Toll-like Receptor 4 Polymorphisms Research Articles

Breed-specific variations in the coding region of toll-like receptor 4 in the domestic cat

Specific point mutations in the human toll-like receptor 4 (TLR4) confer altered risk for diverse diseases including sepsis, aspergillosis and inflammatory bowel disease. Some of these TLR4 polymorphisms are racially specific. We hypothesised that feline TLR4 polymorphisms might underlie an observed increased risk to infectious and inflammatory diseases in some cat breeds. The aim of this study was to identify breed-specific variations in the coding region of feline TLR4 and to model the effect of mutations on protein structure and function in silico. The entire coding region of TLR4 was sequenced in 8 groups (7 pure-bred, 1 crossbred) of domestic cats (Felis catus) comprising 158 individuals. Twenty-two single nucleotide polymorphisms (SNPs) were identified in TLR4, with 16 located in the coding region (11 non-synonymous) and four in the 3′UTR. Comparison of breed specific allelic frequencies indicated that Burmese and British shorthairs most commonly differed from other breeds. In silico analyses to predict the impact of the 11 non-synonymous variants indicated a deleterious effect on protein structure for one SNP (c.869 G > A), which was not associated with a specific breed. Overall, findings from this study do not support a role of TLR4 dysfunction in breed-predispositions to infectious diseases in domestic cats in Australia.

The associations between Toll-like receptor 4 gene polymorphisms and hepatitis C virus infection: a systematic review and meta-analysis.

Background and objective: The hepatitis C virus (HCV) is able to cause a life-threatening disease relating to lethal hepatocellular carcinoma. Previous, Toll-like receptor polymorphisms were proposed as promising biomarker for HCV-related hepatocellular carcinoma and disease progression. This study aimed to summarize the association of TLR4 polymorphisms and HCV infection through meta-analysis.Methods: We applied a systematic review and meta-analysis performed by using PubMed, EMBASE and Web of Science searches. The Modified Newcastle-Ottawa scale was used for quality assessment. The odd-ratio (OR) and 95% confidence interval (CI) were calculated to assess the association. In silico analysis was applied for proposing the function as microRNA (miRNA) of non-coding polymorphism. Finally, the miRNA target was predicted and annotated to suggest the possible relationship between polymorphism and HCV infection.Results: Our meta-analysis incorporated seven studies involving rs4986791, rs4986790 and rs2149356. No association exists between rs4986791 and HCV infection. However, the heterozygous model (AG vs GG) of rs4986790 significantly associates with HCV infection (OR = 0.33, 95% CI = 0.21–0.49, P<0.0001). Moreover, the rs2149356 TG genotype also associates with HCV infection in the over-dominant model (TG vs TT+TG: OR = 0.54, 95% CI = 0.40–0.75). In silico analysis of rs2149356G allele showed that this mutation is siRNA, which targets the set of genes, especially in the autophagy pathway.Conclusion: We demonstrated that rs4986790 and rs2149356 are associated with HCV infection.

A single-nucleotide polymorphism in TLR4 is linked with the risk of HIV-1 infection

ABSTRACTIntroduction: Toll-like receptors (TLRs) are pattern recognition receptors that play a role in innate immunity. Mounting evidence shows that single-nucleotide polymorphisms (SNPs) in TLRs link to various infectious diseases, including human immunodeficiency virus (HIV). We hypothesized links between two TLR4 SNPs (rs4986790 leading to Asp299Gly and rs4986791 leading to Thr399Ile) and HIV, to investigate the frequency of TLR4 polymorphism and its role in patients infected with HIV.Materials and methods: We recruited 160 HIV-1 seropositive patients, who were further divided on disease severity based on CD4 count (stages I, II and III), and 270 age- and sex matched healthy HIV-1 seronegative individuals. Subjects were genotyped for TLR4 gene polymorphism by polymerase chain reaction restriction fragment length polymorphism.Results: The TLR4 Asp299Gly heterozygous genotype (OR=2.160; p=0.004) and the mutant allele G (OR=2.051; p=0.002) was higher in HIV-1 infection than healthy controls and also in stage I (OR=2.559; p=0.034) compared to different clinical stages of infection. There was no link between the Thr399Ile polymorphism and HIV infection.Conclusion: The TLR4 (Asp299Gly) SNP is a risk factor in HIV-1 disease susceptibility.

