TLR4 Polymorphisms Research Articles

Single Nucleotide Polymorphisms in TLR4 Affect Susceptibility to Tuberculosis in Mexican Population from the State of Veracruz.

Tuberculosis is still a global public health problem, with an estimated 10 million new cases and 1.6 million deaths in 2017. Of all humans infected with M. tuberculosis, only 10-15% will develop active tuberculosis disease during their lifetime, and data suggest that along with environmental factors, genetic factors influence susceptibility to develop active disease. Toll-like receptors (TLRs) are pattern recognition receptors that play a central role in the initiation and shaping of adaptive immune responses, and several TLRs have been shown to recognize mycobacterial components. In this work, we performed a case-control study to determine if common single nucleotide polymorphisms (SNPs) in genes encoding TLRs 1, 2, 4, 6, and 10 are associated with susceptibility to develop active tuberculosis in population from the state of Veracruz, Mexico. The study included 279 cases and 569 controls. The results show that the frequency of two SNPs in TLR4 was significantly higher in controls than in tuberculosis patients. The minor allele (G) of rs4986790 in TLR4 (D299G) decreased the risk of active tuberculosis in the allelic (A vs. G, OR = 0.31, 95%CI = 0.09‐0.81, p = 0.01) and in the dominant genetic model (AA vs. GG+AG, OR = 0.26, 95%CI = 0.09‐0.77, p = 0.02). Similarly, the minor allele (T) of rs4986791 in TLR4 (T399I) decreased the risk of active disease in the allelic model (C vs. T, OR = 0.29, 95%CI = 0.10‐0.90, p = 0.03). We did not find an association of SNPs in TLR1 (N248S), TLR2 (R753Q), TLR6 (S249P), and TLR10 (A153S and V298I) with tuberculosis disease. These results suggest that in this population, genetic variants of TLR4 affect the susceptibility for suffering active tuberculosis disease.

GENETIC POLYMORPHISM IN PATIENTS WITH EARLY AND LATE ONSET OF ULCERATIVE COLITIS

The aim was to investigate SNPs of TLR-2,3,4, NOD2/CARD15, JAK-2, and IL-10 in patients with the early and late UC onset. Matherials and methods: 126 patients with UC were investigated. To assess the predisposition of the early and late UC onset the incidence of the following SNPs: Arg753Gln TLR2 gene, Phe412Leu TLR3 gene, Asp299Gly and Thr399Ile TLR4 gene, C-819T, G-1082A and C-592A gene IL-10, Val617Phe gene JAK2, Gly908Arg gene NOD2/CARD15 were analyzed. Results: 76 patients had early disease onset and 50 had a late one. SNPs of TLR3 were observed in 50.8% cases. TLR4 polymorphism was more common than TLR3, and was observed in 81 (64.3%) UC patients. Polymorphism of NOD2/CARD15 and IL-10 genes were revealed with almost the same frequency 49 (38.9%) and 50 (39.9%) patients, respectively. Conclusions: Polymorphisms of TLR-2,3 genes and TLR4 Asp299Gly, NOD2/CARD15 prevailed in patients with the late UC onset that allows to suppose that bacterial flora plays one of the key roles in modification of immune response and UC development. In patients with early UC onset polymorphisms of the JAK2 and IL-10 genes prevailed responsible for the cytokine cascade activation and cause the immune mechanism that might lead to a more aggressive course of the disease.

Role of Toll Like Receptor 2 and 4 (TLR2 and TLR4) in Susceptibility and Resistance to Mycobacterium Tuberculosis Infection among Sudanese Patients

