Persistent Helicobacter pylori Specific Th17 Responses in Patients with Past H. pylori Infection Are Associated with Elevated Gastric Mucosal IL-1β

10.1371/journal.pone.0039199PLoS ONE76

Stromal Fibroblasts in Digestive Cancer

The normal gastrointestinal stroma consists of extra-cellular matrix and a community of stromal cells including fibroblasts, myofibroblasts, smooth muscle cells, pericytes, endothelium and inflammatory cells. α-smooth muscle actin (α-SMA) positive stromal fibroblasts, often referred to as myofibroblasts or activated fibroblasts, are critical in the development of digestive cancer and help to create an environment that is permissive of tumor growth, angiogenesis and invasion. This review focusses on the contribution of activated fibroblasts in carcinogenesis and where possible directly applies this to, and draws on examples from, gastrointestinal cancer. In particular, the review expands on the definition, types and origins of activated fibroblasts. It examines the molecular biology of stromal fibroblasts and their contribution to the peritumoral microenvironment and concludes by exploring some of the potential clinical applications of this exciting branch of cancer research. Understanding the origin and biology of activated fibroblasts will help in the development of an integrated epithelial-stromal sequence to cancer that will ultimately inform cancer pathogenesis, natural history and future therapeutics

The Shc family protein adaptor, Rai, acts as a negative regulator of Th17 cell development.

Objective Rai acts as a negative regulator of antigen receptor signaling in T and B cells. Rai-/- mice develop lupus-like autoimmunity associated to the spontaneous activation of self-reactive lymphocytes. Here we have addressed the potential role of Rai in the development of the proinflammatory Th1 and Th17 subsets. Materials and methods Lymph node T cells or naïve T cells were isolated from wild-type and Rai-/- mice and their cytokine profile was determined by ELISPOT and qRT-PCR both as such and after stimulation in vitro with immobilized anti-CD3 mAb in the presence or absence of polarizing cytokines. The expression of rai was measured in PBL from SLE patients and healthy donors by qRT-PCR. Results We show that Rai-/- mice display a spontaneous Th1/Th17 bias. In vitro polarization experiments demonstrate that rai deficiency favours the development and expansion of Th17, but not Th1, cells, indicating that Rai modulates TCR signaling to antagonize the pathways driving naive CD4+ T cell differentiation to the Th17 lineage. Th1 and Th17 cell infiltrates were found in the kidneys of Rai-/- mice, providing evidence that Rai deficiency contributes to the development of lupus nephritis not only by enhancing lymphocyte activation but also by promoting the development and expansion of proinflammatory effector T cells. Interestingly, T cells from SLE patients were found to have a defect in Rai expression, suggesting a role for Rai in disease pathogenesis. Conclusions We have identified Rai as a negative regulator of Th17 cell differentiation and expansion in the mouse and found evidence of an impairment of Rai expression in PBL from SLE patients

Increasing LFA-1 expression enhances immune synapse architecture and T cell receptor signaling in Jurkat E6.1 cells

The Jurkat E6.1 clone has been extensively used as a powerful tool for the genetic and biochemical dissection of the TCR signaling pathway. More recently, these cells have been exploited in imaging studies to identify key players in immunological synapse (IS) assembly in superantigen-specific conjugates and to track the dynamics of signaling molecules on glass surfaces coated with activating anti-CD3 antibodies. By comparison, Jurkat cells have been used only scantily for imaging on supported lipid bilayers (SLBs) incorporating laterally mobile TCR and integrin ligands, which allow to study synaptic rearrangements of surface molecules and the fine architecture of the mature IS, likely due to limitations in the assembly of immune synapses with well-defined architecture. Here we have explored whether upregulating the low levels of endogenous LFA-1 expression on Jurkat E6.1 cells through transduction with CD11a- and CD18-encoding lentiviruses can improve IS architecture. We show that, while forced LFA-1 expression did not affect TCR recruitment to the IS, E6.1 LFA-1high cells assembled better structured synapses, with a tighter distribution of signaling-competent TCRs at the center of the IS. LFA-1 upregulation enhanced protein phosphotyrosine signaling on SLBs but not at the IS formed in conjugates with SEE-pulsed APCs, and led to the constitutive formation of an intracellular phosphotyrosine pool co-localizing with endosomal CD3ζ. This was paralleled by an increase in the levels of p-ZAP-70 and p-Erk both under basal conditions and following activation, and in enhanced Ca2+ mobilization from intracellular stores. The enhancement in early signaling E6.1 LFA-1high cells did not affect expression of the early activation marker CD69 but led to an increase in IL-2 expression. Our results highlight a new role for LFA-1 in the core architecture of the IS that can be exploited to study the spatiotemporal redistribution of surface receptors on SLBs, thereby extending the potential of E6.1 cells and their derivatives for fine-scale imaging studies