TLR9 polymorphism correlates with immune activation, CD4 decline and plasma IP10 levels in HIV patients

BackgroundThe mechanism behind HIV mediated immune activation remains debated, although the role of virus replication in this process is increasingly evident. Toll like Receptor 9 (TLR9) has been implicated in HIV mediated immune activation via sensing of viral CpG DNA. Polymorphisms in the TLR9 gene and promoter region including TLR9 1635A/G and 1486C/T have been found to be associated with multiple infectious diseases and cancers.MethodsIn the current study, we looked at the correlation of TLR9 polymorphisms 1635A/G and 1486C/T with key hallmarks of HIV disease in a cohort of 50 HIV infected patients. We analyzed CD4 counts, T cell immune activation characterized by upregulation of CD38 and HLA-DR and upregulation of plasma biomarkers of inflammation like LPS, sCD14, IL-6 and IP10 in the HIV patient cohort and compared it to healthy controls.ResultsWe found that TLR9 1635AA genotype was associated with lower CD4 counts and significantly higher immune activation in both CD4+ and CD8+ T cells. Analysis of HIV associated plasma biomarkers including LPS, sCD14, IL-6 and IP10 revealed a strong correlation between IP10 and immune activation. Interestingly, IP10 levels were also found to be higher in HIV patients with the 1635AA genotype. Furthermore, the TLR9 1486C/T polymorphism that is in linkage disequilibrium with 1635A/G was weakly associated with lower CD4 counts, higher CD8 immune activation and higher IP10 levels.ConclusionsAs TLR9 stimulation is known to induce IP10 production by dendritic cells, our findings provide new insights into HIV mediated immune activation and CD4 loss. TLR9 stimulation by viral CpG DNA may be important to HIV immunopathogenesis and the TLR9 polymorphisms 1635A/G and 1486C/T may be associated with disease progression.

Correlations between TLR polymorphisms and inflammatory bowel disease: a meta-analysis of 49 case-control studies.

Recently, the roles of toll-like receptor (TLR) polymorphisms in inflammatory bowel disease (IBD) were intensively explored, with conflicting results. Therefore, we performed this study to better assess the relationship between TLR polymorphisms and the risk of IBD. Eligible studies were searched in PubMed, Medline, Embase, and Web of Science. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate associations between TLR polymorphisms and IBD. Significant associations with the risk of IBD were detected for the TLR1 rs5743611, TLR4 rs4986790, TLR4 rs4986791, and TLR6 rs5743810 polymorphisms in overall analyses. Further subgroup analyses according to ethnicity of participants revealed that the TLR1 rs5743611, TLR4 rs4986790, TLR4 rs4986791, TLR6 rs5743810, and TLR9 rs352140 polymorphisms were significantly associated with the risk of IBD in Caucasians. Moreover, the TLR4 rs4986790 polymorphism was significantly correlated with the risk of IBD in West Asians, while the TLR9 rs352140 polymorphism was significantly associated with the risk of IBD in Africans. When we stratified available data according to type of disease, we found similar positive results for TLR1 rs5743611, TLR4 rs4986790, TLR4 rs4986791, and TLR6 rs5743810 polymorphisms. Our findings indicate that TLR1 rs5743611, TLR4 rs4986790, TLR4 rs4986791, TLR6 rs5743810, and TLR9 rs352140 polymorphisms may serve as genetic biomarkers of IBD in certain ethnicities. However, further well-designed studies are still warranted to confirm our findings.

TLR4 and MMP2 polymorphisms and their associations with cardiovascular risk factors in susceptibility to aortic aneurysmal diseases.

