CCR5-delta 32 allele is associated with the risk of developing multiple sclerosis in the Iranian population

Association of Multiple Sclerosis Phenotypes with Single Nucleotide Polymorphisms of IL7R, LAG3, and CD40 Genes in a Jordanian Population: A Genotype-Phenotype Study

It is thought that genetic variations play a vital role in the Multiple Sclerosis (MS) etiology. However, the role of genetic factors that influence the clinical features of MS remains unclear. We investigated the correlation between 21 single nucleotide polymorphisms within three genes (IL7R, LAG3, and CD40) and MS clinical characteristics in the Jordanian population. Blood samples and clinical phenotypic data were collected from 218 Arab Jordanian MS patients, vitamin D was measured, genomic DNA was extracted, and genotyping of the candidate genes’ polymorphisms were analyzed using the Sequenom MassARRAY^® system. The association of these single nucleotide polymorphisms (SNPs) with MS was performed using a Chi-square, Fisher exact test, and one-way ANOVA. We found a significant association between vitamin D deficiency and three SNPs of the IL7R gene, namely rs987107 (P-value = 0.047), rs3194051 (P-value = 0.03), and rs1494571 (P-value = 0.036), in addition to two SNPs of CD40, namely rs1883832 and rs6074022 (P-value = 0.049 for both). rs3194051 of the IL7R gene (P-value = 0.003) and rs1922452 of the LAG3 gene (P-value = 0.028) were strongly associated with comorbidity. The number of relapses before drug onset was found to be correlated with IL7R SNPs rs969128 (P-value = 0.04) and rs1494555 (P-value = 0.027), whereas the expanded disability status scale (EDSS) was associated with rs1494555 polymorphism of IL7R gene (P-value = 0.026). Current findings indicate important correlations between certain SNPs and the risk of various phenotypes of multiple sclerosis in the Jordanian community. Therefore, this will not only contribute to the understanding of MS, but will also assist with the development of personalized treatment procedures.

Prevalence of CCR5delta32 in Northeastern Iran

Background

A 32-base pair deletion (∆32) in the open reading frame (ORF) of C-C motif chemokine receptor 5 (CCR5) seems to be a protective variant against immune system diseases, especially human immunodeficiency virus type 1 (HIV-1). We aimed to assess the frequency of CCR5∆32 in the healthy Iranian population.

Methods

In this study, 400 normal samples from Khorasan, northeastern Iran, were randomly selected. The frequency of CCR5∆32 carriers was investigated using PCR analysis. Allele prevalence and the fit to the Hardy-Weinberg equilibrium were analyzed.

Results

The prevalence of CCR5∆32 in the northeastern population of Iran was 0.016. Four hundred samples were studied, among which one with CCR5^∆32/∆32 and 11 with CCR5^Wild/∆32 genotype were detected.

Conclusion

This study was the first investigation for an assessment of the prevalence of CCR5∆32 in northeastern Iran. The low prevalence of CCR5∆32 allele in the Iranian population may result in the increased susceptibility to HIV-1. In addition, this prevalence is the same as that of reported in East Asia, while is lower than that in the Europeans.

Combination of interleukin-10 gene promoter polymorphisms with HLA-DRB1*15 allele is associated with multiple sclerosis

BACKGROUND & OBJECTIVES

Multiple sclerosis (MS) is common in some ethnic groups. Interleukin-10 (IL-10) is a potent anti-inflammatory and immunosuppressive cytokine that may be an important regulator in MS disease pathogenesis. IL-10 promoter includes several single nucleotide polymorphisms and the level of IL-10 expression is related to these polymorphisms. Furthermore, loci within the histocompatibility regions are responsible for susceptibility to MS. The aim of this study was to investigate the association of IL-10 gene promoter polymorphisms and HLA-DRB1*15 allele frequencies with MS susceptibility in an Iranian population.

METHODS

In this study 336 MS patients and 454 healthy controls were included. Genomic DNA was purified from peripheral blood samples by a standard protocol. Genotyping was performed by the sequence-specific primer polymerase chain reaction method.

RESULTS

IL-10 -1082 G/G and IL-10 -819 C/C genotypes were more frequent in MS patients than healthy individuals. DRB1*15 allele showed a higher frequency among MS patients compared to controls.

