The NRAMP1, VDR, TNF-α, ICAM1, TLR2 and TLR4 gene polymorphisms in Iranian patients with pulmonary tuberculosis: A case-control study

An Updated Trial Sequential Meta-analysis of Vitamin D Receptor Gene Polymorphism (Fok1, Bsm1, Taq1 and Apa1) and Risk to Tuberculosis

Vitamin D receptor (VDR) is one of the most widely studied genes for the Tuberculosis (TB) susceptibility. Several studies have been conducted to establish some association between them but most of the time they are contradictory and underpowered. So, a trial sequential meta-analysis between VDR gene polymorphisms and TB susceptibility can provide a better understanding of the relationship. A meta-analysis was carried out using a total of 17 case-control studies which includes Fok1 (14 Studies), Bsm1 (8 Studies), Apa1 (8 Studies) and Taq1 (12 Studies) polymorphisms in the VDR gene searched from Pubmed and Google Scholar. Pooled Odds Ratio (OR) and 95% Confidence Interval (CI) were calculated using StatsDirect Version 3, using random effects model. Trial sequential analysis (TSA) was also performed to assess if the statistical significance of the meta-analysis was within monitoring boundaries. It was found that the individuals with BB genotype of Bsm1 polymorphism with OR = 0.713 (95%CI = 0.521, 0.974; p value < 0.05) and FF genotype of Fok1 polymorphism with pooled OR = 0.716 (95%CI = 0.523, 0.979; p value < 0.05) had decreased incidence of TB. Also, the aa genotype of Apa1 gene polymorphism increases susceptibility to TB with pooled OR = 1.997 (95%CI = 1.121, 3.558; p value < 0.05). All these analyses reached the required information size through TSA analysis. No statistically significant result was found for Taq1 polymorphisms and TB susceptibility. VDR polymorphisms in Fok1 and Bsm1 played protective roles against development of TB infection, while Apa1 appeared to have a significant association to TB susceptibility.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12291-022-01091-3.

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.

Association of MMP3, MMP14, and MMP25 gene polymorphisms with cerebral stroke risk: a case-control study

BACKGROUND

Cerebral stroke (CS) is the leading cause of death in China, and a complex disease caused by both alterable risk factors and genetic factors. This study intended to investigate the association of MMP3, MMP14, and MMP25 single nucleotide polymorphisms (SNPs) with CS risk in a Chinese Han population.

METHODS

A total of 1,348 Han Chinese were recruited in this case-control study. Four candidate loci including rs520540 A/G and rs679620 T/C of MMP3, rs2236302 G/C of MMP14, and rs10431961 T/C of MMP25 were successfully screened. The correlation between the four SNPs and CS risk was assessed by logistic regression analysis. The results were analyzed by false-positive report probability (FPRP) for chance or significance. The interactions between four SNPs associated with CS risk were assessed by multifactor dimensionality reduction (MDR).

RESULTS

rs520540 A/G and rs679620 C/T SNP in MMP3 were associated with risk of CS in allele, codominant, dominant and log-additive models. Ischemic stroke risk were significantly lower in carriers with rs520540-A allele and rs679620-T allele than those with G/G or C/C genotypes. However, rs520540-A allele and rs679620-T allele were associated with higher risk of hemorrhagic stroke. Stratified analysis showed that these two SNPs were associated with reduced risk of CS in aged < 55 years, non-smoking and non-drinking participants, and rs679620 SNP also reduced CS risk in male participants. The levels of uric acid, high-density lipoprotein cholesterol, and eosinophil were different among patients with different genotypes of rs520540 and rs679620. No statistically significant association was found between MMP14 rs2236302 G/C or MMP25 rs10431961 T/C with CS even after stratification by stroke subtypes, age, gender as well as smoking and drinking conditions in all the genetic models.

CONCLUSION

MMP3 rs520540 A/G and rs679620 C/T polymorphisms were associated with CS risk in the Chinese Han population, which provides useful information for the prevention and diagnosis of CS.

Role of pattern recognition receptors in sensing Mycobacterium tuberculosis

Mycobacterium tuberculosis is one of the major invasive intracellular pathogens causing most deaths by a single infectious agent. The interaction between host immune cells and this pathogen is the focal point of the disease, Tuberculosis. Host immune cells not only mount the protective action against this pathogen but also serve as the primary niche for growth. Thus, recognition of this pathogen by host immune cells and following signaling cascades are key dictators of the disease state. Immune cells, mainly belonging to myeloid cell lineage, recognize a wide variety of Mycobacterium tuberculosis ligands ranging from carbohydrate and lipids to proteins to nucleic acids by different membrane-bound and soluble pattern recognition receptors. Simultaneous interaction between different host receptors and pathogen ligands leads to immune-inflammatory response as well as contributes to virulence. This review summarizes the contribution of pattern recognition receptors of host immune cells in recognizing Mycobacterium tuberculosis and subsequent initiation of signaling pathways to provide the molecular insight of the specific Mtb ligands interacting with specific PRR, key adaptor molecules of the downstream signaling pathways and the resultant effector functions which will aid in identifying novel drug targets, and developing novel drugs and adjuvants.