Background: Toll-like receptor 4 (TLR4) and matrix metalloproteinase 2 (MMP2) play important roles in aortic pathophysiology. We aimed to evaluate the contribution of TLR4 and MMP2 polymorphisms individually and complex interactions between gene and risk factors in susceptibility to aortic aneurysm (AA) and its subtypes. Methods: KASP method was adopted to detect TLR4rs11536889, rs1927914 and MMP2rs2285053 polymorphisms in 498 controls and 472 AA patients, including 212 abdominal AA (AAA) and 216 thoracic AA (TAA). Results: In the overall analysis, MMP2rs2285053 TC genotype was correlated with TAA risk (P = 0.047, OR = 1.487). Stratified analysis revealed an increased AA risk in males with TLR4rs1927914 TC genotype, while MMP2rs2285053 TC conferred an elevated AA risk in the subjects ≤60 years, and its TC genotype and dominant model were associated with TAA in the subjects ≤60 year. The interaction between TLR4rs1927914 and MMP2rs2285053 was associated with AAA risk (Pinteraction = 0.028, OR = 2.913). Furthermore, significant interaction between TLR4rs11536889 and dyslipidemia was observed for TAA risk, while TLR4rs1927914 could interact with hypertension and diabetes to increase the risk of AA or its subtypes. Two-way interaction effect of TLR4rs1927914 and MMP2rs2285053 was enhanced by diabetes or dyslipidemia. Conclusion: TLR4 and MMP2 polymorphisms and their complex interactions with cardiovascular risk factors contributed to aortic aneurysmal diseases.

TLR9 rs352139 Genetic Variant Promotes Tacrolimus Elimination in Chinese Liver Transplant Patients During the Early Posttransplantation Period.

There are limited markers that could facilitate individualized tacrolimus treatment in the early posttransplantation period. Genetic factors have been found to play critical roles in determining tacrolimus pharmacokinetics. We aimed to examine the association of donor and recipient Toll-like receptor (TLR) polymorphisms with tacrolimus elimination and the potential mechanism for TLR gene polymorphism-mediated tacrolimus metabolism. Two independent cohorts including 297 patients receiving liver transplantation (LT) were enrolled in this study (cohort A was composed of 200 patients; cohort B included 97 patients and served as a validation set). Toll-like receptors polymorphisms were genotyped using TaqMan single nucleotide polymorphisms (SNPs) assays. The protein expressions were detected by Western blotting. The metabolism assay was used to quantify tacrolimus elimination. The activity of nuclear factor-kB (NF-kB) was evaluated by luciferase reporter assay. Tacrolimus dose-adjusted trough blood concentrations (C/D) ratios were significantly lower for donor TLR9 rs352139 AG/GG carriers than AA carriers at weeks 1, 2, and 3 after LT. In multivariate analysis, donor and recipient CYP3A5 rs776746 and donor TLR9 rs352139 were independent predictors of tacrolimus C/D ratios in the early period after transplantation in both cohorts. When investigating the combined effects of donor CYP3A5 rs776746 and donor TLR9 rs352139 genotypes, the C/D ratios were remarkably significant at all time points during the first month after LT within the four groups. Furthermore, CYP3A5 mRNA expression in liver tissue was significantly higher for AG/GG patients than AA carriers after LT. In addition, we demonstrated that the TLR9 rs352139 genetic variant promotes tacrolimus metabolism of liver cells via upregulation of CYP3A5, which is dependent on the repression of NF-κB/pregnane X receptor (PXR) signaling. Donor TLR9 rs352139 genetic variant facilitated tacrolimus elimination during the early stage after LT in Chinese patients, which might be related to the upregulation of CYP3A5 enzyme via the NF-kB/PXR signaling pathway.

Increased risks between TLR2 (-196 to -174 ins/del) and TLR3 1377C>T variants and head and neck cancers in Tunisia.

IntroductionPrevious studies have highlighted the importance of polymorphisms of toll-like receptors (TLRs) in the pathogenesis of certain cancers, including head and neck cancers (HNC).Aim of the studyThe aim of this study was to evaluate the association of TLR2 (-196 to -174 ins/del) and TLR3 (1377 C>T) as potential risk factors for HNC in Tunisians.Material and methodsA case-control study including 246 HNC patients (174 nasopharyngeal carcinoma – NPC and 72 laryngeal cancer – LC) and 250 healthy controls. Genotyping was done by using PCR and PCR-RFLP methods.ResultsHigher minor allele frequencies of TLR2 (-196 to -174 ins/del) and TLR3 1377 C>T polymorphisms were seen in HNC, NPC, and LC compared to controls. In addition, higher increased HNC, NPC, and LC risk was associated with TLR2 ins/del and TLR2 del/del genotypes (p < 0.0001). Positive association with HNC, NPC, and LC risk was seen with TLR2 del-containing genotypes (ins/del + del/del) (p < 0.0001). The T/T genotype of TLR3 is associated with HNC, NPC, and LC susceptibility (p < 0.0001). Positive association with HNC and NPC risk was seen with TLR3 T allele carriers (C/T + T/T) (p < 0.0001). Increased frequency of T-ins, C-del, and T-del haplotypes was revealed in HNC and NPC cases than healthy controls; however, T-del was significantly higher in LC cases.ConclusionsOur results demonstrate an increased risk of HNC, NPC, and LC with TLR2 ins/del, TLR2 del/del, and TLR3 T/T genotypes. And positive association with T-ins, C-del, and T-del haplotypes with HNC and NPC and T-del haplotype with LC.