INTERPRETATION & CONCLUSIONS

The IL-10 and HLA-DRB1*15 polymorphisms were associated with the susceptibility to MS in Iranian patients. Our results suggest that gene-gene interaction of IL-10 polymorphisms and HLA-DRB1*15 alleles may be important factors in the development of MS.

CCR5Δ32 - A piece of protection in the inflammatory puzzle of multiple sclerosis susceptibility

BACKGROUND

Leucocyte infiltration and activation in the central nervous system (CNS) is an important step in the pathogenesis of multiple sclerosis (MS). The Chemokine receptor 5 (CCR5) is implicated in immune cell migration and cytokine release in the CNS, and it was demonstrated to strongly contribute to CNS inflammation and damage in several models of sterile and pathogen-mediated CNS diseases. Although the inhibition of CCR5 results in a beneficial effect in experimental models of MS, conflicting results have been found about the loss-of-function variant CCR5Δ32 (rs333) in MS patients. The aim of this study was to evaluate the association of CCR5Δ32 and MS in a Brazilian case/control cohort.

PATIENTS AND METHODS

261 MS patients and 435 healthy controls were genotyped for CCR5Δ32. Allelic and genotypic frequencies were compared between patients and controls (case/control analysis), and among patients classified according to the MS clinical form (relapsing remitting versus progressive) and severity (EDSS, MSSS and progression index).

RESULTS AND DISCUSSION

The CCR5Δ32 variant frequency was statistically higher in controls as compared to patients presenting European-derived ethnic background. The variant was more frequent in progressive MS as compared to RR-MS patients, and, although not statistically significant, a higher frequency of the truncated allele was observed among patients with less severe forms of MS. These findings emphasize the potential involvement of CCR5 signaling in CNS inflammation and damage in MS.

CONCLUSION

The CCR5Δ32 deletion is a protective factor against the development and progression of MS in European-derived Brazilian patients.

Polymorphisms in CCR5Δ32 and Risk of HIV-1 Infection in the Southeast of Caspian Sea, Iran

Prevalence of CCR5Δ32 among blood samples of more than 400 healthy and HIV-1-infected people was investigated in Iran. Polymerase chain reaction (PCR) following DNA extraction was used. Desired frequency was analyzed by Hardy–Weinberg equilibrium (HWE) analysis and SPSS 16.0 software to harvest the results. The prevalence of CCRΔ32 heterozygote genotype was 3% in healthy people and 0.7% in HIV-1–infected individuals. There was no homozygote CCR5Δ32 in both groups, and the allele Δ32 was only observed in 1.5% and 0.36% of healthy and HIV-1–infected participants, respectively. Therefore according to this study, the frequency of the allele CCR5Δ32 indicates no significant difference between either groups (p = 0.18) and it sounds that the mentioned mutation in heterozygote people would not affect their susceptibility against HIV infection. Genotyping trial in Iranians with HIV infection is supposed to be helpful as a matter of prognostic purposes.

Correlations between polymorphisms in the uridine diphosphate-glucuronosyltransferase 1A and C-C motif chemokine receptor 5 genes and infection with the hepatitis B virus in three ethnic groups in China

Objective

To determine whether genetic polymorphisms in the uridine diphosphate-glucuronosyltransferase 1A (UGT1A) and the C-C motif chemokine receptor 5 (CCR5) genes are associated with hepatitis B virus (HBV) infection in Yi, Yao and Han ethnic groups in the Guizhou Province of China.

Methods

The study enrolled subjects with and without HBV infection. Whole blood was used for DNA genotyping using standard techniques. The study determined the frequencies of several polymorphic alleles (UGT1A6 [rs2070959], UGT1A1 [rs8175347], CCR5-59029 [rs1799987] and CCR5Δ32 [rs333]) and then characterized their relationship with HBV infection.

Results

A total of 404 subjects were enrolled in the study: 138 from the Yao group, 101 from the Yi group and 165 from the Han group. There was a significant difference in the frequency of UGT1A1 rs8175347 polymorphisms among the three groups. The rates of 7TA carriers of UGT1A1 rs8175347 in all three groups were significantly higher than the other genotypes. Individuals with genotype AA of UGT1A6 rs2070959 in the Yi group had a higher risk for HBV infection than in the Yao and Han groups. The frequency of genotype GG in CCR5-59029 in the Yao group was significantly higher than in the Yi group. The genotypes of CCR5Δ32 were not associated with HBV infection.

