Analysis of MIF, FCGR2A and FCGR3A gene polymorphisms with susceptibility to pulmonary tuberculosis in Moroccan population

Comparative Analysis of FCGR Gene Polymorphism in Pulmonary Sarcoidosis and Tuberculosis

The clinical outcome of sarcoidosis (SA) is very similar to tuberculosis (TB); however, they are treated differently and should not be confused. In search for their biomarkers, we have previously revealed changes in the phagocytic activity of monocytes in sarcoidosis and tuberculosis. On these monocytes we found a higher expression of receptors for the Fc fragment of immunoglobulin G (FcγR) in SA and TB patients vs. healthy controls. FcγRs are responsible for the binding of immune complexes (ICs) to initiate an (auto)immune response and for ICs clearance. Surprisingly, our SA patients had a high blood level of ICs, despite the abundant presence of FcγRs. It pointed to FcγR disfunction, presumably caused by the polymorphism of their (FCGR) genes. Therefore, we present here an analysis of the occurrence of FCGR2A, FCGR2B, FCGR2C, FCGR3A and FCGR3B variants in Caucasian SA and TB patients, and healthy individuals with the use of polymerase chain reaction (PCR) and real-time PCR. The presented data point to a possibility of supporting the differential diagnosis of SA and TB by analyzing FCGR2C, FCGR3A and FCGR3B polymorphism, while for severe stages of SA also by studying FCGR2A variants. Additionally, the genotyping of FCGR2A and FCGR3B might serve as a marker of SA progression.

Impact of Macrophage Migration Inhibitory Factor Gene Polymorphisms and Serum Macrophage Migration Inhibitory Factor Levels on Pulmonary and Spinal Tuberculosis Susceptibility: A Pooled Analysis

Objective: This study was designed to evaluate the association between macrophage migration inhibitory factor (MIF) gene polymorphisms, serum MIF levels and tuberculosis (TB) susceptibility. Methods: All satisfactory studies were included; the MIF genotype number and serum MIF levels were reviewed. The Stata and Review Manager software were used for the pooled analyses. Results: The pooled analyses showed that the MIF-173G/C gene polymorphism was associated with TB (allele C vs allele G: odds ratio (OR) = 1.44, 95% confidence interval (CI): 1.28-1.62, p < 0.01; genotype CC vs genotype GG: OR = 1.69, 95% CI: 1.05-2.73, p = 0.03; genotype CC+GC vs genotype GG: OR = 1.56, 95% CI: 1.34-1.81, p < 0.01; genotype GC vs genotype GG: OR = 1.50, 95% CI: 1.28-1.75, p < 0.01). The subgroup analysis showed that the MIF-173G/C gene polymorphism was significantly associated with the risk of both pulmonary tuberculosis (PTB) and spinal tuberculosis (STB).The MIF CATT-794 gene polymorphism was associated with the PTB susceptibility in Asian subjects (genotypes 5/X+6/X vs genotypes 7/X+8/X: OR = 0.39, 95% CI: 0.24-0.64, p < 0.01; genotypes 5 + 6 vs genotypes 7 + 8: OR = 0.57, 95% CI: 0.48-0.69, p < 0.01). Both PTB and STB patients had significantly elevated serum MIF levels compared to healthy controls. Conclusion: The MIF-173G/C gene polymorphism is related to both PTB and STB susceptibility in both Asian and Caucasian populations. The C allele and CC genotype of the MIF-173G/C SNP appear to be TB risk factors. The MIF CATT-794 gene polymorphism is associated with the PTB susceptibility in Asian subjects; serum MIF levels were significantly increased in PTB and STB patients.

Macrophage migration inhibitory factor -173 G>C single nucleotide polymorphism and its association with active pulmonary tuberculosis

PURPOSE

The establishment of candidate genes associated with susceptibility to TB is a challenge especially due to divergent frequencies among different populations. The objective of this study was to evaluate the association between macrophage migration inhibitory factor (MIF) -173 G>C single nucleotide polymorphism (SNP) and susceptibility to pulmonary TB in a population of southern Brazil.

METHODS

Case-control study. Patients > 18 years old, diagnosed with pulmonary TB were included. The control group consisted of blood donors and household contacts, not relatives, healthy and > 18 years old. MIF -173 G>C SNPs were genotyped using real-time PCR using a TaqMan SNP Genotyping assay.

