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Wasp Venom (wasp + venom)
Selected AbstractsThe basophil activation test in the diagnosis of allergy: technical issues and critical factorsALLERGY, Issue 9 2009G. J. Sturm Background:, The basophil activation test (BAT) is a widely validated and reliable tool especially for the diagnosis of hymenoptera venom allergy. Nevertheless, several pitfalls have to be considered and outcomes may differ because of diverse in-house protocols and commercially available kits. We aimed to identify the factors that may influence results of the CD63-based BAT. Methods:, Basophil responses to monoclonal anti-IgE (clone E124.2.8) and bee and wasp venom were determined by BAT based on CD63. The effect of stimulating factors such as, IL-3, cytochalasin B and prewarming of the samples was investigated. Furthermore, we compared two different flow cytometer systems and evaluated the influence of storage time, different staining protocols and anti-allergic drugs on the test results. Results:, Interleukin-3 enhanced the reactivity of basophils at 300 pM, but not at 75 and 150 pM. Prewarming of samples and reagents did not affect basophil reactivity. CD63 expression assayed after storage time of up to 48 h showed that basophil reactivity already started to decline after 4 h. Basophils stained with HLA-DR-PC5 and CD123-PE antibodies gated as HLA-DRneg/CD123pos cells showed the highest reactivity. No effect on test outcomes was observed at therapeutic doses of dimetindene and desloratadine. Finally, slight differences in the percentage of activated basophils, depending on the cytometer system used, were found. Conclusion:, Basophil activation test should be performed as early as possible after taking the blood sample, preferably within 4 h. In contrast to the skin test, BAT can be performed in patients undergoing treatment with antihistamines. For reasons of multiple influencing factors, BAT should be performed only at validated laboratories. [source] In vivo and in vitro activity of venom from the endoparasitic wasp Pimpla turionellae (L.) (Hymenoptera: Ichneumonidae)ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 2 2006Ekrem Ergin Abstract The biological activity of venom from Pimpla turionellae L. (Hymenoptera: Ichneumonidae) was examined in vivo toward larvae and pupae of Galleriae mellonella L. (Lepidoptera: Pyralidae), and in vitro toward bacterial and fungal cultures, as well as cultured insect cells. Pupae of G. mellonella were far more susceptible to the venom than larvae. At low doses of venom [0.1 venom reservoir equivalents (VRE)], pupal abdominal mobility was inhibited within 30 min, and by 24 h, all pupae injected with venom concentrations >0.5 VRE were completely paralyzed. These same doses of venom resulted in an inhibition of adult emergence. Host larvae were far less sensitive to wasp venom as evidenced by all venom injected larvae remaining responsive to mechanical stimulation by 1 h post injection, even at concentrations equivalent to 1 venom reservoir. Eventually (>2 h at 25°C), venom-injected larvae became immobile, then flaccid, and all died within 24 h post-injection. At lower concentrations of wasp venom, the onset of paralysis was delayed by comparison to that evoked by 1 VRE, and few host larvae were able to pupate. Development of host larvae to adult emergence was also reduced in a dose-dependent manner, with eclosion completely prevented at high concentrations (>0.5 VRE) of venom. Venom doses <0.5 VRE did not appear to induce paralysis or alter larval development. When venom was incubated with bacterial or fungal cultures, no antimicrobial activity was detected. However, wasp venom was found to be cytotoxic and cytolytic to cultured cells derived from the cabbage looper Trichoplusia ni Hubner (Lepidoptera: Noctuidae) and the yellow fever mosquito, Aedes aegypti (L.) (Diptera: Culcidae). Though both cell types displayed similar susceptibility in terms of LC50s, the lepidopteran cells responded much more rapidly with regard to the onset of morphological changes and the timing of cell death. A possible mode of action for the venom is discussed. Arch. Insect Biochem. Physiol. 61:87,97, 2006. © 2006 Wiley-Liss, Inc. [source] Crystallization and preliminary X-ray diffraction analysis of a eumenine mastoparan toxin: a new class of mast-cell degranulating peptide in the wasp venomACTA CRYSTALLOGRAPHICA SECTION D, Issue 11 2000F. Canduri Mastoparans are tetradecapeptides found to be the major component of vespid venoms. A mastoparan toxin isolated from the venom of Anterhynchium flavomarginatum micado has been crystallized and X-ray diffraction data collected to 2.7,Å resolution using a synchrotron-radiation source. Crystals were determined to belong to the space group P6222 (P6422). This is the first mastoparan to be crystallized and will provide further insights into the conformational significance of mastoparan toxins with respect to their potency and activity in G-protein regulation. [source] Conformation and lytic activity of eumenine mastoparan: a new antimicrobial peptide from wasp venomCHEMICAL BIOLOGY & DRUG DESIGN, Issue 3 2004M.P. Dos Santos Cabrera Abstract:, Eumenine mastoparan-AF (EMP-AF) is a novel membrane active tetradecapeptide recently isolated from the venom of solitary wasp, Anterhynchium flavomarginatum micado. It was reported previously that EMP-AF peptide presented low cytolytic activities in human erythrocytes and in RBL-2H3 mast cells. In the present work, we observed that this peptide is able to permeate anionic liposomes, and