Toll-like receptor-2 Arg753Gln and Arg677Trp polymorphisms and susceptibility to pulmonary and peritoneal tuberculosis

Correlation of polymorphism in Toll-Like Receptor (TLR1 and TLR2) genes with susceptibility of pulmonary tuberculosis in Doda region of India

BACKGROUND

Pulmonary tuberculosis has emerged as one of the leading causes of deaths across the globe. The prevalence of Mycobacterium tuberculosis has also shown an increasing trend over the time which may be attributed to the increase in multidrug resistant strains and HIV epidemics. There are several factors like change in the gene structure and cellular activities of the host and the bacterium which may have changed the host response towards tuberculosis. Additionally, the recent reports have suggested that Toll-Like Receptors (TLRs) play an important role in the activation of immune responses against various pathogens. Therefore, this study has been designed to investigate the possible correlation of TLR gene polymorphism and prevalence of pulmonary tuberculosis.

METHOD

This study investigates 300 samples collected from patients with pulmonary tuberculosis (150) and healthy controls (150) from the Doda region of Jammu, India. For analysis purpose, DNA from the collected samples were isolated and subjected to sequence specific PCR amplification of TLR-1 and TLR-2 genes. The amplicons of TLR-1 and TLR-2 were further digested with restriction enzymes PvuII and Xbal, respectively, and visualized on agarose gel, subsequently.

RESULT

The results suggest that frequency of TLR2 gene polymorphism (73.9%) is high in the patients below the age of 50 years, whereas, frequency of TLR-1 gene polymorphism is high (71%) in the patients above 50 years of age (p = 0.005). Further, the restriction digestion analysis of TLR1 genes has shown that nearly 78% of the confirmed normal cases exhibit homozygous normal conditions followed by 12% cases with heterozygous conditions and 10% cases of homozygous mutants. Similarly for TLR2 genes, nearly 78.6% of the confirmed normal cases have shown homozygous normal conditions followed heterozygous conditions (12.6%) and homozygous mutants (8.6%).

CONCLUSION

This study establishes a preliminary correlation between TLR polymorphism and tuberculosis.

Human Toll-like receptor 2 genetic polymorphisms with tuberculosis susceptibility: A systematic review and meta-analysis

BACKGROUND

Toll-like receptor 2 (TLR2) is a crucial factor in the development of tuberculosis. However, no studies have explored the association between TLR2 polymorphisms and tuberculosis susceptibility.

OBJECTIVES

This study aimed to explore the correlation between tuberculosis susceptibility and TLR2 polymorphisms (rs3804099, rs3804100, rs1898830, rs5743708, rs121917864, and (-196-174) del).

METHODS

All relevant online databases including PubMed, CNKI, WANFANG DATA, and METSTR-FMRS were systematically searched. STATA17.0 (Stata Corp LP, College Station, Texas, USA) was used.

RESULTS

A total of 37 studies, covering six polymorphisms and comprising 9,474 cases and 10,295 controls, were included in this analysis. rs3804099(C vs T: OR = 1.00, 95 % CI: 0.93-1.08, CC + TC vs TT: OR = 1.04, 95 % CI: 0.98-1.10), rs3804100 (C vs T: OR = 1.19, 95 % CI: 0.93-1.07, CC + TC vs TT: OR = 0.97, 95 % CI: 0.89-1.06), rs1898830(G vs A: OR = 0.90, 95 % CI: 0.81-1.00, GG + AG vs AA: OR = 0.87, 95 % CI: 0.67-1.12), (-196 ∼174) del polymorphism (Del vs Ins: OR = 0.93,95 % CI: 0.76-1.14, DD + DI vs II: OR = 0.92,95 % CI: 0.72-1.17).

CONCLUSIONS

This study indicated that only the TLR2 rs5743708 polymorphism exhibited a significant association with a higher tuberculosis risk, while TLR2 rs3804099, rs3804100, rs1898830, rs121917864, and (-196-174) del polymorphisms were not associated with tuberculosis susceptibility.

