The Experts below are selected from a list of 183 Experts worldwide ranked by ideXlab platform
Stefan Feske - One of the best experts on this subject based on the ideXlab platform.
-
Molecular regulation of CRAC channels and their role in Lymphocyte Function
Cellular and Molecular Life Sciences, 2013Co-Authors: Patrick J. Shaw, Markus Hoth, Stefan FeskeAbstract:Calcium (Ca^2+) influx is required for the activation and Function of all cells in the immune system. It is mediated mainly by store-operated Ca^2+ entry (SOCE) through Ca^2+ release-activated Ca^2+ (CRAC) channels located in the plasma membrane. CRAC channels are composed of ORAI proteins that form the channel pore and are activated by stromal interaction molecules (STIM) 1 and 2. Located in the membrane of the endoplasmic reticulum, STIM1 and STIM2 have the dual Function of sensing the intraluminal Ca^2+ concentration in the ER and to activate CRAC channels. A decrease in the ER’s Ca^2+ concentration induces STIM multimerization and translocation into puncta close to the plasma membrane where they bind to and activate ORAI channels. Since the identification of ORAI and STIM genes as the principal mediators of CRAC channel Function, substantial advances have been achieved in understanding the molecular regulation and physiological role of CRAC channels in cells of the immune system and other organs. In this review, we discuss the mechanisms that regulate CRAC channel Function and SOCE, the role of recently identified proteins and mechanisms that modulate the activation of ORAI/STIM proteins and the consequences of CRAC channel dysregulation for Lymphocyte Function and immunity.
-
Ion channels and transporters in Lymphocyte Function and immunity
Nature reviews. Immunology, 2012Co-Authors: Stefan Feske, Edward Y. Skolnik, Murali PrakriyaAbstract:Lymphocyte Function is regulated by a network of ion channels and transporters in the plasma membrane of B and T cells. These proteins modulate the cytoplasmic concentrations of diverse cations, such as calcium, magnesium and zinc ions, which Function as second messengers to regulate crucial Lymphocyte effector Functions, including cytokine production, differentiation and cytotoxicity. The repertoire of ion-conducting proteins includes calcium release-activated calcium (CRAC) channels, P2X receptors, transient receptor potential (TRP) channels, potassium channels, chloride channels and magnesium and zinc transporters. This Review discusses the roles of ion conduction pathways in Lymphocyte Function and immunity.
John H. Kehrl - One of the best experts on this subject based on the ideXlab platform.
-
G-protein-coupled receptor signaling, RGS proteins, and Lymphocyte Function.
Critical reviews in immunology, 2004Co-Authors: John H. KehrlAbstract:The positioning of Lymphocytes in immune organs and the migration of Lymphocytes that occurs during normal immune surveillance and following immune activation depends on appropriate signaling through receptors that couple to heterotrimeric G-proteins. In addition other mediators that affect Lymphocyte Function, such as histamine, purine nucleosides, C5A, prostaglandins, leukotrienes, serotonin, epinephrine, opioids, and certain phospholipids, also signal through G-protein-coupled receptors (GPCRs). Downstream of heterotrimeric G-proteins are a limited number of downstream effectors, which, in turn, activate a large number of other signaling molecules, many of which are shared with other signaling pathways, such as those activated by antigen receptors, coreceptors, and adhesion receptors. Crucial to signaling through GPCRs are finely developed regulatory systems, which control the activation of heterotrimeric G-proteins and their interactions with their immediate downstream effectors. This review will focus on the overall importance of GPCR signaling in Lymphocyte Function and an upstream regulatory system present in Lymphocytes, which fine tunes heterotrimeric G-protein signaling.
Gail A Bishop - One of the best experts on this subject based on the ideXlab platform.
-
Roles of TRAF molecules in B Lymphocyte Function.
Cytokine & growth factor reviews, 2008Co-Authors: Ping Xie, Zachary J Kraus, Laura L Stunz, Gail A BishopAbstract:Tumor necrosis factor receptor associated factors (TRAFs) play a variety of interesting and important roles in the regulation of B Lymphocyte Function. They act both as cytoplasmic regulatory molecules, and as signal transducers for receptors involved in both innate and adaptive humoral immune responses. In this brief review, we highlight the current state of knowledge of the diverse roles of TRAF molecules in the Functions of B Lymphocytes.
Manabu Fujimoto - One of the best experts on this subject based on the ideXlab platform.
-
cd22 regulates b Lymphocyte Function in vivo through both ligand dependent and ligand independent mechanisms
Nature Immunology, 2004Co-Authors: Jonathan C Poe, Yoko Fujimoto, Minoru Hasegawa, Karen M Haas, Ann S Miller, Isaac G Sanford, Cheryl B Bock, Manabu FujimotoAbstract:The interaction of CD22 with α2,6-linked sialic acid ligands has been widely proposed to regulate B Lymphocyte Function and migration. Here, we generated gene-targeted mice that express mutant CD22 molecules that do not interact with these ligands. CD22 ligand binding regulated the expression of cell surface CD22, immunoglobulin M and major histocompatibility complex class II on mature B cells, maintenance of the marginal zone B cell population, optimal B cell antigen receptor–induced proliferation, and B cell turnover rates. However, CD22 negative regulation of calcium mobilization after B cell antigen receptor ligation, CD22 phosphorylation, recruitment of SHP-1 to CD22 and B cell migration did not require CD22 ligand engagement. These observations resolve longstanding questions regarding the physiological importance of CD22 ligand binding in the regulation of B cell Function in vivo.
John Wong - One of the best experts on this subject based on the ideXlab platform.
-
T Lymphocyte Function in patients with malignant biliary obstruction.
Journal of gastroenterology and hepatology, 1994Co-Authors: St Fan, Edward C. S. Lai, John WongAbstract:The T Lymphocyte Function in 59 patients with malignant biliary obstruction undergoing pre-operative endoscopic drainage (group Ia, n = 24) or surgery (group Ib, n = 35) was evaluated by mitogen stimulation test with phytohaemagglutinin. The T Lymphocyte Function before endoscopic or surgical intervention was found to be impaired as compared with patients with gastric cancer (group II, n = 27) and with normal persons (group III, n = 19). Regression analysis showed a significant negative correlation between T Lymphocyte Function and the serum bilirubin level (correlation coefficient -0.3, P = 0.01) and a positive correlation with serum albumin level (correlation coefficient 0.34, P = 0.01) and serum transferrin level (correlation coefficient 0.45, P = 0.001). After 18 +/- 3 days of endoscopic biliary drainage, the T Lymphocyte Function of group Ia patients did not change substantially. At postoperative day 14, there were more patients in both groups Ia and Ib having deterioration of T Lymphocyte Function than those with improvement. The incidence of postoperative sepsis was found to be significantly higher in patients with deterioration than those with improvement of T Lymphocyte Function (18/31 vs 7/26, P = 0.036). It is concluded that endoscopic biliary drainage and surgery could not reverse the T Lymphocyte dysFunction in patients with malignant biliary obstruction.
