Bruton's Tyrosine Kinase Cooperates with the B Cell Linker Protein SLP-65 as a Tumor Suppressor in Pre-B Cells

Expression of the pre-B cell receptor (pre-BCR) leads to activation of the adaptor molecule SLP-65 and the cytoplasmic kinase Btk. Mice deficient for one of these signaling proteins have an incomplete block in B cell development at the stage of large cycling pre-BCR+CD43+ pre-B cells. Our recent findings of defective SLP-65 expression in ∼50% of childhood pre-B acute lymphoblastic leukemias and spontaneous pre-B cell lymphoma development in SLP-65−/− mice demonstrate that SLP-65 acts as a tumor suppressor. To investigate cooperation between Btk and SLP-65, we characterized the pre-B cell compartment in single and double mutant mice, and found that the two proteins have a synergistic role in the developmental progression of large cycling into small resting pre-B cells. We show that Btk/SLP-65 double mutant mice have a dramatically increased pre-B cell tumor incidence (∼75% at 16 wk of age), as compared with SLP-65 single deficient mice (<10%). These findings demonstrate that Btk cooperates with SLP-65 as a tumor suppressor in pre-B cells. Furthermore, transgenic low-level expression of a constitutive active form of Btk, the E41K-Y223F mutant, prevented tumor formation in Btk/SLP-65 double mutant mice, indicating that constitutive active Btk can substitute for SLP-65 as a tumor suppressor

Peyer\u27s patch M cells derived from Lgr5\u3csup\u3e+\u3c/sup\u3e stem cells require SpiB and are induced by RankL in cultured miniguts

Peyer\u27s patches consist of domains of specialized intestinal epithelium overlying gut-associated lymphoid tissue (GALT). Luminal antigens reach the GALT by translocation through epithelial gatekeeper cells, the so-calledMcells. We recently demonstrated that all epithelial cells required for the digestive functions of the intestine are generated from Lgr5-expressing stem cells. Here, we show thatMcells also derive from these crypt-based Lgr5 stem cells. The Ets family transcription factor SpiB, known to control effector functions of bone marrow-derived immune cells, is specifically expressed inMcells. In SpiB-/-mice, Mcells are entirely absent, which occurs in a cell-autonomous fashion. It has been shown that Tnfsf11 (RankL) can induceMcell development in vivo. We show that in intestinal organoid ( minigut ) cultures, stimulation with RankL induces SpiB expression within 24 h and expression of otherMcell markers subsequently. We conclude that RankL-induced expression of SpiB is essential for Lgr5 stem cell-derived epithelial precursors to develop intoMcells. © 2012, American Society for Microbiology

Rifaximin stimulates nitrogen detoxification by PXR-independent mechanisms in human small intestinal organoids

BACKGROUND AND AIMS: Recurrent hepatic encephalopathy (HE) is characterized by hyperammonaemia in combination with neuropsychiatric abnormalities and is treated with lactulose and rifaximin. Rifaximin is a pregnane X receptor (PXR) agonist with low systemic and high intestinal bioavailability. The mechanisms by which it alleviates HE are unclear. We used human small intestinal (hSI) organoids to study whether rifaximin, via PXR activation, affects the epithelial biotransformation machinery, and to gain understanding of its low systemic availability. METHODS: We generated PXR knockdown hSI organoids via lentiviral delivery of short hairpin RNAs. Organoids were cultured for 24 h with rifaximin or rifampicin. RNA-sequencing and metabolomics were performed to analyse gene expression and amino acid metabolism. Luminal rifaximin was quantified by photospectrometry. RESULTS: Treatment of wild-type hSI organoids with rifaximin resulted in >twofold differential expression of 131 genes compared to DMSO. These effects were largely PXR independent and related to amino acid metabolism. Rifaximin decreased expression of glutaminase-2 and increased expression of asparagine synthetase and solute carrier 7A11, thereby increasing intracellular glutamine and asparagine concentrations, indicating active ammonia detoxification. Rifaximin was apically excreted into the lumen in an ATP binding cassette B1 (ABCB1)-dependent manner. CONCLUSIONS: Rifaximin-after uptake into enterocytes-stimulates intracellular nitrogen detoxification by PXR-independent mechanisms. Active apical excretion of rifaximin by ABCB1 into the intestinal lumen explains its low systemic bioavailability. Our study implies that rifaximin, next to modulation of the microbiome, has direct effects on ammonia scavenging in the human small intestinal epithelium

Медицинские и социальные аспекты коммерческого секса

Представлены демографические, медицинские, психологические и социальные характеристики женщин, оказывающих платные сексуальные услуги. Обсуждается проблема легализации и регламентации проституции в контексте профилактики инфекций, передающихся половым путем, и заражения ВИЧ.Demographic, medical, psychological and social characteristics of women rendering sexual services are described. The problem of legalization and regulation of prostitution in the context of prevention of sexually transmitted infections and HIV is discussed

The Effect of Artichoke Leaf Extract on Alanine Aminotransferase and Aspartate Aminotransferase in the Patients with Nonalcoholic Steatohepatitis

<div><p>Objective</p><p>In current clinical practice, optimal treatment of inflammatory bowel disease (IBD) aims at the induction and maintenance of clinical remission. Clinical remission is apparent when laboratory markers of inflammation are normal and clinical symptoms are absent. However, sub-clinical inflammation can still be present. A detailed analysis of the immune status during this inactive state of disease may provide a useful tool to categorize patients with clinical remission into subsets with variable states of immune activation.</p><p>Design</p><p>By using Affymetrix GeneChips, we analysed RNA gene expression profiles of peripheral blood leukocytes from pediatric IBD patients in clinical remission and controls. We performed (un)supervised clustering analysis of IBD-associated genes and applied Ingenuity® pathway software to identify specific molecular profiles between patients.</p><p>Results</p><p>Pediatric IBD patients with disease in clinical remission display heterogeneously distributed gene expression profiles that are significantly distinct from controls. We identified three clusters of IBD patients, each displaying specific expression profiles of IBD-associated genes.</p><p>Conclusion</p><p>The expression of immune- and IBD-associated genes in peripheral blood leukocytes from pediatric IBD patients in clinical remission was different from healthy controls, indicating that sub-clinical immune mechanisms are still active during remission. As such, RNA profiling of peripheral blood may allow for non-invasive patient subclassification and new perspectives in treatment regimes of IBD patients in the future.</p></div

Epithelial and dendritic cells in the thymic medulla promote CD4(+)Foxp3(+) regulatory T cell development via the CD27-CD70 pathway

This work was supported by grants NKI 2004-3087 and NKI 2008-2023 from the Dutch Cancer Society to J. Borst, European Molecular Biology Organization long-term fellowships to J.M. Coquet and J.C. Ribot, a Rubicon (The Netherlands Organisation for Scientific Research [NWO]) fellowship to J.M. Coquet, and a Fundação para a Ciência e Tecnologia project grant (PTDC/SAU-MII/104158/2008) and a European Research Council starting grant (StG260352) to B. Silva-Santos. J.F. Neves is funded by the Fundação para a Ciência e Technologia of Portugal; D.J. Pennington is funded by the Wellcome Trust