in less extension also the neutral ones. We present evidences showing that the permeation ability is well correlated with the amount of helical conformation assumed by the peptides in these environments. This peptide also showed a broad-spectrum inhibitory activity against Gram-positive and Gram-negative bacteria. The permeability of liposomes and the antibiotic effect showed a significant reduction when C-terminus was deamidated (in acidic form). The removal of the three first amino acid residues from the N-terminus rendered the peptide inactive both in liposomes and in bacteria. The results suggest that the mechanism of action involves a threshold in the accumulation of the peptide at level of cell membrane. [source] The N-glycans of yellow jacket venom hyaluronidases and the protein sequence of its major isoform in Vespula vulgarisFEBS JOURNAL, Issue 20 2005Daniel Kolarich Hyaluronidase (E.C. 3.2.1.35), one of the three major allergens of yellow jacket venom, is a glycoprotein of 45 kDa that is largely responsible for the cross-reactivity of wasp and bee venoms with sera of allergic patients. The asparagine-linked carbohydrate often appears to constitute the common IgE-binding determinant. Using a combination of MALDI MS and HPLC of 2-aminopyridine-labelled glycans, we found core-difucosylated paucimannosidic glycans to be the major species in the 43,45 kDa band of Vespula vulgaris and also in the corresponding bands of venoms from five other wasp species (V. germanica, V. maculifrons, V. pensylvanica, V. flavopilosa and V. squamosa). Concomitant peptide mapping of the V. vulgaris 43 kDa band identified the known hyaluronidase, Ves v 2 (SwissProt P49370), but only as a minor component. De novo sequencing by tandem MS revealed the predominating peptides to resemble a different, yet homologous, sequence. cDNA cloning retrieved a sequence with 58 and 59% homology to the previously known isoform and to the Dolichovespula maculata and Polistes annularis hyaluronidases. Close homologues of this new, putative hyaluronidase b (Ves v 2b) were also the major isoform in the other wasp venoms. [source] Effects of the paratemnus elongatus pseudoscorpion venom in the uptake and binding of the L -glutamate and GABA from rat cerebral cortexJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 1 2006Wagner Ferreira dos Santos Abstract L -Glu is the most important and widespread excitatory neurotransmitter of the vertebrates. Four types of receptors for L -glu have been described. This neurotransmitter modulates several neuronal processes, and its dysfunction causes chronic and acute diseases. L -Glu action is terminated by five distinct transporters. Antagonists for these receptors and modulators of these transporters have anticonvulsant and neuroprotective potentials, as observed with the acylpoliamines and peptides isolated from spiders, solitary and social wasp venoms. On the other hand, the major inhibitory neurotransmitter in mammalian nervous tissue is the GABA. Drugs that enhance GABA neurotransmission comprise effective approaches to protecting the brain against neuronal injury. Is this study, we demonstrate for the first time the inhibition of the [3H]L -glu binding to its specific sites in synaptosomal membranes from rat cerebral cortex, produced by 0.027 U of Paratemnus elongatus venom (EC50). The venom of P. elongatus changes Km and Vmax into the high affinity uptake of the L -glu and decreases Km and Vmax into the parameters of the GABA uptake from rat synaptosomes. This leads us to speculate on the possible presence of selective and specific compounds in this venom that act in L -glu and GABA dynamics, and therefore, that can serve as tools and new drug models for understanding these neurotransmissions. © 2006 Wiley Periodicals, Inc. J Biochem Mol Toxicol 20:27,34, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20113 [source] Differential gene expression profiles in the venom gland/sac of Orancistrocerus drewseni (Hymenoptera: Eumenidae)ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 4 2009Ji Hyeong Baek Abstract To determine differential gene expression profiles in the venom gland and sac (gland/sac) of a solitary hunting wasp species, Orancistrocerus drewseni Saussure (1857), a subtractive cDNA library was constructed by suppression subtractive hybridization. A total of 498 expressed sequence tags (EST) were clustered and assembled into 205 contigs (94 multiple sequences and 111 singletons). About 65% (134) of the contigs had matched BLASTx hits (E,10,4). Among these, 115 contigs had similarity to proteins with assigned molecular function in the Gene Ontology database, and most of them (112 contigs, 83%) were homologous to genes from Hymenoptera, particularly to Apis mellifera (98 contigs). The contigs encoding hyaluronidase and phospholipase A2, known to be main components of wasp venoms, were found in high frequencies (27 and 4%, respectively, as judged by the number of ESTs) in the gene ontology category of catalytic activity. Full-length open reading frames of hyaluronidase and phospholipase A2 were characterized and their abundance in the venom gland/sac was confirmed by quantitative real-time PCR. Several contigs encoding enzymes, including zinc-metallopeptidases that are likely involved in the processing and activation of venomous proteins or peptides, were also identified from the library. Discovery of venom gland/sac-specific genes should promote further studies on biologically active components in the venom of O. drewseni. © 2009 Wiley Periodicals, Inc. [source] | ||||||||||