NRAMP1 and VDR gene polymorphisms in susceptibility to pulmonary tuberculosis among Andhra Pradesh population in India: a case-control study

Exploring host-pathogen interactions in the Dictyostelium discoideum-Mycobacterium marinum infection model of tuberculosis

Mycobacterium tuberculosis is a pathogenic mycobacterium that causes tuberculosis. Tuberculosis is a significant global health concern that poses numerous clinical challenges, particularly in terms of finding effective treatments for patients. Throughout evolution, host immune cells have developed cell-autonomous defence strategies to restrain and eliminate mycobacteria. Concurrently, mycobacteria have evolved an array of virulence factors to counteract these host defences, resulting in a dynamic interaction between host and pathogen. Here, we review recent findings, including those arising from the use of the amoeba Dictyostelium discoideum as a model to investigate key mycobacterial infection pathways. D. discoideum serves as a scalable and genetically tractable model for human phagocytes, providing valuable insights into the intricate mechanisms of host-pathogen interactions. We also highlight certain similarities between M. tuberculosis and Mycobacterium marinum, and the use of M. marinum to more safely investigate mycobacteria in D. discoideum.

Differential NRAMP1gene's D543N genotype frequency: Increased risk of contracting tuberculosis among Venezuelan populations

NRAMP1 and VDR gene polymorphisms have been variably associated with susceptibility to tuberculosis (TB) amongst populations having different genetic background. NRAMP1 and VDR gene variants' association with susceptibility to active infection by Mycobacterium tuberculosis (Mtb) was analyzed in the Warao Amerindian population, an ethnic population from Venezuela's Orinoco delta region. Genomic DNA was extracted from individuals with and without TB to evaluate genetic polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Four NRAMP1 gene polymorphisms were analyzed: D543N (rs17235409), 3' UTR (rs17235416), INT4 (rs3731865), and 274C/T (rs2276631), and one VDR gene polymorphism: FokI (rs2228570). The results showed that the genotypes D543N-A/A, 3'UTR-TGTG+/+, INT4-C/C, and 274C/T-T/T of known polymorphism in the NRAMP1 gene, as well as the genotypes FokI-F/f and FokI-f/f in the VDR gene were most often found in indigenous Warao with active TB. Binomial logistic regression was used for evaluating associations between polymorphisms and risk of contracting TB, an association between NRAMP1-D543N-A/A genotype distribution and TB susceptibility was found in Warao Amerindians. Regarding Venezuelan populations having different genetic backgrounds; statistically significant TB associations concerning NRAMP1-D543N-A/A, INT4-C/C and 3'UTR-TGTG+/+ variant genotype distributions in Warao Amerindians (indigenous) compared to Creole (admixed non-indigenous population) individuals were found. In conclusion, the results thus indicated that the association between NRAMP1-D543N-A/A genotype and TB in Warao Amerindians could support such allele's role in host susceptibility to Mtb infection.

Association of Single-Nucleotide Polymorphisms in the VDR Gene with Tuberculosis and Infection of Beijing Genotype Mycobacterium tuberculosis

Background

The aim of the present study was to investigate the association between vitamin D receptor (VDR) gene polymorphism and tuberculosis susceptibility, as well as the potential interaction of host genetic factors with the heterogeneity of Mycobacterium tuberculosis in the population from Xinjiang, China.

Methods

From January 2019 to January 2020, we enrolled 221 tuberculosis patients as the case group and 363 staff with no clinical symptoms as the control group from four designated tuberculosis hospitals in southern Xinjiang, China. The polymorphisms of Fok I, Taq I, Apa I, Bsm I, rs3847987 and rs739837 in the VDR were detected by sequencing. M. tuberculosis isolates were collected from the case group and identified as Beijing or non-Beijing lineage by multiplex PCR. Propensity score (PS), univariate analysis and multivariable logistic regression models were used to perform the analysis.