Genetic polymorphisms in TLR1, TLR2, TLR4, and TLR10 of Helicobacter pylori-associated gastritis: a prospective cross-sectional study in Thailand

The toll-like receptors (TLRs) mediate the recognition of Helicobacter pylori and initiate the innate immune response to infection. We hypothesized those genetic polymorphisms in the TLR1, TLR2, TLR4, and TLR10 influence bacterial infection, affecting susceptibility H. pylori to disease outcomes. Genomic DNA was extracted and genotypes of TLR1 (rs4833095), TLR2 (rs3804099 and rs3804100), TLR4 (rs10759932), and TLR10 (rs10004195) polymorphism were detected by the TagMan single-nucleotide epolymorphisms genotyping assay using the real-time PCR hybridization probe method. The TLR1 (rs4833095), C allele and the TLR10 (rs10004195), A allele frequency was significantly increased risk in the H. pylori infection group (odds ratio=1.76, 95% confidence interval=1.84-2.15, P=0.01 and odds ratio=1.81, 95% confidence interval=1.18-3.26, P=0.04, respectively). The TLR1 (rs4833095), C allele and TLR10 (rs10004195), A allele are susceptible TLRs polymorphisms in the Thai population. These findings suggest that TLR1 rs4833095 and TLR10 rs10004195 may play crucial roles in H. pylori susceptibility and gastric pathogenesis.

TLR1 and PRKAA1 Gene Polymorphisms in the Development of Atrophic Gastritis and Gastric Cancer.

Previous genome-wide association studies showed that genetic polymorphisms in toll-like receptor 1 (TLR1) and protein kinase AMP-activated alpha 1 catalytic subunit (PRKAA1) genes were associated with gastric cancer (GC) or increased Helicobacter pylori (H. pylori) infection susceptibility. The aim of this study was to evaluate the association between TLR1 and PRKAA1 genes polymorphisms and H. pylori infection, atrophic gastritis (AG) or GC in the European population. Single-nucleotide polymorphisms (SNPs) were analysed in 511 controls, 340 AG patients and 327 GC patients. TLR1 C>T (rs4833095) and PRKAA1 C>T (rs13361707) were genotyped by the real-time polymerase chain reaction. H. pylori status was determined by testing for anti-H. pylori IgG antibodies in the serum. The study included 697 (59.2%) H. pylori positive and 481 (40.8%) H. pylori negative cases. We observed similar distribution of TLR1 and PRKAA1 alleles and genotypes in H. pylori positive and negative cases. TLR1 and PRKAA1 SNPs were not linked with the risk of AG. TC genotype of TLR1 gene was more prevalent in GC patients compared to the control group (29.7% and 22.3% respectively, p=0.002). Carriers of TC genotype had a higher risk of GC (aOR=1.89, 95% CI: 1.26-2.83, p=0.002). A similar association was observed in a dominant inheritance model for TLR1 gene SNP, where comparison of CC+TC vs. TT genotypes showed an increased risk of GC (aOR=1.86, 95% CI: 1.26-2.75, p=0.002). No association between genetic polymorphism in PRKAA1 gene and GC was observed. TLR1 rs4833095 SNP was associated with an increased risk of GC in a European population, while PRKAA1 rs13361707 genetic variant was not linked with GC. Both genetic polymorphisms were not associated with H. pylori infection susceptibility or the risk of AG.

Pattern recognition receptor polymorphisms in early periodontitis.

