Association of interferon-gamma and interleukin-4 gene polymorphisms with susceptibility to brucellosis in Iranian patients

Whole-Genome Resequencing to Study Brucellosis Susceptibility in Sheep

Brucellosis is a zoonotic disease and a major public health problem. However, the genetic mechanism of brucellosis in sheep remains unclear. In this study, serum samples were collected from 6,358 sheep from the F2 population (Dorper sheep ♂ × Hu sheep ♀), and antibody levels were continuously measured at 14 days and 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 months after administration of brucellosis vaccine. Finally, 19 brucellosis-resistant group (BRG) sheep and 22 brucellosis-susceptible group sheep (BSG) were screened for whole-genome sequencing. Using the fixation index, Fisher’s exact test, and chi-square test, a total of 205 candidate SNP sites were identified. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis suggested that 138 candidate genes were significantly enriched in adherens junction (CTNNA3, PARD3, and PTPRM), cell adhesion molecules (NLGN1, CNTNAP2, NCAM1, and PTPRM), salivary secretion (LOC101102109, PRKG1, and ADCY2), and hippo signaling pathway (CTNNA3, YAP1, and PARD3). These findings provide valuable molecular markers for brucellosis resistance breeding in sheep and novel insights into the genetic mechanism of brucellosis resistance.

Association of TNF rs668920841 and INRA111 polymorphisms with caprine brucellosis: A case-control study of candidate genes involved in innate immunity

Caprine brucellosis is an infectious, contagious zoonotic disease caused by Brucella melitensis. Multiple factors, including host genetics, can influence the outcome of the exposure to Brucella; and it is expected that genetic variants that affect the host innate immune response could have a key role in Brucella infection and pathogenesis. In this study, we evaluated if polymorphisms in innate immunity-related genes are associated with results of Brucella infection in goats. Nine polymorphisms within interferon gamma (IFNG), tumor necrosis factor (TNF), MyD88 innate immune signal transduction adaptor (MYD88), interleukin 10 (IL10) and IL-10 receptor subunit alpha (IL10RA) genes and two molecular markers (BMS2753 and INRA111) were resolved by PCR-capillary electrophoresis in samples from 81 seronegative and 61 seropositive goats for brucellosis. A heterozygous genotype at INRA111, a microsatellite near the VRK serine/threonine kinase 2 (VRK2) gene, was associated with absence of Brucella-specific antibodies in goats naturally exposed to the pathogen (P = .004). Conversely, variants in the TNF gene (rs668920841) and near the IFN gamma receptor 1 (IFNGR1) gene (microsatellite BMS2753) were significantly associated with presence of Brucella-specific antibodies at allelic (P = .042 and P = .046) and genotypic level (P = .012 and P = .041, respectively). Moreover, an in silico analysis predicted a functional role of the insertion-deletion polymorphism rs668920841 on the transcriptional regulation of the caprine TNF gene. Altogether, these results contribute to the identification of genetic factors that have a putative effect on the resistance / susceptibility phenotype of goats to Brucella infection.

Association between polymorphisms of cytokine genes and brucellosis: A comprehensive systematic review and meta-analysis

OBJECTIVE

Owing to involvement of host genetic factors in susceptibility to brucellosis infection and its outcome, this study aimed to carry out a comprehensive systematic review and meta-analysis to derive a precise evaluation of the association between the risk of brucellosis and its focal complication and all cytokines examined in case-control studies, including Interferon gamma (IFN-γ), Tumor Necrosis Factor (TNF)-α, TNF-β, Transforming Growth Factor(TGF)-β, IL-2, IL-4, IL-6, IL-10, IL-12B, IL-15, and IL-18 polymorphisms.

METHODS

A systematic literature search in PubMed, Web of Science, Google Scholar, and Scopus was performed to identify the relevant studies, and related information was extracted. The effect size (ES) and corresponding 95% confidence intervals (CIs) were calculated to estimate the association.