Results

Our results showed that the allele and genotype frequencies of Fok I, Taq I, Apa I, Bsm I, rs3847987 and rs739837 in VDR were not correlated with tuberculosis susceptibility or lineages of M. tuberculosis. Two out of six loci of the VDR gene formed one haplotype block, and none of the haplotypes was found to correlate with tuberculosis susceptibility or lineages of M. tuberculosis infected.

Conclusion

Polymorphisms in the VDR gene may not indicate susceptibility to tuberculosis. There was also no evidence on the interaction between the VDR gene of host and the lineages of M. tuberculosis in the population from Xinjiang, China. Further studies are nonetheless required to prove our conclusions.

Research progress on genetic control of host susceptibility to tuberculosis

The "Lübeck disaster", twins studies, adoptees studies, and other epidemiological observational studies have shown that host genetic factors play a significant role in determining the host susceptibility to Mycobacterium tuberculosis infection and pathogenesis of tuberculosis. From linkage analyses to genome-wide association studies, it has been discovered that human leucocyte antigen (HLA) genes as well as non-HLA genes (such as SLC11A1, VDR, ASAP1 as well as genes encoding cytokines and pattern recognition receptors) are associated with tuberculosis susceptibility. To provide ideas for subsequent studies about risk prediction of MTB infection and the diagnosis and treatment of tuberculosis, we review the research progress on tuberculosis susceptibility related genes in recent years, focusing on the correlation of HLA genes and non-HLA genes with the pathogenesis of tuberculosis. We also report the results of an enrichment analysis of the genes mentioned in the article. Most of these genes appear to be involved in the regulation of immune system and inflammation， and are also closely related to autoimmune diseases.

Resistance and Susceptibility Immune Factors at Play during Mycobacterium tuberculosis Infection of Macrophages

Tuberculosis (TB), caused by infection with Mycobacterium tuberculosis (M.tb), is responsible for >1.5 million deaths worldwide annually. Innate immune cells, especially macrophages, are the first to encounter M.tb, and their response dictates the course of infection. During infection, macrophages exert a variety of immune factors involved in either controlling or promoting the growth of M.tb. Research on this topic has been performed in both in vitro and in vivo animal models with discrepant results in some cases based on the model of study. Herein, we review macrophage resistance and susceptibility immune factors, focusing primarily on recent advances in the field. We include macrophage cellular pathways, bioeffector proteins and molecules, cytokines and chemokines, associated microbiological factors and bacterial strains, and host genetic factors in innate immune genes. Recent advances in mechanisms underlying macrophage resistance and susceptibility factors will aid in the successful development of host-directed therapeutics, a topic emphasized throughout this review.

Association of SLC11A1 Polymorphisms With Tuberculosis Susceptibility in the Chinese Han Population

Tuberculosis (TB) is an important health issue in the world. Although the relation of SLC11A1 polymorphisms with TB risk has been extensively studied, it has not been reported in the northwest Chinese Han population. Therefore, this study aimed to investigate the relationships between five polymorphisms in or near the SLC11A1 gene and susceptibility to TB. The Agena MassARRAY platform was conducted for genotyping from 510 TB patients and 508 healthy controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were analyzed through logistic regression adjustment age and gender to assess the relationships between polymorphisms and TB risk. Our results identified that rs7608307 was related to increased TB risk in males (CT vs. CC: OR = 1.69, 95%CI: 1.12–2.56, p = 0.013; CT-TT vs. CC: OR = 1.61, 95%CI: 1.08–2.41, p = 0.020) and age ≤41 group (CT vs. CC: OR = 1.66, 95%CI: 1.04–2.65, p = 0.035), respectively. The SNP rs13062 was associated with the TB risk both in males (p = 0.012) and age >41 group (p = 0.021). In addition, we observed that the CC genotype of rs4674301 was correlated with increased TB risk in females (p = 0.043). Our results demonstrated the relationships between polymorphisms (rs7608307, rs4674301, and rs13062) in or near the SLC11A1 gene and age- and sex-specific TB risk in the northwest Chinese Han population.

