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

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.

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.

Macrophage migration inhibitory factor - 794 CATT5-8 microsatellite polymorphism and susceptibility of tuberculosis

PURPOSE

The establishment of candidate genetic determinants associated with tuberculosis (TB) is a challenge, considering the divergent frequencies among populations. The objective of this study was to evaluate the association between MIF - 794 CATT _5-8 polymorphism and susceptibility to TB.

METHODS

Case-control study. Patients > 18 years, with pulmonary TB were included. The control group consisted of blood donors and household contacts, not relatives, healthy and > 18 years. MIF - 794 CATT _5-8 were genotyped using sequencing of PCR and capillary electrophoresis.

RESULTS

126 patients and 119 controls were included. The genotype 5/5 was more frequent among cases (15.1%) than in controls (5.9%) (p = 0.019). Cases had more frequently the allele 5 (29.4%) as compared with controls (19.3%) (p = 0.010). Prevalence of 7/X + 8/X genotypes was not different between cases and controls (p = 0.821). There was no difference between patients with alleles 7 and 8 and those with alleles 5 and 6 (p = 0.608).

CONCLUSIONS

The genotype 5/5 and the allele 5 of MIF - 794 CATT _5-8 were more frequent among TB patients than in controls.

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.

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.

Role of Macrophage Migration Inhibitory Factor in Granulomatosis With Polyangiitis

OBJECTIVE

To examine the association between macrophage migration inhibitory factor (MIF) promoter polymorphisms and granulomatosis with polyangiitis (GPA) in human subjects, and to assess the role of MIF in a murine model of granulomatous vasculitis.

METHODS

The human study involved 1,077 patients with GPA and healthy controls whose serum was genotyped by capillary electrophoresis for the MIF -794 CATT_5-8 promoter microsatellite (rs5844572). MIF promoter, CATT-length-dependent gene expression in response to β-glucan was assessed by gene reporter assays. In mouse studies, granulomatous disease was induced by injection of Candida albicans β-glucan into wild-type (WT) or Mif-knockout (Mif-KO) C57BL/6 mice and C57BL/6 mice transgenically overexpressing Mif in lung epithelium (Mif lung-Tg2.1). Mice were treated with a neutralizing anti-MIF antibody and analyzed for the density of pulmonary granulomas, expression of inflammatory chemokines, and frequency of mortality.

RESULTS

The percentage of human subjects carrying >5 CATT repeats in each MIF allele (high genotypic MIF expressers) was 60.2% among patients with GPA and 53.9% among healthy controls (adjusted P = 0.049). In response to granulomatous stimulation, human MIF gene expression increased proportionally with CATT length. Mif lung-Tg2.1 mice exhibited more pulmonary granulomas than WT mice, which in turn showed more granulomas than Mif-KO mice. A significantly higher percentage of Mif lung-Tg2.1 mice, compared to Mif-KO or WT mice, died when injected with Candida albicans β-glucan, and treatment of these mice with an anti-MIF monoclonal antibody protected against a lethal outcome. Levels of MIF-dependent neutrophil/macrophage chemokines were elevated in the bronchoalveolar lavage fluid or plasma of Mif lung-Tg2.1 mice.

CONCLUSION

Patients with GPA have an increased frequency of high MIF expression CATT alleles. Higher Mif expression increases the incidence of mortality and pulmonary granulomas in Mif lung-Tg2.1 mice, while anti-MIF treatment protects these mice against death. Blockade of MIF in high genotypic MIF expressers may therefore offer a selective pharmacologic therapy for GPA.

CATT polymorphism in MIF gene promoter is closely related to human pulmonary tuberculosis in a southwestern China population

Macrophage migration inhibitory factor (MIF) is deemed as an immunoregulatory and proinflammatory cytokine related to the progression of tuberculosis. A CATT short tandem repeat (STR) polymorphism at position −794 in the MIF gene promoter region is associated with the susceptibility to tuberculosis (TB). To investigate whether macrophage MIF gene mif CATT variants are associated with susceptibility to retreatment cases of TB and drug-resistant TB prevalence, genotyping of MIF −794 CATT polymorphism and quantifying of serum MIF were performed to associate MIF−794 CATT polymorphism with new patients and retreatment cases. Significant increases in MIF −794 CATT genotypes 7/8 and allele CATT 8 were observed in TB patients. Significant differences in the genotypic frequencies of MIF −794 CATT (5/X + 6/X vs 7/7 + 7/8) were demonstrated upon comparing the total cases and the new cases of TB with the controls. Significant differences in the allelic frequencies of MIF −794 CATT (5 + 6 vs 7 + 8) were observed in the total cases and new cases of TB. No differences in the genotypic frequencies of the MIF −794 CATT (5/X + 6/X vs 7/7 + 7/8) were observed between the retreatment cases and the controls or between the new cases and retreatment cases. In conclusion, the MIF −794 CATT genotypes 7/8 and allele CATT 8 were highly associated with TB; no differences in the genotypic frequencies of the MIF −794 CATT (5/X + 6/X vs 7/7 + 7/8) were observed between the new cases and retreatment cases.

