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Platelet-Activating Factor Receptors in the Airways
Published in Devendra K. Agrawal, Robert G. Townley, Inflammatory Cells and Mediators in Bronchial Asthma, 2020
Several lines of evidence suggest that T-lymphocytes and their soluble products regulate the cellular components of allergic inflammation in the late-phase allergic reaction.122 Deficiency of concanavalin A-induced suppressor cell function in asthmatic subjects has been observed by a number of investigators.201–203 Very recently, Frew and colleagues204 have demonstrated significant infiltration by CD3+/CD4+ T-lymphocytes together with evidence of T-cell activation in the allergen-induced late-phase skin reaction in human atopic subjects. It is therefore possible that T-cell products may influence the allergic response by interacting with other inflammatory cells such as eosinophils. In fact, Gerblich and colleagues205 have demonstrated a selective loss of circulating helper (OKT4) T-cells and an apparent increase in activated (Ia positive) T-cells after antigen-induced asthma. There was a good correlation between these changes and blood eosinophilia. This suggests the activation of T-cells and the concomitant release of the eosinophil-stimulating substances.
Design of Bioresponsive Polymers
Published in Deepa H. Patel, Bioresponsive Polymers, 2020
Anita Patel, Jayvadan K. Patel, Deepa H. Patel
A glucose-binding protein i.e., concanavalin A (Con A) is proficient in upholding four glucose units for each molecule. The competitive binding behavior of Con A with glucose and glycosylated insulin developed by the glycosylated insulin-Con A complex. The free glucose molecule brings about the displacement of glycosylated Con A-insulin couples within the surrounding tissues and is bioactive. Additional studies stated the synthesis of monosubstituted conjugates of glucosyl-terminal PEG as well as insulin. Covalent attachment took place between the G-PEG-insulin conjugates and Con A that was joined to a PEG-polyvinyl pyrrolidine-co-acrylic acid backbone, and when the concentration of glucose augmented competitive bonding of glucose with Con A directed to displacement and G-PEG insulin conjugates release [112, 113].
Interleukin-1 Inhibitors and Their Significance in Rheumatoid Arthritis
Published in Thomas F. Kresina, Monoclonal Antibodies, Cytokines, and Arthritis, 2020
Gloria C. Higgins, Arnold E. Postlethwaite
The assay most commonly used to detect IL-1 inhibitors has been the thymocyte costimulation or comitogenesis assay (85,86). The basis for this assay is the ability of IL-1α or β to enhance the in vitro proliferation of mouse thymocytes stimulated with a suboptimal dose of plant lectin. Proliferation is measured by incorporation of tritiated thymidine into DNA. The lectins concanavalin A (ConA) and phytohemagglutinin are usually employed. These mitogens, which have binding specificity for oligosaccharides, are presumed to bind glycosylated moieties on the cell surface and signal activation and proliferation (87). The specific binding sites and signal transduction mechanisms are not well understood, but cross-linking of T cell receptors is probably involved (72,75,88). With large (mitogenic) doses, binding of lectin is sufficient to cause activation, proliferation, and concomitant production of and/or responsiveness to lymphokines (89). With small (sub-mitogenic) doses of lectin, exogenous IL-1 must be supplied to give comparable proliferation.
Concanavalin A promotes angiogenesis and proliferation in endothelial cells through the Akt/ERK/Cyclin D1 axis
Published in Pharmaceutical Biology, 2022
Jing-Zhou Li, Xiao-Xia Zhou, Wei-Yin Wu, Hai-Feng Qiang, Guo-Sheng Xiao, Yan Wang, Gang Li
During atherosclerosis, endothelial cells injury or apoptosis was induced by numerous risk factors such as smoking, hyperlipidaemia, diabetes, and vascular inflammation (Chen et al. 2000; Pober et al. 2009). Endothelial cell (ECs) injury is an essential deleterious factor for endothelial integrity, while the proliferated and healthy ECs can sustain endothelial integrity (Schober et al. 2014). Concanavalin A (Con A) is a plant lectin extracted from jack beans and binds specifically to terminal mannose or glucose residues on cell surface glycoconjugates, such as glycoproteins, regulates physiological functions (Sasaki and Toyoda 2013). Con A has shown the effects of stimulating cell immunity and generating an immune memory, reported as a phytohemagglutinin with potent mitogenic effects (Li et al. 2011), and is associated with a variety of biological effects, such as mitogenic, cytotoxic, hepatotoxic, and teratogenic (Ballerstadt et al. 2006). However, little is known about the functional role and mechanisms involved in replicative endothelial regeneration of Con A, especially in cell proliferation and angiogenic activity.
Triterpenoids of Rhus chinensis Supressed Colorectal Cancer Progress by Enhancing Antitumor Immunity and CD8 + T Cells Tumor Infiltration
Published in Nutrition and Cancer, 2022
Gang Wang, Yang Yu, Zi-Meng Li, Zhi-Min Zhu, Zhi-Jie Wang, Min-Fang Tao
Choosing four groups with six mice per group, then, preparing spleen cell suspensions, and adjusting the cell density to 2 × 105/mL and counting under the microscope (Olympus Corporation) for use. A total of 100 µL of spleen cell suspension was added to each well of a ٩٦-well flat-bottomed culture plate. The final concentration of concanavalin A (ConA; Nanjing Jinyibai Biotechnology Co., Ltd.) was 7.5 µg/µL, and added 100 µL of RPMI 1640 medium (Gibco, Thermo Fisher Scientific, Inc.) to the control wells. The culture plate was placed in a 37 °C, 5% CO2 incubator and incubated for 66 h. The state of the cells was observed once a day. The plate was removed and 20 µL of CCK-8 (Dojindo Institute of Japan) was added to each well and incubated for a further 2.5 h. Following incubation, the absorbance (A) was measured with a microplate reader (Molecular Devices, LLC) at a wavelength of 450 nm. The splenic lymphocyte proliferation rate and stimulation index were calculated according to the following formulas: Proliferation rate=(AConA-ARPMI1640)/ARPMI1640; and stimulus index = AConA/ARPMI1640.
Immunological effects of AFM1 in experimental subchronic dosing in mice prevented by lactic acid bacteria
Published in Immunopharmacology and Immunotoxicology, 2020
Jalila Ben Salah-Abbès, Hela Belgacem, Khawla Ezdini, Marwa Mannai, Ridha Oueslati, Samir Abbès
Cell suspensions (50 ml; 6 × 106 cells/ml) were dispensed into each well of 96-well culture plates containing 100 ml of culture medium (RPMI 1640). Concanavalin A (ConA type IV; Sigma, St. Louis, MO) was added at an optimal final concentration of 10 mg/ml. The viability of cells was assessed by the Trypan blue (0.1%) exclusion test. The culture was incubated with the mitogens at 37 °C in an atmosphere containing 5% CO2 and was labeled during the last 18 h of 96-h cultures with 3.7 × 104 Bq of [3H] thymidine (CNEA). These cells were harvested 18 h thereafter on a glass fiber filter using an automated cell harvester (Skatron, Molecular Devices, Sunnyvale, CA). Incorporation of tritiated thymidine into cellular DNA was measured in triplicate using a beta liquid scintillation counter.