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Abstract Insect venom phospholipases have been identified in nearly all clinically relevant social Hymenoptera, including bees, wasps and ants. Among other biological roles, during the envenoming process these enzymes cause the disruption of cellular membranes and induce hypersensitive reactions, including life threatening anaphylaxis. While phospholipase A2 (PLA2) is a predominant component of bee venoms, phospholipase A1 (PLA1) is highly abundant in wasps and ants. The pronounced prevalence of IgE-mediated reactivity to these allergens in sensitized patients emphasizes their important role as major elicitors of Hymenoptera venom allergy (HVA). PLA1 and -A2 represent valuable marker allergens for differentiation of genuine sensitizations to bee and/or wasp venoms from cross-reactivity. Moreover, in massive attacks, insect venom phospholipases often cause several pathologies that can lead to fatalities. This review summarizes the available data related to structure, model of enzymatic activity and pathophysiological roles during envenoming process of insect venom phospholipases A1 and -A2. Graphical abstract Image 1 Highlights • Phospholipases A1 (PLA1) and -A2 (PLA2) are prominent toxins in wasp/ant and bee venoms; respectively. • Insect venom PLA1 and PLA2 cause direct toxic effects and hypersensitive reactions including anaphylaxis. • After a massive attack, insect venom PLA1 and PLA2 activities often trigger several life-threatening pathologies. • Structural and functional characterization of PLA1 and PLA2 help to understand their role in the envenoming process. • Venom PLA1 and -A2 are marker allergens widely used in diagnosis of Hymenoptera venom allergy. [ABSTRACT FROM AUTHOR]

Although the importance of parasitoids as biocontrol agents has long been recognized, systematic studies of the physiological mechanisms are scarce, especially in those parasitoids that are able to successfully invade their hosts by activating host immune responses. This study explored this phenomenon by investigating the effects of ovarian fluid, venom and egg surface characteristics of Tetrastichus brontispae (Hymenoptera: Eulophidae) on host immunity. The results showed that the injection of venom alone induced higher phenoloxidase activity, while a mixture of ovarian plus venom fluids provoked higher granulocyte and plasmatocyte spreading ratios, highlighting the role that egg surface characteristics may play in successful parasitism. After thorough investigation, the presence of a hemomucin homologue was documented on the egg surface (which was named Tetrastichus brontispae adipocyte plasma membrane associated protein-like, TbAPMAP-like), while the absence of polydnaviruses, fibrous layers and virus-like filaments was confirmed. The higher encapsulation index of eggs incubated with TbAPMAP-like polyclonal antibody demonstrated the protection of the protein against encapsulation. These results contribute to our understanding of the mechanisms used by endoparasitoids to evade encapsulation during the early parasitism stage while enriching our knowledge of local active regulatory mechanisms. It is likely that this is the first study to determine the egg protective properties of TbAPMAP-like in host-parasite systems. [ABSTRACT FROM AUTHOR]

Vespa tropica , a social wasp locally found in Thailand is responsible for many out off the record accidental stings due to close encounters with human activities and because of the animal's highly potent venom. Phospholipase (PLA) is one of the major proteins commonly found in insect venom. In this work, V. tropica phospholipase was successfully isolated, purified and characterized. Three isoforms PLAs have been purified using reversed phase HPLC, and are named VesT1s (VesT1.01a, VesT1.01b and VesT1.02). They are not glycoproteins. VesT1.01s has a molecular weight of 33.72 kDa while for VesT1.02 a mass of 34 kDa was found. The deduced sequence of the mature VesT1.02 protein is composed of 301 amino acid residues (1005 bp), including the catalytic triad (Ser-His-Asp), which is similar to other wasp venom PLAs. The 12 cysteine residues found are conserved among venom PLA1. They form six disulfide bonds, and therefore have no free sulfhydryl groups. Based on homology modelling, VesT1.02 belongs to the α/β hydrolase fold family. Its structure is composed of 10 β-sheets and 11 α-helixes, characterized by a β-strand/εSer/α-helix structural motif, which contains the Gly-X-Ser-X-Gly consensus sequence. The shortened lid and shortened β9 loop, which play important roles in substrate selectivity, cause this enzyme to only exhibit PLA activity. Moreover, these PLAs have been shown to be highly thermally stable after heating at 100 °C for 5 min. We propose that an inserted Pro residue might be involved in this high thermo-stability. [ABSTRACT FROM AUTHOR]

