Read by QxMD icon Read

Immunological synapse

Lucie Bracq, Maorong Xie, Serge Benichou, Jérôme Bouchet
While HIV-1 infection of target cells with cell-free viral particles has been largely documented, intercellular transmission through direct cell-to-cell contact may be a predominant mode of propagation in host. To spread, HIV-1 infects cells of the immune system and takes advantage of their specific particularities and functions. Subversion of intercellular communication allows to improve HIV-1 replication through a multiplicity of intercellular structures and membrane protrusions, like tunneling nanotubes, filopodia, or lamellipodia-like structures involved in the formation of the virological synapse...
2018: Frontiers in Immunology
A Borreca, V Latina, V Corsetti, S Middei, S Piccinin, F Della Valle, R Bussani, M Ammassari-Teule, R Nisticò, P Calissano, G Amadoro
The NH2 tau 26-44 aa (i.e., NH2 htau) is the minimal biologically active moiety of longer 20-22-kDa NH2 -truncated form of human tau-a neurotoxic fragment mapping between 26 and 230 amino acids of full-length protein (htau40)-which is detectable in presynaptic terminals and peripheral CSF from patients suffering from AD and other non-AD neurodegenerative diseases. Nevertheless, whether its exogenous administration in healthy nontransgenic mice is able to elicit a neuropathological phenotype resembling human tauopathies has not been yet investigated...
March 5, 2018: Molecular Neurobiology
Wei Xiong, Yuhui Chen, Xi Kang, Zhiying Chen, Peilin Zheng, Yi-Hsin Hsu, Joon Hee Jang, Lidong Qin, Hao Liu, Gianpietro Dotti, Dongfang Liu
Chimeric antigen receptor (CAR)-modified T cell therapy has the potential to improve the overall survival of patients with malignancies by enhancing the effectiveness of CAR T cells. Precisely predicting the effectiveness of various CAR T cells represents one of today's key unsolved problems in immunotherapy. Here, we predict the effectiveness of CAR-modified cells by evaluating the quality of the CAR-mediated immunological synapse (IS) by quantitation of F-actin, clustering of tumor antigen, polarization of lytic granules (LGs), and distribution of key signaling molecules within the IS...
March 1, 2018: Molecular Therapy: the Journal of the American Society of Gene Therapy
John A Hammer
Cytotoxic T cells and natural killer cells defend us against disease by secreting lytic granules. Whether actin facilitates or thwarts lytic granule secretion has been an open question. Recent results now indicate that the answer depends on the maturation stage of the immune cell-target cell contact.
February 19, 2018: Current Biology: CB
George W Ashdown, Dylan M Owen
Many cellular processes are regulated by the spatio-temporal organisation of signalling complexes, cytoskeletal components and membranes. One such example is at the T cell immunological synapse where the retrograde flow of cortical filamentous (F)-actin from the synapse periphery drives signalling protein microclusters towards the synapse centre. The density of this mesh however, makes visualisation and analysis of individual actin fibres difficult due to the resolution limit of conventional microscopy. Recently, super-resolution methods such as structured illumination microscopy (SIM) have surpassed this resolution limit...
February 1, 2018: Methods: a Companion to Methods in Enzymology
Katarzyna I Jankowska, Edward K Williamson, Nathan H Roy, Daniel Blumenthal, Vidhi Chandra, Tobias Baumgart, Janis K Burkhardt
Full T cell activation requires coordination of signals from multiple receptor-ligand pairs that interact in parallel at a specialized cell-cell contact site termed the immunological synapse (IS). Signaling at the IS is intimately associated with actin dynamics; T cell receptor (TCR) engagement induces centripetal flow of the T cell actin network, which in turn enhances the function of ligand-bound integrins by promoting conformational change. Here, we have investigated the effects of integrin engagement on actin flow, and on associated signaling events downstream of the TCR...
2018: Frontiers in Immunology
Alexandre F Carisey, Emily M Mace, Mezida B Saeed, Daniel M Davis, Jordan S Orange
Natural killer (NK) cells are innate immune effectors that lyse virally infected and tumorigenic cells through the formation of an immunological synapse. Actin remodeling at the lytic immunological synapse is a critical requirement for multiple facets of cytotoxic function. Activating receptor and integrin signaling leads to the regulated turnover and remodeling of actin, which is required for adhesion, sustained receptor signaling, and ultimately exocytosis. NK cells undergo lytic granule exocytosis in hypodense regions of a pervasive actin network...