Conclusion

These findings provide genetic and epidemiological evidence for an association of UGT1A and CCR5-59029 polymorphisms with HBV infection in Chinese Yi and Yao populations.

Novel functional polymorphism in IGF-1 gene associated with multiple sclerosis: A new insight to MS

BACKGROUND

Interactions between several genes and environment may play a role in susceptibility to multiple sclerosis (MS). The IGF-1 plays a key role in proliferation, maintenance and survival of nerve cells. Therefore, we hypothesized that IGF-1 may be a target for prediction and control MS. We aimed to analysis IGF-1 gene promoter sequence, to investigate the effect of the single nucleotide variants on IGF-1 expression and its association with MS.

METHODS

We enrolled 339 MS patients and 431 healthy controls. A specific region in IGF-1 gene promoter was investigated by SSCP analysis. All samples were genotyped by SSP-PCR. In-vitro and in-vivo IGF-1 production was measured by ELISA assay. IGF-1 expression in PBMCs was measured using real-time PCR.

RESULTS

We identified a T to C single nucleotide substitution at position -1089 and a C to T at position -383 from transcription start site in the IGF-1 gene promoter. There was a significant association between MS and genotypes IGF-1(-383) C/T (p=0.001) and IGF-1(-383) C/C (p<0.001). There was also a significant association between IGF-1(-383) allele C and MS (p=0.001). In-vitro and in-vivo IGF-1 level showed that IGF-1 production in samples with genotype IGF-1(-383) C/C significantly was less than T/T (p=0.004) but not T/C (p=0.220).

CONCLUSION

According to IGF-1 roles in CNS and our results, this study suggests that low IGF-1 level may be associated with susceptibility to MS.

CCR5 Polymorphism as a Protective Factor for Hepatocellular Carcinoma in Hepatitis B Virus-Infected Iranian Patients

The CC chemokine receptor 5 (CCR5) delta 32 allele results in a nonfunctional form of the chemokine receptor and has been implicated in a variety of immune-mediated diseases. CCR5Δ32 may also predispose one to chronic liver disease or be linked with resistance to HBV infection. This study was undertaken to investigate any association between CCR5 polymorphism with resistance to hepatitis B or susceptibility to HBV infection. A total of 812 Iranian individuals were enrolled into two groups: HBV infected cases (n=357), who were HBsAg-positive, and healthy controls (n=455). We assessed polymorphisms in the CCR5 gene using specific CCR5 oligonucleotide primers surrounding the breakpoint deletion. Genotype distributions of the HBV infected cases and healthy controls were determined and compared. The CCR5/CCR5 (WW) and CCR5/CCR5Δ32 (W/D) genotypes were found in (98%) and (2%) of HBV infected cases, respectively. The CCR5 Δ32/Δ32genotype was not found in HBV infected cases. Genotype distributions of CCR5 in healthy controls were W/W genotype in (87.3%), W/D genotype in (11.2%) and D/D genotype in (1.5%). Heterozygosity for CCR5/CCR5Δ32 (W/D) in healthy controls was greater than in HBV infected cases (11.2% vs 2%, p < 0.001). W/D and D/D genotypes were more prominent in healthy controls than in HBV infected cases. This study provides evidence that the CCR5Δ32 polymorphism may have a protective effect in resistance to HBV infection at least in the Iranian population.

Chemokine receptor V Δ32 deletion in multiple sclerosis patients in Csongrád County in Hungary and the North-Bácska region in Serbia

The roles of chemokine receptor V (CCR5) and its polymorphism, rs333 in multiple sclerosis (MS) are controversial. We investigated the receptor and its deletion in a large MS (428) and a numerous control (831) population in Csongrád County (Hungary) and North-Bácska (Serbia). Taqman probes firstly were used for the allele discrimination. There was no significant difference in genotype (OR=1.092, 95% CI=0.807-1.478, p=0.568 for wt/wt (wt=wild type allele) vs wt/Δ32, Δ32/Δ32 (Δ32=Δ32 base pair deletion allele)) or allele frequency (OR=0.914, 95% CI=0.692-1.207, p=0.525). Neither the deletion nor the wt allele affected the Expanded Disability Status Scale score or the age at onset. Our results indicate no association between the CCR5 Δ32 allele and MS.