Background: Tuberculosis (TB), an infectious disease caused by Mycobacterium Tuberculosis (MTB). Toll-like receptors (TLRs) are the best-studied class of PRRs, and they recognize specific pathogen-associated molecular patterns (PAMPs) from various microorganisms. Objectives: This study aimed to determine and measure cellular TLR2 and TLR4 in active TB, latent TB and healthy individuals. Also aimed to define correlation between gene expression and present of TLR4 and TLR2 in study volunteers. Materials & Methods: This Multi-site, prospective unmatched age and sex case-control, hospital and community-based study. 244 Consented volunteersor patients diagnosed as active tuberculosis, diagnosed latent TBI and a community controls volunteers with negative both TST and INF γ release assay were enrolled. Three-color Flow cytometry using Heparinized blood to study surface expression of TLR4 (CD284) and TLR2 (CD282), by Mean channel fluorescence intensity (MFI). EDTA blood was used for mRNA expression of both receptors using Quantitative RT-PCR. Results: TLR2, TLR4 cell surface expression by Flow cytometry was decreased in all study volunteers with no significance differences (p.value 0.24).mRNA expression of TLR2 were increased in active TB compared to Latent TBI and healthy individuals,while mRNA TLR4 decreased in active TB and showed increased pattern in latent and low level of expression in healthy volunteers, associated with no significant difference in the expression of TLR-2 mRNA between patients and close contacts with LTBI (p. value 0.045), compared with significance correlation between cellular TLR2 and expression and BCG status (p. value 0.00) respectively. There was highly significance correlation between TST indurations and level of both TLR2 and TLR4 (p. value 0.00). Also there was significant correlation between mRNA expression of TLR2 and disease types (p value 0.01). Single Nucleotide Polymorphisms (SNPs) in TLR2and TLR4,in active Tb Patients Showed three alleles,group one were heterozygous allele, homozygous wild type in group two, while homozygous mutant present in group three with statistical significant with disease stages, (P.value 0.02), while LTBI volunteers had only homozygous mutant present and group two had undetermined alleles, and four of them develop active TB infection, while healthy controls had similar alleles. Conclusion: Up-regulation of TLR-2 and TLR-4 due to SNPs may be involved in the process of tuberculosis infection in Sudanese individuals.

EFFICACY OF SPECIFIC PREVENTION OF INFLUENZA IN INDIVIDUALS WITH POLYMORPHISMS ARG753GLN OF TLR-2, LEU412PHE OF TLR-3, ASP299GLY OF TLR-4 GENES

The aim: Is to study the efficacy of influenza vaccination for individuals with polymorphism Arg753Gln of TLR-2 gene, Leu412Phe of TLR-3 gene, and Asp299Gly of TLR-4 gene. Materials and methods: 66 people with mutant genotypes and normal distribution of alleles of TLR-2, TLR-3, TLR-4 genes, aged 18-63, were inoculated with anti-influenza vaccine. The genotyping of Arg753Gln polymorphic site of TLR-2, Asp299Gly of TLR-4, and Leu412Phe of TLR-3 gene was carried out by polymerase chain reaction with oligonucleotide primers usage. The immunological efficacy of vaccination was evaluated by seroconversion, seroprotection, and dynamics of mean geometric titers of antibodies. Results: It has been established that individuals with mutant genotypes Arg/Gln of TLR-2, Leu/Phe, Phe/Phe of TLR-3, Asp/Gly of TLR-4 genes have a vaccinal response to administering anti-influenza vaccine at the level of subjects with normal distribution of TLR alleles, as evidenced by the growth in dynamics of mean geometric titers of antibodies to vaccine strains, the level of seroprotection and seroconversion. Clinical and epidemiological efficacy of vaccination in this category of people is characterized by: reduction of ARI cases in the postvaccinal period by 2,0-3,0 times; prevention of pneumonia in all vaccinated subjects; decrease in the frequency of bronchitis by 2,5-3,8 times. Conclusions: Effectiveness of influenza vaccination in individuals with Arg573Gln polymorphism of TLR-2, Leu412Phe of TLR-3, Asp299Gly of TLR-4 genes by immune and clinical epidemiological parameters is determined at the level of vaccinated subjects with normal distribution of TLR-2, TLR-3, TLR-4 alleles. Specific influenza immunization of people with polymorphic modified genotypes of TLR-2, TLR-3, TLR-4 genes can prevent the development of pneumonia and reduce the incidence of bronchitis.

Fungal cutaneous microbiome and host determinants in preterm and term neonates.

The neonatal cutaneous mycobiome has not been characterized in preterm infants. Invasive fungal infections in preterm neonates are associated with high mortality. The immaturity of the preterm skin predisposes neonates to invasive infection by skin colonizers. We report the clinical and host determinants that influence the skin mycobiome. Skin swabs from the antecubital fossa, forehead, and gluteal region of 15 preterm and 15 term neonates were obtained during the first 5 weeks of life. The mycobiome was sequenced using the conserved pan-fungal ITS2 region. Blood samples were used to genotype immune modulating genes. Clinical metadata was collected to determine the clinical predictors of the abundance and diversity of the skin mycobiome. The neonatal mycobiome is characterized by few taxa. Alpha diversity of the mycobiome is influenced by antibiotic exposure, the forehead body site, and the neonatal intensive care unit (NICU) environment. Beta diversity varies with mode of delivery, diet, and body site. The host determinants of the cutaneous microbiome include single-nucleotide polymorphisms in TLR4, NLRP3,CARD8, and NOD2. The neonatal cutaneous mycobiome is composed of few genera and is influenced by clinical factors and host genetics, the understanding of which will inform preventive strategies against invasive fungal infections.