Even though bacteria trigger inflammation, most of the tissue destruction in periodontitis is due to the host inflammatory response. In addition to immunological events that drive development of early periodontitis, numerous environmental factors like genetics and smoking play a role. We investigated whether the carriage of selected single nucleotide polymorphisms (SNP) of toll-like receptors (TLR), NOD-like receptors (NLR) and RIG-I-like receptors (RLR) was associated with the diagnosis of early periodontitis in a case-control study. Adolescents with positive (n=87) and negative (n=73) diagnosis for periodontitis had blood samples taken. All participants were genotyped for 42 SNP in the genes encoding TLR1-10, NOD1-2, DDX58, and IFIH1 using multiplex assays. Associations between SNP and periodontitis diagnosis were tested. TLR1-rs5743611 showed protective effect for periodontitis (CC versus GG and GC, P=0.01, odds ratio [OR] 0.10, 95% confidence interval [CI] 0.01-0.78). Carriage of the TLR4-rs7873784 was associated with higher odds for periodontitis (GG versus CC and GC, P=0.05, OR 2.30, 95% CI 1.00-5.63; GG versus GC, P=0.05, OR 2.46, 95% CI 1.01-5.99). In male participants, reduced susceptibility to periodontitis was observed in carriers of TLR7-rs3853839 (CC versus GG and CG, P=0.02, OR 0.30, 95% CI 0.11-0.85) and TLR8-rs3764879 (CC versus GG and CG, P=0.02, OR 0.31, 95% CI 0.12-0.82). Associations were maintained after adjustments for sex, smoking habits, and mother´s education. This study demonstrated an association between TLR1-rs5743611, TLR4-rs7873784, TLR7-rs3853839, and TLR8-rs3764879 and susceptibility to periodontitis in adolescents.

Interaction of H. pylori with toll-like receptor 2-196 to -174 ins/del polymorphism is associated with gastric cancer susceptibility in southern China.

Genetic polymorphisms of Toll-like receptors play important roles in gastric carcinogenesis. The aim of this study was to determine the role of TLR2-196 to -174 ins/del polymorphism in gastric cancer susceptibility and prognosis. This study included 520 people from southern China. Samples were genotyped by the allele-specific polymerase chain reaction, among which 10% were randomly selected for sequencing. The serological method was used to determine Helicobacter pylori. The TLR2 genotype was not associated with the risk of H. pylori infection. The del/del genotype exhibited significantly higher gastric cancer risk (adjusted OR 2.59, 95% CI 1.33‒5.07) than that of the ins/ins genotype. Further stratification analyses demonstrated that the del/del genotype was associated with a risk of intestinal gastric cancer (adjusted OR 2.62, 95% CI 1.34-5.14). In addition, the presence of the del/del genotype and the H. pylori infection conferred a synergistic effect (OR 3.04, 95% CI 1.33‒6.98) for the development of gastric cancer. The del/del genotype was not associated with a poor prognosis in gastric cancer patients. The del/del genotype is associated with an increased gastric cancer risk in the southern Chinese population. However, TLR2 polymorphism is neither associated with H. pylori infection, nor with a poor prognosis.

Polymorphisms of TLR1, TLR4 and SLC11A1 Genes in Some Cattle Breeds Reared in Turkey

The objective of this study was to examine the allelic and genotypic profiles of four SNPs of bovine Toll-Like receptor 1 (TLR1), Toll-Like Receptor 4 (TLR4) and Solute Linkete Carier 11A1 (SLC11A1) genes in Holstein, two Turkish native breeds and their crossbreds in Turkey. For this purpose, a total of 1023 cattle from Holstein (HL, n= 410), Anatolian Black (AB, n= 106), East Anatolian Red (EAR, n= 84), Anatolian Black Crossbreed (ABC, n= 124) and East Anatolian Red crossbreed (EARC, n= 299) breeds were examined for four SNPs. Samples were genotyped using by the PCR-RFLP method. According to the TLR1 (+1380) SNP, EAR was in Hardy-Weinberg equilibrium (HWE) while the AB, HL and native crossbreeds were deviated from HWE. All cattle breeds were in HWE for the TLR1 (+1596) SNP. In terms of TLR4 (+10) SNP, the CC genotype had the highest frequency in HL and native crossbreeds whereas the AB and EAR breeds were monomorphic and only CC genotype was found these breeds. According to the SLC11A1 (+1066) SNP, the CC genotype had the highest while the GG genotype frequency the lowest in all breeds. In addition EAR breed was in HWE while the AB, HL and native crossbreeds deviated from HWE.

Association between polymorphisms in the genes encoding toll-like receptors and dectin-1 and susceptibility to invasive aspergillosis: a systematic review.