RESULTS

From 158 initial results, twenty-five eligible studies were included in the meta-analysis. Overall, the pooled results showed that the dominant models of IFN-γ UTR5644, TGF-β rs1800470 and rs1800471, TNF-α rs1800629, and IL-10 rs1800872 were significantly less frequent in brucellosis patients than the controls. Also, the pooled analysis of the mutant allele vs. wild allele of TGF-β rs1800471 and IL-10 rs1800872 showed negative association with brucellosis risk. On the other hand, our pooled analysis demonstrated that the mutant allele of IL-4 rs2243250 and IL-18 rs1946519 were associated with increased susceptibility to brucellosis. In addition, the IFN-γ UTR5644 and TGF-β rs1800470 were more frequent in the patients without focal forms.

CONCLUSIONS

IL-4 rs2243250 and IL-18 rs1946519 have a positive correlation with brucellosis whereas the IFN-γ UTR5644, TGF-β rs1800470 and rs1800471, TNF-α rs1800629, and IL-10 rs1800872 showed a negative association with this disease. The association between the other single nucleotide polymorphisms (SNP) and brucellosis risk was not confirmed in the current meta-analysis. PROSPERO Registration: CRD42018117203.

IL-4 polymorphism influences susceptibility to Pneumocystis jirovecii pneumonia in HIV-positive patients

OBJECTIVES

Pneumocystis jirovecii pneumonia (PJP) is an important cause of morbidity and mortality in HIV-positive patients. Polymorphisms in immune genes are increasingly reported to influence susceptibility to fungal infections. We analysed the role of 21 single nucleotide polymorphisms from 19 candidate genes on PJP development in patients from the Swiss HIV Cohort Study.

DESIGN AND METHODS

The analysis included patients with a nadir CD4 T-cell count less than 200 cells/μl, divided into a discovery (N = 1645) and a replication (N = 1861) cohort. The associations were analysed by using cumulative incidence curves as well as competing risk regression over 18 years, starting from the estimated date of HIV infection, considering death a competing risk, with censoring at lost follow-up, and assuming the dominant mode of inheritance.

RESULTS

The minor allele of rs2243250 in IL-4 was associated with the risk of PJP in the discovery cohort (cumulative incidence 0.18 versus 0.12, P = 0.002). This association was replicated in the validation cohort (0.16 versus 0.12, P = 0.02). It was still significant in multivariate models, adjusted for HIV transmission mode, viral load, CD4 T cells slope, age, antiretroviral therapy, tobacco smoking, hepatitis C virus coinfection, year of cohort entry and PJP prophylaxis (global subhazard ratio 1.42, 95% confidence interval 1.17-1.73, P = 0.0004).

CONCLUSION

Our data suggest rs2243250, a single nucleotide polymorphism known to influence IL-4 production, is associated with susceptibility to PJP in HIV-positive patients.

Polymorphisms in Promoter Region of the Interferon-Gamma Receptor-1 Gene and its Relation with Susceptibility to Brucellosis

Background & Objective:

Brucellosis is one of the most prevalent bacterial zoonotic diseases which afflicts both humans and animals. Genetic factors play an important role in susceptibility to brucellosis. One of these factors is interferon-gamma (IFN-), which is vital in the defense mechanism against infectious diseases such as brucellosis. The purpose of this study was to evaluate the relationship between two single nucleotide polymorphisms (SNPs) at positions -611 and -56 within the promoter region of interferon-gamma receptor-1 gene (IFN- R1) and brucellosis.

Methods:

In this research, the genomic DNA was collected from 60 peripheral blood samples infected with brucellosis and 68 healthy volunteers. DNA was extracted by salting out method. Then, DNA genotypes were analyzed using polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP).

Results:

The results showed that there is a significant difference in -611 SNP frequencies between control and patient groups. At position -611, CC genotype was related to patient group (P=0.024) and TT genotype was related to the control group. According to the results, males had a higher frequency of Brucella infection.

