Search

Research has been conducted on microaerophilic flagellate parasitic protozoon Giardia intestinalis which can detoxify O (sub)2. The authors have investigated the limits of O (sub)2 tolerance of this microorganism and have characterized the functional and structural consequences of reactive O (sub)2 species accumulation.

Human blood myeloid DCs can be subdivided into CD1c ( BDCA-1)+ and CD141 ( BDCA-3)+ subsets that display unique gene expression profiles, suggesting specialized functions. CD1c+ DCs express TLR4 while CD141+ DCs do not, thus predicting that these two subsets have differential capacities to respond to Escherichia coli. We isolated highly purified CD1c+ and CD141+ DCs and compared them to in vitro generated monocyte-derived DCs ( Mo DCs) following stimulation with whole E. coli. As expected, MoDCs produced high levels of the proinflammatory cytokines TNF, IL-6, and IL-12, were potent inducers of Th1 responses, and processed E. coli-derived Ag. In contrast, CD1c+ DCs produced only low levels of TNF, IL-6, and IL-12 and instead produced high levels of the anti-inflammatory cytokine IL-10 and regulatory molecules IDO and soluble CD25. Moreover, E. coli-activated CD1c+ DCs suppressed T-cell proliferation in an IL-10-dependent manner. Contrary to their mouse CD8+ DC counterparts, human CD141+ DCs did not phagocytose or process E. coli-derived Ag and failed to secrete cytokines in response to E. coli. These data demonstrate substantial differences in the nature of the response of human blood DC subsets to E. coli. [ABSTRACT FROM AUTHOR]

Identification of the precise location, where hematopoietic stem cells (HSCs) reside in the bone marrow, has made a great leap forward with the advance of live time-lapse video 2-photon fluorescent microscopy. These studies have shown that HSCs preferentially resides in the endosteal region of the BM, at an average of two cell diameters from osteoblasts covering endosteal bone surfaces. However, this equipment is very sophisticated and only a very few laboratories can perform these studies. To investigate functional attributes of these niches, we have developed a flow cytometry technique in which mice are perfused with the cell-permeable fluorescent dye Hoechst33342 in vivo before bone marrow cells are collected and antibody stained. This method enables to position phenotypic HSC, multipotent and myeloid progenitors, as well as BM nonhematopoietic stromal cells relative to blood flow in vivo. This technique enables prospective isolation of HSCs based on the in vivo perfusion of the niches in which they reside.

Inflammatory bowel diseases (IBD) consist of Crohn's disease (CD) and ulcerative colitis (UC) affecting about 0.1% of the western population. These two chronic gut diseases affect youth at their prime of life causing diarrhoea, intestinal bleeding, and severe gut discomfort. Mouse models of colitis have been major tools in understanding the pathogenesis of IBD. A number of mouse models are available to assess the contribution of T cells in the pathogenesis of CD and UC. Among these, the T cell transfer model of colitis is the most widely used model to dissect the initiation, induction, and regulation of immunopathology in chronic colitis mediated by T cells. The methodology below describes the classification of various animal models and explains the T cell transfer model in detail, including flow cytometry-based isolation of naïve T cells that are used in the transfer, immunological concepts, detailed immune-pathological assessment, shortcomings of the model, and the latest improvements to this colitis model. A special focus is paid to the utilisation of the T cell transfer model in delineating the immunopathology in a primary epithelial defect model of colitis, namely Winnie.