January 30, 2018: Current Biology: CB
Mi Na Kim, Jung Yeon Hong, Doo Hee Shim, In Suk Sol, Yun Seon Kim, Ji Hyun Lee, Kyung Won Kim, Jae Myun Lee, Myung Hyun Sohn
RATIONALE: Activated leukocyte cell-adhesion molecule (ALCAM) is a cluster of differentiation 6 ligand that is important for stabilizing the immunological synapse and inducing T cell activation and proliferation. OBJECTIVES: This study investigated the role of ALCAM in the development of inflammation in allergic asthma. METHODS: An ovalbumin (OVA)-induced allergic asthma model was established in wild-type (WT) and ALCAM-deficient (ALCAM-/-) mice...
February 2, 2018: American Journal of Respiratory and Critical Care Medicine
Vid Šuštar, Marika Vainio, Pieta K Mattila
The formation of the immunological synapse upon B cell activation critically depends on the rearrangement of the submembranous actin cytoskeleton. Polymerization of actin monomers into filaments provides the force required for B cell spreading on the antigen-presenting cell (APC). Interestingly, the actin network also participates in cellular signaling at multiple levels. Fluorescence microscopy plays a critical role in furthering our understanding of the various functions of the cytoskeleton, and has become an important tool in the studies on B cell activation...
2018: Methods in Molecular Biology
Ivan Rey, David A Garcia, Brittany A Wheatley, Wenxia Song, Arpita Upadhyaya
Cells of the adaptive immune system recognize pathogenic peptides through specialized receptors on their membranes. The engagement of these receptors with antigen leads to cell activation, which induces profound changes in the cell including cytoskeleton remodeling and membrane deformation. During this process, receptors and signaling molecules undergo spatiotemporal reorganization to form signaling microclusters and the immunological synapse. The cytoskeletal and membrane dynamics also leads to exertion of forces on the cell-substrate interface...
2018: Methods in Molecular Biology
Jennifer A Westwood, Sarah Ellis, Jill Danne, Chad Johnson, Viola Oorschot, Georg Ramm, David C Tscharke, Alexander J Davenport, James C Whisstock, Phillip K Darcy, Michael H Kershaw, Clare Y Slaney
While immunotherapy employing chimeric antigen receptor (CAR) T cells can be effective against a variety of tumor types, little is known about what happens within the tumor at an ultrastructural level during tumor regression. Here, we used transmission electron microscopy to investigate morphologic and cellular features of tumors responding to immunotherapy composed of adoptive transfer of dual-specific CAR T cells and a vaccine, supported by preconditioning irradiation and interleukin-2. Tumors responded rapidly, and large areas of cell death were apparent by 4 days after treatment...
December 29, 2017: Oncotarget
Marcus Lettau, Fred Armbrust, Katharina Dohmen, Lisann Drews, Tobias Poch, Michelle Dietz, Dieter Kabelitz, Ottmar Janssen
It is widely accepted that cytotoxic T and NK cells store effector proteins including granzymes, perforin and FasL in intracellular granules, often referred to as secretory lysosomes. Upon target cell encounter, these organelles are transported to the cytotoxic immunological synapse, where they fuse with the plasma membrane to release the soluble effector molecules and to expose transmembrane proteins including FasL on the cell surface. We previously described two distinct species of secretory vesicles in T and NK cells that differ in size, morphology and protein loading, most strikingly regarding FasL and granzyme B...
January 24, 2018: International Immunology
Robert Dantzer
Because of the compartmentalization of disciplines that shaped the academic landscape of biology and biomedical sciences in the past, physiological systems have long been studied in isolation from each other. This has particularly been the case for the immune system. As a consequence of its ties with pathology and microbiology, immunology as a discipline has largely grown independently of physiology. Accordingly, it has taken a long time for immunologists to accept the concept that the immune system is not self-regulated but functions in close association with the nervous system...
January 1, 2018: Physiological Reviews
Viveka Mayya, Edward Judokusumo, Enas Abu Shah, Christopher G Peel, Willie Neiswanger, David Depoil, David A Blair, Chris H Wiggins, Lance C Kam, Michael L Dustin
T cells engage in two modes of interaction with antigen-presenting surfaces: stable synapses and motile kinapses. Although it is surmised that durable interactions of T cells with antigen-presenting cells involve synapses, in situ 3D imaging cannot resolve the mode of interaction. We have established in vitro 2D platforms and quantitative metrics to determine cell-intrinsic modes of interaction when T cells are faced with spatially continuous or restricted stimulation. All major resting human T cell subsets, except memory CD8 T cells, spend more time in the kinapse mode on continuous stimulatory surfaces...