Polymorphisms in PI3K/AKT genes and gene‑smoking interaction are associated with susceptibility to tuberculosis

BACKGROUND

Phosphatidylinositol 3-kinase (PI3K) and protein kinase B (AKT) are involved in the clearance of Mycobacterium tuberculosis (MTB) by macrophages.

AIM

This study aimed to investigate the effects of polymorphisms in the PI3K/AKT genes and the gene-smoking interaction on susceptibility to TB.

METHODS

This case-control study used stratified sampling to randomly select 503 TB patients and 494 control subjects. Logistic regression analysis was used to determine the association between the polymorphisms and TB. Simultaneously, the marginal structure linear dominance model was used to estimate the gene-smoking interaction.

RESULTS

Genotypes GA (OR 1.562), AA (OR 2.282), and GA + AA (OR 1.650) at rs3730089 of the PI3KR1 gene were significantly associated with the risk to develop TB. Genotypes AG (OR 1.460), GG (OR 2.785), and AG + GG (OR 1.622) at rs1130233 of the AKT1 gene were significantly associated with the risk to develop TB. In addition, the relative excess risk of interaction (RERI) between rs3730089 and smoking was 0.9608 (95% CI: 0.5959, 1.3256, p < 0.05), which suggests a positive interaction.

CONCLUSION

We conclude that rs3730089 and rs1130233 are associated with susceptibility to TB, and there was positive interaction between rs3730089 and smoking on susceptibility to TB.

Offense and Defense in Granulomatous Inflammation Disease

Granulomatous inflammation (GI) diseases are a group of chronic inflammation disorders characterized by focal collections of multinucleated giant cells, epithelioid cells and macrophages, with or without necrosis. GI diseases are closely related to microbes, especially virulent intracellular bacterial infections are important factors in the progression of these diseases. They employ a range of strategies to survive the stresses imposed upon them and persist in host cells, becoming the initiator of the fighting. Microbe-host communication is essential to maintain functions of a healthy host, so defense capacity of hosts is another influence factor, which is thought to combine to determine the result of the fighting. With the development of gene research technology, many human genetic loci were identified to be involved in GI diseases susceptibility, providing more insights into and knowledge about GI diseases. The current review aims to provide an update on the most recent progress in the identification and characterization of bacteria in GI diseases in a variety of organ systems and clinical conditions, and examine the invasion and escape mechanisms of pathogens that have been demonstrated in previous studies, we also review the existing data on the predictive factors of the host, mainly on genetic findings. These strategies may improve our understanding of the mechanisms underlying GI diseases, and open new avenues for the study of the associated conditions in the future.

Correlation between polymorphism of vitamin D receptor TaqI and susceptibility to tuberculosis: An update meta-analysis

BACKGROUND

To investigate the association between TaqI polymorphism of the vitamin D receptor gene and tuberculosis (TB).

METHODS

A systematic search was performed in PubMed, Embase, Web of Science, Elsevier Science Direct, Cochrane Library, Chinese National Knowledge Infrastructure, Wanfang, and Chongqing VIP databases for case-control study on TaqI gene polymorphism and TB susceptivity. Quality assessment of studies was performed using the Newcastle-Ottawa Scale for the methodological assessment of case-control studies, and R 4.0.5 software was used for the meta-analysis.

RESULTS

Among the 243 selected articles, 27 in the meta-analysis. The meta-analysis showed that the TaqI gene polymorphism allene gene model (t vs T, odds ratio [OR]: 1.12, 95% confidence interval [CI]: 0.99-1.27); dominant model (tt + tT vs TT, OR: 1.12, 95% CI: 0.98-1.29); recessive model (tt vs tT + TT, OR: 1.25, 95% CI: 1.03-1.51); codominant A (tt vs TT, OR: 1.37, 95% CI: 1.00-1.87); codominant B (tT vs TT, OR: 1.09, 95% CI: 0.99-1.19). And subgroup dominant model (tt + tT vs TT, OR: 1.27, 95% CI: 1.03-1.55) in Indianas, recessive model (tt vs tT + TT, OR: 1.49, 95% CI: 1.05-2.11) in Iranians, co-dominant B (tT vs TT, OR: 1.28, 95% CI: 1.03-1.59; OR: 1.42, 95% CI: 1.05-1.93) in Indianas and Iranians.