Tuberculosis and Autoimmunity

Tuberculosis remains a common and dangerous chronic bacterial infection worldwide. It is long-established that pathogenesis of many autoimmune diseases is mainly promoted by inadequate immune responses to bacterial agents, among them Mycobacterium tuberculosis. Tuberculosis is a multifaceted process having many different outcomes and complications. Autoimmunity is one of the processes characteristic of tuberculosis; the presence of autoantibodies was documented by a large amount of evidence. The role of autoantibodies in pathogenesis of tuberculosis is not quite clear and widely disputed. They are regarded as: (1) a result of imbalanced immune response being reactive in nature, (2) a critical part of TB pathogenicity, (3) a beginning of autoimmune disease, (4) a protective mechanism helping to eliminate microbes and infected cells, and (5) playing dual role, pathogenic and protective. There is no single autoimmunity-mechanism development in tuberculosis; different pathways may be suggested. It may be excessive cell death and insufficient clearance of dead cells, impaired autophagy, enhanced activation of macrophages and dendritic cells, environmental influences such as vitamin D insufficiency, and genetic polymorphism, both of Mycobacterium tuberculosis and host.

Polymorphisms of SLC11A1(NRAMP1) rs17235409 associated with and susceptibility to spinal tuberculosis in a southern Han Chinese population

OBJECTIVE

To investigate the association between SLC11A1 (NRAMP1) rs17235409 (D543N) polymorphisms and susceptibility to spinal tuberculosis (STB) in the Han population in southern China.

METHODS

This study included 227 STB patients and 516 controls. Polymorphisms of SLC11A1 rs17235409 were genotyped using a SNPscan™ kit, and the protein was detected by western blotting.

RESULTS

The genotype and allele frequency distributions of SLC11A1 rs17235409 differed significantly between the STB group and the control group(χ² = 17.650, P = 0.000). The distribution of GA genotype(GA vs. GG: P = 0.000, OR [95% CI] = 2.203[1.520-3.192] was significantly different between STB group and control group, but there was no significant difference in the distribution of AA genotypes(AA vs. GG: P = 0.889, OR [95%CI] = 0.674[0.142-3.208]). The A allele was more common in the STB group than in the control group (A vs. G: P = 0.001, OR [95%CI] = 1.767[1.273-2.452]). Under the dominant model, the GA + AA genotype was more common in the STB group than in the control group (GA + AA vs. GG: P = 0.000, OR [95%CI] = 2.067[1.438-2.971]). However, under the recessive model, there was no difference in GA + GG genotype between the STB and control groups(GA + GG vs. AA: P = 0.701, OR [95%CI] =1.772[0.373-8.409]). NRAMP1 protein expression in the STB group(n = 9) was significantly higher than that in the control group(n = 9) (t = 5.292,P = 0.001).

CONCLUSIONS

Variant genotypes at the rs17235409 locus of the SLC11A1 gene are associated with STB in the southern Han Chinese population. NRAMP1 protein expression is increased in patients with spinal tuberculosis, and the presence of the A allele increases the risk of developing STB.

Effect of breastfeeding on children's health and its relationship to NRAMP1 expression: A cross-sectional study

Toddlers with exclusive breastfeeding can increase immunity in preventing infectious diseases such as Upper Respiratory Tract Infections (ARI). The body's resistance to disease is controlled by Natural Resistance-Associated Macrophage Protein 1 (NRAMP1). NRAMP1 contributes to the pathophysiology of several intercellular infections, including ARI. The purpose of this study was to determine the effect of breastfeeding on children's health and its relationship to NRAMP1 expression. A cross-sectional study was conducted on 124 toddlers in October 2020–June 2021. Toddlers were selected purposively from three Community Health Centers in Central Jakarta. The first group (n = 62) was exclusive breastfeeding and the second group (n = 62) was not exclusive breastfeeding. The characteristics of mothers and toddlers were collected using a structured questionnaire supported by medical record data. Meanwhile, NRAMP1 expression and NRAMP1 protein levels were obtained from the examination of blood samples. Examination of NRAMP1 gene mRNA expression by real-time PCR method and serum NRAMP1 protein levels by ELISA method. Data were analyzed using t-test, ANOVA, and multiple linear regression. The results obtained that the average mRNA expression of NRAMP1 gene and protein levels of NRAMP1 in infants who were not exclusive breastfeeding were 6.88 fold change (FC) and 315.02 pg/ml compared to those who received exclusive breastfeeding of 11.36 FC and 1087.74 pg./ml. Parity, immunization history, exclusive breastfeeding, and frequency of ARI were significantly associated with NRAMP1 gene mRNA expression and NRAMP1 protein levels (P < 0.05). Maternal and under-five age, gender, and nutritional status were not significantly related (P > 0.05). Exclusive breastfeeding was the dominant factor influencing NRAMP1 gene mRNA expression (OR: 4268) and NRAMP1 protein content (OR: 737,362). Antibodies obtained from exclusive breastfeeding in synergy with the NRAMP1 gene form the body's immunity in infants suffering from ARI.