Among venomous animals, Hymenoptera have been suggested as a rich source of natural toxins. Due to their broad ecological diversity, venom from Hymenoptera insects (bees, wasps and ants) have evolved differentially thus widening the types and biological functions of their components. To date, insect toxinology analysis have scarcely uncovered the complex composition of bee, wasp and ant venoms which include low molecular weight compounds, highly abundant peptides and proteins, including several allergens. In Hymenoptera, these complex mixtures of toxins represent a potent arsenal of biological weapons that are used for self-defense, to repel intruders and to capture prey. Consequently, Hymenoptera venom components have a broad range of pharmacological targets and have been extensively studied, as promising sources of new drugs and biopesticides. In addition, the identification and molecular characterization of Hymenoptera venom allergens have allowed for the rational design of component-resolved diagnosis of allergy, finally improving the outcome of venom immunotherapy (VIT). Until recently, a limited number of Hymenoptera venoms had been unveiled due to the technical limitations of the approaches used to date. Nevertheless, the application of novel techniques with high dynamic range has significantly increased the number of identified peptidic and proteinaceous toxins. Considering this, the present review summarizes the current knowledge about the most representative Hymenoptera venom peptides and proteins which are under study for a better understanding of the insect-caused envenoming process and the development of new drugs and biopesticides. [ABSTRACT FROM AUTHOR]

Introduction: The Megalopyge opercularis caterpillar is covered with spines that break off and release venom on contact, resulting in severe pain, erythema, rash, and other adverse effects. In Texas, these caterpillars are abundant and of potential health threat. This study describes M opercularis caterpillar stings reported to Texas poison centers.Methods: Cases were M opercularis caterpillar stings reported to Texas poison centers during 2000-2016. The distribution of stings was determined related to exposure circumstances and management.Results: There were 3484 M opercularis caterpillar stings reported during 2000-2016. The annual number of stings did not consistently change over the 17-year time period. The monthly number of stings was highest in July (12%) and October to November (59%). The patients were female in 53% of cases and aged 20 years or more in 56%. The sting occurred at the patient's own residence in 91% of cases. The patients were managed outside of a healthcare facility in 89% of cases; 93% of the patients were known or expected to have no or at most minor clinical effects. Dermal clinical effects were reported in 90% of cases, the most common being irritation/pain (84%), puncture/wound (45%), erythema/flushed (29%), and edema (15%).Conclusions: M opercularis caterpillar stings reported to Texas poison centers were more frequently reported in July and October to November. Most of the patients were adults. The majority of patients were managed outside of healthcare facilities and did not have serious outcomes. Most of the adverse clinical effects were dermal in nature. [ABSTRACT FROM AUTHOR]

