Childhood type 1 diabetes mellitus and risk factor of interactions between dietary cow's milk intake and HLA-DR3/DR4 genotype

Short-term breastfeeding and early exposure to dairy products into infant diets, may be critical factors for development of type 1 diabetes. In this study, we investigate whether cow's milk proteins are risk factors for type 1 diabetes in genetically susceptible individuals (HLA DR3/DR4) by using statistical analysis and in silico approach. In order to verify the potential risk of the early introduction of cow's milk, we conducted this study to validate the veracity of this hypothesis in our population. We included 121 subjects, 55 type 1 diabetics and 74 controls from the region of Tlemcen (Algeria). Thus, the in silico approach was performed to determine the molecular mimicry region between Bovine serum albumin and beta-lactoglobulin with self-Islet antigen 2 and glutamate decarboxylase 65 by determining their sequences and their 3D structures. The risk factors associated with type 1 diabetes in a genetically predisposed individual (HLA DR3/DR4) retained by the logistic model are: type 1 and type 2 diabetes inheritance, the early introduction of cow's milk before 6 months and breastfeeding less than 9 months. Besides, the epitopes of cow's milk proteins have the capacity to bind to predisposing HLA class II molecules (HLA DR3/DR4) and induce an immune reaction by the secretion of Interleukin 4 (Th2) and Interferon (Th1) which lead to the destruction of pancreatic beta cells. The early introduction of cow's milk proteins in susceptible individuals is considered as risk factors for the pathogenesis of T1DM. The in silico approach confirm that BSA and BLG share sequence and structure homology with IA2 and GAD65.Communicated by Ramaswamy H. Sarma.

Molecular mimicry between varicella, measles virus and Hsp60 in type 1 diabetes associated HLA-DR3/DR4 molecules

BACKGROUND AND AIMS

Type 1 diabetes (T1D) is a multifactorial autoimmune disease that combines genetics and environmental factors. The aim of this study is to determine the environmental risk factors and to investigate how virals infections are risks factors for type 1 diabetics whom have HLA DR3/DR4 predisposition in our population.

METHODS

This study includes 233 subjects, 145 diabetics and 88 controls from regions of the extreme western of Algeria. All the informations related to the disease were collected using predesigned questionnaire. Using in silico approach, we attempt to improve the understanding of this analytical result by molecular mimicry, which is associated with the breakdown of several autoimmune pathologies.

RESULTS

The statistical study showed that history of varicella and measles infection and T1D related inheritance and type 2 diabetes are risk factors for T1D in the population of Tlemcen. We have determined the homologous antigenic regions between the glycoprotein "gE" of the varicella virus, the "hemagglutinin" of measles and the human protein "HSP60" at the level of their sequence and 3D structure. These cross-reactive epitopes bind to MHC class II molecules (HLA DR3/DR4) that predispose to T1D but not to MHC class II molecules (HLA DR2) that protect against T1D. This epitopes induce Th2 cells but only "hemagglutinin" and "Hsp60" can activate Th1 differentiation. This indicates their potential to destroy pancreatic cells β.

CONCLUSION

Our study can allow us to adapt biological markers to genetically predisposed T1D and to establish a preventive strategy for healthy genetic predisposed individuals in Tlemcen population.