Theoretical comparison of two new fusion vaccine of multiple sclerosis

Multiple sclerosis (MS) is an autoimmune demyelinating disease targeting the human central nervous system. It is believed that the activation of the T cells reacting with the CNS antigens is the first autoimmune event in MS. MOG and MBP are the myelin sheath proteins and highly pathogenic antigen epitopes involved in immune response. Today, more researchers are looking for drugs with high specificity to function on the immune system. Tolerogenic vaccines are a new class of drugs that reduce the immune response to the MS antigens by presenting the associated antigens. This study aimed to compare two fusion vaccines using the combination of MOG(11-30) and MBP(13-32) linked to interlukine-16 and examination their antigenic properties. At first a model for MOG and a model for MBP were made by modeler 9.10 and these free antigen separately used for 20 ns MD simulation via Gromacs 5.1.1 package. Then 3D structure of IL-16 obtained from PDB bank and ubiquitinated and simulated for 20 ns. Then we made two compounds as follows: compound 1: MOG-MBP-IL16 and compound 2: MBP-MOG-IL16. In these compounds, IL16 set in C-terminal. Finally, the compound 1 and 2 separately were simulated for 20 ns. The results revealed that both compounds 1 and 2 had stable structure and compound 1 was better because the solvent accessible surface areas of MOG and MBP epitopes were more than compound 2. Then we can conclude that compound 1 preserves antigenic property of MOG and MBP epitopes better than compound 2

Keywords:

Multiple sclerosis , Vaccine , Fusion protein , Molecular dynamics simulation , MOG , MBP