RESULTS

174 patients and 166 controls were included. There were no statistically significant differences between cases and controls regarding genotype prevalence (p>0.05). Comparing patients with normal genotype (GG) with those with at least one C allele, there was also no statistically significant difference (p = 0.135). Also, there was no statistically significant difference comparing the homozygous for the mutation (CC) with the other patients (GG and CG) (p = 0.864).

CONCLUSIONS

We did not find association between MIF -173 G>C polymorphism and susceptibility to pulmonary TB.

Prognostic value of serum macrophage migration inhibitory factor levels in pulmonary tuberculosis

Background

Macrophage migration inhibitory factor (MIF) makes chemokine-like functions and plays critical roles in various inflammatory diseases. This study was designed to explore the significance of MIF serum levels in predicting the prognosis of pulmonary tuberculosis (PTB) following anti-TB treatment.

Methods

Patients diagnosed with culture-confirmed PTB without treatment were included and the serum was collected. Levels of MIF in serum were quantified with immunoassay, and the levels of established biomarkers were also determined, including C-reactive protein (CRP) and Interleukin 6 (IL-6). The outcome was estimated with all-cause mortality, with the mortality in 12 months as the primary outcome and the mortality in 3, 6, 9 months as other outcomes. The prognostic value of MIF and other factors in PTB were tested.

Results

Two hundred eighty-seven PTB patients were included. The median MIF levels in patients with advanced disease, disseminated and drug-resistant TB were significantly higher than that observed in mild -to- moderate disease, non-disseminated and drug-sensitive TB. MIF levels in patients with the outcome of death were higher than those survived [28.0 ng/ml (Inter-quartile range [IQR]: 24.2–33.1) vs. 22.3 ng/ml (IQR: 18.7–26.5); P < 0.001]. Multivariate model analysis was performed for comparing the highest quartiles to the lowest quartile of MIF levels. MIF levels were related to the mortality, with an elevated mortality risk of 236% [Odds ratio (OR) = 3.36; 95% Confidence interval (CI): 1.21–15.14; P = 0.012]. The model was re-analysis after combing MIF with currently established risk indicators. The obtained Area Under the Receiver Operating Characteristic Curve (±standard error) was elevated from 0.81 (±0.035) to 0.84 (±0.031), with a significant difference before and after adding the MIF (difference, 0.03[0.004]; P = 0.03).

Conclusion

Serum level of MIF was a better biomarker than CRP or IL-6 for predicting death in HIV-negative PTB patients, and increased MIF serum levels were related to higher mortality.

Low expression Macrophage Migration Inhibitory Factor (MIF) alleles and tuberculosis in HIV infected South Africans

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Low expression MIF alleles are prevalent in South Africa, which has the greatest burden of TB and HIV.

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Low genotypic MIF expressers were more frequent among HIV cases with TB compared to those without TB.

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Serum MIF correlated with lower CD4 cells regardless of TB, suggesting HIV impacts MIF expression.

Host immunity is crucial for controlling M. tuberculosis infection. Functional polymorphisms in the cytokine macrophage migration inhibitory factor (MIF) show global population stratification, with the highest prevalence of low expression MIF alleles found in sub-Saharan Africans, which is a population with the greatest confluence of both TB and HIV infection and disease. We investigated the association between MIF alleles and tuberculosis (TB) and HIV in South Africa. We acquired clinical information and determined the frequency of two MIF promoter variants: a functional −794 CATT_5-8 microsatellite and an associated −173 G/C SNP in two HIV-positive cohorts of patients with active laboratory-confirmed TB and in controls without active TB who were all HIV positive. We found a greater frequency of low expression MIF promoter variants (-794 CATT_5,6) among TB disease cases compared to controls (OR = 2.03, p = 0.023), supporting a contribution of genetic low MIF expression to the high prevalence of TB in South Africa. Among those with HIV, circulating MIF levels also were associated with lower CD4 cell counts irrespective of TB status (p = 0.016), suggesting an influence of HIV immunosuppression on MIF expression.