Lesion size is associated with genetic polymorphisms in TLR1, TLR6, and TIRAP genes in patients with major abscesses and diabetic foot infections

Genetic variation in Toll-like receptors (TLRs) has previously been associated with susceptibility to complicated skin and skin structure infections (cSSSIs). The aim of this study was to investigate associations between the severity of cSSSIs, i.e., major abscesses and diabetic foot infections (DFIs), and a set of genetic polymorphisms in the Toll-like receptor pathway. A total of 121 patients with major abscesses and 132 with DFIs participating in a randomized clinical trial were genotyped for 13 nonsynonymous single-nucleotide polymorphisms (SNPs) in genes coding for TLRs and the signaling adaptor molecule TIRAP. Infection severity was defined by lesion size at clinical presentation for both types of infections. The PEDIS infection score was also used to define severity of DFIs. Linear regression models were used to study factors independently associated with severity. In patients with large abscesses, hetero- or homozygosity for the allelic variant TLR6 (P249S) was associated with significantly smaller lesions while homozygosity for the allelic variant TLR1 (R80T) was associated with significantly larger lesions. PRRs genes were not significantly associated with PEDIS. However, patients with DFI hetero- or homozygous for the allelic variant TLR1 (S248N) had significantly larger lesions. Polymorphisms in TLR1 and TLR6 influence the severity of cSSSIs as assessed by the lesion size of major abscesses and DFIs. ClinicalTrial.gov Identifier: NCT 00402727

Toll-like receptor 2 polymorphisms and their effect on the immune response to ESAT-6, Pam3CSK4 TLR2 agonist in pulmonary tuberculosis patients and household contacts

Toll-like receptors (TLRs) play a pivotal role in organizing the effective immune response through inducing the pro-inflammatory cytokines for control of tuberculosis infection and TLR polymorphisms are associated with altered cytokine levels have been described. Therefore, the main aim of the present study was to confirm whether TLR2 (C2029T, G2258A) polymorphisms effects the cytokine production in PTB patients and Household contacts (HHC), healthy controls (HC). The polymorphisms were performed by amplification refractory mutation system-polymerase chain reaction (ARMS) & Restriction Fragment Length Polymorphism (RFLP) in 336 subjects. Cytokine levels were estimated in Pam3CSK4, antigen ESAT-6 stimulated culture supernatants by Enzyme-Linked Immunosorbent Assay. Under the over-dominant model GA genotype of G2258A SNP and CT genotype of the co-dominant model in C2029T SNP showed a susceptible effect in patients, whereas in HHC, CT genotype showed a protective effect. A significant decreased TNF-α, IL-12 and increased IL-1β levels were observed after Pam3CSK4, antigen ESAT-6stimulation; our results showed the following associations: TLR2 G2258A SNP of GA with decreased TNF-α; TLR2 C2029T SNP of CT, TT with decreased IL-12 and increased IL-1β levels. Regression analysis demonstrated that age, BCG, gender and T allele were significantly associated with TB. Pre-mRNA secondary structure of the A, T alleles are more stable than G, C alleles. Altogether, we suggest that cytokine levels, 2029T allele, TLR2 polymorphisms were considered as predictive markers for identification of high-risk individuals in TB.

Genetic Polymorphisms of Toll-like receptors 2 and 9 as Susceptibility Factors for the Development of Ankylosing Spondylitis and Psoriatic Arthritis.

