Read by QxMD icon Read


Alexandre P Meli, Ghislaine Fontés, Danielle T Avery, Scott A Leddon, Mifong Tam, Michael Elliot, Andre Ballesteros-Tato, Jim Miller, Mary M Stevenson, Deborah J Fowell, Stuart G Tangye, Irah L King
T follicular helper (Tfh) cells are a CD4(+) T cell subset critical for long-lived humoral immunity. We hypothesized that integrins play a decisive role in Tfh cell biology. Here we show that Tfh cells expressed a highly active form of leukocyte function-associated antigen-1 (LFA-1) that was required for their survival within the germinal center niche. In addition, LFA-1 promoted expression of Bcl-6, a transcriptional repressor critical for Tfh cell differentiation, and inhibition of LFA-1 abolished Tfh cell generation and prevented protective humoral immunity to intestinal helminth infection...
October 18, 2016: Immunity
Pontus Nordenfelt, Hunter L Elliott, Timothy A Springer
For a cell to move forward it must convert chemical energy into mechanical propulsion. Force produced by actin polymerization can generate traction across the plasma membrane by transmission through integrins to their ligands. However, the role this force plays in integrin activation is unknown. Here we show that integrin activity and cytoskeletal dynamics are reciprocally linked, where actin-dependent force itself appears to regulate integrin activity. We generated fluorescent tension-sensing constructs of integrin αLβ2 (LFA-1) to visualize intramolecular tension during cell migration...
October 10, 2016: Nature Communications
Guido Wabnitz, Emre Balta, Yvonne Samstag
T-cells need to be tightly regulated during their activation and effector phase to assure an appropriate defence against cancer or pathogens and - vice versa - to avoid autoimmune reactions. Regulatory signals are provided via the immune synapse between T-cells and antigen-presenting cells (APCs) or target cells. The stability and kinetics of immune synapse formation is critical for proper T-cell functions. It requires dynamic rearrangements of the actin cytoskeleton necessary for organized spatio-temporal redistribution of receptors and adhesion molecules...
September 27, 2016: Advances in Biological Regulation
Melissa Frick, Pierre Mouchacca, Grégory Verdeil, Yannick Hamon, Cyrille Billaudeau, Michel Buferne, Mathieu Fallet, Nathalie Auphan-Anezin, Anne-Marie Schmitt-Verhulst, Claude Boyer
Cancer-germline genes in both human and mice have been shown to encode antigens susceptible to targeting by cytotoxic CD8 T effector cells (CTL). We analyzed the ability of CTL to kill different tumor cell lines expressing the same cancer-germline gene P1A (Trap1a). We previously demonstrated that CTL expressing a TCR specific for the P1A35-43 peptide associated with H-2L(d) , although able to induce regression of P1A-expressing P815 mastocytoma cells, were much less effective against P1A-expressing melanoma cells...
October 7, 2016: Immunology
R Palomba, A Parodi, M Evangelopoulos, S Acciardo, C Corbo, E de Rosa, I K Yazdi, S Scaria, R Molinaro, N E Toledano Furman, J You, M Ferrari, F Salvatore, E Tasciotti
Recent advances in the field of nanomedicine have demonstrated that biomimicry can further improve targeting properties of current nanotechnologies while simultaneously enable carriers with a biological identity to better interact with the biological environment. Immune cells for example employ membrane proteins to target inflamed vasculature, locally increase vascular permeability, and extravasate across inflamed endothelium. Inspired by the physiology of immune cells, we recently developed a procedure to transfer leukocyte membranes onto nanoporous silicon particles (NPS), yielding Leukolike Vectors (LLV)...
October 5, 2016: Scientific Reports
Garth L Burn, Georgina H Cornish, Katarzyna Potrzebowska, Malin Samuelsson, Juliette Griffié, Sophie Minoughan, Mark Yates, George Ashdown, Nicolas Pernodet, Vicky L Morrison, Cristina Sanchez-Blanco, Harriet Purvis, Fiona Clarke, Rebecca J Brownlie, Timothy J Vyse, Rose Zamoyska, Dylan M Owen, Lena M Svensson, Andrew P Cope
Integrins are heterodimeric transmembrane proteins that play a fundamental role in the migration of leukocytes to sites of infection or injury. We found that protein tyrosine phosphatase nonreceptor type 22 (PTPN22) inhibits signaling by the integrin lymphocyte function-associated antigen-1 (LFA-1) in effector T cells. PTPN22 colocalized with its substrates at the leading edge of cells migrating on surfaces coated with the LFA-1 ligand intercellular adhesion molecule-1 (ICAM-1). Knockout or knockdown of PTPN22 or expression of the autoimmune disease-associated PTPN22-R620W variant resulted in the enhanced phosphorylation of signaling molecules downstream of integrins...