Establishment and application of TSDPSO-SVM model combined with multi-dimensional feature fusion method in the identification of fracture-related infection

Fracture-related infection (FRI) is one of the most common and intractable complications in orthopedic trauma surgery. This complication can impose severe psychological burdens and socio-economic impacts on patients. Although the definition of FRI has been proposed recently by an expert group, the diagnostic criteria for FRI are not yet standardized. A total of 4761 FRI patients and 4761 fracture patients (Non-FRI) were included in the study. The feature set of patients included imaging characteristics, demographic information, clinical symptoms, microbiological findings, and serum inflammatory markers, which were reduced by the Principal Component Analysis. To optimize the Support Vector Machine (SVM) model, the Traction Switching Delay Particle Swarm Optimization (TSDPSO) algorithm, a recognition method was proposed. Moreover, five machine learning models, including TSDPSO-SVM, were employed to distinguish FRI from Non-FRI. The Area under the Curve of TSDPSO-SVM was 0.91, at least 5% higher than that of other models. Compared with the Random Forest, Backpropagation Neural Network (BP), SVM and eXtreme Gradient Boosting (XGBoost), TSDPSO-SVM demonstrated remarkable accuracy in the test set ([Formula: see text]). The recall of TSDPSO-SVM was 98.32%, indicating a significant improvement ([Formula: see text]). Compared with BP and SVM, TSDPSO-SVM exhibited significantly superior specificity, false positive rate and precision ([Formula: see text]. The five models yielded consistent results in the training and testing of FRI patients across different age groups. TSDPSO-SVM is validated to have the maximum overall prediction ability and can effectively distinguish between FRI and Non-FRI. For the early diagnosis of FRI, TSDPSO-SVM may provide a reference basis for clinicians, especially those with insufficient experience. These results also lay a foundation for the intelligent diagnosis of FRI. Furthermore, these findings exhibit the application potential of this model in the diagnosis and classification of other diseases.

Toll-like receptor and matrix metalloproteinase single-nucleotide polymorphisms, haplotypes, and polygenic risk score differentiated between tuberculosis disease and infection

OBJECTIVES

The association of toll-like receptors (TLRs) and matrix metalloproteinases (MMPs) single-nucleotide polymorphisms (SNPs) among latent tuberculosis (TB) infection and active TB remained less studied.

METHODS

We recruited participants with TB disease (active TB) (n = 400) and TB infection (latent TB infection) (n = 203) in this study. We genotyped SNPs in TLR1, TLR2, TLR4, MMP1, MMP8, MMP9, MMP12, and tissue inhibitor of MMP2. Single-variant analysis and haplotype analysis were performed, and a polygenic risk score (PRS) was created.

RESULTS

We found that SNPs in TLR1 (rs5743580, rs5743551), TLR2 (rs3804100), and MMP8 (rs2508383) were associated with different TB disease status risks. TLR1 rs5743580 was associated with a higher risk of TB disease status in genotypic, recessive, and additive models. TLR2 rs3804100 polymorphisms demonstrated significant association with TB disease status in genotypic, dominant, and additive models. In the haplotype analysis, the TLR1 haplotype was associated with a higher risk of TB disease, and the MMP12 haplotype was associated with a lower risk of TB disease. A PRS using 3 SNPs was associated with a higher risk of TB disease.

CONCLUSION

This study revealed that SNP variants in TLR1, TLR2, and MMP8 differed among TB infection and disease. Haplotypes and PRS could potentially help predict TB disease status.