Introduction Ankylosing spondylitis (AS) and psoriatic arthritis (PsA) are classified as spondyloarthritis (SpA), a group of inflammatory rheumatic diseases with complex genetic etiology. Toll-like receptors (TLRs) have an important role in the mechanism of innate immunity and may influence inflammatory responses. Polymorphisms in TLR genes that lead to changes in these receptors or that interfere with the transcription rates of mRNA TLR may be involved in the chronic inflammatory immune response observed in SpA. Currently, there is a lack of studies associating genetic polymorphisms in TLRs and SpA. Objective Therefore, this case-control study is aimed at analyzing the influence of the respective SNPs on TLR2 rs5743708, TLR6 rs5743810, and TLR9 rs5743836 and rs187084 in the immunopathogenesis of SpA. Methods The polymorphisms genotyped by PCR-RFLP were TLR2 rs5743708, TLR6 rs5743810, and TLR9 rs5743836 and rs187084. The HLA-B∗27 was performed by PCR-SSP. Results Logistic regression analysis showed a strong association between SNPs in TLR2 and TLR9 and susceptibility to SpA (OR = 12.56; CI = 6.5-25.9 and OR = 1.62; CI = 1.20-2.21, respectively). No association was observed among HLA-B∗27 and TLR polymorphisms (p = 0.72), nor among BASDAI and TLR polymorphisms (p = 0.85). Discussion Our findings suggest that polymorphisms in TLR2 and TLR9 genes may contribute to the immunopathogenesis of the SpA. The rs187084, rs5743836, and rs5743708 polymorphisms were associated with the risk of SpA development, in this study, and lead to significant changes in the innate and adaptive immune response profile, as well as the maintenance of the regulation of immunological mechanisms. Conclusion The polymorphism rs5743708 for the TLR2 and the rs187084_rs5743836 TLR9 haplotypes appear to be involved in the development of clinical forms of SpA and can be a possible therapeutic target for the spondyloarthritis.

Association of the CD14 C159T and the Toll-like receptor 4 Asp299Gly polymorphisms with various phenotypes of asthma in adults from Crimea.

Background: This study assessed gene polymorphisms of the CD14 receptor (C-159T) and Toll-like receptor 4 (Asp299Gly) in a patient population in Crimea, Ukraine, stratified by clinical (early versus late onset; frequent versus occasional relapses; fixed versus reversible obstruction) and immunologic (atopic versus nonatopic; eosinophilic; neutrophilic or paucigranulocytic inflammation) subtype. Methods: Two polymorphisms, CD14 C-159T and TLR4 Asp299Gly, were assessed in 331 patients with asthma. The control group included 285 volunteers who were nonatopic. The single nucleotide polymorphisms were studied by using polymerase chain reaction with electrophoretic detection. Results: There were increased odds of asthma development in patients with the Asp299Gly TLR4 mutation compared with the general population underdominant odds ratio (OR) 1.52 [95% confidence interval (CI), 1.00-2.32] and overdominant (OR 1.55 [95% CI, 1.01-2.38]) models after adjustment for gender and age. In addition, mutations in this gene decreased the odds of nonatopic asthma in underdominant (OR 0.26 [95% CI, 0.07-0.93]; p = 0.027), overdominant (OR 0.27 [95% CI, 0.07-0.96]; p = 0.033), and log-additive models (OR 0.26 [95% CI, 0.07-0.93]; p = 0.026) compared with the atopic subgroup after adjustment for gender, age, number of exacerbations, and type of airway inflammation. Allele frequencies for CD14 and TLR4 polymorphisms did not show statistical differences between the patients with asthma and the control subjects. Conclusion: CD14 C-159T polymorphisms were not associated with asthma in the adult population in Crimea. TLR4 Asp299Gly polymorphisms were associated with asthma and with decreased odds of nonatopic asthma compared with atopic asthma in the adult population in Crimea.

Association of TLR2 Gene Polymorphisms with Presumed Viral-Induced Anterior Uveitis in male Han Chinese

The purpose of this study was to investigate whether single nucleotide polymorphisms (SNPs) of TLR2, TLR3, TLR4 and TLR9 genes are associated with susceptibility to presumed viral-induced anterior uveitis (PVIAU) and Posner-Schlossman syndrome (PSS). A case-control study was performed in 205 PVIAU patients and 1007 healthy controls. A total of 15 SNPs were genotyped by MassARRAY platform and iPLEX Gold Assay. Data were analyzed using a Chi-square (χ2) test and Fisher's exact calibration test. Two hundred and three PSS patients served as an extra control to investigate whether there were similar genetic factors between PVIAU and PSS in the context of these tested SNPs in TLR genes. The results showed that the frequency of TLR2/rs7656411 GG genotype and G allele were significantly higher in PVIAU patients as compared with healthy controls (P = 1.10 × 10−4, corrected P value [Pc] = 4.93 × 10−3, odds ratio [OR] = 1.848; P = 3.57 × 10−4, Pc = 1.07 × 10−2, OR = 1.478, respectively). Gender stratification analysis showed a significantly increased frequency of the G allele in male patients (P = 7.46 × 10−5, Pc = 2.24 × 10−3, OR = 1.894). A weak correlation was found between two SNPs (rs3804100 and rs5743705) of the TLR2 gene with PSS. However, after Bonferroni correction, statistical significance was lost. This study shows that the polymorphisms of TLR2/rs7656411 are positively associated with PVIAU in male Chinese patients. PVIAU and PSS have a different genetic background in the context of the tested SNPs.