Conclusion:

The presence of C allele in position -611 in IFNγ R1 gene promoter was related to a higher risk of disease and susceptibility to brucellosis. Moreover, the presence of T allele in position γ

A review of the immunopathogenesis of Brucellosis

Brucellosis, caused by the intracellular pathogens Brucella, is one of the major zoonotic infections. Considering the economic burden, its prevalence has been a health concern especially in endemic regions. Brucella is able to survive and replicate within host cells by expressing different virulence factors and using various strategies to avoid the host's immune response. This leads to progression of the disease from an acute phase to chronic brucellosis. Exploration of genetic variations has confirmed the expected influence of gene polymorphisms on susceptibility and resistance to brucellosis of humans. Since there is no approved human vaccine and treatment is uncertain with risk of relapse, it is important to increase knowledge about pathogenesis, diagnosis and treatment of brucellosis in order to manage and control this infection, especially in endemic regions.

Influence of genetic variants of gamma interferon, interleukins 10 and 12 on Visceral Leishmaniasis in an endemic area, Iran

Visceral leishmaniasis (VL) is a life threatening disease in which a variety of cytokines regulating the immune responses can determine its outcome. As based on their region in the gene, some single nucleotide polymorphisms (SNP) can influence the expression of their corresponding proteins, this study aimed to investigate the association between SNP in the IL-10, IL-12, IFN-γ genes and susceptibility to VL. The study was carried out on 120 patients with VL, 67 patients' families (family group), and 102 healthy individuals with positive leishmanin skin test as positive control group. SNPs in IL-10 (-592, -819, -1082), IL-12 (+1188) were analyzed using PCR-RFLP and allele specific polymerase chain reaction (ASPCR) was used to analyze SNPs in IFN-γ (+874 A/T). The results showed that at position +874 of IFN-γ, AT genotype was significantly more frequent in patients than that in families and controls, but TT genotype was significantly more frequent in families than in patients. Distributions of IFN-γ alleles were not significantly different between the study groups. As for IL-12 and IL-10 genotypes and alleles, no significant difference was observed between the groups. Although a strong linkage disequilibrium was observed between alleles -592, -819 and -1082 of IL-10, distributions of the most common haplotypes and haplogenotypes reconstructed from IL-10 alleles were not significantly different between the study groups. It could be suggested that heritage of AT genotype at position +874 of IFN-γ may predispose and TT genotype can resist individual to VL in an endemic area in the southwest of Iran.

IL-4 POLYMORPHISM IN PATIENTS WITH ACUTE BRUCELLOSIS IN THE REPUBLIC OF AZERBAIJAN

Currently, there are isolated data on the relationship between IL-4 polymorphism (C-589T) and susceptibility to brucellosis. Therefore, the purpose of the study was to determine the frequency of polymorphism of IL-4 (C-589T) in patients with acute brucellosis. Materials and methods: the article presents the results of surveys of 120 patients with acute brucellosis. The control group consisted of 30 practically healthy persons. The diagnosis of brucellosis was based on complaints, anamnesis, epidemiological and clinical data, and the results of a specific study. The definition of the polymorphism of IL-4 (C-589T) was performed for all patients in the main and control group. A detailed description of patients with brucellosis is presented. Among the observed prevailed men and young people of working age. Results: A mild degree was established in 74 (61.66 %) patients, while severe - only in 11 (9.17 %) patients. It was determined that the genotype CT (65.83 %) was significantly more common among patients with brucellosis than in the control group, where the frequency of this genotype was only 16.66 %. While the CC genotype was 3.2 times more common among healthy individuals than among patients in the main group (76.67 % versus 24.17 %), it was found that the CC genotype of the IL-4 gene was 13 times more common in patients for acute brucellosis with mild progress than with severe. Conclusions: The genotype IL-4 (C-589T) SS is significantly associated with the mild course of brucellosis.