Investigation of TLR2 and TLR4 Polymorphisms and Sepsis Susceptibility: Computational and Experimental Approaches

Toll-like receptors (TLR) play an eminent role in the regulation of immune responses to invading pathogens during sepsis. TLR genetic variants might influence individual susceptibility to developing sepsis. The current study aimed to investigate the association of genetic polymorphisms of the TLR2 and TLR4 with the risk of developing sepsis with both a pilot study and in silico tools. Different in silico tools were used to predict the impact of our SNPs on protein structure, stability, and function. Furthermore, in our prospective study, all patients matching the inclusion criteria in the intensive care units (ICU) were included and followed up, and DNA samples were genotyped using real-time polymerase chain reaction (RT-PCR) technology. There was a significant association between TLR2 Arg753Gln polymorphisms and sepsis under the over-dominant model (p = 0.043). In contrast, we did not find a significant difference with the TLR4 Asp299Gly polymorphism with sepsis. However, there was a significant association between TLR4 Asp299Gly polymorphisms and Acinetobacter baumannii infection which is quite a virulent organism in ICU (p = 0.001) and post-surgical cohorts (p = 0.033). Our results conclude that the TLR2 genotype may be a risk factor for sepsis in adult patients.

The Keratinocyte as a Crucial Cell in the Predisposition, Onset, Progression, Therapy and Study of the Atopic Dermatitis

The keratinocyte (KC) is the main functional and structural component of the epidermis, the most external layer of the skin that is highly specialized in defense against external agents, prevention of leakage of body fluids and retention of internal water within the cells. Altered epidermal barrier and aberrant KC differentiation are involved in the pathophysiology of several skin diseases, such as atopic dermatitis (AD). AD is a chronic inflammatory disease characterized by cutaneous and systemic immune dysregulation and skin microbiota dysbiosis. Nevertheless, the pathological mechanisms of this complex disease remain largely unknown. In this review, we summarize current knowledge about the participation of the KC in different aspects of the AD. We provide an overview of the genetic predisposing and environmental factors, inflammatory molecules and signaling pathways of the KC that participate in the physiopathology of the AD. We also analyze the link among the KC, the microbiota and the inflammatory response underlying acute and chronic skin AD lesions.

Association between TLR2 polymorphisms (- 196-174 Ins/Del, R677W, R753Q, and P631H) and schizophrenia in a Tunisian population

Since immune dysregulation has been well studied in schizophrenia pathophysiology, recent studies showed a potent role of TLR2 in neuroinflammation process underlying schizophrenia pathogenesis. However, the genetic predisposition is still unclear. Thus, we hypothesized that TLR2 polymorphisms - 196-174 Ins/Del (rs111200466), R753Q (rs5743708), R677W (rs121917864), and P631H (rs5743704) could be involved in schizophrenia predisposition. A case-control study was performed on a Tunisian population composed of 250 healthy controls and 250 patients genotyped by PCR-RFLP. Genotype and allele distribution were evaluated with sex, schizophrenia subtypes, and other clinical features. We also assessed a haplotype analysis for TLR2 polymorphisms with schizophrenia. Our results showed higher ins/del genotype frequency in healthy women compared to patients (p = 0.006; OR = 0.2). In the other hand, logistic regression showed higher ins/del genotype frequency in controls compared to paranoid patients (p = 0.05; OR = 0.48, adjusted). Frequencies of CT and T allele of R677W were significantly higher in patients compared to controls (p < 10^-4, OR = 10.39; p < 10^-4, OR = 4, adjusted, respectively). R753Q polymorphism was exclusively detected in patients (GA + AA = 2.5%) particularly in men with disorganized subtype. P631H did not show any association with schizophrenia. Finally, haplotype analysis showed that InsGTC and delGTC were associated with higher risk of schizophrenia (p = 0.0001, OR = 8.58; p = 0.04, OR = 5.01, respectively). In the Tunisian population, our results suggested that TLR2 R677W could be associated with susceptibility for schizophrenia, while - 196-174 Ins/Del suggested a trend of protection in women. Otherwise, R753Q could have an effect on schizophrenia especially for disorganized subgroup.