Polymorphism of FCGR3A gene in chronic beryllium disease

Previously we showed that alveolar macrophages(AMs) from patients with chronic beryllium disease(CBD) and beryllium sensitization(BeS) demonstrated significantly greater cell surface CD16(encoded by the FCGR3A gene) than controls. We hypothesized that these differences were related to polymorphisms in the FCGR3A gene. This study was to determine the association between FCGR3A polymorphisms in CBD, BeS versus controls as well as clinical data, providing potential information about disease pathogenesis, risk and activity. 189 CBD/154 BeS /150 controls (92 Be-exposed-non-diseased and 58 healthy controls) were included in this study. Sequence specific primers polymerase chain reaction(PCR-SSP) was used to determine FCGR3A 158V/F polymorphisms. We found significantly higher frequencies of the 158V allele (OR:1.60 (CI: 1.17-2.19),p=0.004) and 158VV homozygotes (OR:2.97 (CI:1.48-5.97) p=0.007) in CBD versus controls. No differences were found in the frequencies of FCGR3A alleles or genotypes between BeS versus controls and CBD versus BeS. Average changes in exercise testing maximum workload(Wlm),maximum oxygen consumption(VO₂m) and diffusion capacity of carbon monoxide(DLCO) demonstrated greater decline over time in those CBD cases with the 158VV gene, modelled between 10 and 40 years from first beryllium exposure. The FCGR3A V158F polymorphism is associated with CBD compared to BeS and controls and may impact lung function in CBD.

MIF -173 G > C (rs755622) Gene Polymorphism Modulates Tuberculosis Risk: Evidence from a Meta-analysis and Trial Sequential Analysis

The macrophage migration inhibitory factor (MIF) is a cytokine that plays an important role in inhibiting the growth of pathogenic Mycobacterium tuberculosis (M.tb) and regulates immune responses against M.tb pathogen. MIF -173 G > C gene polymorphism may affect immunity in an individual and leads to susceptibility to tuberculosis (TB). A large number of studies have investigated the relevance of this polymorphism with TB risk, but their results were inconclusive. To obtain a precise conclusion, a meta-analysis was performed by retrieving six eligible studies from Google Scholar, PubMed (Medline), and EMBASE online databases. Overall combined analysis suggested increased TB risk between MIF -173 G > C polymorphism and overall risk in four genetic models, i.e., allelic (C vs. G: p = 0.001; OR = 1.517, 95% CI = 1.312 to 1.753), homozygous (CC vs. GG: p = 0.026; OR = 1.874, 95% CI = 1.079 to 3.257), heterozygous (GC vs. GG: p = 0.001; OR = 1.542, 95% CI = 1.273 to 1.868) and dominant model (CC + GC vs. GG: p = 0.001; OR = 1.631, 95% CI = 1.362 to 1.955). Similarly, increased TB risk was observed in subgroup analysis of Asian ethnicity. No publication bias was observed. These results suggested that MIF -173 G > C variant is a significant risk factor for TB in overall and in Asian populations, and can be used as prognostic marker for TB susceptibility.

New variant identified in major susceptibility locus to tuberculosis on chromosomal region 8q12-q13 in Moroccan population: a case control study

Background

Tuberculosis (TB) remains a global health problem. Several studies have implicated genetic host factors in predisposing populations to TB disease. In this study, we have selected NSMAF (Neutral Sphingomyelinase Activation Associated Factor) as a candidate gene to evaluate its level of association with TB disease in a Moroccan population for two reasons: first, this gene is located in a major susceptibility locus on chromosomal region 8q12-q13 in the Moroccan population, closely linked to the CYP7A1 gene, which was previously shown to be associated with TB disease; second, NSMAF has an important role in immune system function.

Methods

We conducted a case-control study including 269 genomic DNA samples extracted from pulmonary TB (PTB) patients and healthy controls (HC). We genotyped three selected SNPs (rs2228505, rs36067275 and rs10505004) using TaqMan® allelic discrimination assays.

Results

Only the rs1050504 C > T genotype was observed to be significantly associated with an increased risk for developing pulmonary TB (41.8% vs 27%, OR 1.95, 95% CI 1.16–3.27; p = 0.01). In contrast, the TT genotype was significantly associated with resistance to PTB (4.1% vs 15.6%, OR 0.23, 95% CI 0.08–0.63; p = 0.002).

Conclusion

Our findings suggest that genetic variations in the NSMAF gene could modulate the risk of PTB development in a Moroccan population. Further functional studies are needed to confirm these findings.

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.

