Search results for "Peyer's Patches"
showing 9 items of 9 documents
Group 3 Innate Lymphoid Cells Program a Distinct Subset of IL-22BP-Producing Dendritic Cells Demarcating Solitary Intestinal Lymphoid Tissues.
2019
Solitary intestinal lymphoid tissues such as cryptopatches (CPs) and isolated lymphoid follicles (ILFs) constitute steady-state activation hubs containing group 3 innate lymphoid cells (ILC3) that continuously produce interleukin (IL)-22. The outer surface of CPs and ILFs is demarcated by a poorly characterized population of CD11c+ cells. Using genome-wide single-cell transcriptional profiling of intestinal mononuclear phagocytes and multidimensional flow cytometry, we found that CP- and ILF-associated CD11c+ cells were a transcriptionally distinct subset of intestinal cDCs, which we term CIA-DCs. CIA-DCs required programming by CP- and ILF-resident CCR6+ ILC3 via lymphotoxin-β receptor sig…
Th17 skewing in the GALT of a Crohn disease patient upon Lactobacillus rhamnosus GG consumption.
2015
We wish to report on a recent observation we made and that might represent a useful hint for the employment of the so called probiotics in the management of some pathological immune reactions of the gut. By analyzing GALT-associated T cells upon consumption of L. rhamnosus-GG, we obtained some hints that probiotics might have locoregional immunological effects mainly when administered in patients with IBDs rather than in individuals with non-inflamed gut mucosa.
Tolerance towards resident intestinal flora in mice is abrogated in experimental colitis and restored by treatment with interleukin-10 or antibodies …
1996
There is now increasing evidence that hyperresponsiveness towards intestinal flora is a crucial event in the pathogenesis of inflammatory bowel disease (IBD). In support of this hypothesis, we recently described in humans that tolerance exists towards indigenous intestinal flora but is broken in active IBD lesions. In the present study, we have attempted to transfer this model into mice from different genetic backgrounds (BALB/c, SJL/J, C3H/HeJ). We found that mononuclear cells from spleen, small bowel and large bowel of mice do not proliferate, i.e. are tolerant when exposed to bacterial sonicates derived from autologous intestine (BsA) but do proliferate, i.e. are immune when exposed to b…
Compromised integrity of excised porcine intestinal epithelium obtained from the abattoir affects the outcome of in vitro particle uptake studies
2002
Excised porcine intestinal tissue obtained from the local abattoir was studied for its suitability to examine the uptake and transport of poly(lactic-co-glycolic acid) (PLGA) nanoparticles in Peyer's (PP) and non-Peyer's patch (NPP) tissue in vitro. Incubation of such tissue with fluorescent PLGA and polystyrene particles revealed negligible uptake into the intercellular space with no noticeable difference between PP and NPP tissue. Similarly, yeast cells, which were used as a positive control for selective uptake into PP tissue, were found in the subepithelial area of both PP and NPP tissue. Therefore we examined the morphological integrity of the tissue for the duration of the experiments…
Th17 responses in Echinostoma caproni infections in hosts of high and low compatibility.
2011
In order to investigate the factors determining the expulsion of intestinal helminths, we have analyzed the in vivo expression of IL-17, TGF-β and IL-23 in several tissues of two host species displaying different compatibility with Echinostoma caproni (Trematoda). We did not observe upregulation of these cytokines in any of the tissues of the high compatible host (mice). In contrast, the responses in the host of low compatibility (rats) with the parasite were markedly different. Significant increases in the expression of IL-17 and TGF-β were observed in the Peyer's patches and the intestine from the 2 to 8 weeks post-infection. The expression of IL-23 was upregulated from 2 to 4 weeks post-…
Echinostoma caproni (Trematoda): differential in vivo cytokine responses in high and low compatible hosts.
2011
In order to investigate the factors determining the expulsion of intestinal trematodes, we have analyzed the in vivo cytokine responses at several levels and the local responses against Echinostoma caproni (Trematoda) in two host species displaying different compatibility with the parasite. The response of the high compatible host (mice) is characterized by a mixed Th1/Th2 phenotype in the spleen, Peyer's patches and mesenteric lymph nodes. At the intestine, a marked Th1 response with a marked increase of IFN-γ together with elevated number of mucosal neutrophils and expression of induced nitric oxide synthase were observed. The responses in the host of low compatibility (rats) with the par…
In vitrouptake of lysozyme-loaded liposomes coated with chitosan biopolymer as model immunoadjuvants
2009
Chitosan binds to negatively charged soy lecithin liposomes by an electrostatic interaction driven by its cationic amino group. This interaction allows developing stable coated vesicles suitable as a targeted carrier and controlled release system for drugs and vaccines. In this work, we studied the effect of chitosan-coated liposomes on the uptake and antigen presentation of hen egg-white lysozyme (HEL) in Peyer's patches peritoneal macrophages isolated from mice. Chitosan-coated liposomes were characterized according to size, zeta potential, and antigen-loading and release properties. Results showed an increase in the positive net charge and size of the liposomes as the concentration of ch…
The “mode” of lymphocyte extravasation through HEV of Peyer's patches and its role in normal homing and inflammation
2007
The mode of lymphocyte transendothelial migration in the postcapillary high endothelial venules (HEVs) of Peyer's patches during normal homing and acute inflammation in the guinea pig was studied. It is common opinion that the lymphocyte transendothelial passage from the blood stream into the extravasal lymphoid tissue calls for a multistep process of endothelial and lymphocyte molecules favoring tethering, rolling, activation, arrest and its firm adhesion to the endothelial luminal surface. Ultrastructural serial pictures and the three-dimensional reconstruction of HEVs with lymphocytes during different moments of their transmigration through the endothelial wall enabled us to demonstrate …
Distribution and phenotype of rotavirus-specific B cells induced during the antigen-driven primary response to 2/6 virus-like particles administered …
2007
AbstractSelection of mucosal sites is an important step in mucosal vaccine development. The intrarectal (IR) route represents an alternative to the oral route of immunization; nevertheless, immune responses induced by this route are not well defined. Here, we studied the early primary B cell response (induction, homing, and phenotype) induced by IR immunization with rotavirus (RV)-2/6 virus-like particles (VLP). Using flow cytometry, we traced RV-specific B cells in different lymphoid tissues and analyzed the expression of α4β7 and CCR9, which are important receptors for homing to the gut, as well as CD5, a marker expressed by B1-a cells, which are a major source of natural antibodies. We o…