The IL4-VNTR P1 Allele, IL4-VNTR P2P2 Genotype, and IL4-VNTR_IL6-174CG P2P1-GG Genotype Are Associated with an Increased Risk of Brucellosis

In this study, associations between IL-4, IL-6, and macrophage migration inhibitory factor (MIF) polymorphisms and susceptibility to brucellosis were investigated. Consecutive adult patients with no known treatment against brucellosis and who did not have any other autoimmune and/or chronic disorders, were included in this study (n = 120, Group I). Age and sex-matched controls who had no other autoimmune and/or chronic disorders were also included (n = 120, healthy volunteers, Group II). The IL4_P2P2 genotype, IL4_P1 allele, and IL4_variable number of tandem repeats (VNTR)_IL6-174CG compound genotype were found to be more frequent in the patient group than in control subjects. There were significant differences between the patients and controls with respect to the frequencies of the IL4_P2P2 genotype (77.5% versus 87.5%; p = 0.001; OR, 0.36; 95% confidence interval [CI], 0.21-0.62) and the IL4_P1 allele (12.1% versus 6.7%; p = 0.030; OR, 0.92; CI, 1.02-3.64). The IL4-VNTR_IL6-174CG compound genotype was also present at a significantly higher frequency in the patient group than in control subjects (11.7% versus 4.2%; p = 0.027, OR, 3.04; CI, 1.06-8.68). No statistically significant differences in the frequencies of the IL-6-174, MIF-173, IL-4_P1P1, and IL4_P2P1 genotypes were observed between patients and control subjects. The IL4_VNTR P1 allele, P2P2 genotypes, and IL4-VNTR_IL6-174CG P2P1-GG genotypes are common in southern Turkey, and carriers of these polymorphisms are susceptible to brucellosis.

CXCR2 Mediates Brucella-Induced Arthritis in Interferon γ-Deficient Mice

BACKGROUND

Brucella species are facultative intracellular gram-negative bacteria that cause brucellosis, a common global zoonosis. Infection of the joints is the most common focal complication of brucellosis in humans. The purpose of this study was to identify mediators of focal inflammation during brucellosis.

METHODS

Wild-type (WT) mice are naturally resistant to Brucella infection; therefore, we infected anti-interferon γ (IFN-γ)-treated, or IFN-γ(-/-) mice with Brucella to induce osteoarticular and musculoskeletal inflammation, as we previously described. Mice were infected intraperitoneally with Brucella melitensis, and the clinical course of disease, histopathologic changes, and cytokine levels were compared among groups.

RESULTS

Rag1(-/-) mice (B- and T-cell deficient) and µMT(-/-) mice (B-cell deficient) developed paw inflammation at a similar rate and severity as WT mice following infection with B. melitensis and treatment with anti-IFN-γ. Joints from B. melitensis-infected IFN-γ(-/-) mice had markedly increased levels of CCR2 and CXCR2 ligands. While anti-IFN-γ-treated CCR2(-/-) and WT mice behaved similarly, anti-IFN-γ-treated CXCR2(-/-) or IFN-γ(-/-)/CXCR2(-/-) mice had strikingly reduced focal swelling relative to anti-IFN-γ-treated WT or IFN-γ(-/-) mice, respectively. Additionally, neutrophil recruitment was dependent on CXCR2.

CONCLUSIONS

Adaptive immune cells and CCR2 are dispensable, while CXCR2 is necessary for Brucella-induced focal neutrophil recruitment and inflammation.

The Impact of IFN-γ Gene Polymorphisms on Spontaneous Clearance of HCV Infection in Fars Province, Southern of Iran

BACKGROUND

Certain polymorphisms in cytokine genes such as IFN-γ may influence the outcome of hepatitis C virus (HCV) infection. Here the frequency of the genotype, allele, and haplotype of IFN-γ gene at some loci is investigated in HCV-infected patients.

METHODS

Totally 255 patients with chronic HCV infection and 44 spontaneously cleared individuals were included. The chronic or clearance states were confirmed using enzyme-linked immunosorbent assay (ELISA) and two different qualitative reverse transcriptase polymerase chain reaction (RT-PCR) techniques. IFN-γ gene polymorphisms were performed by PCR using sequence-specific primers and PCR-RLFP on extracted genomic DNA.

RESULTS

The frequency of GG genotype (P = 0.0001, OR: 5.69 and CI: 2.21-14.62) and allele (P = 0.0003, OR: 2.73 and CI: 1.54-4.83) of IFN-γ gene at +2109 locus was significantly higher in cases that spontaneously cleared the infection. Haplotype analysis showed the association of AG haplotype (P = 0.0046, OR = 6.14 and CI = 1.56-25) with spontaneous clearance of the infection.