Association between the MIF-173G/C Polymorphism and Serum MIF levels with Pulmonary Tuberculosis: A Meta-analysis

Many studies have indicated that Macrophage migration inhibitory factor (MIF)-173G/C gene polymorphisms are associated with susceptibility to pulmonary tuberculosis (PTB). Additionally, some studies have suggested that there are higher levels of serum MIF in patients with PTB than the controls. However, the results of these studies were underpowered. The current study aimed to precisely evaluate the association between the MIF-173G/C polymorphism and serum MIF concentrations with PTB. Therefore, a systematic literature search was preformed to identify studies involving the indicated association. Eleven articles (1316 cases and 1272 controls) were included in the study. The results indicated that the MIF-173G/C polymorphism was significantly associated with PTB susceptibility, especially in Asians. Interestingly, the results further detected that circulating MIF levels were significantly higher in patients with PTB than in healthy controls, but this was only the case among Asians. Moreover, the statistical significance was also similar to that of the high quality group. The present study indicated that the MIF-173G/C polymorphism may contribute to the development of PTB. Furthermore, significantly higher serum MIF levels were observed in PTB patients than in controls, which further indicated that the MIF may play an important role in PTB progression, particularly in Asians.

Macrophage migration inhibitory factor -173 G > C polymorphism and risk of tuberculosis: A meta-analysis

The aim of the present meta-analysis was to find out the impact of MIF -173 G > C polymorphism on risk of tuberculosis (TB). We conducted a search of case-control studies on the associations of -173 G > C variant of MIF with susceptibility to tuberculosis in PubMed, ISI Web of Science, and Scopus. We extracted the data from eligible studies and achieved a meta-analysis to examine the relationship between MIF -173 G > C polymorphism and the risk of TB. Odds ratios (ORs) with the corresponding 95 % confidence intervals (CIs) were pooled to find out the impact of MIF -173G > C promoter polymorphism on TB risk. The pooled ORs were calculated for the codominant, dominant, recessive, and allelic model comparison. The findings revealed that MIF -173 G > C variant increased the risk of TB in codominant (OR = 1.54, 95 %CI = 1.26-1.88, p < 0.0001; CG vs GG), and dominant (OR = 1.62, 95 %CI = 1.33-1.96, p < 0.00001; GC+CC vs GG) inheritance models tested. The results suggested that the MIF -173 C allele significantly increased the risk of PTB (OR = 1.49, 95 %CI = 1.28-1.74, p < 0.00001). The findings of this meta-analysis propose that MIF -173 G > C variant is associated with the risk of TB. More case-control studies with well-designed in different ethnic groups and larger sample size are needed to confirm the findings.

Construction and analysis of the transcription factor-microRNA co-regulatory network response to Mycobacterium tuberculosis: a view from the blood

Mycobacterium tuberculosis (Mtb) infection has been regional outbreak, recently. The traditional focus on the patterns of "reductionism" which was associated with single molecular changes has been unable to meet the demand of early diagnosis and clinical application when current tuberculosis infection happened. In this study, we employed a systems biology approach to collect large microarray data sets including mRNAs and microRNAs (miRNAs) to identify the differentially expressed mRNAs and miRNAs in the whole blood of TB patients. The aim was to identify key genes associated with the immune response in the pathogenic process of tuberculosis by analyzing the co-regulatory network that was consisted of transcription factors and miRNAs as well as their target genes. The network along with their co-regulatory genes was analyzed utilizing Transcriptional Regulatory Element Database (TRED) and Database for Annotation, Visualization and Integrated Discovery (DAVID). We got 21 (19 up-regulated and 2 down-regulated) differentially expressed genes that were co-regulated by transcription factors and miRNAs. KEGG pathway enrichment analysis showed that the 21 differentially expressed genes were predominantly involved in Tuberculosis signaling pathway, which may play a major role in tuberculosis biological process. Quantitative real-time PCR was performed to verify the over expression of co-regulatory genes (FCGR1A and CEBPB). The genetic expression was correlated with clinicopathological characteristics in TB patients and inferences drawn. Our results suggest the TF-miRNA gene co-regulatory network may help us further understand the molecular mechanism of immune response to tuberculosis and provide us a new angle of future biomarker and therapeutic targets.