CONCLUSION

This meta-analysis suggests a significant association between TB and the risk of TaqI in Iranians and Indians, but the vitamin D receptor polymorphism TaqI was not associated with Chinese. Thus, validation studies will be required to confirm these findings.

Synergistic effect of genetic polymorphisms in TLR6 and TLR10 genes on the risk of pulmonary tuberculosis in a Moldavian population

Polymorphisms in genes that control immune function and regulation may influence susceptibility to pulmonary tuberculosis (TB). In this study, 14 polymorphisms in 12 key genes involved in the immune response (VDR, MR1, TLR1, TLR2, TLR10, SLC11A1, IL1B, IL10, IFNG, TNF, IRAK1, and FOXP3) were tested for their association with pulmonary TB in 271 patients with TB and 251 community-matched controls from the Republic of Moldova. In addition, gene-gene interactions involved in TB susceptibility were analyzed for a total of 43 genetic loci. Single nucleotide polymorphism (SNP) analysis revealed a nominal association between TNF rs1800629 and pulmonary TB (Fisher exact test P = 0.01843). In the pairwise interaction analysis, the combination of the genotypes TLR6 rs5743810 GA and TLR10 rs11096957 GT was significantly associated with an increased genetic risk of pulmonary TB (OR = 2.48, 95% CI = 1.62-3.85; Fisher exact test P value = 1.5 × 10^-5, significant after Bonferroni correction). In conclusion, the TLR6 rs5743810 and TLR10 rs11096957 two-locus interaction confers a significantly higher risk for pulmonary TB; due to its high frequency in the population, this SNP combination may serve as a novel biomarker for predicting TB susceptibility.

Role of genetic variants of Vitamin D receptor, Toll-like receptor 2 and Toll-like receptor 4 in extrapulmonary tuberculosis

BACKGROUND

Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis (MTB). Vitamin D deficiency and vitamin D receptor (VDR) gene abnormalities confer susceptibility to tuberculosis. Toll-like receptors (TLRs), such as TLR-2, are also important mediators of inflammatory response against Mycobacterium tuberculosis. We evaluated VDR, TLR-2 and TLR-4 gene polymorphisms in patients with extrapulmonary tuberculosis (EPTB).

OBJECTIVES

To find out a possible association of Vitamin D receptor (VDR) (rs731236), TLR-2 (196-174 Ins > Del) and TLR-4 (Thr399Ile) gene polymorphisms with extrapulmonary tuberculosis in ethnic Kashmiri population.

METHODS

A total of 100 extrapulmunary tuberculosis cases and 102 healthy controls were analyzed for Vitamin D receptor (VDR) (rs731236), TLR-2 (196-174 ins > del) and TLR-4 (Thr399Ile) gene polymorphisms using PCR-RFLP and Allele-Specific PCR methods.

RESULTS

We found increased frequency of TLR-4 Thr/Ile heterozygous genotype in cases as compared with healthy controls (22% vs 5.8%). Thus acting as a risk factor for extrapulmonary tuberculosis, as was elucidated from statistical analysis [OR, 4.5; 95% CI (1.74-11.68); P < 0.001]. In case of TLR-2 (196-174 ins > del) we observed significant differences in the homozygous variant (Del/Del) genotype of cases and controls (28% in cases & 2.94% in controls). Thus, TLR-2 (Del/Del) genotype acts as a strong risk factor for extrapulmonary tuberculosis predisposition [OR, 12.2; 95% CI (3.5-42.69); P < 0.001]. We did not find any significant differences in the genotypic distribution of (VDR) (rs731236) T > C SNP between cases and controls (P > 0.05).

CONCLUSION

TLR-4 (Thr/Ile) and TLR-2 (Del/Del) act as significant risk factors for extrapulmonary tuberculosis predisposition in ethnic Kashmiri population.

FokI polymorphism of the vitamin D receptor (VDR) gene and susceptibility to tuberculosis: Evidence through a meta-analysis

BACKGROUND

Tuberculosis is one of the top ten causes of deaths worldwide. The deficiency of vitamin D was reported to be associated with the increased susceptibility of tuberculosis. Various previous reports were published to check the association of FokI polymorphism of the vitamin D receptor gene with tuberculosis risk. But their results were inconsistent so, we performed a meta-analysis to know the exact relation of the two.

METHODS

Different databases were screened up to November 2020 with the keywords "Vitamin D receptor", "VDR", and "FokI", along with "Tuberculosis" and "TB" to find the suitable articles. All the statistical analyses were performed by the Open Meta-Analyst program and all p-values were two-tailed with a significance level of 0.05.