CONCLUSION

Our finding indicated that individuals with GG genotype at +2109 loci of IFN-γ gene and also AG haplotype (A allele at +874 loci and G allele at +2109 loci) may clear HCV infection more frequently than those with AA and AG genotype at +2109 loci and AA, TA, and TG haplotype.

Relationship between γ-interferon gene polymorphisms and susceptibility to brucellosis infection

Interferon-gamma (IFN-γ) is a pro-inflammatory cytokine that plays a pivotal role in the defense mechanism against Brucella infection. It was hypothesized that the IFN-γ in (+874 A/T in intron 1) TT and +5644 T/A, TT genotypes, which are reportedly associated with high IFN production, are associated with susceptibility to brucellosis in Iranian subjects. Genotyping of these IFN-γ variants by an allele-specific polymerase chain reaction method was performed in 281 subjects, comprising 153 patients with active brucellosis and 128 healthy controls. It was found that the +874 minor allele (A) and homozygote genotype (AA) were significantly more frequently present in brucellosis patients than in controls (OR = 2.588; 95% CI, 1.313-5.104; P = 0.006 for the AA genotype; OR = 1.575; 95% CI, 1.124-2.216; P = 0.010 for the A allele). However, the allelic and genotypic distribution of the IFN-γ polymorphism at position UTR5644 A>T did not differ significantly between patients and controls (P > 0.05). The distribution of haplotypes in this study suggests that the T/A haplotype (+874/UTR5644), which was present more frequently in controls than in patients, may protect subjects against Brucella infection. It is suggested that IFN-γ +874 AA genotype and A allele are risk factors for developing brucellosis infection in Iranian subjects.

Polymorphism of cytokine and innate immunity genes associated with bovine brucellosis in cattle

Genetic susceptibility to brucellosis is multifactorial, and it is known that impairment of the immune system could contribute to risk for getting brucellosis. The aim of the study was to find association of bovine brucellosis with 20 SNPs pertaining to bovine cytokine (IFNG, IFNGR1, IFNGR2, TNFA) and innate immunity (SLC11A1, TLR1, TLR4, and TLR9) genes using PCR-RFLP genotyping technique and it was observed that SLC11A1 (+1066 C/G), TLR1 (+1446 C/A), TLR1 (+1380 G/A), TLR4 (+10 C/T) and TLR4 (+399 C/T) loci were significantly (P≤0.05) associated with bovine brucellosis. The odds ratios (OR) of CG and CC genotypes versus GG genotype were 0.31 (0.12-0.82; 95% CI) and 0.18 (0.03-1.06; 95% CI) at SLC11A1 (+1066 C/G) locus in cases of brucellosis affected cattle. For TLR1 (+1380 G/A) locus, the OR for AG and AA genotypes versus GG genotypes were 0.15 (0.05-0.44; 95% CI) and 0.26 (0.04-1.47; 95% CI) which indicated that proportion of GG homozygote was significantly higher in brucellosis affected animals as compared to control. At TLR1 (+1446 C/A) locus the OR of AC genotype versus CC genotype was 0.24 (0.08-0.68; 95% CI) which revealed that relative proportion CC genotypes was significantly higher in case population. The TLR4 (+10 C/T) locus had three genotypes (TT, CT and CC) where OR of CT and CC genotypes versus TT genotype were near to zero. The OR of CT genotypes versus CC genotypes was 8.25 (0.94-71.92; 95% CI) at TLR4 (+399 C/T) locus and indicated that CT genotype had higher odds of bovine brucellosis than control animals.

The Role of Interferon Gamma Gene Polymorphism (+874A/T, +2109A/G, and -183G/T) in Response to Treatment Among Hepatitis C Infected Patients in Fars Province, Southern Iran

BACKGROUND

Hepatitis C virus (HCV) infection as a worldwide health problem is associated with cirrhosis and hepatocellular carcinoma. With current treatment regimen, pegylated interferon (PEG-IFN) plus ribavirin, sustain virological response (SVR) is achieved in only 50% of infected individuals. In HCV infection, an inappropriate ratio of cytokines may affect the benefit of antiviral therapy. Given the polymorphisms in regulatory regions of cytokines genes may influence cytokines production.

