Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 6

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
EAE (Experimental Allergic Encephalomyelitis) is the animal model of Multiple Sclerosis, an autoimmune and neurodegenerative human disease. Proposed method for autoimmune diseases treatment is to evoke oral tolerance, which is lack of response to fed antigen. Our previous experiments showed that pig spinal cord hydrolysate, which is source of myelin antigens is able to evoke oral tolerance in EAE rats. The aim of our study was to investigate, if treatement with pig spinal cord hydrolysate has any toxic effects on rats. Twelve female Lewis rats were fed with pig spinal cord hydrolysate (500mg/kg) or PBS (control group, 0,5ml per rat) each day for one month. One day after the last day of feeding animals were sacrified, and the main organs were collected. Organs were fixed in 10% formalin, postfixed in paraffin, cut into slices and stained with hematoxylin and eosin. Slices were analysed using the light microscope. Every spleen, thymus and adrenal gland was weighted to count relative mass. Number of spleen megakaryocytes in 1mm2 was counted. There were no changes observed in any brain, heart, stomach, intestine, uterus and ovary preparations. We observed single changes in rats liver, kidney, thymus, mesenteric lymph node, adrenal gland, and in the number of spleen megakaryocytes, but not corelated with experimental group. The fact that we did not find any significant changes in rat organs can confirm that pig spinal cord hydrolysate is safe for rats. Supported by N302 009 32/1139 grant.
Experimental Allergic Encephalomyelitis (EAE) is the animal model of Multiple Sclerosis (MS), human autoimmunological disease that causes neurodegeneration. The autoimmune base of the disease leads to treatment searching in immunological mechanisms. Earlier we proposed the application of pig spinal cord hydrolysate as a mean to induce oral tolerance. The positive effects observed in EAE rats, stimulated us to develop bacteria that may express active peptide related to myelin fragment. For our experiments we used mixture of Lactococcus lactis producing fragments of three main myelin peptides, MBP (MBP 85-97), PLP (PLP 139-151) and MOG (MOG 35-55). We fed female Lewis rats with spectrum of bacteria doses, from 101 to 108 cells/ rat daily, for twenty days, from day −10 to 9. At the day 0 we evoked EAE in rats. Based on the results obtained from clinical symptoms, we selected two doses, 103 and 106 bacteria cells/rat for investigation of histopathological changes in spinal cord of animals. We observed slighter inflammatory cells infiltration in spinal cord in EAE rats fed with both doses of bacteria in comparison to non-fed ones. Supported by N302 00932/1139 grant.
The aim of this study was to use the hydrolysate of pig spinal cord proteins to induce oral tolerance in the animal model of sclerosis multiplex experimental allergic encephalomyelitis. The female Lewis rats were fed with hydrolysate of pig spinal cord proteins in two doses for one week before immunization, which was induced by injection of guinea pig spinal cord homogenate. At the peak of clinical symptoms (the 13th day post immunization) the rats were sacrificed and the spleen removed. Splenocytes were suspended in a culture medium and placed in microculture plates. The cells were stimulated with homogenate. The cells were cultured for seven days. Proliferation of splenocytes was estimated by means of methyl- 3H thymidine incorporation. In supernatants of cultures of splenocytes the level of cytokines INF-γ, IL-10, IL-4, and TGF-γ was measured. It was demonstrated that homogenate-induced splenocytes of hydrolysate-fed rats gave rise to low proliferation as compared to the controls used. The IFN-γ was inhibited in hydrolysate-fed animals. The hydrolysate of pig spinal cord proteins has a modulatory effect on the immune reaction, particularly on the orally-induced antigen-specific modulation of autoimmune response.
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.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.