RESULTS

No statistically significant association was observed in the allele contrast model (OR_fvs.F = 1.11, 95%CI = 0.99-1.24, p = 0.05, I² = 73.46%), in the dominant model (OR_ff+Ffvs.FF = 1.11, 95%CI = 0.96-1.28, p = 0.14, I² = 71.39%), and in the co-dominant model (OR_Ffvs.FF = 1.05, 95%CI = 0.92-1.21, p = 0.41, I² = 65.97%). However, a significant association was found in the homozygote model (OR_ffvs.FF = 1.32, 95%CI = 1.03-1.69, p = 0.02, I² = 67.02%) and in the recessive model (OR_{FF+Ff vs.ff} = 1.26, 95%CI = 1.03-1.54, p = 0.02, I² = 58.01%). Further analysis was performed on the bases of the ethnicity. In Asian population a significant association was found in the homozygote model (OR_ffvs.FF = 1.57, 95%CI = 1.12-2.21, p = 0.008, I² = 70.37%) and in the recessive model (OR_{FF+Ff vs.ff} = 1.43, 95%CI = 1.08-1.89, p = 0.01, I² = 63.13%).

CONCLUSION

In conclusion, a significant association of FokI with tuberculosis susceptibility was found in the overall analysis and in the Asian population.

Interaction of TLR4 and TLR8 in the Innate Immune Response against Mycobacterium Tuberculosis

The interaction and crosstalk of Toll-like receptors (TLRs) is an established pathway in which the innate immune system recognises and fights pathogens. In a single nucleotide polymorphisms (SNP) analysis of an Indian cohort, we found evidence for both TLR4-399T and TRL8-1A conveying increased susceptibility towards tuberculosis (TB) in an interdependent manner, even though there is no established TLR4 ligand present in Mycobacterium tuberculosis (Mtb), which is the causative pathogen of TB. Docking studies revealed that TLR4 and TLR8 can build a heterodimer, allowing interaction with TLR8 ligands. The conformational change of TLR4-399T might impair this interaction. With immunoprecipitation and mass spectrometry, we precipitated TLR4 with TLR8-targeted antibodies, indicating heterodimerisation. Confocal microscopy confirmed a high co-localisation frequency of TLR4 and TLR8 that further increased upon TLR8 stimulation. The heterodimerisation of TLR4 and TLR8 led to an induction of IL12p40, NF-κB, and IRF3. TLR4-399T in interaction with TLR8 induced an increased NF-κB response as compared to TLR4-399C, which was potentially caused by an alteration of subsequent immunological pathways involving type I IFNs. In summary, we present evidence that the heterodimerisation of TLR4 and TLR8 at the endosome is involved in Mtb recognition via TLR8 ligands, such as microbial RNA, which induces a Th1 response. These findings may lead to novel targets for therapeutic interventions and vaccine development regarding TB.

Integrative genomics analysis identifies promising SNPs and genes implicated in tuberculosis risk based on multiple omics datasets

More than 10 GWASs have reported numerous genetic loci associated with tuberculosis (TB). However, the functional effects of genetic variants on TB remains largely unknown. In the present study, by combining a reported GWAS summary dataset (N = 452,264) with 3 independent eQTL datasets (N = 2,242) and other omics datasets downloaded from public databases, we conducted an integrative genomics analysis to highlight SNPs and genes implicated in TB risk. Based on independent biological and technical validations, we prioritized 26 candidate genes with eSNPs significantly associated with gene expression and TB susceptibility simultaneously; such as, CDC16 (rs7987202, rs9590408, and rs948182) and RCN3 (rs2946863, rs2878342, and rs3810194). Based on the network-based enrichment analysis, we found these 26 highlighted genes were jointly connected to exert effects on TB susceptibility. The co-expression patterns among these 26 genes were remarkably changed according to Mycobacterium tuberculosis (MTB) infection status. Based on 4 independent gene expression datasets, 21 of 26 genes (80.77%) showed significantly differential expressions between TB group and control group in mesenchymal stem cells, mice blood and lung tissues, as well as human alveolar macrophages. Together, we provide robust evidence to support 26 highlighted genes as important candidates for TB.

[Molecular mechanism underlying the inhibitory effect of propofol on lipopolysaccharide-induced pyroptosis of mouse bone marrow-derived macrophages]

OBJECTIVE

To investigate the molecular mechanism underlying the inhibitory effect of propofol on pyroptosis of macrophages.