Macrophage migration inhibitory factor-794 CATT microsatellite polymorphism and risk of tuberculosis: a meta-analysis

Tuberculosis (TB) is a chronic infectious disease that has been threatening public health for many years. Several studies have shown the relationship between the macrophage migration inhibitory factor (MIF)-794 CATT (MIF-794 CATT) microsatellite polymorphism and susceptibility to TB. However, the results remain inconclusive. Therefore, we aim to find out the impact of MIF-794 CATT microsatellite polymorphism on risk of TB by a comprehensive meta-analysis. We conducted a systematic study search in PubMed, Embase, the Cochrane Library, and the China National Knowledge Infrastructure (CNKI) up to October 2017. Five studies involving 836 cases and 678 controls were included in the current meta-analysis. We calculated the pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) to estimate the association between the MIF-794 CATT microsatellite polymorphism and risk of TB. The reliability of the results were evaluated with trial sequential analysis (TSA). The results suggested that the MIF-794 CATT microsatellite polymorphism was significantly associated with the susceptibility of TB in all comparisons for allele (7 + 8 compared with 5 + 6, OR = 1.56, 95% CI = 1.31–1.87, P<0.00001) and genotype (7/X + 8/X compared with 5/X + 6/X, OR = 1.81, 95% CI = 1.39–2.36, P<0.0001). Therefore, the meta-analysis indicated the MIF-794 allele CATT₇ and CATT₈ may be a risk factor to increase the susceptibility of TB, which was confirmed by TSA.

Macrophage Migration Inhibitory Factor -173GC Variant Might Increase the Risk of Behçet's Disease

OBJECTIVE

The aim of the present study was to investigate any possible association between the macrophage migration inhibitory factor (MIF) -173GC variant and Behçet's disease (BD) in a group of Turkish patients.

SUBJECTS AND METHODS

A total of 111 patients with BD and 100 healthy controls were enrolled in this study. Genomic DNA was extracted from peripheral lymphocytes. The MIF -173GC variant was genotyped using polymerase chain reaction restriction fragment length polymorphism. The allele and genotype frequencies of patients and controls were compared using the χ2 test.

RESULTS

A statistically significant difference in the distribution of the genotype was observed between BD patients and healthy controls. The homo-genotype CC was more prevalent in the patient group compared to the control group (p = 0.008, OR: 0.24, 95% Cl: 0.05-0.78). A significant association was observed when the patients were compared with the controls according to GG + GC versus CC ge-notypes (p = 0.003, OR: 1.21, 95% CI: 0.06-0.063). Allele frequencies of the MIF -173GC variant did not show any statistically significant difference between patients and controls.

CONCLUSION

In this study, we conclude that the CC ge-notype of the MIF -173GC variant may be a risk factor in the pathogenesis of BD in the Turkish population. However, further studies with larger samples are needed to address the exact role of this variant in BD.

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.

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.

Evaluation of TNF-alpha gene (G308A) and MBL2 gene codon 54 polymorphisms in Turkish patients with tuberculosis

OBJECTIVE

MBL acts as a binding protein that enables uptake of mycobacteria into macrophages. And, TNF-alpha is an important cytokine that is involved in control of mycobacterial infections both in-vivo and in-vitro. A large number of genetic factors exerting susceptibility to tuberculosis has been identified, among which mannose-binding lectin and tumor necrosis factor-alpha call attention. The objective of this study is to compare the frequency of TNF-alpha and MBL gene polymorphisms between patients diagnosed with tuberculosis and healthy volunteers in Turkey, and determine the association between tuberculosis and TNF-alpha gene (G308A) and MBL2 gene codon 54 polymorphisms.

MATERIAL AND METHODS

The study included 69 patients who were diagnosed with tuberculosis and 70 control subjects. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used to detect TNF-alpha (G308A) gene and MBL2 gene codon 54 polymorphisms. For statistical analysis, the significance level was determined as p<0.05.

RESULTS

A comparison between patient and control groups in TNF-alpha (G308A) gene and MBL2 gene codon 54 polymorphisms showed no statistically significant difference (p>0.05). However, a comparison of mean body mass index (BMI) and smoking status showed a statistically significant difference between the tuberculosis and control groups (p=0.01 and p=0.009, respectively).