Invasive aspergillosis is a common fungal infection in immunocompromised individuals. Some studies have shown that toll-like receptor and dectin-1 genetic polymorphisms may alter signaling pathways, thus increasing an individual's susceptibility to invasive aspergillosis. We investigated the pertinent literature to determine whether polymorphisms in the genes encoding toll-like receptors and dectin-1 increase the susceptibility to invasive aspergillosis. This study systematically reviewed the literature using the databases PubMed/PMC, Scopus, and Web of Science using the keywords invasive aspergillosis, polymorphism, Toll-like, and Dectin-1. From the initial search, 415 studies were found and according to our inclusion and exclusion criteria, eight studies were selected. Several studies described single-nucleotide polymorphisms (SNPs) that are associated with a greater susceptibility to invasive aspergillosis. These SNPs were found in the genes that encode toll-like receptors 1, 3, 4, and 5 and the gene that encodes dectin-1; upon activation, both cellular receptors initiate a signaling cascade that can result in the production of cytokines and chemokines. Thus, our literature review uncovered a significant association between polymorphisms in the genes that encode toll-like receptors and dectin-1 and invasive aspergillosis. More studies should be performed to better understand the relationship between toll-like receptor and dectin-1 genetic polymorphisms and invasive aspergillosis susceptibility.

Invasive fungal disease and cytomegalovirus infection: is there an association?

Invasive fungal disease (IFD) and cytomegalovirus (CMV) infections occur frequently, either concomitantly or sequentially in immune-compromised hosts. Although there is extensive knowledge of the risk factors for these infections as single entities, the inter-relationship between opportunistic fungii and CMV has not been comprehensively explored. Both solid organ and stem cell transplant recipients who develop CMV invasive organ disease are at an increased risk of developing IFD, particularly aspergillosis and Pneumocystis pneumonia (PCP). Moreover, CMV viremia and recipient CMV serostatus also increased the risk of both early and late-onset IFD. Treatment-related factors, such as ganciclovir-induced neutropenia and host genetic Toll-like receptor (TLR) polymorphisms are likely to be contributory. Less is known about the relationship between CMV and IFD outside transplantation, such as in patients with hematological cancers or other chronic immunosuppressive conditions. Finally, few studies report on the relationship between CMV-specific treatments or the viral/antigen kinetics and its influence on IFD management. CMV infection is associated with increased risk of IFD in posttransplant recipients because of a number of overlapping and virus-specific risk factors. Better understanding of how CMV virus, its related treatment, CMV-induced immunosuppression and host genetic factors impact on IFD is warranted.

A Polymorphism in Toll-like Receptor 2 Gene Is Associated with Occurrence of Bacterial Infections in Sickle Cell Disease Patients