OBJECTIVES

We aimed to investigate both the frequency of genotypes and alleles of interferon gamma (IFN-γ) gene at +874A/T, +2109A/G, and -183G/T loci in HCV-infected patients and their associations with response to therapy.

PATIENTS AND METHODS

A total of 158 patients were included and treated with PEG-IFN plus ribavirin. The presence of HCV infection in patients was confirmed by reverse transcription polymerase chain reaction, and genomic DNA was extracted from peripheral leukocytes using salting out method. IFN-γ gene polymorphisms were identified by polymerase chain reaction using sequence specific primers and restriction fragment length polymorphism analysis on genomic DNA.

RESULTS

Of 158 patients, 110 (69.5%) subjects achieved SVR and 48 (30.5%) subjects did not respond to therapy. The frequency of AA genotype (P = 0.001; OR: 11.2; CI: 2.26-63.21) and A allele (P = 0.01; OR: 3.23; CI: 1.23 8.56) of IFN-γ gene at +2109 locus were significantly different between the responder and non-responder subjects infected with genotype 1. Regardless of HCV genotype, the frequency of AG genotype was also higher in responder group than those who did not respond to therapy (P = 0.041; OR: 05.05; CI: 1.05-33.25)). In case of IFN-γ gene at +874 locus, there was no difference in genotypes and alleles frequencies between the responder and non-responder subjects infected with HCV genotypes 1 and 3. Haplotype analysis showed no association between haplotypes and response to therapy. All participants had G/T genotype at -183 locus.

CONCLUSIONS

Our findings indicate that heterogeneity at +2109 locus of IFN-γ gene but not at +874 locus could interfere with successful therapy in patients infected with HCV genotype 1.

The gene-immune-behavioral pathway: Gamma-interferon (IFN-γ) simultaneously coordinates susceptibility to infectious disease and harm avoidance behaviors

Cytokine gene variants are known to influence both infectious disease susceptibility and harm-avoidant behaviors, suggesting that these risk variants may be pleiotropically linked to instinctual disease-avoidant traits. The gamma-interferon (IFNG) +874 T>A polymorphism (rs2430561) is an ideal candidate gene variant for immune-behavioral studies. It is a functional SNP, regulating IFNG mRNA expression; it is known to modulate serotonergic activity and is therefore capable of modifying behavior; and it has previously been associated with increased susceptibility to malaria, tuberculosis, leprosy and Chagas disease. We hypothesized that the infectious disease-high-risk IFNG +874 A-allele would be associated with four personality traits previously reported as behavioral defenses against infection: Harm Avoidance (HA), Extraversion (E), Exploratory Excitability (Exp E), and Openness to Experience (O). We tested this hypothesis in a sample of 168 healthy university students from Southern California genotyped for IFNG +874 T>A and evaluated by the Temperament and Character Inventory-Revised (TCI-R) and the NEO Five-Factor Inventory (NEO-FFI). We found that the infectious disease-high-risk IFNG +874 A-allele was associated with increased HA (P=0.001) and decreased E (P=0.030) and Exp E (P=0.030). These findings suggest that the IFNG +874 A gene variant is linked both to infectious disease susceptibility and to proactive behavioral defenses that reduce infection risk in healthy subjects.

Effect of anti-inflammatory (IL-4, IL-10) cytokine genes in relation to risk of cervical carcinoma

OBJECTIVES

Cervical cancer is rated the second most common malignant tumor globally and is etiologically linked to human papillomavirus infection. Interleukin-4 (IL-4) and IL-10 are cytokines with anti-inflammatory properties. The purpose of this study was to determine the relationship of different alleles of IL-4 and IL-10 genes with risk of cervical cancer among passive smokers and users of oral contraceptives.