Is the CCR5 Δ 32 mutation associated with immune system-related diseases?

Hypersensitivity and autoimmunity are the main features of immune system-related diseases such as type 2 diabetes (T2D), multiple sclerosis (MS), and asthma. It has been established that chemokines play key roles in the activation and regulation of immune cell migration which is important in the pathogenesis of the diseases mentioned. CC chemokines receptor 5 or CCR5 is a receptor for RANTES, MIP-1α, and MIP-1β and is expressed by several immune cells including NK cells, T lymphocytes, and macrophages. It plays key roles in the regulation of migration and activation of the immune cells during immune responses against microbe and self-antigens during autoimmunity and hypersensitivity disorders. Therefore, any alteration in the sequence of CCR5 gene or in its expression could be associated with immune system-related diseases. Previous studies revealed that a 32-base pair deletion (Δ 32) in exon 1 of the CCR5 gene led to downregulation of the gene. Previous studies demonstrated that not only CCR5 expression was altered in autoimmune and hypersensitivity disorders, but also that the mutation is associated with the diseases. This review addresses the recent information regarding the association of the CCR5 Δ 32 mutation in immune-related diseases including T2D with and without nephropathy, MS, and asthma. Based on the collected data, it seems that the CCR5 Δ 32 mutation can be considered as a risk factor for MS, but not asthma and T2D with and without nephropathy.

The influence of the HLA-DRB1 and HLA-DQB1 allele heterogeneity on disease risk and severity in Iranian patients with multiple sclerosis

Multiple sclerosis (MS) is a common autoimmune disorder of the central nervous system. Recent studies have shown that the HLA-DRB1 and DQB1 alleles are associated with MS susceptibility and severity. However, this is controversial in different population studies. In the present study, the roles of HLA-DRB1 and DQB1 alleles and the amino acids were investigated on disease risk and severity in 120 Iranian patients with MS and 120 controls. Our findings indicate that the DRB1*1501 allele (OR = 3.203 P = 0.001), the DRB1*1501-DQB1*0602 haplotype (OR = 7.792 P = 0.003) and the DRB1*1501/0701- genotype (OR = 3.320 P = 0.006) and amino acid Leu26 (OR = 1.645 P = 0.005) and Phe9 (OR = 1.893 P = 0.009) on the DQβ1 chain are significantly associated with MS susceptibility. DRB1*1001 was the only allele that had a protective effect against MS (P = 0.0004). We also found that the DQB1*0303 allele was significantly associated with disease severity (mean Multiple Sclerosis Severity Score difference = 1.979, P = 0.002). However, protective effect of the DRB1*1001 against MS and also association of DQB1*0303 allele with MS severity need to be confirmed by larger sample size.

Investigation of CD24 and its expression in Iranian relapsing-remitting multiple sclerosis

CD24 is a glycosylphosphatidylinositol (GPI)-linked cell surface glycoprotein expressed in central nervous system cells. Recent investigations have suggested that CD24 participates in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). However, a limited number of studies have been published regarding the contribution of CD24 to the risk and severity of MS in humans. We investigated the contribution of a CD24 single nucleotide polymorphism (SNP) to MS disease risk and severity. We also studied mRNA expression of the CD24 gene in Iranian MS patients using quantitative real-time polymerase chain reaction (PCR). Our findings showed that the CD24(v/v) genotype was significantly more frequent in MS patients compared with controls (p(c) = .004). Moreover, a statistically significant difference in the Multiple Sclerosis Severity Score (MSSS) was found between MS patients carrying CD24(a/a) and CD24(v/v) genotypes (p = .008). The results also indicated that the expression of CD24 mRNA was 1.7 times more in MS patients compared with controls. In conclusion, our results suggest that the CD24(v/v) genotype influences both MS disease risk and severity in Iranian MS patients, and the high disease severity in CD24(v/v) patients may indicate that they require more aggressive treatment than do patients carrying CD24(a/a).