Résumé Les données épidémiologiques concernant la mortalité par anaphylaxie sont rares et discordantes. Notre objectif était de déterminer le taux de mortalité par anaphylaxie (exprimé par million et par an) en France métropolitaine et d’analyser l’évolution entre 1979 et 2011, les spécificités selon la cause (iatrogène, venin d’insectes, aliment ou non spécifiée), le sexe et l’origine géographique. Méthodes Les données ont été obtenues : (1) du CépiDC (Inserm) pour colliger les cas de décès par anaphylaxie et les données complémentaires (sexe, âge, origine géographique lors du décès) ; (2) de l’INSEE pour déterminer les populations de référence. Un modèle de régression logistique multivariée a été utilisé pour évaluer l’impact de l’âge, du sexe, de l’origine géographique lors du décès, de la durée sur les décès par anaphylaxie. Résultats Au total, 1603 décès ont été analysés : 1564 chez l’adulte et 39 chez l’enfant (âge < 19 ans). La prévalence globale des décès par anaphylaxie était de 0,84 par million et par an (IC 95 % : 0,80–0,88), comprise entre 0,08 (IC 95 % : 0,05–0,10) chez l’enfant et 1,12 (IC 95 % : 1,06–1,17) chez l’adulte. Pendant la période, il existait une diminution de ce taux de 2,1 % dans la population générale (IC 95 % : −2,6 à −1,7 ; p < 10 −4 ) et de 2,5 % (IC 95 % : −5,6–0,9) dans la population pédiatrique. Le taux de mortalité était plus élevé chez les hommes (1,08 [IC 95 % : 1,00–1,16] que chez les femmes (0,86 [IC 95 % : 0,80–0,92]) ( p < 10 −4 ). Les causes de décès par anaphylaxie étaient iatrogènes (63 %), principalement liés aux médicaments, les venins d’insectes (14 %) et les aliments (0,6 %). Dans 23 % des cas, la cause n’était pas spécifiée. Le taux de mortalité était le plus élevé chez les personnes âgées de plus de 70 ans (3,50 [IC 95 % : 3,25–3,76]). Le taux de mortalité par décès liés aux venins d’insectes était plus élevé dans le sud de la France (0,16 [IC 95 % : 0,13–0,19]) que dans le nord (0,11 [IC 95 % : 0,09–0,13]) ( p = 0,004). Seulement 8 décès (dont 7 survenus chez des personnes âgées de moins de 32 ans) par anaphylaxie de cause alimentaire étaient identifiés. L’analyse multivariée a montré que l’âge, l’évolution dans le temps et le sexe masculin étaient des facteurs de risque de décès par anaphylaxie toute cause confondue ( p < 10 −4 ). Conclusion La mortalité par anaphylaxie diminue de 2 % par an au cours des 3 dernières décennies en France métropolitaine. Les causes iatrogéniques sont les principales causes. L’âge et le sexe masculin sont des facteurs de risque d’anaphylaxie létale, en dehors des anaphylaxies de cause alimentaire. Data about anaphylaxis mortality are limited and conflicting. Objective To determine the anaphylaxis mortality rate (AMR), time trends and specificities according to trigger factor, age group, sex and geographical region in France from 1979 to 2011. Patients and methods Data were obtained from databases of: (1) the French Mortality Center (CepiDC) to collect cases of lethal anaphylaxis and; (2) the French Statistics Institute (INSEE) to define the reference populations. AMRs were expressed per million persons/year. Results Overall, 1603 cases of deaths from anaphylaxis were collected: 1564 in adults and 39 in children (age < 19 years). Overall and pediatric AMRs were respectively 0.83 (95%CI, 0.80–0.88) and 0.08 (95%CI: 0.05–0.10). AMR was higher in men (1.08 [95%CI, 1.00–1.16] than women (0.86 [95%CI, 0.80–0.92]) ( P < 10 −4 ). Annual percentage change for the case fatality rate was −2.1% (95%CI, −2.6; −1.7) indicating a decrease during the study period ( P < 10 −4 ). Causes of anaphylactic shock were iatrogenic (63%), mostly drugs, venom (14%) and food (0.6%). AMR was the highest in persons aged ≥ 70 years (3.50 [95%IC: 3.25–3.76]). The venom-induced mortality rate was higher in the south of France (0.16) compared to the north (0.11) ( P = 0.003). Only eight food-induced fatalities were recorded (age < 32 years in seven). Multivariate analysis showed that greater age, changes over time, and male gender were associated with a significant risk for death from anaphylaxis, irrespective of cause ( P < 10 −4 ). Conclusion Overall, AMR has decreased over the last three decades in France (2%/year). Iatrogenic causes are the most frequently involved trigger. Higher age and male gender are risk factors for fatal anaphylaxis of any cause other than food-related causes. [ABSTRACT FROM AUTHOR]

