Репозиторий Университета

© Saint Petersburg Pasteur Institute. All rights reserved. Microfold cells (M cells) are specialized intestinal epithelial cells that initiate mucosal immune responses. These unique phagocytic epithelial cells are specialized for the transfer of a broad range of particulate antigens and microorganisms across the follicle-associated epithelium (FAE) into the gut-associated lymphoid tissue (GALT) by a process termed transcytosis. The molecular basis of antigen uptake by M cells has been gradually identified in the last decade. Active sampling of intestinal antigen initiates regulated immune responses that ensure intestinal homeostasis. The delivery of luminal substances across the intestinal epithelium to the immune system is a critical event in immune surveillance resulting in tolerance to dietary antigens and immunity to pathogens (e.g., bacteria, viruses, and parasites) and their toxins. Several specialized mechanisms transport luminal antigen across the gut epithelium. Discovery of M cell-specific receptors are of great interest, which could act as molecular tags for targeted delivery oral vaccine to M cells. Recent studies demonstrated that M cells utilize several receptors to recognize and transport specific luminal antigens. Vaccination through the mucosal immune system can induce effective systemic immune responses simultaneously with mucosal immunity. How this process is regulated is largely unknown. This review aims to show a new understanding of the factors that influence the development and function of M cells; to show the molecules expressed on M cells which appear to be used as immunosurveillance receptors to sample pathogenic microorganisms in the gut; to note how certain pathogens appear to exploit M cells to inject the host; and, finally, how this knowledge is used to specifically "target" antigens to M cells to attempt to improve the efficacy of mucosal vaccines. Recently, substantial progress has been made in our understanding of the factors that influence the development and function of M cells.

© 2018 Media Sphera Publishing Group. All rights reserved. The outcome of diseases accompanied or caused by mucostasis depends both on the restoration of drainage function of the airways and on the effectiveness of immune mechanisms against pathogens. N-acetylcysteine (NAC) is widely used as mucolytic and antioxidant remedy in clinical practice. In this regard, the data of the scientific literature on the direct and indirect effects of NAC on the mucosal immunity of the respiratory tract have been reviewed. NAC possesses pleiotropic immunomodulating properties, most of which contribute to the regression of clinical manifestations of acute and chronic inflammatory diseases of the respiratory tract. Biological and pharmacological effects of NAC include improvement in rheological properties of mucus, reduction of excess mucin production, restoration of mucociliary clearance and production of sIgA, suppression of excess production of IgE and IgG4, destruction of biofilms and inhibition of their formation, suppression of adhesion of pathogenic bacteria to epithelial cells, antioxidant activity, regulation of the production of pro-inflammatory and profibrotic cytokines. There was no convincing evidence that NAC is able to suppress any component of mucosal immunity. For final conclusions on this subject, further research are required.