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MLN Cells (mln + cell)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

CD4+ T lymphocytes mediate colitis in HLA-B27 transgenic rats monoassociated with nonpathogenic Bacteroides vulgatus

INFLAMMATORY BOWEL DISEASES, Issue 3 2007
Frank Hoentjen MD
Abstract Background: HLA-B27/,2 microglobulin transgenic (TG) rats develop spontaneous colitis when raised under specific pathogen-free (SPF) conditions or after monoassociation with Bacteroides vulgatus (B. vulgatus), whereas germ-free TG rats fail to develop intestinal inflammation. SPF HLA-B27 TG rnu/rnu rats, which are congenitally athymic, remain disease free. These results indicate that commensal intestinal bacteria and T cells are both pivotal for the development of colitis in TG rats. However, it is not known if T cells are also required in the induction of colitis by a single bacterial strain. The aim of this study was therefore to investigate the role of T cells in the development of colitis in B. vulgatus,monoassociated HLA-B27 TG rats. Methods: HLA-B27 TG rnu/rnu and rnu/+ rats were monoassociated with B. vulgatus for 8,12 weeks. CD4+ T cells from mesenteric lymph nodes (MLNs) of B. vulgatus,monoassociated rnu/+ TG donor rats were transferred into B. vulgatus,monoassociated rnu/rnu TG recipients. Results:B. vulgatus,monoassociated rnu/+ rats showed higher histologic inflammatory scores and elevated colonic interferon-, mRNA, cecal myeloperoxidase, and cecal IL-1, levels compared to those in rnu/rnu TG rats that did not contain T cells. After transfer of CD4+ cells from colitic B. vulgatus,monoassociated rnu/+ TG donor rats, B. vulgatus,monoassociated rnu/rnu TG recipients developed colitis that was accompanied by B. vulgatus- induced IFN-, production by MLN cells in vitro and inflammatory parameters similar to rnu/+ TG rats. Conclusions: These results implicate CD4+ T cells in the development of colitis in HLA-B27 TG rats monoassociated with the nonpathogenic bacterial strain B. vulgatus. (Inflamm Bowel Dis 2007) [source]

Interleukin-18 overproduction exacerbates the development of colitis with markedly infiltrated macrophages in interleukin-18 transgenic mice

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 8 2003
TAKAHIRO ISHIKURA
Abstract Background and Aim:, The authors have previously shown that production of interleukin (IL)-18 was increased in the inflamed mucosa of patients with Crohn's disease (CD) and blockade of IL-18 ameliorated the murine model of CD. This demonstrated that IL-18 plays a significant role during intestinal inflammation. However, the initial role of IL-18 during intestinal inflammation was unclear; therefore the susceptibility of IL-18 transgenic (Tg) mice to acute dextran sulfate sodium (DSS)-induced colitis was examined. Methods:, Interleukin-18 Tg and wild-type (WT) mice were fed 2.0% of DSS for 8 days. The total clinical scores (bodyweight loss, stool consistency, and rectal bleeding), colon length and histological scores were assessed. The expressions of surface markers and IL-18 on infiltrating lamina propria mononuclear cells were analyzed immunohistochemistrically. Mesenteric lymph node (MLN) cells were isolated and the expressions of CD4+ T-cell activation markers (CD69, CD25 and IL18R) were analyzed by flow cytometry. Results:, The IL-18 Tg mice exhibited an increased susceptibility to DSS-induced colitis, as shown by significantly increased clinical, histological scores, and more severe colonic shortening compared with WT mice. Immunohistochemical analysis revealed a significant increase of IL-18 production and CD11b+ macrophages but not CD4+ T cells in the inflamed mucosa in DSS-fed IL-18 Tg compared with DSS-fed WT mice. Furthermore, MLN cells revealed no evidence of increased CD4+ T-cell activation in DSS-fed IL-18 Tg. Conclusions:, These findings suggest that IL-18 overproduction in the mucosa plays an important role in the marked infiltration of macrophages and exacerbates colitis in IL-18 Tg mice. [source]

The immune response during a Strongyloides ratti infection of rats

PARASITE IMMUNOLOGY, Issue 7 2007
C. P WILKES
SUMMARY A range of immune parameters was measured during a primary infection of Strongyloides ratti in its natural rat host. The immune parameters measured were interleukin-4 (IL-4) and interferon-, from both the spleen and mesenteric lymph node (MLN) cells; parasite-specific immunoglobulin G1(IgG1), IgG2a and IgG2b in serum and in intestinal tissue; parasite-specific IgG and total IgE in serum; parasite-specific and total IgA in intestinal tissue and rat mast cell protease II in intestinal tissue. Parasite-specific IgG1, IgG2a and total IgE in serum and parasite-specific IgA and rat mast cell protease II in intestinal tissue all occurred at significantly greater concentrations in infected animals, compared with non-infected animals. Similarly, the production of IL-4 by MLN cells stimulated with parasitic female antigen or concanavalin A occurred at significantly greater concentrations in infected animals, compared with non-infected animals. In all, this suggests that there is a T-helper 2-type immune response during a primary S. ratti infection. These data also show the temporal changes in these components of the host immune response during a primary S. ratti infection. [source]

Polyphenol-enriched apple extract attenuates food allergy in mice

CLINICAL & EXPERIMENTAL ALLERGY, Issue 6 2010
A. W. Zuercher
Summary Background The immune system may be modulated with nutrition to prevent the development or to treat the symptoms of allergy. Among other foods, consumption of apples has been linked to reduced incidence of atopic dermatitis and respiratory allergy. Objective We evaluated the efficacy and mechanisms of a polyphenol-enriched apple extract in reducing symptoms of food allergy. Methods In a model of food allergy to ovalbumin (OVA), BALB/c mice were fed with an apple extract either during sensitization or just before the challenge. After the challenge, allergic symptoms were scored, OVA-specific serum immunoglobulins were determined by ELISA, cytokine production by mesenteric lymph node (MLN) cells was measured by a multiplex assay and gene expression profiles in the intestine were addressed using quantitative real-time PCR. Results Consumption of the apple extract reduced symptoms of food allergy upon challenge. This was paralleled by reduced levels of intestinal mast cell protease, diminished cytokine secretion by MLN cells and reduced local intestinal mRNA expression of various T-helper type-2 associated and pro-inflammatory genes. Mechanistic studies suggested decrease of mediator release by effector cells and reduction of allergenicity by protein,polyphenol interaction as potential mechanisms responsible for protection. Conclusion Polyphenol-enriched apple extract can attenuate food allergy symptoms in sensitized mice via two distinct possible mechanisms. [source]