EN
Experimental Allergic Encephalomyelitis (EAE) is the animal model of Multiple Sclerosis (MS), human chronic and progressive autoimmunological disease that lead to neurodegeneration in Central Nervous System (CNS). Although there are some hypothesis, like genetic, environmental or viral factors involvement, cause and patophysiology of MS remains still unknown, and that is the reason why there is no sufficient MS treatment so far. Most common MS therapy is use of immunosupressive drugs, but that is not very effective and costs number of health complications. Also new targeted therapies are burdened with the risk of side effects, which may be even lethal. Therefore, the efficient alternative treatment is urgently needed. The autoimmune base of the disease directed treatment searching into immunological mechanisms. Few years ago we proposed application of animal spinal cord hydrolysate for inducing oral tolerance, which effect lies in reducing of immunoresponse for previously fed antigen. We presented the effectiveness of this type of treatment in EAE rat model. The success of oral tolerance with mixture of peptides stimulates us to development bacteria that may express active peptide related to myelin fragment. As far as it is known, that the dose of fed antigen is crucial in evoking oral tolerance, the aim of our study, was to investigate which dose or doses of Lactococcus lactis expressing myelin peptides is sufficient for EAE treatment. We used autolising strain of Lactococcus lactis, producing one of three myelin peptides, which are considered to be crucial in MS developement: Myelin Basic Protein (MBP aa85-97), Proteolipid Protein (PLP aa139- 151) or Myelin Oligodendrocyte Protein (MOG aa35-55). We mixed all three peptide variants, and made whole-cell extracts. For our experiments we used female Lewis rats (180–200 g), which were fed with ball-pointed needle with mixed bacteria extracts for 20 days. Doses of preparations ranged from 101 to 108 cells/rat/feeding suspended in 0.5 ml PBS. At the 10th day of feeding, EAE was evoked by hind paw injection of guinea pig spinal cord homogenate in Freund Adjuvant with Mycobacterium tuberculosis. During the whole experiment animals were weighted, and clinical symptomes were observed. The obtained results demonstrated, that the sufficient doses of Lactococcus lactis expressing myelin peptides, given orally to animals are 103 and 106 cells/rat/feeding. Further experiments including cytokine level measurement and microscopic observation of rats spinal cord are in progress.