Background: Sickle cell disease (SCD) patients (pts) are at increased risk of infection. This susceptibility is partially explained by the loss of spleen function, but other factors such as inflammatory status might also play a role. Despite adequate immunization and antimicrobial prophylaxis, bacterial infection remains a major cause of morbidity and mortality in SCD pts. Toll-like receptors (TLR), transmembrane proteins that recognize a wide range of pathogen molecular patterns, are key receptors in innate immune response. The association among TLR and infections in SCD has scarcely been explored.Objective: To analyze if functional polymorphisms in TLR genes can modulate the susceptibility to bacterial infections in SCD pts.Methods: Case-control retrospective study; 430 SCD pts followed in university hospitals in Brazil (n=196), France (n=180, mainly from Subsaharan Africa and French West Indies) and Senegal (n=54) were included. Sites of bacterial infection were lower respiratory system, abdominal, upper urinary system, bone/joints, central nervous system, blood stream, or any site for tuberculosis. For pts who underwent hematopoietic stem cell transplant (HSCT), only bacterial infections before HSCT were considered. All pts were tested for 7 single nucleotide polymorphisms (SNP) in TLR-1(rs4833095), TLR-2 (rs4696480, rs3804099, rs3804100), TLR-6 (rs5743810) and TLR-10 (rs11466653, rs11096957) using TaqMan 5'-nuclease assay. Univariate analysis was performed with chi-square or Mann-Whitney for categorical and continuous variables respectively. Associations were measured by odds ratio (OR). For SNP associations, significant P-value corrected by Bonferroni (cP) was 0.007; for genetic models, cP was 0.01.Results: Median age of cohort was 30 years (range: 2-70) and 87% were ≥18 years; 57% of pts were female. SCD genotype was SS in 81%, SC in 11%, SB in 7% and other in 1%. Fifty-eight percent received hydroxyurea and 79% received red blood cell transfusions; seven pts underwent HSCT. Eleven pts died during follow-up, mostly from acute chest syndrome and hemorrhagic stroke. All pts had access to immunization against encapsulated bacteria and to penicillin prophylaxis. One hundred ninety-five pts (45%) did not present any bacterial infection, whereas 235 (55%) pts presented at least one episode of bacterial infection, of which 20% had ≥ 3 episodes. Bacterial infections were mainly respiratory (51%), bone/joints (23%) and urinary (20%). In 106 cases, etiological agents were identified; most common agents were Escherichia coli, Streptococcuspneumoniae, Mycobacterium tuberculosis and Salmonella spp. In univariate analysis, there was no association among occurrence of infections and gender, origin and age distribution. Gene analysis: all tested SNPs had a typing rate >90% and minimum allele frequency >1%. The TLR-2 SNP rs4696480 (n=425) showed significant association with infection (p<0.001). Next, we tested genetic models for this association. Distribution of rs4696480 genotypes was: infected - AA=35%, TA=50%, TT=15%; non infected - AA=28%, TA=67%, TT=5%. In the overdominant model, the heterozygous genotype (TA) occurred significantly more in non infected (67%) than in infected pts (50%) compared with TT+AA (OR 0.5, 95%CI 0.34-0.75, P<0.001). Also, in the recessive model, genotype TT occurred significantly more in infected (15%) than in non infected pts (5%) compared with TA+AA (OR 3.18, 95%CI 1.53-6.61, P<0.001). Furthermore, in comparison with an African/African-American population described in the 1000 genomes database (n=661), TA genotype was more frequent in SCD pts, and TT genotype was significantly less frequent. Other TLR SNPs genotype and haplotype analysis did not show any significant association with occurrence of infections.Discussion: In SCD pts, TLR-2 rs4696480 TA genotype might be protective against bacterial infections, whereas TT genotype might increase risk of such infections. Previous reports demonstrated higher secretion of inflammatory factors in cells from AA individuals, lower occurrence and severity of immune diseases in T carriers. TA genotype might stand between deleterious effects of over inflammatory response (AA genotype) and under response (TT genotype) to infectious agents. DisclosuresNo relevant conflicts of interest to declare.

Association between Toll-like receptors (TLR) and NOD-like receptor (NLR) polymorphisms and lipid and glucose metabolism

Recent evidences had shown activation of TLR (toll-like receptors) and NLR (nod-like receptors) in response to imbalance in nutrients intake, such as lipid and glucose. The main aim of this study was to investigate possible associations between 11 SNPs in TLR2, TLR4, NLRC4, CARD8 and NEK7 genes and lipid and glucose metabolism. Sample was composed by healthy children and adolescents (n = 158) and adults (n = 115). DNA extraction was obtained by salting-out and sample genotyping by matrix-assisted laser desorption ionization time-of-flight mass spectrometry based system. LDL-cholesterol, HDL-cholesterol, triglycerides, total cholesterol, glucose and insulin were measured by standard automated methods. Means were compared by t-test or Mann-Whitney test. Univariate and multivariate logistic regression were used to verify association between polymorphisms and lipid and glucose markers. Seven polymorphisms in 5 genes were associated with lipid and glucose parameters. For lipid parameters, the following associations were found: higher LDL-C levels and C allele of rs1554973 (TLR4) and G allele of rs6671879 (NEK7); higher HDL-cholesterol levels and A allele of rs13105517 (TLR2); higher total cholesterol and TT genotype of rs3804099 (TLR2) and G allele of rs6671879 (NEK7); higher triglycerides levels and G allele of rs455060 (NLRC4). For glucose parameters associations were found between C allele of rs7258674 (CARD8) and higher glucose levels, and between C allele of rs212704 (NLRC4) and G allele of rs455060 (NLRC4) and insulin levels. These findings indicate a relationship between polymorphisms of TLRs and NLRs genes and markers of lipid and glucose metabolism.

