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Integrins, Integrin Regulators, and the Extracellular Matrix
Published in Bruce S. Bochner, Adhesion Molecules in Allergic Disease, 2020
Stephen W. Hunt, Sirid-Aimée Kellermann, Yoji Shimizu
Members of the 4-transmembrane protein superfamily (TM4), such as CD9, CD63, and CD81, have been colocalized with certain β1 and β3 integrins (107–109). TM4:integrin interaction appears to involve extracellular regions (107). Expression of CD9 on an early B-cell line enhances motility, but not adhesion, of this cell line on Fn and laminin (109). This activity was blocked by antibodies against either CD9 or the β1 integrin subunit, as well as the tyrosine kinase inhibitor herbimycin A. Potential biochemical functions of TM4 proteins might include ion transport or as adapter proteins that can couple to G proteins (107).
Allergy: Basic Mechanisms and Tests
Published in John C Watkinson, Raymond W Clarke, Louise Jayne Clark, Adam J Donne, R James A England, Hisham M Mehanna, Gerald William McGarry, Sean Carrie, Basic Sciences Endocrine Surgery Rhinology, 2018
The whole blood of the patient is incubated with the allergen of interest. Basophils are stimulated due to the cross-linking of the specific IgE-FcεRI on basophil. Degranulation of basophils leads to the expression of molecules (e.g. CD63) on the basophil cell surface. In an unstimulated phase these molecules are anchored on the membrane of intracellular basophil granules, which contain histamine. CD63 expression closely correlates with histamine release in the degranulation. These can be detected by the flow cytometry method.
Agricultural Chemicals
Published in Ana M. Giménez-Arnau, Howard I. Maibach, Contact Urticaria Syndrome, 2014
Vincent Cunanan, Christopher J. Dannaker, Howard I. Maibach
Contact urticaria to agrichemicals may be immunological (allergic) or nonimmunological (irritant). The former is thought to be linked with immunoglobulin E-mediated histamine release from basophils. The latter is thought to be linked with histamine release from basophils via an alternate, nonimmune mechanism.[26] A study by Galassi et al. described increased surface expression of the transmembrane protein CD63 on the basophils of a DEET-sensitive patient after exposure to the chemical [27] CD63 is a membrane-associated protein with four hydrophobic transmembrane domains (tetraspanin). It is believed that tetraspanins are present on secretory lysosomes and exosomes. The study also made the connection that in neutrophils—another type of granulated leukocyte—CD63 may be involved in targeting the serine protease neutrophil elastase to the neutrophil’s primary secretory granules.[28] Basophils are thought to also contain a type of elastase in its granules.[29] Thus, research could be conducted to determine if elastase in basophils is also targeted to granules with CD63. If so, it is possible to determine if there is concomitant targeting of histamine with elastase to secretory granules.
Identification of mite-specific eosinophils in the colon of patients with ulcerative colitis
Published in Autoimmunity, 2022
Shu-Wang Peng, Jiang-Ming Sheng, Bai-Sui Feng, Ke-Ping Peng, Gui-Xiang Tian, Cheng-Bai Liang, Ming-Hui Liu, Hai-Qing Xie, Qing Shu, Yan Li, Ping-Chang Yang
Eosinophilic inflammation in the gastrointestinal tract has been well-documented, including Eo esophagitis, Eo gastritis, Eo ileitis, and Eo colitis [13]. The common feature of eosinophilic inflammation includes profound Eo infiltration into the local tissues. The Eos release pre-formed inflammatory mediators, such as MBP and ECP, into the tissues to induce local inflammation. However, the triggers for activating Eo still require further investigation. The present data provide important evidence that a fraction of Eo in UC colon tissues is HDM-specific. Upon exposure to HDM, these Eos can be activated, and release inflammatory mediators [14], MBP and ECP, as demonstrated by the present data. The data show that elevated IgG and IgE levels in serum in UC patients with HDM positive SPT, which were positively correlated with UC clinical symptoms. The data suggest that these immunoglobulins contribute to UC clinical symptoms. Eos are known to not express high affinity IgE receptors, but to express IgG receptors [15–17]. Previous reports indicate that exposure to sIgG can activate allergen-specific Eos [18]. The present data are in line with these studies by showing HDM-specific Eos in the colon of UC patients. These Eos can be activated upon exposure to HDM both in vivo and in vitro. CD63 was used as a cell activation marker. CD63 localizes on the plasma membrane and lysosomes in Eos at resting status. It moves towards the cell surface and releases out upon activation [12]. The data suggest that the regulation of the process by which HDM activates Eos may have therapeutic importance for UC.
Platelets after burn injury – hemostasis and beyond
Published in Platelets, 2022
B. Z. Johnson, A. W. Stevenson, L. W. Barrett, M. W Fear, F. M. Wood, M. D. Linden
Ex vivo measurement of platelet activation can be performed with a range of tools targeting different aspects of activation. One of the earliest measurements of platelet activation was aggregometry, whereby platelet-rich plasma is exposed to agonists under sheer in order to induce platelet aggregation [45]. The rate and amplitude of aggregation is measured by turbidometry. Platelet-derived thromboxane metabolites, sCD62P (P-selectin), sCD40L and beta-thromboglobulin (β-TG) measured in plasma can provide further evidence of platelet activation in vivo [70–73]. β-TG is released from platelet alpha granules during exocytosis, while CD62P and CD40L are bound to alpha granule membranes which fuse with platelet surface membrane during granule exocytosis, before they are cleaved and released from the platelet surface as soluble proteins. CD63 is similarly associated with the membrane of platelet dense granules, and expression is increased with activation-dependent granule exocytosis [74].
Extracellular vesicles from human iPSC-derived neural stem cells: miRNA and protein signatures, and anti-inflammatory and neurogenic properties
Published in Journal of Extracellular Vesicles, 2020
Raghavendra Upadhya, Leelavathi N. Madhu, Sahithi Attaluri, Daniel Leite Góes Gitaí, Marisa R Pinson, Maheedhar Kodali, Geetha Shetty, Gabriele Zanirati, Smrithi Kumar, Bing Shuai, Susan T Weintraub, Ashok K. Shetty
The final concentration and size distribution of particles was measured by nanoparticle tracking analysis, as described in our previous report [24].The expression of CD63 was investigated using ELISA [17]. The expression of other EV markers such as CD9 and ALIX were examined through Western blotting. For this, an aliquot of EVs in 100 µl volume was mixed with 300 µl of mammalian protein extractor reagent (Thermo Fischer Scientific, Waltham, MA, USA) and lysed, as detailed in our recent study [24]. The total protein in the lysate was quantified by the Pierce BCA protein assay kit (Thermo Fisher Scientific), and 40 µg of protein was loaded and separated by 4–12% NuPAGE Bis-Tris Gels (Thermo Fisher Scientific). Following the transfer of proteins onto a nitrocellulose membrane using the iBlot2 gel transfer device (Thermo Fisher scientific), the membrane was processed for protein detection using antibodies against CD9 (1:500; BD Biosciences, San Jose, CA, USA), or ALIX (1:500; Santa Cruz). Then, the signal was detected using the ECL detection kit (ThermoFisher) and visualized using a Versadoc Imaging System (Bio-Rad). In order to rule out the contamination of EV lysate with deep cellular proteins, the protein separated membrane was identified for GM130 (1:500; BD Biosciences) and compared with the NSC lysate [25,26].