METHODS

Macrophages derived from bone marrow were extracted and divided into three groups: control group, LPS+ATP group and propofol+LPS+ATP group. The control group was not given any treatment; LPS+ATP group was given LPS 1 μg/mL stimulation for 4 h, then ATP 4 mM stimulation for 1 h; Propofol+LPS+ATP group was given propofol+LPS 1 μg/mL stimulation for 4 h, then ATP stimulation for 1 h. After treatment, the supernatant and cells of cell culture were collected. the cell activity was detected by CCK8 and flow cytometry. The inflammatory cytokines IL-1βand IL-18 were detected by Elisa. Western blot was used to detect the expression of caspase-1 protein and TLR4 on cell membran Immunohistochemical fluorescence was used to detect apoptosis of cells.

RESULTS

LPS+ATP significantly decreased the viability of the macrophages and increased the cellular production of IL-1β and IL-18, activation of caspase-1 protein and the expression of TLR-4 on the cell membrane (P &lt; 0.05). Treatment with propofol obviously reversed the changes induced by LPS+ATP.

CONCLUSIONS

LPS+ATP can induce pyroptosis of mouse bone marrow-derived macrophages, and propofol effectively inhibits such cell death, suggesting that propofol anesthesia is beneficial during operation and helps to regulate the immune function of in patients with sepsis.

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.

Vitamin D receptor ApaI (rs7975232), BsmI (rs1544410), Fok1 (rs2228570), and TaqI (rs731236) gene polymorphisms and susceptibility to pulmonary tuberculosis in an Iranian population: A systematic review and meta-analysis

Polymorphisms of vitamin D receptors (VDRs), ApaI, BsmI, FokI, and TaqI might affect susceptibility to tuberculosis (TB). In this systematic review and meta-analysis, all published articles which investigated the effects of these polymorphisms on the risk of TB in the Iranian population were retrieved. PubMed and Scopus were searched with no date or language restrictions. In this meta-analysis, the Comprehensive Meta-Analysis (CMA) version 2.0 and random effects model were applied. The association of polymorphisms with TB risk was assessed by measuring the odds ratio (ORs) at 95% CI. Heterogeneity was investigated based on Cochran Q-test and I2-index statistics. The significance level was set at 0.05. Also, Egger's regression intercept was determined to measure publication bias. A total of six articles on Iranian populations were included. TaqI (5/6 included studies) showed a significant association with the increased risk of TB based on ORs (allele comparison: 1.57 (1.0, 2.3), p-value: 0.02; additive model of tt/TT: 1.57 (0.9, 2.5), p-value: 0.05; recessive model (tt/Tt + TT): 1.99 (1.2, 3.2), p-value: 0.00; dominant model (tt + Tt/TT): 1.98 (1.1, 3.5), p-value: 0.01). BsmI showed a significant positive effect on TB risk only in its dominant genotype (bb + bB/BB) (1.44 (1.0, 1.9); p-value: 0.02). FokI and ApaI did not show any significant effects on TB development in Iranian populations. Findings showed the significant effect of TaqI polymorphism in all genetic models and the dominant model of BsmI on the increased risk of TB. However, the effects of TaqI and BsmI should be further investigated in a larger sample size.

3'UTR polymorphisms in NRAMP1 are associated with the susceptibility to pulmonary tuberculosis: A MOOSE-compliant meta-analysis

Many studies have investigated the association between the 3'UTR polymorphism in natural resistance-associated macrophage protein 1 (NRAMP1) and the risk of pulmonary tuberculosis (PTB), Revealing inconclusive results. This study aimed to investigate the correlation between the NRAMP1 3'UTR polymorphism and the risk of PTB.This meta-analysis included 29 case-control studies to better and comprehensively assess this correlation. Pooled odds ratios (ORs) and 95% confidence interval (95% CIs) were calculated to assess the strength of the association.These 29 case-control studies included 4672 cases and 6177 controls. The NRAMP1 3'UTR polymorphism displayed a significant positive correlation with the risk of PTB in 3 models (for del/del vs ins/ins: OR = 1.22, 95% CI = 1.01-1.47; for Ins/del vs ins/ins: OR = 1.19, 95% CI 1.08-1.30; for Ins/del + del/del vs ins/ins: OR = 1.25, 95% CI = 1.08-1.45). A stratified analysis by ethnicity revealed that the NRAMP1 3'UTR polymorphism was associated with an increased risk of PTB in the Asian population, but not in Caucasian, African, and South American populations.The present results indicate that the NRAMP1 3'UTR polymorphism may be considered a risk factor for PTB in the Asian population.

Toll-Like Receptor 4 as an Immune Receptor Against Mycobacterium tuberculosis: A Systematic Review

OBJECTIVE

To review the main Mycobacterium tuberculosis (Mtb) pathogen-associated molecular patterns (PAMPs) and the roles played by toll-like receptor (TLR)4 in determination of Mtb infection outcome.