Contact with the caterpillars of the pine processionary moth (CPPM) Thaumetopoea pityocampa induces severe local allergic reactions. The purpose of this large-scale retrospective cohort-study was to describe the clinical manifestations and related risk factors of CPPM exposure. This cohort-study included 109 dogs between the years of 2000 and 2016. Tongue lesions ranging from oedema to severe necrosis were observed in 94/109 dogs (86%). The following systemic signs were observed in 60/109 dogs (55%): vomiting (52/109, 48%), dyspnoea (6/109, 5%), hypovolemia (4/109, 4%) and diarrhoea (2/109, 2%). Based on the time elapsed from CPPM contact to the first oral flushing, three groups were defined: <2 h (group 1, 37/105, 35%), 2 h–6 h (group 2, 39/105, 37%) and >6 h (group 3, 29/105, 28%). Tongue necrosis (TN) at admission was significantly more common in the dogs in group 3 than those in groups 1 and 2 (45% vs. 5% and 5% respectively, p = 0.0002). In addition, the development of TN during hospitalisation was significantly more common in the dogs in group 3 (65%) than in those in the other groups (21% in group 1, p = 0.02) and 31% in group 2, p = 0.001). The dogs in group 3 presented a 14.63-fold higher risk of TN at admission and a 3.78-fold higher risk of developing necrosis during hospitalisation compared with the other groups. The survival rate after exposure was 97%. Long-term follow-up data were available for 69/109 dogs (63%). Twenty-three dogs (37%) had persistent, definitive TN without major consequences on quality of life. Elapsed time between contact and first oral flushing appears to be a key determinant for the progression of necrotic lesions, and the best results were observed when flushing occurred within 6 h of contact. The prognosis of CPPM envenomation is excellent, with a short hospitalisation duration. [ABSTRACT FROM AUTHOR]

The effect of Habrobracon hebetor venom and the role of the adipokinetic hormone (AKH) in poisoned adult females of the firebug Pyrrhocoris apterus were studied 24 and 48 h after treatments. Venom application elicited total neuromuscular paralysis in firebugs, but the co-application of venom and Pyrap-AKH significantly reduced paralysis (up to 3.2 times) compared to the application of venom only. Although the mechanisms of their action are unknown, both agents might affect neuromuscular junctions. Venom application significantly increased the expression of both P. apterus Akh genes ( Pyrap - Akh 5.4 times and Peram - Cah - II 3.6 times), as well as the level of AKHs in the central nervous system (2.5 times) and haemolymph (3.0 times). In the haemolymph, increased AKH levels might have led to the mobilization of stored lipids, which increased 1.9 times, while the level of free carbohydrates remained unchanged. Total metabolism, monitored by carbon dioxide production, significantly declined in paralysed P. apterus individuals (1.4 times and 1.9 times, 24 and 48 h after the treatment, respectively), probably because of a malfunction of the muscular system. The results suggest an active role of AKH in the defence mechanism against the stress elicited by neuromuscular paralysis, and the possible involvement of this hormone in neuronal/neuromuscular signalling. [ABSTRACT FROM AUTHOR]

Currently, new antimicrobial molecules extracted or obtained by natural sources, could be a valide alternative to traditional antibiotics. Most of these molecules are represented by antimicrobial peptides (AMPs), which are essential compounds of insect, arachnids and centipedes venom. AMPs, due to their strong effectiveness, low resistance rates and peculiar mode of action, seem to have all the suitable features to be a powerful weapon against several bacteria, especially considering the increasing antibiotic-resistance phenomena. The present literature review focuses on the antibacterial activity of bee, wasp, ant, scorpion, spider and scolopendra crude venom and of their main biological active compounds. After a brief overview of each animal and venom use in folkloristic medicine, this review reports, in a comprehensive table, the results obtained by the most relevant and recent researches carried out on the antibacterial activity of different venom and their AMPs. For each considered study, the table summarizes data concerning minimal inhibitory concentration values, minimal bactericidal concentration values, the methods employed, scientific name and common names and provenience of animal species from which the crude venom and its respective compounds were obtained. [ABSTRACT FROM AUTHOR]