Features of the pathogenetic mechanisms of tuberculous peritonitis in an experiment

The prevalence of tuberculous peritonitis that has been observed in the recent decades is the result of lymphohematogenous spread of Mycobacterium tuberculosis (MBT) from lungs and other extrapulmonary sources. It is still unclear why certain organs and anatomical regions get involved in the inflammatory process during generalization of the tuberculosis infection. Why do some cases develop into peritoneal tuberculosis and other into kidney tuberculosis? Thus study aimed to investigate the pathogenesis of tuberculous peritonitis in a reproducible biological model. Tuberculous peritonitis was modeled in 18 rabbits (10 in the test group, 8 in control) by intraperitoneal inoculation of the MBT suspension. In order to suppress peritoneal macrophages and major cytokines, test group rabbits were injected with the TNFα inhibitor and iron (III) hydroxide sucrose complex before being infected, while control group rabbits received no immunosuppressive drugs. Autopsy of the control group animals revealed changes characteristic of pulmonary tuberculosis in 37.5% of cases, with no damage to other organs and systems registered. Conversely, test group rabbits had the signs of tuberculous peritonitis in their abdominal cavities. The results of this study suggest that it is the local immunity of an anatomical area that largely determines whether a secondary focus of extrapulmonary tuberculosis infection will develop there or not. For the peritoneum, a smaller pool of peritoneal macrophages and weaker cytokine production is a necessary and sufficient condition to have tuberculous peritonitis developing therein.

Polymorphisms in TLR4 and TNFA and Risk of Mycobacterium tuberculosis Infection and Development of Active Disease in Contacts of Tuberculosis Cases in Brazil: A Prospective Cohort Study

BACKGROUND

The role of genetic polymorphisms in latent tuberculosis (TB) infection and progression to active TB is not fully understood.

METHODS

We tested the single-nucleotide polymorphisms (SNPs) rs5743708 (TLR2), rs4986791 (TLR4), rs361525 (TNFA), rs2430561 (IFNG) rs1143627 (IL1B) as risk factors for tuberculin skin test (TST) conversion or development of active TB in contacts of active TB cases. Contacts of microbiologically confirmed pulmonary TB cases were initially screened for longitudinal evaluation up to 24 months, with clinical examination and serial TST, between 1998 and 2004 at a referral center in Brazil. Data and biospecimens were collected from 526 individuals who were contacts of 177 active TB index cases. TST conversion was defined as induration ≥5 mm after a negative TST result (0 mm) at baseline or month 4 visit. Independent associations were tested using logistic regression models.

RESULTS

Among the 526 contacts, 60 had TST conversion and 44 developed active TB during follow-up. Multivariable regression analysis demonstrated that male sex (odds ratio [OR]: 2.3, 95% confidence interval [CI]: 1.1-4.6), as well as SNPs in TLR4 genes (OR: 62.8, 95% CI: 7.5-525.3) and TNFA (OR: 4.2, 95% CI: 1.9-9.5) were independently associated with TST conversion. Moreover, a positive TST at baseline (OR: 4.7, 95% CI: 2.3-9.7) and SNPs in TLR4 (OR: 6.5, 95% CI: 1.1-36.7) and TNFA (OR: 12.4, 95% CI:5.1-30.1) were independently associated with incident TB.

CONCLUSIONS

SNPs in TLR4 and TNFA predicted both TST conversion and active TB among contacts of TB cases in Brazil.

Toll-like receptors as a therapeutic target in cancer, infections and inflammatory diseases

Toll-like receptors (TLRs) are widely expressed pattern recognition receptors that bind to conserved molecular patterns expressed by pathogens and damaged cells. After recognition, activated TLRs induce the expression of various proinflammatory and antiviral molecules. Thus, TLRs are potential targets for treatment strategies aimed at boosting the adaptive immune response to vaccines, controlling infections, enhancing immune responses during tumor treatment and attenuating immune responses in inflammatory disorders. This Special Report examines the potential of TLRs as targets for the treatment of cancer, infections and inflammatory diseases. Here, we make a particular emphasis on molecules capable of modulating TLRs and their therapeutic applications.