METHODS

Several scientific databases, including Scopus, PubMed, and Google Scholar, were used for searching appropriate research articles from the literature for information on our topic.

RESULTS

TLR4 plays positive roles in induction of immune responses against Mtb and participates in eradication of the infection. Some limited investigations approved the roles of TLR4 in induction of apoptosis in macrophages during tuberculosis (TB) and attenuation of immune responses in some situations.

CONCLUSIONS

TB outcome appears to be dependent on TLR4/Mtb interaction and several factors, including bacterial load and immune or nonimmune cells, as hosts. Also, other TLR/Mtb interactions can affect TLR4 responses.

Associations between vitamin D receptor genetic variants and tuberculosis: a meta-analysis

We performed a meta-analysis to evaluate potential associations between vitamin D receptor (VDR) genetic variants and tuberculosis (TB). Systematic literature research was conducted in PubMed, Web of Science, and Embase. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) to estimate strength of associations in all possible genetic models, and P values ≤ 0.05 were considered to be statistically significant. In total, 42 studies were enrolled for analyses. Pooled overall analyses suggested that VDR rs1544410 (dominant model: P = 0.02; allele model: P = 0.03) and rs731236 (dominant model: P = 0.04; recessive model: P = 0.02; allele model: P = 0.01) variants were significantly associated with TB. Further subgroup analyses by ethnicity revealed that rs1544410 (dominant and allele models) and rs731236 (dominant, recessive, and allele models) variants were both significantly associated with TB in South Asians. When we stratified data by type of disease, positive results were detected for rs7975232 variant in EPTB (dominant, recessive, over-dominant, and allele models) subgroup, and for rs2228570 variant in PTB (dominant, recessive, and allele models) and EPTB (dominant, recessive, over-dominant, and allele models) subgroups. Our meta-analysis supported that rs7975232, rs1544410, rs2228570, and rs731236 variants might serve as genetic biomarkers of certain types of TB.

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.

Influence of Genetic Polymorphism Towards Pulmonary Tuberculosis Susceptibility

Tuberculosis (TB) is still remains the major threat for human health worldwide. Several case-control, candidate-gene, family studies and genome-wide association studies (GWAS) suggested the association of host genetic factors to TB susceptibility or resistance in various ethnic populations. Moreover, these factors modulate the host immune responses to tuberculosis. Studies have reported genetic markers to predict TB development in human leukocyte antigen (HLA) and non-HLA genes like killer immunoglobulin-like receptor (KIR), toll-like receptors (TLRs), cytokine/chemokines and their receptors, vitamin D receptor (VDR) and SLC11A1 etc. Highly polymorphic HLA loci may influence antigen presentation specificities by modifying peptide binding motifs. The recent meta-analysis studies revealed the association of several HLA alleles in particular class II HLA-DRB1 with TB susceptibility and valuable marker for disease development especially in Asian populations. Case-control studies have found the association of HLA-DR2 in some populations, but not in other populations, this could be due to an ethnic specific association of gene variants. Recently, GWAS conducted in case-control and family based studies in Russia, Chinese Han, Morocco, Uganda and Tanzania revealed the association of genes such as ASAP1, Alkylglycerol monooxygenase (AGMO), Forkhead BoxP1 (FOXP1), C-terminal domain phosphatase 1 (UBLCP1) and intergenic SNP rs932347C/T with TB. Whereas, SNP rs10956514A/G were not associated with TB in western Chinese Han and Tibetan population. In this review, we summarize the recent findings of genetic variants with susceptibility/resistance to TB.

Evaluation of TLR2, TLR4, and TOLLIP polymorphisms for their role in tuberculosis susceptibility

Previous studies indicated that single-nucleotide polymorphisms (SNPs) of genes coding for toll-like receptors (TLRs) and toll-interacting protein (TOLLIP) may be involved in the pathogenesis of pulmonary tuberculosis (PTB). This study was designed to investigate potential associations between the polymorphisms in TLR2, TLR4, and TOLLIP and susceptibility to latent tuberculosis infection (LTBI) or subsequent PTB in a Chinese Han population. A total of 209 PTB and 201 LTBI patients and 204 healthy control subjects (HCS) were enrolled in our study. We performed a logistic regression including sex and age as covariates to test the effect of genotype. Genotyping was conducted using the improved multiplex ligase detection reaction (iMLDR). Eleven markers in TLR2, TLR4, and TOLLIP were assessed. No significant association between polymorphisms of TLR2 and TLR4 with PTB or LTBI was detected. For TOLLIP, rs5743899 (p = 0.005, OR = 1.83, 95% CI: 1.20-2.80) CC genotype were risk factors for PTB progression. Moreover, rs5743867 under addictive (p = 0.005, OR = 1.54, 95% CI: 1.14-2.07) and recessive model (p = 0.004, OR = 1.86, 95% CI: 1.22-2.83) were also risk factors for PTB susceptibility. Our results indicate that polymorphisms in TOLLIP affected the risk of PTB disease.