[Display omitted] Limacodidae is a family of lepidopteran insects comprising >1500 species. More than half of these species produce pain-inducing defensive venoms in the larval stage, but little is known about their venom toxins. Recently, we characterised proteinaceous toxins from the Australian limacodid caterpillar Doratifera vulnerans , but it is unknown if the venom of this species is typical of other Limacodidae. Here, we use single animal transcriptomics and venom proteomics to investigate the venom of an iconic limacodid, the North American saddleback caterpillar Acharia stimulea. We identified 65 venom polypeptides, grouped into 31 different families. Neurohormones, knottins, and homologues of the immune signaller Diedel make up the majority of A. stimulea venom, indicating strong similarities to D. vulnerans venom, despite the large geographic separation of these caterpillars. One notable difference is the presence of RF-amide peptide toxins in A. stimulea venom. Synthetic versions of one of these RF-amide toxins potently activated the human neuropeptide FF1 receptor, displayed insecticidal activity when injected into Drosophila melanogaster , and moderately inhibited larval development of the parasitic nematode Haemonchus contortus. This study provides insights into the evolution and activity of venom toxins in Limacodidae, and provides a platform for future structure-function characterisation of A. stimulea peptide toxins. [ABSTRACT FROM AUTHOR]

Polybia paulista (Hymenoptera: Vespidae) is a clinically relevant social wasp that frequently causes stinging accidents in southeast Brazil. To date, diagnosis and specific immunotherapy (SIT) of allergy are based on the use of crude venom extracts. Production of recombinant forms of major allergens from P. paulista venom will improve diagnosis and SIT of allergic patients by reducing the incidence of cross-reactivity and non-specific sensitization. Here, we describe the molecular cloning, heterologous expression, purification and IgE-mediated immunodetection of phospholipase A1 ( Poly p 1), a major allergen from P. paulista venom. The cDNA of Poly p 1 was extracted from venom glands and then cloned, and further expression of the recombinant allergen (r Poly p 1) was achieved in Escherichia coli BL21 (DE3) cells. Purification of r Poly p 1 was performed using immobilized Ni 2+ metal affinity chromatography. Also, a single-step chromatographic method allowed the purification of native Poly p 1 (n Poly p 1) from the wasp's venom glands. We used western blotting to evaluate IgE-reactivity of the sera from 10 P. paulista venom-allergic patients to r Poly p 1 and n Poly p 1. High levels of insoluble r Poly p 1 were obtained during heterologous expression. After solubilization of inclusion bodies and purification of the recombinant protein, a unique band of ∼34 kDa was detected in SDS-PAGE analysis. Allergen-specific IgE (sIgE) from allergic patients' sera recognized r Poly p 1, n Poly p 1 and crude venom extract to a similar extent. Our results showed that r Poly p 1 could be used for development of component-resolved diagnosis (CRD) and molecular-defined SIT of P. paulista venom allergy. [ABSTRACT FROM AUTHOR]

Alkaloids, including 2,5-dialkylpyrrolidines and 2,5-dialkylpyrrolines, have been reported to be components in the venom of little black ants, Monomorium minimum (Buckley). Two fatty amines were recently reported as minor compounds. By analyzing the discharge collected from the stinger apparatus (milking), this study revealed the presence of an additional seven compounds in the defensive secretion of this ant species. Compounds identified were 9-decenyl-1-amine, N -methylenedecan-1-amine, N -methylenedodecan-1-amine, 2-(1-non-8-enyl)-5-(1-hex-5-enyl)-1-pyrroline, N -methyl-2-(hex-5-enyl)-5-nonanyl-1-pyrrolidine, β -springene (( E , E )-7,11,15-trimethyl-3-methylene-1,6,10,14-hexadecatetraene) and neocembrene (( E , E , E )-1-isopropenyl-4,8,12-trimethylcyclotetradeca-3,7,11-triene). β -springene and neocembrene were found only in the defensive secretion of queens. Analyses of the contents of isolated poison and Dufour's glands of the queen indicated that all amines and alkaloids were from the poison gland and that β -springene and neocembrene were from the Dufour's gland. This demonstrated that the defensive secretion in M . minimum queens consists of components from both glands. This is also the first report on the natural occurrence of 9-decenyl-1-amine, N-methylenedecan-1-amine, and N-methyllenedodecan-1-amine. [ABSTRACT FROM AUTHOR]