The Role of Host Genetics (and Genomics) in Tuberculosis

Familial risk of tuberculosis (TB) has been recognized for centuries. Largely through studies of mono- and dizygotic twin concordance rates, studies of families with Mendelian susceptibility to mycobacterial disease, and candidate gene studies performed in the 20th century, it was recognized that susceptibility to TB disease has a substantial host genetic component. Limitations in candidate gene studies and early linkage studies made the robust identification of specific loci associated with disease challenging, and few loci have been convincingly associated across multiple populations. Genome-wide and transcriptome-wide association studies, based on microarray (commonly known as genechip) technologies, conducted in the past decade have helped shed some light on pathogenesis but only a handful of new pathways have been identified. This apparent paradox, of high heritability but few replicable associations, has spurred a new wave of collaborative global studies. This review aims to comprehensively review the heritability of TB, critically review the host genetic and transcriptomic correlates of disease, and highlight current studies and future prospects in the study of host genomics in TB. An implicit goal of elucidating host genetic correlates of susceptibility to Mycobacterium tuberculosis infection or TB disease is to identify pathophysiological features amenable to translation to new preventive, diagnostic, or therapeutic interventions. The translation of genomic insights into new clinical tools is therefore also discussed.

Antibodies and tuberculosis

Tuberculosis (TB) remains a major public health problem internationally, causing 9.6 million new cases and 1.5 million deaths worldwide in 2014. The Bacillus Calmette-Guérin vaccine is the only licensed vaccine against TB, but its protective effect does not extend to controlling the development of infectious pulmonary disease in adults. The development of a more effective vaccine against TB is therefore a pressing need for global health. Although it is established that cell-mediated immunity is necessary for the control of latent infection, the presupposition that such immunity is sufficient for vaccine-induced protection has recently been challenged. A greater understanding of protective immunity against TB is required to guide future vaccine strategies against TB.

In contrast to cell-mediated immunity, the human antibody response against M.tb is conventionally thought to exert little immune control over the course of infection. Humoral responses are prominent during active TB disease, and have even been postulated to contribute to immunopathology. However, there is evidence to suggest that specific antibodies may limit the dissemination of M.tb, and potentially also play a role in prevention of infection via mucosal immunity. Further, antibodies are now understood to confer protection against a range of intracellular pathogens by modulating immunity via Fc-receptor mediated phagocytosis. In this review, we will explore the evidence that antibody-mediated immunity could be reconsidered in the search for new vaccine strategies against TB.

Polymorphisms in Host Immunity-Modulating Genes and Risk of Invasive Aspergillosis: Results from the AspBIOmics Consortium

Recent studies suggest that immune-modulating single-nucleotide polymorphisms (SNPs) influence the risk of developing cancer-related infections. Here, we evaluated whether 36 SNPs within 14 immune-related genes are associated with the risk of invasive aspergillosis (IA) and whether genotyping of these variants might improve disease risk prediction. We conducted a case-control association study of 781 immunocompromised patients, 149 of whom were diagnosed with IA. Association analysis showed that the IL4Rrs2107356 and IL8rs2227307 SNPs (using dbSNP numbering) were associated with an increased risk of IA (IL4Rrs2107356 odds ratio [OR], 1.92; 95% confidence interval [CI], 1.20 to 3.09; IL8rs2227307 OR, 1.73; 95% CI, 1.06 to 2.81), whereas the IL12Brs3212227 and IFNγrs2069705 variants were significantly associated with a decreased risk of developing the infection (IL12Brs3212227 OR, 0.60; 95% CI, 0.38 to 0.96; IFNγrs2069705 OR, 0.63; 95% CI, 0.41 to 0.97). An allogeneic hematopoietic stem cell transplantation (allo-HSCT)-stratified analysis revealed that the effect observed for the IL4Rrs2107356 and IFNγrs2069705 SNPs was stronger in allo-HSCT (IL4Rrs2107356 OR, 5.63; 95% CI, 1.20 to 3.09; IFNγrs2069705 OR, 0.24; 95% CI, 0.10 to 0.59) than in non-HSCT patients, suggesting that the presence of these SNPs renders patients more vulnerable to infection, especially under severe and prolonged immunosuppressive conditions. Importantly, in vitro studies revealed that carriers of the IFNγrs2069705C allele showed a significantly increased macrophage-mediated neutralization of fungal conidia (P = 0.0003) and, under stimulation conditions, produced higher levels of gamma interferon (IFNγ) mRNA (P = 0.049) and IFNγ and tumor necrosis factor alpha (TNF-α) cytokines (P value for 96 h of treatment with lipopolysaccharide [PLPS-96 h], 0.057; P value for 96 h of treatment with phytohemagglutinin [PPHA-96 h], 0.036; PLPS+PHA-96 h = 0.030; PPHA-72 h = 0.045; PLPS+PHA-72 h = 0.018; PLPS-96 h = 0.058; PLPS+PHA-96 h = 0.0058). Finally, we also observed that the addition of SNPs significantly associated with IA to a model including clinical variables led to a substantial improvement in the discriminatory ability to predict disease (area under the concentration-time curve [AUC] of 0.659 versus AUC of 0.564; P-2 log likehood ratio test = 5.2 · 10(-4) and P50.000 permutation test = 9.34 · 10(-5)). These findings suggest that the IFNγrs2069705 SNP influences the risk of IA and that predictive models built with IFNγ, IL8, IL12p70, and VEGFA variants can used to predict disease risk and to implement risk-adapted prophylaxis or diagnostic strategies.

