Agricultural Chemicals
Ana M. Giménez-Arnau, Howard I. Maibach in Contact Urticaria Syndrome, 2014
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.
Mother and Embryo Cross Communication during Conception
Carlos Simón, Carmen Rubio in Handbook of Genetic Diagnostic Technologies in Reproductive Medicine, 2022
Microvesicles (100–1000 nm) were first described as subcellular material originating from platelets in normal plasma and serum. The molecular markers of microvesicles are ADP-ribosylation factor 6 (ARF6), integrins, selectins, and CD40 ligand. Microvesicles have been studied mainly for their role in blood coagulation and cancer cell-to-cell communication, where they are called oncosomes. Unlike apoptotic bodies and microvesicles, exosomes are small, virus-sized particles (30–150 nm), formed by inward budding of the cytoplasmic membrane. Exosomes are derived from the endolysosomal pathway and represent a more homogeneous population of vesicles than microvesicles. For a long time, they were considered to be nanodust, or dust in electron microscopy. This perception changed dramatically in the past years and their role evolved from debris bins to biologically active particles [89,90]. The immunomodulatory role of exosomes is the most studied [87,91], followed by angiogenesis, thrombosis [92], and pathologies, such as cancer [88]. The molecular markers of exosomes include: CD63, CD9, CD81, ALIX, TSG101, flotillin-1, HSC70, and syntenin-1 [13]. Cargo sorting into exosomes involves the endosomal sorting complex required for transport (ESCRT) and other associated proteins.
Serological (In Vitro) Testing Methods in the Diagnosis of Human Allergic Disease
Richard F. Lockey, Dennis K. Ledford in Allergens and Allergen Immunotherapy, 2014
Analytically, there are technical challenges to optimization and validation of basophil-based assays. If whole blood can be delivered to the laboratory within 24 hours, it is pre-incubated with buffer containing varying concentrations of allergen and often IL3 that modifies the extent of mediator release or CD64/CD203c upregulation. Crude allergen extracts are often toxic to basophils, and so allergen preparations need to be qualified for basophil assay use. Criteria for defining positive results vary with different simulating allergen lots and sources. Platelet adherence on basophils can create false-positive results in the flow-based CD63 basophil assay. Details of the assay design and protocols, methods of optimizing reagent concentrations and qualifying allergen preparations, strategies for quality control and data analysis, and strengths and pitfalls of the various assay formats are presented in detail elsewhere [46–51].
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.
Tumor-secreted extracellular vesicles promote the activation of cancer-associated fibroblasts via the transfer of microRNA-125b
Published in Journal of Extracellular Vesicles, 2019
Luyen Tien Vu, Boya Peng, Daniel Xin Zhang, Victor Ma, Camille A. Mathey-Andrews, Chun Kuen Lam, Theodoros Kiomourtzis, Jingmin Jin, Larry McReynolds, Linfeng Huang, Andrew Grimson, William C. Cho, Judy Lieberman, Minh Tn Le
To obtain tumour EVs with higher purity, we optimized a new protocol that involves two rounds of ultracentrifugation with a 60% sucrose cushion and one round of size exclusion chromatography (SEC) (Figure 4(a)). This purification process separated tumour EVs from proteins in the medium into distinct fractions (Figure 4(b)). Using Western blot analysis, we found a clear enrichment of EV markers, Alix and Tsg101, in SEC fractions 7 to 11 but not in fractions 16 to 22, which contain EV-free proteins (Figure 4(c) compared to Figure 4(b)). In addition, beta actin (Actb) was almost absent in EV fractions 7 to 11, suggesting that this cytoskeleton protein was not exported in EVs and the fractionated EVs did not contain cellular debris. These data were further confirmed using FACS analysis of CD63, a transmembrane exosomal marker. CD63 was detected on the surface of 4T1 EVs in fractions 7 to 11 but barely detectable in EV-free proteins in fractions 16–22 (Figure 4(d)). Hence, we collected SEC fractions 7 to 11 for EV analysis in all subsequent experiments. After SEC purification, EVs collected from SEC fractions 7 to 11 were intact, as judged by their typical cup shape and double membrane under transmission electron microscopy (Figure 4(e)). The diameters of purified EVs ranged from 50 to 300 nm, with most ~120 nm, as shown by nanoparticle tracking analysis (Figure 4(f)).
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].
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