October 4, 2016: Science Signaling
Martin G Sauer, Jessica Herbst, Ulf Diekmann, Christopher E Rudd, Christian Kardinal
The clinical potential of transplantation is often reduced by T cell-mediated alloresponses that cause graft rejection or graft versus host disease. Integrin-mediated adhesion between alloreactive T cells and antigen-presenting cells is essential for allorejection. The identity of the signaling events needed to the activation of integrins such as LFA-1 is poorly understood. Here, we identify a novel role of the protein tyrosine phosphatase SHP-1 in the regulation of murine LFA-1-mediated adhesion in an allograft setting...
October 3, 2016: Molecular and Cellular Biology
Ru Li, Cordula Klockenbusch, Liwen Lin, Honghui Jiang, Shujun Lin, Juergen Kast
Physiological stimuli such as thrombin, or pathological stimuli such as lysophosphatidic acid (LPA), activate platelets. The activated platelets bind to monocytes through P-selectin-PSGL-1 interactions, but also release the contents of their granules, commonly called "platelet releasate". It is known that monocytes in contact with platelet releasate produce reactive oxygen species (ROS). Reversible cysteine oxidation by ROS is considered to be a potential regulator of protein function. In a previous study, we used THP-1 monocytic cells exposed to LPA- or thrombin-induced platelet releasate and a modified biotin switch assay to unravel the biological processes that are influenced by reversible cysteine oxidation...
October 3, 2016: Journal of Proteome Research
Masato Mori, Motomu Hashimoto, Takashi Matsuo, Takao Fujii, Moritoshi Furu, Hiromu Ito, Hiroyuki Yoshitomi, Jun Hirose, Yoshinaga Ito, Shuji Akizuki, Ran Nakashima, Yoshitaka Imura, Naoichiro Yukawa, Hajime Yoshifuji, Koichiro Ohmura, Tsuneyo Mimori
OBJECTIVE: To determine how cell-cell contact with synovial fibroblasts (SF) influence on the proliferation and cytokine production of CD4(+ )T cells. METHODS: Naïve CD4(+ )T cells were cultured with SF from rheumatoid arthritis patients, stimulated by anti-CD3/28 antibody, and CD4(+ )T cell proliferation and IFN-γ/IL-17 production were analyzed. To study the role of adhesion molecules, cell contact was blocked by transwell plate or anti-intracellular adhesion molecule-1 (ICAM-1)/vascular cell adhesion molecule-1(VCAM-1) antibody...
September 13, 2016: Modern Rheumatology
Huaijian Guo, Stacey A Cranert, Yan Lu, Ming-Chao Zhong, Shaohua Zhang, Jun Chen, Rui Li, Sarah E Mahl, Ning Wu, Dominique Davidson, Stephen N Waggoner, André Veillette
No abstract text is available yet for this article.
September 19, 2016: Journal of Experimental Medicine
Riccardo V Mancuso, Karl Welzenbach, Peter Steinberger, Stephan Krähenbühl, Gabriele Weitz-Schmidt
The integrin leucocyte function-associated antigen-1 (αLβ2, LFA-1) plays crucial roles in T cell adhesion, migration and immunological synapse (IS) formation. Consequently, αLβ2 is an important therapeutic target in autoimmunity. Three major classes of αLβ2 inhibitors with distinct modes of action have been described to date: Monoclonal antibodies (mAbs), small molecule α/β I allosteric and small molecule α I allosteric inhibitors. The objective of this study was to systematically compare these three modes of αLβ2 inhibition for their αLβ2 inhibitory as well as their potential agonist-like effects...
November 1, 2016: Biochemical Pharmacology
Huaijian Guo, Stacey A Cranert, Yan Lu, Ming-Chao Zhong, Shaohua Zhang, Jun Chen, Rui Li, Sarah E Mahl, Ning Wu, Dominique Davidson, Stephen N Waggoner, André Veillette
Signaling lymphocytic activation molecule (SLAM) family receptors (SFRs) can mediate either activating or inhibitory effects during natural killer cell (NK cell) activation. In this study, we addressed the global role, regulation, and mechanism of action of the SLAM family in NK cells by analyzing a mouse lacking the entire ∼400-kilobase Slam locus, which encodes all six SFRs and CD48, the ligand of SFR 2B4. This mouse displayed enhanced NK cell activation responses toward hematopoietic target cells. Analyses of mice lacking individual SFRs showed that the inhibitory function of the Slam locus was due solely to 2B4 and was not influenced positively or negatively by other SFRs...
September 19, 2016: Journal of Experimental Medicine
Shimona Starling, Clare Jolly
: HIV-1 efficiently disseminates by cell-cell spread at intercellular contacts called virological synapses (VS), where the virus preferentially assembles and buds. Cell-cell contact triggers active polarization of organelles and viral proteins within infected cells to the contact site to support efficient VS formation and HIV-1 spread; critically, however, which cell surface protein triggers contact-induced polarization at the VS remains unclear. Additionally, the mechanism by which the HIV-1 envelope glycoprotein (Env) is recruited to the VS remains ill defined...