January 9, 2018: Cell Reports
Fernando Spiller, Corwin M Nycholat, Chika Kikuchi, James C Paulson, Matthew S Macauley
CD22 and sialic acid-binding Ig-like lectin (Siglec)-G are members of the Siglec family of inhibitory coreceptors expressed on B cells that participate in enforcement of peripheral B cell tolerance. We have shown previously that when a BCR engages its cognate Ag on a cell surface that also expresses Siglec ligands, B cell Siglecs are recruited to the immunological synapse, resulting in suppression of BCR signaling and B cell apoptosis. Because all cells display sialic acids, and CD22 and Siglec-G have distinct, yet overlapping, specificities for sialic acid-containing glycan ligands, any cell could, in principle, invoke this tolerogenic mechanism for cell surface Ags...
December 29, 2017: Journal of Immunology: Official Journal of the American Association of Immunologists
Hsin-Fang Chang, Stefanie Mannebach, Andreas Beck, Keerthana Ravichandran, Elmar Krause, Katja Frohnweiler, Claudia Fecher-Trost, Claudia Schirra, Varsha Pattu, Veit Flockerzi, Jens Rettig
Cytotoxic T lymphocytes (CTLs) kill target cells by the regulated release of cytotoxic substances from granules at the immunological synapse. To kill multiple target cells, CTLs use endocytosis of membrane components of cytotoxic granules. We studied the potential calcium dependence of endocytosis in mouse CTLs on Flower, which mediates the calcium dependence of synaptic vesicle endocytosis in Drosophila melanogaster Flower is predominantly localized on intracellular vesicles that move to the synapse on target cell contact...
December 29, 2017: Journal of Cell Biology
Gilli Galore-Haskel, Erez N Baruch, Amy L Berg, Iris Barshack, Itzhak Zilinsky, Camila Avivi, Michal J Besser, Jacob Schachter, Gal Markel
Intercellular adhesion molecule 1 (ICAM-1) protein is an important adhesion molecule that facilitates metastasis on one hand, and on the other hand supports the immunological synapse necessary for T-cell mediated elimination. The expression pattern of ICAM-1 in melanoma was studied more than two decades ago, mainly in cell lines or in unmatched melanoma specimens. By using real time PCR we could not demonstrate a clear difference in ICAM-1 mRNA levels between primary melanocytes and primary cultures of metastatic melanoma...
November 21, 2017: Oncotarget
Justyna M Meissner, Aleksander F Sikorski, Tomasz Nawara, Jakub Grzesiak, Krzysztof Marycz, Dżamila M Bogusławska, Izabela Michalczyk, Marie-Christine Lecomte, Beata Machnicka
T-lymphocyte activation after antigen presentation to the T-Cell Receptor (TCR) is a critical step in the development of proper immune responses to infection and inflammation. This dynamic process involves reorganization of the actin cytoskeleton and signaling molecules at the cell membrane, leading to the formation of the Immunological Synapse (IS). The mechanisms regulating the formation of the IS are not completely understood. Nonerythroid spectrin is a membrane skeletal protein involved in the regulation of many cellular processes, including cell adhesion, signaling and actin cytoskeleton remodeling...
2017: PloS One
Aleksandra Gil-Krzewska, Mezida B Saeed, Anna Oszmiana, Elizabeth R Fischer, Kathryn Lagrue, William A Gahl, Wendy J Introne, John E Coligan, Daniel M Davis, Konrad Krzewski
BACKGROUND: Chediak-Higashi syndrome (CHS) is a rare disorder caused by biallelic mutations in the LYST gene, resulting in formation of giant lysosomes or lysosome-related organelles in several cell types. The disease is characterized by immunodeficiency and a fatal hemophagocytic lymphohistiocytosis due to impaired function of cytotoxic lymphocytes, mainly Natural Killer (NK) cells. OBJECTIVE: We sought to determine the underlying biochemical cause of the impaired cytotoxicity of NK cells in CHS...
December 11, 2017: Journal of Allergy and Clinical Immunology
Kimberly M Ramonell, Wenxiao Zhang, Annette Hadley, Ching-Wen Chen, Katherine T Fay, John D Lyons, Nathan J Klingensmith, Kevin W McConnell, Craig M Coopersmith, Mandy L Ford
Sepsis is a dysregulated systemic response to infection involving many inflammatory pathways and the induction of counter-regulatory anti-inflammatory processes that results in a state of immune incompetence and can lead to multi-organ failure. CXCR4 is a chemokine receptor that, following ligation by CXCL12, directs cells to bone marrow niches and also plays an important role in T cell cosignaling and formation of the immunological synapse. Here, we investigated the expression and function of CXCR4 in a murine model of polymicrobial sepsis...
2017: PloS One
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"