Hymenoptera venom allergy is known to cause life-threatening and sometimes fatal IgE-mediated anaphylactic reactions in allergic individuals. About 30–50% of patients with insect venom allergy have ...IgE antibodies that react with both honeybee and yellow jacket venom. Apart from true double sensitisation, IgE against cross-reactive carbohydrate determinants (CCD) are the most frequent cause of multiple reactivities severely hampering the diagnosis and design of therapeutic strategies by clinically irrelevant test results.
In this study we addressed allergenic cross-reactivity using a recombinant approach by employing cell lines with variant capacities of α-1,3-core fucosylation. The venom hyaluronidases, supposed major allergens implicated in cross-reactivity phenomena, from honeybee (Api m 2) and yellow jacket (Ves v 2a and its putative isoform Ves v 2b) as well as the human α-2HS-glycoprotein as control, were produced in different insect cell lines. In stark contrast to production in
Trichoplusia ni (HighFive) cells, α-1,3-core fucosylation was absent or immunologically negligible after production in
Spodoptera frugiperda (Sf9) cells. Consistently, co-expression of honeybee α-1,3-fucosyltransferase in Sf9 cells resulted in the reconstitution of CCD reactivity. Re-evaluation of differentially fucosylated hyaluronidases by screening of individual venom-sensitised sera emphasised the allergenic relevance of Api m 2 beyond its carbohydrate epitopes. In contrast, the vespid hyaluronidases, for which a predominance of Ves v 2b could be shown, exhibited pronounced and primary carbohydrate reactivity rendering their relevance in the context of allergy questionable. These findings show that the use of recombinant molecules devoid of CCDs represents a novel strategy with major implications for diagnostic and therapeutic approaches.
Summary
Background
Comparability of previous studies assessing the incidence of systemic reactions during Hymenoptera venom immunotherapy (VIT) is impaired by methodical differences concerning the ...definition and classification of VIT‐induced anaphylaxis. Our study aims to systematically evaluate the time course and clinical symptoms of VIT‐related systemic reactions.
Patients and Methods
12‐year data on 818 buildup cycles including 8,504 single injections were retrieved from detailed inpatient treatment protocols. The severity of VIT‐related anaphylaxis was graded according to a system proposed by the World Allergy Organization in 2010.
Results
Objective allergic reactions occurred in 28 (3.4 %) buildup cycles; treatment with antihistamines and/or corticosteroids was invariably effective. 23 exclusively cutaneous reactions occurred after a median time interval of 60 minutes (5–480 min.) following the last injection. 0.6 % of the buildup cycles were complicated by moderate to severe anaphylaxis, which occurred more rapidly than mere urticaria and predominantly during honeybee VIT. Patients with moderate to severe anaphylaxis more frequently reported severe index sting reactions and had higher baseline serum tryptase concentrations.
Conclusions
Objective allergic reactions during VIT are rare, and severe anaphylaxis is extremely rare. The use of a consistent classification system for VIT‐induced systemic reactions is required to identify risk factors not only for their general incidence, but also for the exceptionally severe anaphylactic reactions.
Phospholipase A2 (PLA2) enzymes catalyze hydrolysis of phospholipids in membranes. Elucidation of the kinetics of interfacial enzymatic activity is best accomplished by investigating the interface ...substrate concentration dependence of the activity for which appropriate diluents are required. PLA2 is stereoselective toward the L_enantiomers of phospholipids. A novel approach employing D_phospholipids as diluents to perform surface dilution kinetic studies of PLA2 is presented. Activity of bee venom PLA2 at mixed L+D_DPPC (dipalmitoylphosphatidylcholine) bilayer interfaces was measured as a function of substrate L_DPPC mole fraction and vesicle concentration using a sensitive fluorescence assay. A model for interface enzymatic activity based on the three-step kinetic scheme of (i) binding of PLA2 to the bilayer interface, (ii) binding of a lipid to PLA2 at the interface, and (iii) hydrolysis was applied to the hydrolysis data. Activity profiles showed that D_enantiomers also bind to the enzyme but resist hydrolysis. Activity dependences on vesicle and substrate concentrations could be disentangled, bringing resolution to an outstanding problem in membrane hydrolysis of separating the effects of the three steps. Individual values of the kinetic parameters of the model, including the vesicle-PLA2 equilibrium dissociation constant of step (i), interface Michaelis-Menten-Henri constant for L and D_DPPC of step (ii), and the rate constant for interface hydrolysis, step (iii), were obtained as solutions to equations resulting from fitting the model to the data.
The capacitance‐to‐digital single chip detector was upgraded. The paper discusses hardware issues and benefits of the designed/upgraded detector. The device can be operated from rechargeable ...lithium‐ion battery as stand‐alone, portable system and is capable of transmitting real‐time data wirelessly. The detector and additional modules (battery, battery holder, microcontroller board, wireless module) weight is less than 85 g. Electrophoretic separation in low conductivity 20 mM MES/L‐His buffer, pH 6.1, was performed in order to evaluate detection parameters. The system is capable of quantification of potassium ions down to 0.31 μM. Investigation of differential signal acquisition configuration showed improved performance regarding external noise and temperature fluctuations. The system can be a solution for stand‐alone, field‐portable capillary format separation detector.
► P2X7 receptor antagonist inhibited BV-induced persistent spontaneous nociception and mechanical allodynia. ► P2X7 receptor antagonist had no effect on BV-induced inflammatory edema. ► Spinal P2X7 ...receptors contribute to BV-induced nociception, but not inflammation.
Recently, P2X7 receptor (P2X7R) has been found to contribute to the development of inflammatory pain, however, the role of spinal P2X7R is not clear. The present study was designed to determine the roles of spinal P2X7R in the bee venom (BV) model, characterized by multiple pain-related behaviors and obvious inflammatory edema. We determined the effects of P2X7R antagonist A438790 on BV-induced PSN, mechanical allodynia and inflammatory swelling. Pre-treatment with intrathecal administration of A438079 significantly inhibited BV-induced PSN and mechanical allodynia in a dose-dependent manner, but had no effect on BV-induced inflammatory swelling. These data suggest that the activation of spinal P2X7Rs may play a key role in BV-induced nociception, but not inflammation.
Lung cancer accounts for a significant percentage of all cancer‑associated mortalities in men and women, with non‑small cell lung cancer being the most frequently occurring type of lung cancer. ...Melittin is the principal active component of apitoxin (bee venom) that has been reported to exert anti‑chronic inflammatory and anti‑cancer effects. In the present study, the antitumor effect of melittin was evaluated using in vivo and in vitro analyses. The results demonstrated that melittin significantly inhibited the epidermal growth factor‑induced invasion and migration of non‑small cell lung cancer cells. Subcutaneous injection of melittin at doses of 1 and 10 mg/kg significantly suppressed non‑small cell lung cancer tumor growth by 27 and 61%, respectively. In addition, melittin significantly inhibited the secretion of vascular endothelial growth factor (VEGF) in non‑small cell lung cancer cells. Furthermore, melittin decreased the protein expression of VEGF and hypoxia‑inducible factor 1‑α. Therefore, the antitumor activity of melittin may be associated with the anti‑angiogenic actions of inhibiting the VEGF and hypoxia‑inducible factor signaling pathways.
Highlight ► This work shows that the neuro-protective effect of BV is associated with its antiinflammatory properties in the brain and modulation of peripheral immune tolerance by Tregs.
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