A Genotyping and Posttranscriptional Regulatory Mechanism study of The Cytotoxic T-Lymphocyte Antigen-4 (CTLA4) Gene Associated with Type 1 Diabetes Disease in EGYPT

Abstract

Type 1 diabetes (T1D) is an organ-specific autoimmune disease characterized by T cell-mediated destruction of pancreatic islets. T cell proliferation is negatively regulated by cytotoxic lymphocyte antigen-4 (CTLA-4). CTLA-4 polymorphisms are associated with T1D in some but not all populations. We investigated the prevalence of the selected single nucleotide polymorphisms (SNPs) in the entire CTLA-4 gene sequence and di-nucleotide repeats polymorphism (AT)n of 3’UTR region in the CTLA4 gene with the 396 Egyptian patients ≤ 14 years old and 396 control subjects >24 years old, with a similar ratio of males to females in both groups. Genotyping study was performed using single strand conformation polymorphism (SSCP), polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), Genescan, DNA sequencing techniques and haplotype analysis on the selected SNPs was performed. Moreover, we investigated the role of the (AT)n of 3' UTR on CTLA4 expression, mRNA stability and protein expression via Real time PCR , Western blotting and Luciferase reporter gene assays. The final goal was to contribute to the understanding of the mechanisms that negatively regulate T cell activation by CTLA4 gene and contribute to the development of T1D disease among Egyptian population.