Contribution of Toll like receptor polymorphisms to dengue susceptibility and clinical outcome among eastern Indian patients.

Dengue infection has been one of the major public health concerns in India causing simple dengue fever (DF) to severe dengue infection. In the present study, contribution of TLR3, 7 and 8 polymorphisms towards dengue disease susceptibility and severity among Eastern Indian patients was analysed. Genomic DNA was extracted from blood of 201 dengue infected patients and 157 healthy individuals, followed by genotyping of eight polymorphisms of TLR3 (rs3775290), TLR7 (rs5741880, rs3853839, rs179008 and rs179010) and TLR8 (rs3764879, rs3764880 and rs5744080) genes by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Functional analyses of the polymorphisms were predicted. Genotypic association of polymorphisms, alone and in combination, with dengue disease susceptibility and development of WHO-defined warning signs among patients was calculated by using SPSS software. TLR7-rs179008 & TLR8-rs3764880 were implicated to be non-synonymous polymorphisms. Specific genotypes of majority of the analysed TLR polymorphisms exhibited significant positive association with disease susceptibility. CC/C and AA/A of TLR7-rs179008 (p < 0.0001) and TLR8-rs3764880 (p < 0.00001) respectively were significantly associated with development of warning signs among dengue infected patients. Particular genotypic combinations of rs3853839-rs5744080 and rs179008-rs3764880 increased the risk of dengue infectivity, whereas, presence of last combination was more prevalent among dengue patients with warning signs. Thus these polymorphic variants of TLR3, 7 and 8 might act as potential prognostic biomarkers for predicting disease severity among dengue virus infected patients.

PECULIARITIES OF TLR-2 (ARG753GLN) AND TLR-4 (ASP299GLY) POLYMORPHISM PREVALENCE IN PATIENTS WITH ACUTE BRUCELLEIS AND CARDIOVASCULAR SYSTEM DISEASES

Currently, there are single data on the relationship between TLR-2 polymorphisms (Arg753Gln) and TLR-4 (Asp299Gly) polymorphisms and susceptibility to brucellosis. Therefore, the aim of the study was to determine the frequency of TLR-2 (Arg753Gln) and TLR-4 (Asp299Gly) polymorphisms in patients with acute brucellosis with cardiovascular lesions in the Republic of Azerbaijan. Materials and methods: 178 patients with a brucellosis clinic were examined. According to the criteria for inclusion in the study, only 120 people fully met all the criteria, which made up the main group. The control group consisted of 30 healthy individuals. TLR-2 (Arg753Gln) and TLR-4 (Asp299Gly) polymorphisms were also determined for all patients in both groups. In order to assess the state of the cardiovascular system, an electrocardiogram was recorded, blood pressure was measured, and an ultrasound scan of the heart was performed for all patients. Results: it was found that 93 patients (77.50±3.13 %) with acute brucellosis had some or other signs of impairment in the work of the cardiovascular system, identified clinically or as a result of functional examination. Among carriers of the Asp / Gly genotype of the TLR-4 gene, an increased risk of brucellosis with CVS diseases was determined (χ2=30.19; p &lt;0.0001; OR=24.29; 95 % CI [5.45 – 108.37]), while the carriage of the homozygous genotype Asp / Asp, by contrast, had a protective effect on the development of brucellosis (OR=0.06, 95 % CI [0.02 – 0.20]). Among the carriers of the Arg / Gln genotype and the Gln / Gln genotype of the TLR-2 gene, a significantly increased risk of brucellosis with CVS diseases was determined (χ2=5.68; p=0.02; OR=3.10; 95 % CI [0.99 – 9.67]) and (OR=2.48; 95 % CI [0.53 – 11.61]), respectively. While the carriage of the homozygous Arg / Arg genotype, by contrast, was rarely seen in patients with brucellosis (OR=0.28, 95 % CI [0.10 – 0.74]). Conclusions: The Asp / Gly genotype of the TLR-4 gene was 12.7 times more frequently detected in patients with acute brucellosis with CVS diseases than in healthy individuals and 9.5 times more often than in patients without CVS diseases (p&lt;0.05). The Arg / Gln genotype of the TLR-2 gene was 2.4 times more frequently detected in patients with acute brucellosis with CVS diseases than in healthy individuals (p&lt;0.05).

