The aim of review. To present analysis of data on immunopathogenesis of inflammatory bowel diseases.Key points. At genetically sensitive animals inflammatory bowel diseases (IBD) develop at various effects on innate and adaptive systems of immune defense (knock-out and transgenic mice), causing changes of expression of significant immunologic factors with distortion of pro- and anti-inflammatory cells and molecules ratio at their contact to microbiota structures. The physiological state of intestine is characterized by balanced interaction of effector (Th1, Th2, Th17) and regulatory (Treg) cells determining presence of immune tolerance to resident microflora antigens. Innate immunity changes revealed in last years, related to mutations of genes of bacterial structures receptors (NOD2, toll-like receptors, autophagy), cause disorder of endocellular signal processes and pathological activation of cells of adaptive immunodefense of intestinal mucosa and conforming profile of cytokines with development of chronic inflammation which will be mediated: at Crohn's disease – by Th1-and Th17-cells, cytokines IL-12, interferon-γ etc., at ulcerative colitis – by Th2-and NKT-cells, cytokines IL-4 and IL-3 in combination to incompetence of suppressor function of regulatory Т-cells and their cytokines TGF-β (transforming growth factor) and IL-10.Conclusion. Investigations of experimental enterocolites and human IBD confirm immunologic hypothesis of pathogenesis: relation of their development to defects of innate and adaptive immune system