Polymorphisms and haplotypes in the promoter of the TNF-α gene are associated with disease severity of severe fever with thrombocytopenia syndrome in Chinese Han population

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease that is caused by a novel bunyavirus, SFTSV. We assessed whether the single nucleotide polymorphisms (SNPs) in the tumor necrosis factor-alpha (TNF-α) were associated with risk to severity of SFTS. Five TNF-α SNPs (SNP1: T-1031C; SNP2: C-863A; SNP3: C-857T; SNP4: G-308A; SNP5: G-238A) were genotyped in 987 hospitalized SFTS patients and 633 asymptomatic/mild SFTSV-infected subjects of Chinese Han origin. Multivariate logistic regression analysis was used to calculate adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs). The hospitalized SFTS patients had significantly lower frequency of G-238A A allele than those with mild/asymptomatic infection (P = 0.006). Furthermore, T-1031C C allele (P < 0.001) and G-238A A allele (P < 0.001) were significantly associated with decreased risk of death. Multiple haplotypes were significantly associated with decreased risk of SFTS hospital admission (SNP1-2, CC; SNP1-3, CCC; SNP1-4, CCCG; SNP1-5, CCCGA; SNP2-4, CCGA; SNP3-5, CGA; SNP4-5, GA) and death (SNP1-2, CA; SNP1-3, CAG; SNP1-4, CACG; SNP1-5, CACGG; SNP2-3, AC; SNP2-4, ACG; SNP2-5, ACGG) after correction for multiple comparisons. By using the ELISA assay, we observed that TNF-α concentration of hospitalized patients was significantly increased in acute phase than in convalescent phase (P < 0.001). Elevated TNF-α concentration was also revealed from fatal patients (P < 0.001). The -238A allele was associated with decreased serum TNF-α levels in SFTS patients in acute phase (P = 0.01). Our findings suggest that polymorphisms in TNF-α gene may play a role in mediating the risk to disease severity of SFTS in Chinese Han population.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease that is caused by a novel bunyavirus. The current study disclosed the single nucleotide polymorphisms (SNPs) in the tumor necrosis factor-alpha (TNF-α) were associated with risk to disease severity of SFTS. These findings suggest that polymorphisms in TNF-α gene may play a role in mediating the risk to disease severity of SFTS in Chinese Han population. The study will be of interest to either the clinicians devoted to the prevention and therapy of SFTS or the geneticists devoted to studying the genetic susceptibility mechanisms of common diseases.

Searching for signals of recent natural selection in genes of the innate immune response - ancient DNA study

The last decade has seen sharp progress in the field of human evolutionary genetics and a great amount of genetic evidence of natural selection has been provided so far. Since host-pathogen co-evolution is difficult to trace due to the polygenic nature of human susceptibility to microbial diseases, of particular interest is any signal of natural selection in response to the strong selective pressure exerted by pathogens. Analysis of ancient DNA allows for the direct insight into changes of a gene pool content over time and enables monitoring allele frequency fluctuations. Among pathogenic agents, mycobacteria are proved to have remained in an intimate, long-lasting relation with humans, reflected by the current high level of host resistance. Therefore, we aimed to investigate the prevalence of several polymorphisms within innate immune response genes related to susceptibility to mycobacterial diseases (in SLC11A1, MBL2, TLR2, P2RX7, IL10, TNFA) in time series data from North and East Poland (1st-18th century AD, n = 207). The comparison of allele frequencies over time revealed a predominant role of genetic drift in shaping past gene pool of small, probably isolated groups, which was explained by the high level of population differentiation and limited gene flow. However, the trajectory of frequency fluctuations of two SNPs suggested the possibility of their non-neutral evolution and the results of applied forward simulations further strengthened the hypothesis of natural selection acting on those loci. However, we observed an unusual excess of homozygosity in the profile of several SNPs, which pinpoints to the necessity of further research on temporally and spatially diverse samples to support our inference on non-stochastic evolution, ideally employing pathway-based approaches. Nevertheless, our study confirms that time series data could help to decipher very recent human adaptation to life-threatening pathogens and assisting demographic events.