Polymorphisms in toll-like receptor (TLR) 1, 4, 9 and SLC11A1 genes and their association with paratuberculosis susceptibility in Holstein and indigenous crossbred cattle in Turkey

Mycobacterium avium subsp. paratuberculosis (MAP) causes major problem in a wide range of animal species. In ruminant livestock including cattle, it causes a chronic disease called Johne's disease, or paratuberculosis (pTB) which is currently considered as potential zoonosis, causing Crohn's disease in humans. MAP infection susceptibility is suspected to be controlled by host genetics. Thus, selecting individuals according to their genetic structure could help to obtain bovine populations that are increasingly resistant to MAP infection. The aim of the present work was to investigate the association between toll-like receptor (TLR) 1 (+1380 G/A), TLR1 (+1446 C/A), TLR4 (+10 C/T), TLR9 (+1310 G/A) and solute carrier family 11 member 1 (SLC11A1) (+1066 C/G) mutations and MAP infection status in 813 cattle comprising East Anatolian Red crossbred, Anatolian Black crossbred and Holstein breed. TLR1 (+1380 G/A) mutation showed an association with bovineMAP (P<0.05). For the TLR1 (+1380 G/A) locus, the odds ratio for AG and AA genotypes versus GG genotypes were 2.31 (1.24-4.30; 95% confidence interval (CI)) and 0<0.001 (<0.001 to >999.999; 95% CI) which indicated that a proportion of AG homozygote was significantly higher in pTB-affected animals as compared with the control. General linear model analysis demonstrated higher MAP antibody response in TLR1 (+1380 AG) genotype as compared with TLR1 (+1380 GG) (P<0.0001). Present findings suggest that selection against TLR1 (+1380 G/A) may reduce the risk of pTB in bovine herds.

Toll-like receptor 2 and 4 polymorphisms associated with Helicobacter pylori susceptibility and gastric cancer.

Genetic polymorphisms in Toll-like receptors (TLRs) are important influence on gastric lesion development and Helicobacter pylori susceptibility. TLR2 rs3804099 and rs3804100 and TLR4 rs10759932 were determined in a total of 400 patients. The association among genotypes and the risk of gastric lesion development and H. pylori susceptibility were evaluated by the odds ratios (ORs) and 95% confidence intervals (95% CIs) from logistic regression analyses. TLR4 rs10759932, C/C homozygous genotype was associated with an increased risk of premalignant/malignant (OR=2.48, 95% CI=1.96-4.62, p=0.015). The recessive model of TLR4 rs10759932 showed a decreased risk of H. pylori susceptibility (adjusted OR=0.52, 95% CI=0.38-0.82, p=0.046). Meanwhile, the recessive model was associated with an increased risk of non-malignant (OR=3.46, 95% CI=2.25-5.67, p=0.001). In subjects with H. pylori infection, the recessive model was associated with an increased risk of non-malignant (OR=2.28, 95% CI=1.24-3.57, p=0.001) and premalignant/malignant (OR=1.83, 95% CI=1.16-2.84, p=0.027). TLR4 rs10759932, but not TLR2 rs3804099 and rs3804100, was associated with risk of premalignant and/or malignant and H. pylori susceptibility. H. pylori infection seems to contribute to chronic gastritis, and premalignant/malignant supported the development of the premalignant/malignant lesions involved in H. pylori infection that is critical to gastric cancer in Thai patients.

Polymorphisms in the Toll-like receptor 3 (TLR3) gene are associated with the natural course of hepatitis B virus infection in Caucasian population

Innate immunity can induce spontaneous hepatitis B surface antigen (HBsAg) seroclearance (SC) of hepatitis B virus (HBV) infection or transition towards an inactive carrier state. Toll-like receptor (TLR) 3 signalling has been linked to these processes. Alterations in the TLR3 gene might impair immune responses against HBV. In our study, we analysed the impact of the TLR3 polymorphisms rs3775291 and rs5743305 on the natural course of HBV infection. In this retrospective study, a Caucasian cohort of 621 patients with chronic HBV infection (CHB), 239 individuals with spontaneous HBsAg SC, and 254 healthy controls were enrolled. In the CHB group, 49% of patients were inactive carriers, and 17% were HBeAg-positive. The TLR3 rs3775291 A allele was associated with a reduced likelihood of spontaneous HBsAg SC and HBeAg SC, and an increased risk of developing chronic hepatitis B. In haplotype analysis, the haplotype including both risk variants rs3775291A and rs5743305A had the lowest likelihood of HBsAg SC. Further research in larger cohorts and functional analyses are needed to shed light on the impact of TLR3 signalling.