CONCLUSION

Our results suggest that the MBL2 gene Codon 54 and TNF-alpha gene G308A polymorphisms are not associated with an increased risk for development of tuberculosis in our patients. Further studies are required including more cases of tuberculosis patients and other potentially relevant gene polymorphisms.

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.

Functional polymorphisms in the gene encoding macrophage migration inhibitory factor (MIF) are associated with active pulmonary tuberculosis

OBJECTIVE

The role of the cytokine, macrophage migration inhibition factor (MIF) was assessed in tuberculosis. This case-control study investigated whether commonly occurring functional MIF polymorphisms are associated with active tuberculosis as well as with serum levels of MIF, IFN-γ and TNF-α.

METHODS

Two MIF promoter polymorphisms, a functional -794 CATT5-8 microsatellite repeat (rs5844572) and a -173G/C single-nucleotide polymorphism (rs755622), were analysed by PCR and PCR-RFLP, respectively, in 47 patients and 50 healthy subjects. The mRNA level of MIF was performed by real-time PCR (RT-PCR), and MIF, IFN-γ and TNF-α serum levels were determined by ELISA.

RESULTS

A significant increase of MIF mRNA expression and MIF protein level were found in patients compared to healthy controls. Meanwhile, the increase of IFN-γ and TNF-α serum levels were confirmed. According to the profile of genetic model, a significant association was found of genotypes carrying the -794 CATT 7 or 8 and -173 C risk alleles with susceptibility to active tuberculosis and with a significant increase of MIF, IFN-γ and TNF-α.

CONCLUSIONS

These data suggested a distinct genetic and immunopathogenic basis for tuberculosis at the MIF locus. Serum MIF, IFN-γ and TNF-α profiles distinguish tuberculosis from the more inflammatory phenotype and may play a role in pathogenesis and as biomarkers of active tuberculosis.

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.

A genetic role for macrophage migration inhibitory factor (MIF) in adult-onset Still's disease

Introduction

Adult-onset still's disease (AOSD) is a rare systemic inflammatory disorder in which abnormalities in inflammatory cytokines production appear to play a pathophysiological role. Our previous work has reported increased expression of macrophage migration inhibitory factor (MIF) and revealed its correlation with disease severity and activity in AOSD. A -173 G/C single nucleotide polymorphism (SNP) (rs755622) and a -794 CATT_5-8 repeat (rs5844572) in the MIF promoter have been reported. In this study, we sought to explore the relationship between functional MIF promoter polymorphisms and MIF expression in AOSD.

Methods

100 patients and 200 controls were recruited in the study. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay was utilized to analyze the -173 G/C SNP (rs755622) and PCR-based size discrimination assay was applied to detect the -794 CATT_5-8 repeat (rs5844572) in the MIF promoter. Plasma MIF levels were measured by ELISA. MIF mRNA levels were quantified by real-time reverse transcription (RT)-PCR. Bisulfate genomic sequencing was employed to evaluate DNA methylation status within the MIF promoter.

Results

We identified that the frequencies of MIF -794 CATT₅ (P = 0.001) allele and the expression of MIF (P <0.001) were increased in patients compared to healthy controls. Plasma levels of MIF in patients with CC genotype were higher than those of patients with GC or GG genotypes (P = 0.05). In patients with established AOSD, a higher frequency of -794 CATT₇ containing MIF genotypes was observed in those with liver dysfunction (P = 0.009). Haplotype analysis revealed a higher representation of the MIF haplotype defined by -173*C/-794 CATT₅ (C5) in AOSD patients (P = 0.001).

Conclusion

Functional promoter polymorphisms in the MIF gene influence plasma MIF levels in AOSD and may contribute to disease susceptibility or clinical presentation of AOSD.

Host response to respiratory bacterial pathogens as identified by integrated analysis of human gene expression data

Respiratory bacterial pathogens are one of the leading causes of infectious death in the world and a major health concern complicated by the rise of multi-antibiotic resistant strains. Therapeutics that modulate host genes essential for pathogen infectivity could potentially avoid multi-drug resistance and provide a wider scope of treatment options. Here, we perform an integrative analysis of published human gene expression data generated under challenges from the gram-negative and Gram-positive bacteria pathogens, Pseudomonas aeruginosa and Streptococcus pneumoniae, respectively. We applied a previously described differential gene and pathway enrichment analysis pipeline to publicly available host mRNA GEO datasets resulting from exposure to bacterial infection. We found 72 canonical human pathways common between four GEO datasets, representing P. aeruginosa and S. pneumoniae. Although the majority of these pathways are known to be involved with immune response, we found several interesting new interactions such as the SUMO1 pathway that might have a role in bacterial infections. Furthermore, 36 host-bacterial pathways were also shared with our previous results for respiratory virus host gene expression. Based on our pathway analysis we propose several drug-repurposing opportunities supported by the literature.

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.