Parham Nejati; Marzieh Attar; Maryam Rahimian; Davood Fathi; Majid Shahbazi
Volume 14, Issue 3 , Summer 2017, , Pages 231-239
Abstract
Background: Multiple sclerosis (MS), as a multifactorial autoimmune disease with complex genetic basis, causes demyelination in the central nervous system via cytokine responses to myelin antigens. Myelin basic protein (MBP) is the main protein component of the myelin sheath. HLA-DRB (human leukocyte ...
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Background: Multiple sclerosis (MS), as a multifactorial autoimmune disease with complex genetic basis, causes demyelination in the central nervous system via cytokine responses to myelin antigens. Myelin basic protein (MBP) is the main protein component of the myelin sheath. HLA-DRB (human leukocyte antigen-DR beta) alleles, particularly HLA-DRB1*1501, may be of significance in the pathogenesis of MS. Objective: To examine the association of HLA-DRB1*1501 alleles and MBP VNTR (variable number tandem repeat) polymorphism with the MS susceptibility in Iranian population. Methods: Genomic DNA was extracted from peripheral blood. The alleles were determined by the Polymerase Chain Reaction (PCR) method in 259 MS patients and 312 healthy control individuals and analyses were carried out using Fisher's exact test. Results: The frequencies of MBP VNTR genotypes (AA, AB and BB) were 47%, 42% and 11% among patients, and 45%, 43% and 12% in control subjects, respectively. HLA-DRB1*1501 allele was more frequent among patients than healthy individuals (OR=1.65, P=0.0045). The frequency of allele A and genotype A/A was significantly higher among HLA-DRB1*1501 positive patients (61% and 32%) than controls (46% and 19%) (OR=1.88, P=0.0013; A/A vs. B/B: OR=5.09, P=0.0004). The two-locus analysis of the interaction between the MBP VNTR polymorphism and the HLA-DRB1 allele showed that the HLADRB1* 1501/A haplotype was more frequent among MS patients than the healthy controls. Conclusion: The interaction between the HLA-DRB1*1501 allele and MBP gene may be considered as a predisposing factor in the development and pathogenesis of MS in the case of gene-gene interaction.
Henu Kumar Verma; Aditya Nath Jha; Prafulla Kumar khodiar; Pradeep Kumar Patra; Lakkakula Venkata Kameswara Subrahmanya Bhaskar
Volume 13, Issue 2 , Spring 2016, , Pages 124-131
Abstract
Background: Cytokines are cell signaling molecules which upon release by cells facilitate the recruitment of immune-modulatory cells towards the sites of inflammation. Genetic variations in cytokine genes are shown to regulate their production and affect the risk of infectious as well as autoimmune diseases. ...
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Background: Cytokines are cell signaling molecules which upon release by cells facilitate the recruitment of immune-modulatory cells towards the sites of inflammation. Genetic variations in cytokine genes are shown to regulate their production and affect the risk of infectious as well as autoimmune diseases. Intron-3 of interleukin-4 gene (IL-4) harbors 70-bp variable number of tandem repeats (VNTR) that may alter the expression level of IL-4 gene. Objective: To determine the distribution of IL-4 70-bp VNTR polymorphism in seven genetically heterogeneous populations of Chhattisgarh, India and their comparison with the finding of other Indian and world populations. Methods: A total of 371 healthy unrelated individuals from 5 caste and 2 tribal populations were included in the present study. The IL-4 70-bp VNTR genotyping was carried out using PCR and electrophoresis. Results: Overall, 3 alleles of IL-4 70-bp VNTR (a2, a3 and a4) were detected. The results demonstrated the variability of the IL-4 70-bp VNTR polymorphism in Chhattisgarh populations. Allele a3 was the most common allele at the 70-bp VNTR locus in all populations followed by a2 allele. This study reports the presence four repeat allele a4 at a low frequency in the majority of the Chhattisgarh populations studied. Further, the frequency of the minor allele (a2) in Chhattisgarh populations showed similarity with the frequencies of European populations but not with the East Asian populations where the a2 allele is a major allele. Conclusions: Our study provides a baseline for future research into the role of the IL-4 locus in diseases linked to inflammation in Indian populations.