November 1, 2016: Journal of Virology
G H Wabnitz, E Balta, S Schindler, H Kirchgessner, B Jahraus, S Meuer, Y Samstag
Cytotoxic T-cells (CTLs) play an important role in many immune-mediated inflammatory diseases. Targeting cytotoxicity of CTLs would allow to interfere with immune-mediated tissue destruction. Here we demonstrate that WF-10, a pro-oxidative compound, inhibits CTL-mediated cytotoxicity. WF-10 did not influence early steps of target-cell killing, but impaired the ability of CTLs to detach from the initial target cell and to move to a second target cell. This reduced serial killing was accompanied by stronger enrichment of the adhesion molecule LFA-1 in the cytolytic immune synapse...
2016: Cell Death Discovery
Navin K Verma, M H U Turabe Fazil, Seow Theng Ong, Madhavi Latha S Chalasani, Jian Hui Low, Amuthavalli Kottaiswamy, Praseetha P, Atish Kizhakeyil, Sunil Kumar, Aditya K Panda, Michael Freeley, Sinead M Smith, Bernhard O Boehm, Dermot Kelleher
No abstract text is available yet for this article.
September 1, 2016: Journal of Immunology: Official Journal of the American Association of Immunologists
Anders G Kjaergaard, Anders Dige, Jeppe S Nielsen, Else Tønnesen, Jan Krog
Endothelial activation is pivotal in the development and escalation of sepsis. Central to endothelial activation is the endothelial up-regulation of cellular adhesion molecules (CAMs) including E-selectin, ICAM-1, VCAM-1, and PECAM-1. Shed CAMs are also found in circulating soluble forms (sCAMs). We investigated whether sCAMs can be used as biomarkers for the differentiation between septic and non-septic patients. Furthermore, we investigated lymphocyte and monocyte expression of LFA-1 (CD11a/CD18) and VLA-4 (CD49d/CD29) ligands for ICAM-1 and VCAM-1, respectively...
October 2016: APMIS: Acta Pathologica, Microbiologica, et Immunologica Scandinavica
Maria Raquel Cosate, Gabriela Hase Siqueira, Gisele Oliveira de Souza, Silvio Arruda Vasconcellos, Ana Lucia T O Nascimento
A severe re-emergingzoonosis, leptospirosis, is caused by pathogenic spirochetes of the genus Leptospira. Several studies have identified leptospiral surface proteins with the ability to bind ECM and plasma components, which could mediate adhesion and invasion through the hosts. It has been shown that Mce of pathogenic Leptospira spp. is an RGD (Arg-Gly-Asp)-motif-dependent virulence factor, responsible for infection of cells and animals. In the present article, we decided to further study the repertoire of the Mce activities in leptospiral biological properties...
September 2016: Microbiology and Immunology
Samuel M S Cheung, Hanne L Ostergaard
Protein tyrosine kinase 2 (Pyk2) is required for T cell adhesion to ICAM-1; however, the mechanism by which it regulates adhesion remains unexplored. Pyk2 function in murine CTL clones and activated ex vivo CD8(+) T cells was disrupted by pharmacological inhibition, knockdown of expression with small interfering RNA, or expression of the dominant-negative C-terminal domain. We found that Pyk2 is not absolutely required for adhesion of CTL to ICAM-1, but rather delays the initial adhesion. Disruption of Pyk2 function caused cells to display an unusual elongated appearance after 1 h on ICAM-1, consistent with abnormally strong adhesion...
September 1, 2016: Journal of Immunology: Official Journal of the American Association of Immunologists
Manuel Sarmiento Soto, Emma R O'Brien, Kleopatra Andreou, Simon F Scrace, Rasheed Zakaria, Michael D Jenkinson, Eric O'Neill, Nicola R Sibson
Over 20% of cancer patients will suffer metastatic spread to the brain, and prognosis remains poor. Communication between tumour cells and host tissue is essential during metastasis, yet little is known of the processes underlying such interactions in the brain.Here we test the hypothesis that cross-talk between tumour cells and host brain cells, through tumour cell leukocyte function associated protein-1 (LFA-1), is critical in metastasis development. Temporal expression of LFA-1 and its major ligand intercellular adhesion molecule-1 (ICAM-1) was determined in two different mouse models of brain metastasis...
July 20, 2016: Oncotarget
Anne-Elisabeth Petit, Nathalie Demotte, Benoît Scheid, Claude Wildmann, René Bigirimana, Monica Gordon-Alonso, Javier Carrasco, Salvatore Valitutti, Danièle Godelaine, Pierre van der Bruggen
Surface galectin has been shown to contribute to dysfunctions of human tumour-infiltrating lymphocytes (TILs). We show here that galectin-covered CD8 TILs produce normal amounts of intracellular cytokines, but fail to secrete them because of defective actin rearrangements at the synapse. The non-secreting TILs also display reduced adhesion to their targets, together with defective LFA-1 recruitment and activation at the synapse. These defects are relieved by releasing surface galectin. As mild LFA-1 blockade on normal blood T cells emulate the defects of galectin-covered TILs, we conclude that galectin prevents the formation of a functional secretory synapse by preventing optimal LFA-1 triggering...
2016: Nature Communications
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"