CCR5Δ32 Polymorphism Associated with a Slower Rate Disease Progression in a Cohort of RR-MS Sicilian Patients

Multiple sclerosis (MS) disease is carried through inflammatory and degenerative stages. Based on clinical feaures, it can be subdivided into three groups: relapsing-remitting MS, secondary progressive MS, and primary progressive MS. Multiple sclerosis has a multifactorial etiology with an interplay of genetic predisposition, environmental factors, and autoimmune inflammatory mechanism in which play a key role CC-chemokines and its receptors. In this paper, we studied the frequency of CCR5 gene Δ32 allele in a cohort of Sicilian RR-MS patients comparing with general Sicilian population. Also, we evaluate the association between this commonly polymorphism and disability development and age of disease onset in the same cohort. Our results show that presence of CCR5Δ32 is significantly associated with expanded disability status scale score (EDSS) but not with age of disease onset.

Interaction of HLA-DRB1*1501 allele and TNF-alpha -308 G/A single nucleotide polymorphism in the susceptibility to multiple sclerosis

Multiple sclerosis is a multifactorial disorder with complex genetic basis. It is believed that genes encoding HLA molecule and cytokines are involved in the pathogenesis of MS. In this study, we have evaluated the impact of HLA-DRB1*1501 allele and TNF-alpha -308 G/A single nucleotide polymorphism, and their interaction, in the susceptibility to MS in Iranian population. Genomic DNA samples were prepared from whole blood of 366 MS Patients and 414 control subjects. The genotypes were determined by SSP-PCR method. Frequency of alleles and genotypes were compared between the two groups by using Fisher's exact test. HLA-DRB1*1501 allele was more frequent among patients (OR=1.57, P=0.0026). TNF-α -308 G allele and G/G genotype had higher frequency among MS patients than control subjects (G vs. A: OR=1.26, P<0.05); G/G vs. A/A: OR=4.59, P=0.0003). The odds ratio was higher among HLA-DRB1*1501 positive individuals. Co-existence of TNF G and HLA-DRB1*1501 alleles showed higher prevalence among MS patients (OR=7.07, P=0.0007). Our results have shown that HLA-DRB1*1501 allele and TNF-α -308 G/A polymorphism are associated with the risk of multiple sclerosis in Iranian population. We also observed an interaction between these two loci that support the role of HLA alleles and cytokine genes and gene-gene interaction in the development and pathogenesis of MS.

HLA-DRB1*1501 intensifies the impact of IL-6 promoter polymorphism on the susceptibility to multiple sclerosis in an Iranian population

Background: The multifunctional cytokine interleukin-6 (IL-6) is involved in inflammatory processes in the central nervous system. It is well documented that amount of IL-6 is increased in serum, cerebrospinal fluid and central nervous system lesions of patients with multiple sclerosis. A single nucleotide polymorphism at position -174 in the IL-6 gene promotor appears to influence IL-6 expression. Recently, several researchers have focused on HLA-DRB alleles, specifically HLA-DRB1*1501, as a potential risk allele in the pathogenesis of multiple sclerosis.

Objective: To investigate the possible influence of IL-6/-174 polymorphisms on susceptibility to multiple sclerosis and its integration with HLA-DRB1*1501. Genomic DNA was extracted from whole blood of 345 patients with multiple sclerosis and 426 control subjects.

Method: The SSP-PCR method was used to determine genotypes and Fisher’s exact test was applied to determine differences between groups. HLA-DRB1*1501 was observed more frequently among multiple sclerosis patients compared with healthy subjects (45% and 34%, respectively; OR = 1.6, 95% CI = 1.2—2.2, p = 0.0018). At the IL-6/-174 position, the G allele had higher frequency among multiple sclerosis patients compared with controls (77% and 70%, respectively; OR = 1.4, 95% CI = 1.1—1.8, p = 0.0038). This difference was more significant among HLA-DRB1*1501-positive patients and controls (81% and 67%, respectively; OR = 1.9, 95% CI = 1.5—2.5, p < 0.0001).

Results: Our results have shown that the G allele at the IL-6/-174 promoter polymorphism may be associated with development of multiple sclerosis in this population, and may be strengthened by HLA-DRB1*1501.

Conclusions: We suggest more studies to confirm these results in other populations.