Single nucleotide polymorphisms in cytokine MIF gene promoter region are closely associated with human susceptibility to tuberculosis in a southwestern province of China

The gene encoding macrophage migration inhibitory factor (MIF) has been proposed as candidate tuberculosis (TB) susceptibility gene. In order to elucidate whether MIF gene variants are associated with susceptibility to retreatment cases of TB, and prevent drug-resistant TB prevalence, we conducted a study based on paired human population data. MIF -173 G/C single nucleotide polymorphisms (rs755622) were genotyped using polymerase chain reaction-restriction fragment length polymorphism. MIF levels were detected with enzyme-linked immunosorbent assay. Association analysis of polymorphism to TB showed that distribution of MIF -173 genotypes (GC+CC) was significantly higher in total cases of TB than in the controls. Statistically significant differences of frequencies for MIF -173 (GG vs. GC+CC) were demonstrated when comparing total cases of TB, new cases of TB, and retreatment cases of TB to controls, respectively. In contrast, the frequencies of MIF -173 (GG vs. GC+CC) demonstrated no difference between new cases of TB and retreatment cases of TB. Association analysis of MIF protein concentrations to TB indicated that MIF concentration is significantly higher in total cases of TB, new cases of TB, and retreatment cases of TB than in controls (P<0.01). In summary, our results demonstrated that MIF gene -173 G/C single nucleotide polymorphisms implicate in genetic susceptibility to TB, and GC+CC of MIF -173 site increases the risk of TB. We also found that no correlation between -173 G/C single nucleotide polymorphism and retreatment cases of TB in Yunnan Province population of China.

Macrophage migration inhibitory factor -173 G/C polymorphism is associated with an increased risk of pulmonary tuberculosis in Zahedan, Southeast Iran

Macrophage migration inhibitory factor (MIF) has an important role in controlling infection. The aim of this study was to evaluate the possible association between MIF -173 G/C functional polymorphism and pulmonary tuberculosis (PTB) in an Iranian population from Zahedan Southeast Iran. This case-control study was done on 161 PTB and 142 healthy subjects. Genomic DNA was extracted from all participants by salting out method. The MIF -173 G/C variant was genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The finding showed that the MIF -173 G/C polymorphism increased the risk of PTB in codominant (OR=1.76, 95 % CI=1.05-2.95, p=0.038, GC vs GG) and dominant (OR=1.78, 95 % CI=1.09-2.91, p=0.027, GC+CC vs GG) tested inheritance models. Furthermore, the minor allele frequency (MAF) increased the risk of PTB in comparison with G allele (OR=1.63, 95 % CI=1.07-2.48, p=0.028). In conclusion, the present study provides evidence that -173 G/C polymorphism may increase the risk of PTB.