MATERIALS AND METHODS

We investigated the association of cervical cancer with 2 anti-inflammatory cytokine genes IL-4 and IL-10 using a case-control study. The study sample comprised 200 cases of cervical cancer and an equal number of matched controls who were investisgated by variable number of tandem repeat and Restriction Fragment Length Polymorphism analysis.

RESULTS

In this study we observed that the Rp1/Rp2 genotype of IL-4 marginally increased the risk of developing cervical cancer [odds ratio (OR), 1.3; 95% confidence intervals (CI), 0.45-3.64; P=0.8]. In case of passive smokers we also found a marginal increase in the risk for cervical cancer with AC and combined AC+CC genotypes (OR, 1.7; 95% CI, 0.90-3.34; P=0.1; and OR,1.7; 95% CI, 0.90-3.17; P=0.1, respectively). However, a nonsignificant association was observed between use of oral contraceptives and risk of cervical cancer with anti-inflammatory cytokine genotypes.

CONCLUSIONS

This study suggests that passive smokers among North Indian women having IL-4 Rp1/Rp2 and IL-10 (AC) genotypes had an increased risk for developing cervical cancer.

Toll-like receptor 4 (TLR4) polymorphisms in Iranian patients with visceral leishmaniasis

The role of Toll-like receptor (TLR) 4 in visceral leishmaniasis (VL), a disease caused by an obligate intracellular protozoan parasites belonging to the genus Leishmania, has been shown in the recent leishmaniasis experimental studies. As genetic host factors play an important role in the susceptibility and/or resistance to VL, the association between TLR4 gene mutations [A896G and C1196T single nucleotide polymorphisms (SNPs)] and VL was investigated. Genotyping of A896G (Asp299Gly) and C1196T (Thr399Ile) SNPs was performed in the patients with VL (N = 122) and ethnically matched controls (N = 155) using polymerase chain reaction-restriction fragment length polymorphism method. When VL patients and the controls were compared, no statistically significant differences were observed in A896G and C1196T alleles and genotypes (P > 0.05). The TLR4 A896G and C1196T were in moderate linkage disequilibrium in the controls and patients (r (2) = 0.497, 0.548 and D' = 0.705, 0.808, respectively), and haplotypes reconstructed from these SNPs were not significantly different between the aforementioned study groups. In conclusion, based on the results, TLR4 gene polymorphisms at the positions 896 and 1196 cannot be regarded as the major contributors to VL susceptibility among the Iranian population.

Association of interleukin-15 single nucleotide polymorphisms with resistance to brucellosis among Iranian patients

Interleukin (IL)-15, a Th1-related cytokine, triggers inflammatory cells' recruitment and increases the expression of interferon gamma (IFN-γ), which is an important cytokine in the immunity against brucellosis. Different single-nucleotide polymorphisms (SNPs) have been observed in the IL-15 gene, so this study aimed to investigate the probable association between these SNPs and susceptibility to brucellosis among Iranian patients. A total of 190 patients with brucellosis and 83 healthy milk farmers who consumed contaminated raw milk and dairy products from animals involved with brucellosis were included in this study. All the patients and the controls were genotyped for four IL-15 polymorphisms at positions 267, 367, 13687 and 14035 using polymerase chain reaction-restriction fragment length polymorphisms. The 267C and 13687A alleles, haplotypes CGCT and CAAA and the 267CC and 13687AA genotypes were significantly more frequent in the controls than in the patients (P = 0.014, 0.03, 0.006, 0.024, 0.026 and 0.01, respectively), so the variation in the IL-15 gene may be one of the factors affecting the resistance to brucellosis. In contrast, the frequency of haplotypes CGCA and TACT was significantly higher in patients compared with controls (P = 0.015 and 0.007, respectively), and interestingly the last one was observed only in the patients; therefore, it may serve as a predictive factor for brucellosis. In conclusion, it could be suggested that IL-15 genetic variants can affect resistance or susceptibility to human brucellosis among Iranian patients.

