11 research outputs found
Marine Tourism Development in the Arkhangelsk Region, Russian Arctic : Stakeholderâs Perspectives
Author's accepted version (postprint).This is an Accepted Manuscript of an article published by Springer in Springer Polar Sciences on (07/03/2020).Available online: https://link.springer.com/chapter/10.1007%2F978-3-030-28404-6_17acceptedVersio
REGULATION OF IMMUNE RESPONSE AGAINST MYCOBACTERIUM TUBERCULOSIS BY THE POPULATION OF REGULATORY DENDRITIC CELLS
On the background of a high level of genetic susceptibility to tuberculosis infection (TB), granulomatous reactions in the lung tissue fail to effectively isolate infection foci and rather result in diffuse pathology, confluence of granulomata and formation of necrotic zones. Uncontrolled inflammation severely affect breathing function of the lung. Thus, effective disease control requires a good balance between protective and pathogenic immune responses. Immature regulatory dendritic cells (DCreg) and regulatory T lymphocytes (Treg) represent a pool of important cellular regulators of inflammation. Earlier we have demonstrated that stromal lung cells support development of CD11b+CD11clowCD103â DCreg from their bone marrowderived precursors in in vitro cultures. In addition, significantly larger population size and more rapid development of the lung CD4+Foxp3+ Treg cells characterize TB- resistant B6 mice compare to their TB-susceptible I/St counterparts. Here, we report that adoptive transfer of DCreg cells into TB-infected I/St mice is capable to enlarge the population of Treg cells in the lungs. This, in turn, attenuates lung pathology, decreases mycobacterial multiplication and diminishes lung infiltration with neutrophils, i.e., selectively restricts the population of cell largely responsible for TB pathogenesis. The key difference in lung pathology between DCreg recipients and control animals was the lack of tissue-destructive foci and necrotic zones in the former group. Meanwhile, the groups of mice did not differ in production of regulatory (IL-10 and TGF-β) and key inflammatory (IFNÎł and IL-6) cytokines by lung cells. The latter result suggests that contact rather than secretory mechanisms underlie moderate attenuation of the TB process in the lungs of mice with an elevated lung Treg level, given that plethora of such mechanisms were described for Treg functioning. Although therapeutic effects were relatively weak, our results indicate that cell therapy approaches are applicable to regulation of lung tissue inflammation during TB course
A role for the pattern recognition receptor Nod2 in promoting recruitment of CD103+ dendritic cells in the colon in response to Trichuis muris infection
The ability of the colon to generate an immune response to pathogens, such as the model pathogen Trichuris muris, is a fundamental and critical defense mechanism. Resistance to T. muris infection is associated with the rapid recruitment of dendritic cells (DCs) to the colonic epithelium via epithelial chemokine production. However, the epithelialâpathogen interactions that drive chemokine production are not known. We addressed the role of the cytosolic pattern recognition receptor Nod2. In response to infection, there was a rapid influx of CD103+CD11c+ DCs into the colonic epithelium in wild-type(WT)mice, where as this was absent in Nod2â/â animals. In vitro chemotaxis assays and in vivo experiments using bone marrow chimeras of WT mice reconstituted with Nod2â/â bone marrow and infected with T. muris demonstrated that the migratory function of Nod2â/â DCs was normal. Investigation of colonic epithelial cell (CEC) innate responses revealed a significant reduction in epithelial production of the chemokines CCL2 and CCL5 but not CCL20 by Nod2-deficient CECs. Collectively, these data demonstrate the importance of Nod2 in CEC responses to infection and the requirement for functional Nod2 in initiating host epithelial chemokine-mediated responses and subsequent DC recruitment and T-cell responses following infection