High-density lipoprotein suppresses tumor necrosis factor alpha production by mycobacteria-infected human macrophages

Immune responses to parasitic pathogens are affected by the host physiological condition. High-density lipoprotein (HDL) and low-density lipoprotein (LDL) are transporters of lipids between the liver and peripheral tissues, and modulate pro-inflammatory immune responses. Pathogenic mycobacteria are parasitic intracellular bacteria that can survive within macrophages for a long period. Macrophage function is thus key for host defense against mycobacteria. These basic facts suggest possible effects of HDL and LDL on mycobacterial diseases, which have not been elucidated so far. In this study, we found that HDL and not LDL enhanced mycobacterial infections in human macrophages. Nevertheless, we observed that HDL remarkably suppressed production of tumor necrosis factor alpha (TNF-α) upon mycobacterial infections. TNF-α is a critical host-protective cytokine against mycobacterial diseases. We proved that toll-like receptor (TLR)-2 is responsible for TNF-α production by human macrophages infected with mycobacteria. Subsequent analysis showed that HDL downregulates TLR2 expression and suppresses its intracellular signaling pathways. This report demonstrates for the first time the substantial action of HDL in mycobacterial infections to human macrophages.

Current immunogenetic predisposition to tuberculosis in the Moroccan population

Tuberculosis (TB) is a serious infectious disease that kills approximately two million people per year, particularly in low- and middle-income countries. Numerous genetic epidemiology studies have been conducted of many ethnic groups worldwide and have highlighted the critical impact of the genetic environment on TB distribution. Many candidate genes associated with resistance or susceptibility to TB have been identified. In Morocco, where TB is still a major public health problem, various observations of clinical, microbiological and incidence distribution are heavily affected by genetic background and external environment. Morocco has almost the same clinical profile as do other North African countries, mainly the increase in more extrapulmonary than pulmonary forms of the diseases, when compared to European, Asian or American populations. In addition, a linkage analysis study that examined Moroccan TB patients identified a unique chromosome region that had a strong association with the risk of contracting TB. Other genes in the Moroccan population that were found to be associated seem to be involved predominantly in modulating the innate immunity. In this review, we appraise the major candidate genes that have been reported in Moroccan immunogenetic studies and discuss their updated role in TB, particularly during the first phase of the immune response to Mycobacterium tuberculosis (Mtb) infection.

Human genetic factors in tuberculosis: an update

Tuberculosis (TB) is a major threat to human health, especially in many developing countries. Human genetic variability has been recognised to be of great relevance in host responses to Mycobacterium tuberculosis infection and in regulating both the establishment and the progression of the disease. An increasing number of candidate gene and genome-wide association studies (GWAS) have focused on human genetic factors contributing to susceptibility or resistance to TB. To update previous reviews on human genetic factors in TB we searched the MEDLINE database and PubMed for articles from 1 January 2014 through 31 March 2017 and reviewed the role of human genetic variability in TB. Search terms applied in various combinations were 'tuberculosis', 'human genetics', 'candidate gene studies', 'genome-wide association studies' and 'Mycobacterium tuberculosis'. Articles in English retrieved and relevant references cited in these articles were reviewed. Abstracts and reports from meetings were also included. This review provides a recent summary of associations of polymorphisms of human genes with susceptibility/resistance to TB.

New findings of Toll-like receptors involved in Mycobacterium tuberculosis infection

Tuberculosis (TB), an important issue in the present age, affects millions of people each year. The infectious agent of TB, Mycobacterium tuberculosis (Mtb), interacts with the immune system which prevents the development of this bacterium as much as possible. In fact, the receptors on the surface of immune cells identify the bacteria, one of which is Toll-like receptors (TLRs). Different TLRs including 2, 4, 9 and 8 play critical roles in tuberculosis infection. In this paper, we focused on the role of TLRs which interact with different components of Mtb and, consequently, prevent the entrance and influence of bacteria on the body.

Toll-like receptor 2 in host defense against Mycobacterium tuberculosis: to be or not to be-that is the question

Toll-like receptor (TLR) 2 is expressed on immune cells and respiratory epithelial cells lining the lung. TLR2 is not critical for protection during acute Mycobacterium tuberculosis (Mtb) infection but it has a significant multi-faceted role in containing chronic infection. This review highlights the contribution of TLR2 to host protection, immune evasion by Mtb and immune regulation during chronic Mtb infection. The TLR2-triggered pro-inflammatory cytokines initiate protective mechanisms and limit Mtb replication while the immune evasion pathways counterattack anti-bacterial effector mechanisms. The immune regulation pathways that are activated dampen TLR2 signaling. The combinatorial effect of these functional responses is persistence of Mtb with minimal immunopathology.