The role of B cells and humoral immunity in Mycobacterium tuberculosis infection

Mycobacterium tuberculosis remains a major public health burden. It is generally thought that while B cell- and antibody-mediated immunity plays an important role in host defense against extracellular pathogens, the primary control of intracellular microbes derives from cellular immune mechanisms. Studies on the immune regulatory mechanisms during infection with M. tuberculosis, a facultative intracellular organism, has established the importance of cell-mediated immunity in host defense during tuberculous infection. Emerging evidence suggest a role for B cell and humoral immunity in the control of intracellular pathogens, including obligatory species, through interactions with the cell-mediated immune compartment. Recent studies have shown that B cells and antibodies can significantly impact on the development of immune responses to the tubercle bacillus. In this review, we present experimental evidence supporting the notion that the importance of humoral and cellular immunity in host defense may not be entirely determined by the niche of the pathogen. A comprehensive approach that examines both humoral and cellular immunity could lead to better understanding of the immune response to M. tuberculosis.

The CYP7A1 gene rs3808607 variant is associated with susceptibility of tuberculosis in Moroccan population

Introduction

Despite the medical progress in treatment. Tuberculosis (TB) continues to be a serious global health problem. A genome-wide linkage study identified a major susceptibility locus on chromosomal region 8q12-q13 in Moroccan TB patients. The CYP7A1 gene is located in this region and codes for cholesterol 7a-hydroxylase, an enzyme involved in cholesterol catabolism.

Methods

We selected three SNPs (rs3808607, rs8192875 and rs8192879) and studied their genotype and allele frequencies distribution in patients with pulmonary (PTB) or pleural TB (pTB), and compared them to Healthy Controls (HC). Genotyping of rs8192875 and rs8192879 SNPs was carried out using the Taq Man SNP genotyping Assay while rs3808607 was investigated by PCR-RFLP.

Results

We reported here for the first time a statistically significant increase in the AA homozygote genotype frequency of rs3808607 in PTB patients compared to HC (p = 0.02, OR = 1.93, 95% CI: 1.93 (1.07;3.49). The increased risk of developing TB was maintained when we combined the groups of patients (PTB-pTB) (p = 0.01, OR= 1.91, 95% CI = (1.07 - 3.42). In contrast, no genetic association was observed between the rs8192875 or rs8192879 polymorphisms and TB.

Conclusion

Our investigations suggest that rs3808607 may play a role in susceptibility to TB in a Moroccan population.

Macrophage migration inhibitory factor (MIF) is a critical mediator of the innate immune response to Mycobacterium tuberculosis

Macrophage migration inhibitory factor (MIF), an innate cytokine encoded in a functionally polymorphic genetic locus, contributes to detrimental inflammation but may be crucial for controlling infection. We explored the role of variant MIF alleles in tuberculosis. In a Ugandan cohort, genetic low expressers of MIF were 2.4-times more frequently identified among patients with Mycobacterium tuberculosis (TB) bacteremia than those without. We also found mycobacteria-stimulated transcription of MIF and serum MIF levels to be correlated with MIF genotype in human macrophages and in a separate cohort of US TB patients, respectively. To determine mechanisms for MIF's protective role, we studied both aerosolized and i.v. models of mycobacterial infection and observed MIF-deficient mice to succumb more quickly with higher organism burden, increased lung pathology, and decreased innate cytokine production (TNF-α, IL-12, IL-10). MIF-deficient animals showed increased pulmonary neutrophil accumulation but preserved adaptive immune response. MIF-deficient macrophages demonstrated decreased cytokine and reactive oxygen production and impaired mycobacterial killing. Transcriptional investigation of MIF-deficient macrophages revealed reduced expression of the pattern recognition receptor dectin-1; restoration of dectin-1 expression recovered innate cytokine production and mycobacterial killing. Our data place MIF in a crucial upstream position in the innate immune response to mycobacteria and suggest that commonly occurring low expression MIF alleles confer an increased risk of TB disease in some populations.