IL-1β (-511T/C) gene polymorphism not IL-1β (+3953T/C) and LT-α (+252A/G) gene variants confers susceptibility to visceral leishmaniasis

Lymphotoxin-α (LT-α) and interleukin-1beta (IL-1β) are proinflammatory cytokines playing important roles in immunity against Leishmania infection and the outcome of the disease. As cytokine productions are under the genetic control, this study tried to find any probable relationship between these cytokine gene polymorphisms and the susceptibility to visceral leishmaniasis in Iranian pediatric patients. Ninety-five pediatric patients involved with visceral leishmaniasis and 128 non-relative healthy people, from the same area as the patients, were genotyped for LT-α (+252A/G) and IL-1β (+3953T/C and -511T/C) gene polymorphisms using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). There was not found any significant differences in allele and genotype frequencies of LT-α (+252A/G) and IL-1β (+3953) among the study groups. However, the frequency of IL-1β -511TT genotype was higher in the controls (P = 0.0004) while the frequency of IL-1β -511CC genotype and C allele were higher in the patients (P = 0.008 and P = 0.00006, respectively). Furthermore, IL-1β CC (-511/+3953) haplotype was more frequent in VL patients compared with the controls (P = 0.0002) and the distribution of TT haplotype was higher in the controls compared with the patients (P = 0.003). In conclusion, based on the results, IL-1β -511C allele, CC genotype and CC (-511/+3953) haplotype could be considered as the susceptibility factors for visceral leishmaniasis while IL-1β -511TT genotype, T allele and TT haplotype (-511/+3953) might be counted as the influential factors for resistance to the disease.

Analysis of the results of clinical and laboratory examination of female patients withnon-complicated and complicated forms of the urogenital chlamydia infection

полиморфизмы, хламидийная инфекция, цитокины. The authors provide a detailed clinical and laboratory description of female patients with the Chlamydia infection of the lower urogenital tract and small pelvis organs as well as patients with secondary infertility (Chlamydia infection in the anamnesis). The authors also present the results of a pilot study aimed at determining the content of cellular metabolism mediators (cytokines IL-2, IL-4, IL-6, IL-8, IL-10 and IFN-alpha) in blood and cervical secret samples as well as a study of single-nucleotide polymorphisms of cytokine encoding genes.

Research methods for molecular markers of the individual genetic risk for development ofcomplications of the urogenital chlamydia infection

The authors present the results of the first four stages of research conducted under Government Contract No. 02.740.11.0774: Development of a Technology for Molecular Diagnostics of the Individual Genetic Risk of Development of Reproductive Function Disorders Associated with Human Urogenital Chlamydial Infection.

An evolutionary strategy for a stealthy intracellular Brucella pathogen

Brucella is an intracellular bacterial pathogen that causes abortion and infertility in mammals and leads to a debilitating febrile illness that can progress into a long lasting disease with severe complications in humans. Its virulence depends on survival and replication properties in host cells. In this review, we describe the stealthy strategy used by Brucella to escape recognition of the innate immunity and the means by which this bacterium evades intracellular destruction. We also discuss the development of adaptive immunity and its modulation during brucellosis that in course leads to chronic infections. Brucella has developed specific strategies to influence antigen presentation mediated by cells. There is increasing evidence that Brucella also modulates signaling events during host adaptive immune responses.

Immune and genetic mechanisms of infertility andreproductive function disorders associated with humanurogenital chlamydial infection

This review covers current concepts of immune and genetic mechanisms of infertility associated with human urogenital chlamydial infection. It describes studies of individual polymorphisms of genes coding cytokines and other immune system mediators. It also presents the results of studies aimed at searching for genetic predisposition to the development of complications resulting in human reproductive function disorders caused by past urogenital chlamydial infections.

Cell-mediated immunity in human brucellosis

Brucella can parasitize within human antigen-presenting cells modifying phagocytosis, phagolysosome fusion, antigen presentation, cytokine secretion, and apoptosis. Subversion of innate immune mechanisms by Brucella leads to defective Th1 immune responses and T-cell anergy in chronic brucellosis patients. This review summarizes the cellular immune responses in brucellosis, based on data derived exclusively from human cells or cell lines.