Association between TLR2 Arg677Trp polymorphism and tuberculosis susceptibility: A meta-analysis

BACKGROUND

Toll-like receptor 2 (TLR2) is an important member of TLRs, which is significant in the initial of inflammatory response against bacteria. Several studies have been conducted to investigate the TLR2 Arg677Trp polymorphism and Tuberculosis (TB) susceptibility. Unfortunately, the results of previous studies were inconsistent.

OBJECTIVES

The aim of present study was to investigate the relationship between TLR2 Arg677Trp polymorphisms and TB susceptibility.

METHODS

The association between the TLR2 Arg677Trp polymorphism and TB susceptibility was assessed by odds ratios (OR) together with their 95% confidence intervals (95%CI).

RESULTS

Six case-control studies were enrolled in the meta-analysis. Overall, significant association between TLR2 Arg677Trp polymorphism and TB risk were found neither under allele contrast (C vs. T: OR = 0.59, 95%CI = 0.28-1.23, P = 0.158) nor under recessive genetic model (CC vs. CT/TT: OR = 0.43, 95%CI = 0.12-1.51, P = 0.188).

CONCLUSION

We conclude that TLR2 Arg677Trp polymorphism is not associated with TB susceptibility.

Diagnostic and Therapeutic Strategies for Peritoneal Tuberculosis: A Review

Peritoneal tuberculosis (PTB), although rarer than its pulmonary counterpart, is a serious health concern in regions of the world with high tuberculosis prevalence. Individuals with baseline immunocompromise condition, whether acquired or medically induced, are at greatest risk for experiencing PTB. While medical treatment of the condition is similar to that of the pulmonary disease, the generally immunocompromised state of those infected with PTB, along with a lack of highly sensitive and specific testing methods make early diagnosis difficult. This review discusses the risks factors, clinical features, diagnostic methods, and treatment options for PTB.

TLR2 Arg753Gln Gene Polymorphism Associated with Tuberculosis Susceptibility: An Updated Meta-Analysis

Objective

To date, a series of studies were conducted to investigate the association between TLR2 (Toll-like receptor 2) Arg753Gln gene polymorphism and tuberculosis (TB). However, the results were inconsistent. This meta-analysis was performed to elucidate the roles of TLR2 Arg753Gln gene polymorphism in TB.

Methods

All available articles were searched from online databases such as PubMed, Medline, CNKI, and Wanfang. Statistical analyses were performed using the STATA12.0 (Stata Corp LP, College Station, TX, United States) software.

Results

32 case-control studies comprising 5943 cases and 5991 controls were identified in this meta-analysis. Overall, the TLR2 Arg753Gln gene polymorphism was associated with high TB risk in allele model (A vs. G: OR=2.20, 95%CI=1.60-3.04, P≤0.01), dominant model (AA+AG vs. GG: OR=2.70, 95%CI=2.00-3.65, P≤0.01), and heterozygote model (AG vs. GG contrast: OR=2.97, 95%CI=2.39-3.69, P≤0.01). Subgroup analysis by ethnicity indicated that the A allele increased susceptibility to TB in Asian (OR=3.35, 95%CI=2.36-4.74) and Caucasian populations (OR=2.62, 95%CI=1.77-3.87), but not in African (2.08, 95%CI=0.62-2.72) or mixed populations (OR=0.76, 95%CI=0.36-1.14). Stratified analysis by sample type suggested that the A allele associated with high pulmonary tuberculosis (PTB) risks (OR=2.43, 95%CI=1.66-3.54), but not with extra pulmonary tuberculosis (EPTB) (OR=1.84, 95%CI=0.83-4.06).

Conclusion

this meta-analysis suggested the following: (1) TLR2 Arg753Gln polymorphism is significantly associated with high TB risk. (2) In subgroup analysis based on ethnicity, TLR2 Arg753Gln polymorphism elevates the risk of TB in Asian and Caucasian populations, but not in African or mixed populations. (3) Stratified by sample type, TLR2 Arg753Gln polymorphism is associated with increased PTB risk, but not with EPTB.