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Breast milk contains antibodies that work in synergy with the NRAMP1 gene mRNA expression and NRAMP1 protein levels to form body immunity in children with ARI.

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Exclusive breastfeeding significantly increased the NRAMP1 gene mRNA expression and NRAMP1 protein levels.

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Immunization can significantly increase NRAMP1 gene mRNA expression and NRAMP1 protein levels.

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Exclusive breastfeeding can increase NRAMP1 gene mRNA expression, and NRAMP1 protein levels improved children's health.

Association of Vitamin D Receptor Polymorphism (rs2228570, rs1544410, rs7975232, and rs731236) and Macrophage Migration Inhibitory Factor -173 G/C (rs755622) with the Susceptibility of Active Pulmonary Tuberculosis in Makassar, Indonesia

BACKGROUND: The study of Vitamin D Receptor (VDR) and Macrophage Migration Inhibitory Factor (MIF) polymorphisms, associated with active pulmonary tuberculosis (ATB) presents varying results. AIMS: This study aimed to investigate the association between VDR rs2228570, rs1544410, rs7975232, rs731236 and MIF -173 G/C (rs755622) single nucleotide polymorphism (SNP), with susceptibility of developing ATB, and positivity of Interferon Gamma Release Assay (IGRA) results (in household contact). METHODS AND MATERIAL: This study involved 83 ATB and 73 household contacts in Makassar. We checked IGRA based on ELISA in household contacts by using QuantiFERON TB Gold Plus test, and we found that 61.64% (n = 45) of household contacts had positive IGRA. Polymorphism examination was carried out by Sanger sequencing. RESULTS: VDR rs2228570 T/T and T/C-T/T were significantly associated with higher risk of active tuberculosis. VDR rs7975232 G/G genotype was associated with an increased risk of developing active TB compared to T/T-T/G. Haplotype analysis of VDR rs2228570, rs1544410, rs7975232, rs731236 and combination with MIF rs755622 demonstrated that TGGTG was observed to have a higher risk of tuberculosis. CONCLUSIONS: The combination of VDR and MIF variants may contribute to the susceptibility of active tuberculosis disease.

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.

Human Genetic Variation Influences Enteric Fever Progression

In the 21st century, enteric fever is still causing a significant number of mortalities, especially in high-risk regions of the world. Genetic studies involving the genome and transcriptome have revealed a broad set of candidate genetic polymorphisms associated with susceptibility to and the severity of enteric fever. This review attempted to explain and discuss the past and the most recent findings on human genetic variants affecting the progression of Salmonella typhoidal species infection, particularly toll-like receptor (TLR) 4, TLR5, interleukin (IL-) 4, natural resistance-associated macrophage protein 1 (NRAMP1), VAC14, PARK2/PACRG, cystic fibrosis transmembrane conductance regulator (CFTR), major-histocompatibility-complex (MHC) class II and class III. These polymorphisms on disease susceptibility or progression in patients could be related to multiple mechanisms in eliminating both intracellular and extracellular Salmonella typhoidal species. Here, we also highlighted the limitations in the studies reported, which led to inconclusive results in association studies. Nevertheless, the knowledge obtained through this review may shed some light on the development of risk prediction tools, novel therapies as well as strategies towards developing a personalised typhoid vaccine.