Association of TLR4 and TLR9 gene polymorphisms and haplotypes with cervicitis susceptibility.

BackgroundCervicitis is one of the major health problems amongst women caused by infection of various pathogens including Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Trichomonas vaginalis (TV) as well as human papillomavirus (HPV), and persistent cervical inflammation is one of the etiologic agents of cervical cancer. Toll-like receptors (TLRs) play an important role in the recognition and subsequent elimination of these pathogens. Variations in the Toll-like receptor genes influence susceptibility to pathogens as well as disease progression independently.MethodsTen single nucleotide polymorphisms, five each of TLR4 and TLR9 genes were analyzed among 130 cervicitis patients and 150 controls either using polymerase chain reaction-restriction fragment length polymorphism or allele specific-PCR.ResultsT. vaginalis infection was found at the highest frequency (30.7%) as compared to C. trachomatis (1.5%), N. gonorrhoeae (2.3%) and HPV (4.6%) infections in cervicitis patients. TLR4 rs11536889 CC (age-adjusted OR, 2.469 [95% CI, 1.499 to 4.065]; p < 0.001) and TLR9 rs187084 TC (age-adjusted OR, 2.165 [95% CI, 1.267–3.699]; p = 0.005) genotypes showed the higher distribution in cervicitis patients compared to controls. In addition, TLR4 rs11536889 C allele was shown to increase the risk of cervicitis (age-adjusted OR, 1.632 [95% CI, 1.132 to 2.352]; p = 0.009) compared to controls. The TLR4 haplotype GCA (OR, 0.6 [95% CI, 0.38–0.95]; p = 0.0272) and TLR9 haplotype GTA (OR, 1.99 [95% CI, 1.14–3.48]; p = 0.014) were found to be associated with decreased and increased risk of cervicitis respectively.ConclusionsTLR4 and TLR9 polymorphisms, as well as haplotypes were shown to modulate the cervicitis risk.

Toll-like receptor 4 polymorphisms in Saudi population with cardiovascular diseases.

BackgroundToll‐like receptors play a substantial role in innate immunity and the effects of TLR4 genetic variants on cardiovascular diseases are still largely unknown. Therefore, we aimed to investigate the effects of TLR4 polymorphisms on cardiovascular diseases risk in the Saudi population.MethodsThree tag single‐nucleotide polymorphisms (rs2770150, rs10759931, and rs4986790) in TLR4 were studied on 222 unrelated patients with cardiovascular diseases and 190 healthy volunteers.ResultsWe found that, in patients over 60 years old, the frequency of the TT genotype in rs2770150 and the variant allele G in rs10759931 were higher compared to the control group. Based on gender, the genotype frequency of rs2770150 increases the risk for cardiovascular diseases in female patients by 3.6‐fold. The allele frequency for the G allele of rs10759931 increased the risk for CVDs in male patients by more than 1.5‐fold. Furthermore, the genotype frequency of rs2770150 had a significant association with cardiovascular diseases in patients without hypertension and G allele of rs10759931 significantly increased the risk of cardiovascular diseases in patients that smoked. After Bonferroni correction only patients without hypertension showed significant risk of CVD with rs2770150.ConclusionA deeper understanding of the genetic variability of TLR4 will enable us to better identification of biomarkers for early detection and prognosis, and also enhance the decision‐making process of treatments for cardiovascular diseases.

Associations between genetic polymorphisms of TLRs and susceptibility to tuberculosis: A meta-analysis.

Some genetic association studies have tried to investigate potential associations between TLR polymorphisms and tuberculosis. However, the results of these studies have not been consistent. Thus, we performed the present meta-analysis to explore associations between TLR polymorphisms and tuberculosis in a larger combined population. A systematic literature research of PubMed, Web of Science and Embase was performed to identify eligible studies for combined analyses. I2 statistics were employed to assess between-study heterogeneities. If I2 was >50%, random-effects models were used to combine the data. Otherwise, fixed-effects models were applied for synthetic analyses. A total of 39 genetic association studies were included in the analyses. The combined analyses showed that TLR1 rs4833095, TLR1 rs5743557, TLR1 rs5743596, TLR2 rs3804099, TLR2 rs5743704, TLR2 rs5743708, TLR6 rs5743810 and TLR8 rs3764879 polymorphisms were significantly associated with susceptibility to TB in the overall population. Further subgroup analyses revealed similar significant findings for TLR1 rs4833095, TLR1 rs5743557, TLR1 rs5743596, TLR1 rs5743618, TLR2 rs3804099, TLR2 rs5743704, TLR2 rs5743708, TLR4 rs4986790 and TLR4 rs4986791 polymorphisms in certain ethnicities. In conclusion, our findings support that these TLR polymorphisms may be used to identify individuals at high risk of developing tuberculosis.