Influence of MIF, CD40, and CD226 polymorphisms on risk of rheumatoid arthritis

Macrophage migration inhibitory factor (MIF) is a key pro-inflammatory mediator. It plays an important role part in the pathogenesis of several inflammatory and immune diseases. A functional single nucleotide polymorphism (SNP) of MIF -173 G/C is known to influence MIF promoter activity in T lymphoblast cell lines and is associated with a higher serum MIF level. The CD40 is also crucial for some relevant functions of the immune system and may be related to rheumatoid arthritis (RA). And CD226 is an important cell-surface receptor molecule involved in the adhesion and activation of T-cell. We hypothesized that these polymorphisms may contribute to RA susceptibility. We studied MIF -173 G/C, CD40, and CD226 gene polymorphisms in 214 patients with RA and 478 controls in a Chinese population. Genotyping was done by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). When the MIF -173 GG homozygote genotype was used as the reference group, the CC genotype was associated with a significantly increased risk for RA. In the recessive model, when the MIF -173 GG/GC genotypes were used as the reference group, the CC homozygote genotype was associated with a significant 1.56-fold increased susceptibility to RA. None of the CD40 rs1883832 C/T and CD226 rs763361 C/T polymorphisms achieved a significant difference in genotype distributions between cases and controls. In the stratification analyzes, a significantly increased risk for RA associated with the MIF -173 CC genotype was evident among CRP-negative patients compared with the MIF -173 GG/GC genotype. For the CD40 rs1883832 C/T variant, the risk effects of CD40 rs1883832 TT versus CD40 rs1883832 CC/CT were significant in men. These findings suggested that the functional SNP MIF -173 G/C variant allele was associated with the development of RA. However, CD40 and CD226 gene polymorphisms may not be associated with RA susceptibility. Due to the limitation of sample size, this study should be considered preliminary.

Association of Fcγ receptor IIB polymorphism with cryptococcal meningitis in HIV-uninfected Chinese patients

BACKGROUND

As important regulators of the immune system, the human Fcγ receptors (FcγRs) have been demonstrated to play important roles in the pathogenesis of various infectious diseases. The aim of the present study was to identify the association between FCGR polymorphisms and cryptococcal meningitis.

METHODOLOGY/PRINCIPAL FINDINGS

In this case control genetic association study, we genotyped four functional polymorphisms in low-affinity FcγRs, including FCGR2A 131H/R, FCGR3A 158F/V, FCGR3B NA1/NA2, and FCGR2B 232I/T, in 117 patients with cryptococcal meningitis and 190 healthy controls by multiplex SNaPshot technology. Among the 117 patients with cryptococcal meningitis, 59 had predisposing factors. In patients with cryptococcal meningitis, the FCGR2B 232I/I genotype was over-presented (OR = 1.652, 95% CI [1.02-2.67]; P = 0.039) and the FCGR2B 232I/T genotype was under-presented (OR = 0.542, 95% CI [0.33-0.90]; P = 0.016) in comparison with control group. In cryptococcal meningitis patients without predisposing factors, FCGR2B 232I/I genotype was also more frequently detected (OR = 1.958, 95% CI [1.05-3.66]; P = 0.033), and the FCGR2B 232I/T genotype was also less frequently detected (OR = 0.467, 95% CI [0.24-0.91]; P = 0.023) than in controls. No significant difference was found among FCGR2A 131H/R, FCGR3A 158F/V, and FCGR3B NA1/NA2 genotype frequencies between patients and controls.

CONCLUSION/SIGNIFICANCE

We found for the first time associations between cryptococcal meningitis and FCGR2B 232I/T genotypes, which suggested that FcγRIIB might play an important role in the central nervous system infection by Cryptococcus in HIV-uninfected individuals.

Association of tuberculosis and polymorphisms in the promoter region of macrophage migration inhibitory factor (MIF) in a Southwestern China Han population

The macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that plays an important role in the pathogenesis of immune diseases. High levels of MIF have been detected in the sera of patients with tuberculosis (TB), and it has been proposed that MIF gene polymorphisms may influence the risk of developing TB. The aim of this study was to evaluate the potential relationship between functional polymorphisms of MIF and TB in a Han population from Southwestern China. TB patients (n=215) and healthy unrelated controls (n=245) were recruited for this study. Genomic DNA was isolated from all the participants. The MIF-173 G/C SNP was genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The MIF-794 CATT(5-8) microsatellite was evaluated by direct sequencing of the subsequent PCR products. Association analysis of the two polymorphisms showed that the frequency of -173 (GC+CC) in TB patients and controls was 49.3% and 31.4%, respectively, which was statistically significant (OR=2.12, 95% CI=1.45-3.10, P<0.001); the frequencies of -794 (7/X+8/X) were 56.7% and 45.3%, respectively, also statistically significant between the TB and healthy controls (OR=1.58, 95% CI=1.10-2.29, P=0.015). In summary, Genetic variation in the MIF gene is closely associated with tuberculosis. Both the 173 (GC+CC) SNP and -794 (7/X+8/X) microsatellite increased the risk of Chinese Han developing TB.