore, it was hypothesized that a polymorphism in this gene cluster may be associated with the risk of ESRD. Polymorphisms in the IL-1 gene cluster were examined in a cohort of 222 ESRD patients and 206 controls of similar ethnicity. These individuals were genotyped for IL-1 β (promoter –511 and exon-5 +3953) genes and a variable number of tandem repeats (VNTR) in the IL-1 receptor antagonist gene (IL-1Ra). There was significant difference in genotype frequencies between ESRD patients and control group for IL-1β (promoter region and exon-5) and IL-1Ra gene polymorphism (p<0.001, 0.006 and?<?0.001, respectively). A significant difference was observed in IL-1Ra for 1/1 (410/410) and 1/2 (410/240) genotypes, and the risk for ESRD was higher in those carrying the 1/1 genotype (p=0.014, OR?=?1.692, and p<0.001, OR?=?0.163). Also identified was a novel, rare allele of a single copy of 86 bp in ESRD patients as compared with the controls. The haplotype ‘T-E2-1’ frequency distribution between patients and controls revealed greater than threefold risk (p=0.001, OR?=?3.572, 95% CI?=?1.589–8.032). Genetic linkage between the IL-1β promoter region and exon-5 and between the IL-1β promoter and IL-1Ra of IL-1 gene demonstrated a strong association among the variants in controls (D′?=?0.42, p<0.001, and D′?=?0.39, p=0.001). Thus, the three polymorphisms within the IL-1 cluster are associated with ESRD. This finding is perhaps one of the strongest associations between genotype and ESRD reported, and it suggests that the IL-1 gene cluster affects the risk of development of ESRD.     

Genetic variants of the receptors for thromboxane A2 and IL-4 in atopic dermatitis

Thromboxane A2 (TXA2) is an arachidonate metabolite which is considered to relate to chronic inflammation in atopic diseases characterized by elevated immunoglobulin E productivity. The elevation of immunoglobulin E levels involves many molecules including interleukin-4 (IL-4) and interleukin-4 receptor alpha chain (IL-4R alpha). To assess whether genetic variants of TXA2 receptor, IL-4 and IL-4R alpha genes relate to the elevation of serum immunoglobulin E levels in patients with atopic dermatitis (AD), we conducted an association study of genetic polymorphisms of TXA2 receptor (795C/T), IL-4 (-589C/T), and IL-4R alpha (Ile50Val) in a Japanese population (n = 789). The TXA2 receptor 795TT genotype strongly related to AD with high serum immunoglobulin E concentrations. AD patients with both TXA2 receptor 795TT genotype and the IL-4R alpha Ile50/Ile50 genotype showed the greatest immunoglobulin E concentrations. These results suggest TXA2 receptor polymorphism strongly interacts with IL-4R alpha polymorphism as a major determinant of high serum immunoglobulin E levels in AD.     

Genetic variation in pro-inflammatory cytokines (interleukin-1beta, interleukin-1alpha and interleukin-6) associated with the aggressive forms, survival, and relapse prediction of breast carcinoma

OBJECTIVES: Interleukin-1 (IL-1) and interleukin-6 (IL-6) are determining factors in the immune and inflammatory responses to tumors cells. Experimental data suggest that interleukin-1 and interleukin-6 play important roles in the development and progression of breast cancer. We designed a broad study to investigate the susceptibility and prognostic implications of the genetic variation in IL-1alpha, IL-1beta and IL-6 in breast carcinoma. EXPERIMENTAL DESIGN: We used the polymerase chain reaction and restriction enzyme digestion to characterize the genetic variation of IL-1alpha, IL-1beta and IL-6 in 305, unrelated Tunisian patients with breast carcinoma and 200 healthy control subjects. Associations between the genetic markers and the clinicopathological parameters, the specific overall survival rate (OVS) of breast carcinoma and the disease free-survival rate (DFS) were assessed using univariate and multivariate analyses. RESULTS: Both IL-6 (-597) GA and IL-6 (-174) GC heterozygous genotypes were found to be significantly associated with breast carcinoma (OR = 1.59, p = 0.024 and OR = 1.61, p = 0.022 respectively). A highly significant association was found between the (+3954) T allele of IL1-B gene and the aggressive phenotype of breast carcinoma as defined by the high histological grade, axillary lymph node metastasis and large tumor size. The IL-1alpha (-889) TT homozygous genotype showed a significant association with reduced disease-free survival and/or overall survival rate. The IL-1beta (+3954) TT, IL-6 (-597) GG and IL-6 (-174) GG homozygous genotypes were found to be associated with reduced DFS but not with overall survival. CONCLUSIONS: The polymorphisms in the promoter region of the IL-6 gene may represent a marker for the increased risk of breast carcinoma. Genetic variations in IL-1alpha, IL-1beta and IL-6 may predict the clinical outcome of breast carcinoma.     

Association between the −159C/T CD14 gene polymorphism and tuberculosis in a Korean population

The aim of the present study was to confirm the association between the CD14 −159C/T polymorphism and tuberculosis in the Korean population and to elucidate the functional basis for this putative association. CD14 −159C/T genotypes were determined by PCR – restriction fragment length polymorphism analysis in 274 tuberculosis patients and 422 healthy controls. Recombinant CD14 promoter–luciferase reporter constructs, including the −159T or −159C allele, were transfected into K562 and BEAS-2B cells, and luciferase activities were measured and compared. Levels of serum sCD14 and interferon-γ secreted by peripheral blood mononuclear cells (PBMCs) were measured using enzyme-linked immunosorbent assay.The frequency of −159TT genotypes was higher in tuberculosis patients than in healthy controls. The promoter activity of the −159T allele was higher than that of the −159C allele. Serum sCD14 levels were higher among tuberculosis patients with −159TT genotypes than among those with −159CC genotypes and interferon-γ release by PBMCs was decreased in subjects with −159TT genotypes. In conclusion, the −159TT CD14 genotypes were associated with tuberculosis development in Koreans. This association might be a result of the higher promoter activity of the −159T allele, the higher level of sCD14, and the decreased interferon-γ secretion in subjects with −159TT genotypes.     

RSV毛细支气管炎的肺表面活性蛋白D多态性与TaqMan MGB探针

目的探讨TaqMan MGB探针实时PCR技术检测肺表面活性蛋白D（surfactant protein,SP）-D基冈变异是否与呼吸道合胞病毒（respiratol Tsyneytial virus,RSV）毛细支气管炎易感性有关。方法运用Taq—ManMGB探针检测150例RSV毛细支气管炎和150例健康对照组SP—D基因多态性,并进行基因型、等位基因频率分析。各组的基因型、等位基因频率比较采用χ2检验。结果病例组SP—D Met11 Thr位点TT、CT、CC三种基因型频率分别为7．3％、44．0％、48．7％,T、C等位基因频率分别为29．3％、70．7％。三种基因型及等位基因频率与对照组比较差异有统计学意义（χ2=6．751、5．823,P〈0．05）。结论杭州地区汉族儿童存在SP—D基因多态性,SP—DMet11 Thr位点与RSV毛细支气管炎疾病易感性存在关联,C等位基因可能是RSV毛细支气管炎的易感基因。TaqMan MGB探针实时PCR技术是基因诊断良好技术平台。