Association of Toll-Like Receptor Polymorphisms With Nasal Polyposis.

Nasal polyposis is a disease characterized with chronic inflammation of the nasal mucosa. Toll-like receptors (TLRs) are defined as essential receptors of the innate immune system and may play in the development of nasal polyposis. A total of 71 patients with nasal polyposis and 74 healthy controls were included in this study. Three single-nucleotide polymorphisms (SNPs); TLR2 (2258 A>G), TLR4 (896 A>G), and TLR4 (1196 C>T) were analyzed in all patients. The degree of pair-wise linkage disequilibrium and the genotype and haplotype analyses were conducted using regression in this logistic model and the Multifactor Dimensionality Reduction (MDR) software package was used to construct all possible interactions among different genotype variants belonging to the TLR gene. There was significant difference in genotype and allele frequencies of the TLR4 (1196 C>T) polymorphism between the nasal polyposis and control groups (0.017). Also, it was observed that the probability of nasal polyposis was 62.7% in the presence of TLR4 (1196 C>T) polymorphism with asthma (P = .007). As a conclusion, this study showed that TLR4 and TLR2 polymorphisms were predisposing factors for nasal polyposis. Further functional studies investigating the consequences of loss of TLR function are needed.

Association of TLR4 and TLR9 polymorphisms and haplotypes with cervical cancer susceptibility

Single nucleotide polymorphisms (SNPs) in TLR genes may serve as a crucial marker for early susceptibility of various cancers including cervical cancer. The present study was therefore designed to ascertain the role of TLR4 and TLR9 SNPs and haplotypes to hrHPV infection and cervical cancer susceptibility. The study included 110 cervical cancer biopsies and 141 cervical smears from age-matched healthy controls of Gujarati ethnicity of Western India. hrHPV 16 and 18 were detected using Real-time PCR. Eight SNPs, four each in TLR4 and TLR9 were analyzed using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism and Allele-Specific PCR. HPV 16 and 18 were detected in 68% cervical cancer cases. TLR4 rs4986790, rs1927911 and TLR9 rs187084 showed association with HPV 16/18 infection. CC and CT genotypes of TLR4 rs11536889 and rs1927911 respectively, and TC, CC genotypes of TLR9 rs187084, as well as minor alleles of TLR4 rs4986790 and TLR9 rs187084, were associated with the increased risk of cervical cancer. Stage-wise analysis revealed TLR9 rs187084 and rs352140 to be associated with early-stage cancer. TLR4 haplotype GTAC and TLR9 haplotype GATC were associated with the increased risk of cervical cancer while TLR4 haplotype GCAG was associated with the decreased risk. TLR4 haplotype GCAG and TLR9 haplotype GATC showed association with increased susceptibility to hrHPV infection. In conclusion, the present study revealed association of TLR4 and TLR9 polymorphisms and haplotypes with hrHPV infection and cervical cancer risk. Further evaluation of a larger sample size covering diverse ethnic populations globally is warranted.

Investigation of the Asp299Gly and Thr399Ile polymorphisms of TLR4 gene in Rheumatoid Arthritis