Collocating Novel Targets for Tuberculosis (TB) Drug Discovery

BACKGROUND

Mycobacterium tuberculosis, being a resistive species is an incessant threat to the world population for the treatment of Tuberculosis (TB). An advanced genetic or a molecular level approach is mandatory for both diagnosis and therapy as the prevalence of multi drug-resistant (MDR) and extensively drug- resistant (XDR) TB.

METHODS

A literature review was conducted, focusing essentially on the development of biomarkers and targets to extrapolate the Tuberculosis Drug Discovery process.

RESULTS AND DISCUSSION

In this article, we have discussed several substantial targets and genetic mutations occurring in a diseased or treatment condition of TB patients. It includes expressions in Bhlhe40, natural resistance associated macrophage protein 1 (NRAMP1) and vitamin D receptor (VDR) with its mechanistic actions that have made a significant impact on TB. Moreover, recently identified compounds; imidazopyridine amine derivative (Q203), biphenyl amide derivative (DG70), azetidine, thioquinazole, tetrahydroindazole and 2- mercapto- quinazoline scaffolds for several targets such as adenosine triphosphate (ATP), amino acid and fatty acid have been briefed for their confirmed hits and therapeutic activity.

Association of Fok1 VDR polymorphism with Vitamin D and its associated molecules in pulmonary tuberculosis patients and their household contacts

Status of Fok I VDR polymorphism along with vitamin D, Vitamin D receptor (VDR), and cathelicidin levels in Tuberculosis (TB) patients compared to household contacts and implication of these findings in susceptibility to TB is not known. 150 active TB patients, 150 household contacts and 150 healthy controls were recruited from North Indian population. Fok1 VDR polymorphism was studied by polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP).VDR mRNA and protein levels were studied using quantitative real time PCR (q rt PCR) and enzyme linked immunosorbent assay (ELISA) respectively. Cathelicidin and Vitamin D levels were measured using ELISA and chemiluminescence immunoassay (CLIA) respectively. Significant association was found between Fok1 polymorphism and susceptibility to TB (P < 0.0005). VDR mRNA, VDR protein and vitamin D levels were significantly lower in active TB group when compared to household contacts and healthy controls (P < 0.0001, 0.0001 and 0.0005 respectively). Cathelicidin levels were higher in active TB patients compared to other groups (P < 0.0001). Expression of VDR and cathelicidin was significantly higher among 'FF' genotypes of VDR (more active form of VDR) compared to 'ff' genotype (less active form of VDR). 'f' allele was associated with increased susceptibility to TB. Higher frequency of 'F' allele, increased VDR expression along with increased vitamin D levels in household contacts compared to active TB group might be responsible for protection against active TB.

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.

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.

Eat Prey, Live: Dictyostelium discoideum As a Model for Cell-Autonomous Defenses

The soil-dwelling social amoeba Dictyostelium discoideum feeds on bacteria. Each meal is a potential infection because some bacteria have evolved mechanisms to resist predation. To survive such a hostile environment, D. discoideum has in turn evolved efficient antimicrobial responses that are intertwined with phagocytosis and autophagy, its nutrient acquisition pathways. The core machinery and antimicrobial functions of these pathways are conserved in the mononuclear phagocytes of mammals, which mediate the initial, innate-immune response to infection. In this review, we discuss the advantages and relevance of D. discoideum as a model phagocyte to study cell-autonomous defenses. We cover the antimicrobial functions of phagocytosis and autophagy and describe the processes that create a microbicidal phagosome: acidification and delivery of lytic enzymes, generation of reactive oxygen species, and the regulation of Zn²⁺, Cu²⁺, and Fe²⁺ availability. High concentrations of metals poison microbes while metal sequestration inhibits their metabolic activity. We also describe microbial interference with these defenses and highlight observations made first in D. discoideum. Finally, we discuss galectins, TNF receptor-associated factors, tripartite motif-containing proteins, and signal transducers and activators of transcription, microbial restriction factors initially characterized in mammalian phagocytes that have either homologs or functional analogs in D. discoideum.