Objective: Rheumatoid arthritis (RA) is a chronic and inflammatory disease characterized by synovial inflammation that causes cartilage and bone destruction as well as systemic defects, including cardiovascular, pulmonary, psychological, and skeletal disorders. The etiology of RA is unclear. Evidence suggests that RA is influenced by both genetic and environmental factors and the inflammatory and autoimmune activities take important roles in the development of this disease. In the onset of RA, an interaction between the resident cells of synovium and cells of the innate and adaptive immune system reported. Fibroblast-like synoviocytes (FLS) are one of the resident cells and they play a central role, with a tumor-like behavior, in joint destruction and development of chronic inflammation. Toll-like receptors (TLRs) are transmembrane glycoproteins that are related to inflammation via synthesis of proinflammatory cytokines like TNF-α, IL-6, and IL-1β. Some studies report an association between the activation of FLS and the cytokine environment, cell-to-cell contacts, or the activation of TLR2, TLR4, and TLR3. TLRs and especially TLR4 is involved in the recognition of endogenous molecules released by injured tissues and necrotic cells. TLR4 gene involved in a wide variety of both infectious and non-infectious diseases and two polymorphisms of TLR4, Asp299Gly and Thr399Ile, changed the binding capacity and electrical charge of the protein. There are conflicting or even contradictory results about these polymorphisms and we aimed to determine the distribution of the allele frequencies of these polymorphisms and compare the result of RA patients with healthy subjects. Methods: DNA extraction was realized by salting out method from peripheral blood lymphocytes of RA patients and healthy controls. PCR amplification carried out with appropriate primer pairs against the related DNA sequences. Genotyping performed by the restriction fragment length polymorphism method. Results and Conclusion: According to the results obtained from RA patients and healthy controls, we have not found any statistical difference between both groups. Including the other polymorphisms of the TLR family into this type of studies, will give more information about the role of TLR family in rheumatoid arthritis.

The Influence of TLR4, CD14, OPG, and RANKL Polymorphisms in Periodontitis: A Case-Control Study.

The pathogenesis of periodontitis involves a complex interaction between the microbial challenge and the host immune response. The individual immunoinflammatory response has a great contribution in the pathogenesis of the disease and becomes a trigger in the process of bone remodeling which is a characteristic of the disease. Thus, the aim of this study was to evaluate the influence of the TLR4 A896G (rs4986790), TLR4 C1196T (rs4986791), CD14 C-260T (rs2569190), RANKL (TNFSF11, rs2277438), and OPG (TNFSF11B C163T, rs3102735) polymorphisms in periodontitis. A case-control study was conducted on patients with periodontitis (N = 203) and controls (N = 213) over 30 years of age, without diabetes mellitus, acute infections, and osteoarthritis, and patients without aggressive periodontitis, i.e., stage IV and C degree of periodontitis, and any periodontal treatment performed in the last 6 months. Genotypes were determined by the PCR-RFLP and sequencing method. The frequency comparisons between case and controls were performed using the chi-square test and logistic regression (OpenEpi and SNPStats software). The risk (OR) was evaluated for values of P < 0.05. Differences in TLR4, CD14, RANKL, and OPG genotype and allele frequency distributions were not observed between patients and controls. However, some variants were a risk factor for the development of periodontitis when considering gender and smoking habits. The TLR4 896 A/G genotype was a risk factor for periodontitis in males (OR = 2.86), and the TLR4 1196C/C genotype was a risk factor for nonsmoking males (OR = 1.85) when compared to women. The RANKL A/A and the OPG T/C genotype was associated with the risk of the disease in nonsmoking men compared to nonsmoking women with the same genotype (OR = 1.96 and OR = 2.9, respectively). In conclusion, TLR4, CD14, RANKL, and OPG variants were not associated with periodontitis. However, TLR4, RANKL, and OPG polymorphisms could be a risk for periodontitis in males regardless of smoking habits.

The polymorphism rs4696480 in the TLR2 gene is associated with psoriasis patients in the Turkish population

BackgroundToll-like receptors (TLRs) have an important role in the host defense. Recent studies demonstrated that TLR polymorphisms might have a role in the pathogenesis of psoriasis vulgaris. The aim of this study was to indicate whether TLR2 rs11938228 and rs4696480 were associated with susceptibility to psoriasis in the Turkish population. MethodsThis case-control study included 140 psoriasis patients and 250 controls. Genotyping of 2 rs11938228 and rs4696480 SNPs of TLR2 were determined using LightSNiP Kit (Roche Diagnostic, GmBH, Mannheim, Germany). ResultsOur results demonstrated that the TLR2-rs4696480 AA genotype seemed to have a higher risk for psoriasis [crude 95% CI: 1.495–4.514, and p < 0.001, adjusted 95% CI: 1.349–4.292, and p = 0.003] while as TLR2-rs11938228 polymorphism has not shown any significant association with the risk of psoriasis [p > 0.005]. There was no statistically significant difference between the mean age, gender, onset age, and PASI level and genotypes for rs11938228 and rs4696480 polymorphisms (p > 0.05). ConclusionsThe SNP rs4696480 of TLR2 may have significant effects on the heritability of psoriasis in the Turkish population.