Nasal delivery is a convenient and acceptable route for drug administration, and has been shown to elicit a much more potent local and systemic response compared with other drug delivery routes. We previously demonstrated that rectal administration of poly(lactide- co -glycolide)-encapsulated honeybee venom (P-HBV) could enhance systemic Th 1-specific immune responses. We therefore synthesized chitosan-coated P-HBV (CP-HBV) and then evaluated the immune-boosting efficacy of nasally administered CP-HBV on systemic and local intestinal immunity compared with non-chitosan-coated P-HBV. The nasally delivered CP-HBV effectively enhanced Th 1-specific responses, eliciting a significant increase in the CD3 + CD4 + CD8 − Th cell population, lymphocyte proliferation capacity, and expression of Th 1 cytokines (IFN-γ, IL-12, and IL-2) in peripheral blood mononuclear cells. Furthermore, these immune-boosting effects persisted up to 21 days post CP-HBV administration. Nasal administration of CP-HBV also led to an increase of not only the CD4 + Th 1 and IFN-γ secreting CD4 + Th 1 cell population but also Th 1-specific cytokines and transcription factors, including IL-12, IFN-γ, STAT4, and T-bet, in isolated mononuclear cells from the spleen and ileum. [ABSTRACT FROM AUTHOR]

Analgesic therapy is based on the sequential treatment of pain, in which opioids are drugs of last resource and known to be highly effective, but are also responsible for undesirable side effects, tolerance and addiction. There is a need for new drugs with alternative targets in order to minimize side effects and improve treatment efficacy. Mastoparans are an abundant class of peptides in wasp venom and have shown great potential as new drugs, as well as being excellent tools for the study of G-protein-coupled receptors. The objective of this study was to investigate the antinociceptive activity of the mastoparan Agelaia-MP I and the mechanisms involved. Agelaia-MP I (MW 1565 Da) showed dose-dependent antinociceptive activity in mice submitted to i.c.v. injection in two different models. The highest dose produced a maximum effect for up to 4 h, and nociception remained low three days after injection. Further experiments showed that Agelaia-MPI induced partial and reversible blockade of the amplitude of action potential, probably interacting with voltage-gated sodium channels. These results revealed the significant potential impact of compounds isolated from wasp venom on the central nervous system (CNS). In addition, the antinociceptive effect described here is a novel activity for mastoparans. [ABSTRACT FROM AUTHOR]

Neglected tropical diseases (NTD) are treated with toxic therapy of limited efficacy. Previously, we studied the antimicrobial effect of Dinoponera quadriceps venom (DqV) against bacteria. To continue the study, we report in this short communication the antimicrobial effect of DqV against Leishmania amazonensis and Trypanosoma cruzi . DqV inhibits the promastigote forms of L . amazonensis and all T . cruzi developmental forms, with low toxicity in host cells. DqV causes cell death in T . cruzi through necrotic and apoptotic mechanisms observed by staining the cells with annexin V-FITC (AX) and propidium iodide (PI), loss of mitochondrial membrane potential by flow cytometry analyses and confocal microscopy and morphological alterations, such as loss of membrane integrity and cell shrinkage by scanning electron microscopy (SEM). In conclusion, we suggest there is an antimicrobial effect also on parasites. [ABSTRACT FROM AUTHOR]

Endoparasitoids in the order Hymenoptera are natural enemies of several herbivorous insect pest species. During oviposition they inject a mixture of factors, which include venom, into the host, ensuring the successful parasitism and the development of their progeny. Although these parasitoid factors are known to be responsible for host manipulation, such as immune system suppression, little is known about both identity and function of the majority of their venom components. To identify the major proteins of Toxoneuron nigriceps (Hymenoptera: Braconidae) venom, we used an integrated transcriptomic and proteomic approach. The tandem-mass spectrometric (LC-MS/MS) data combined with T . nigriceps venom gland transcriptome used as a reference database resulted in the identification of a total of thirty one different proteins. While some of the identified proteins have been described in venom from several parasitoids, others were identified for the first time. Among the identified proteins, hydrolases constituted the most abundant family followed by transferases, oxidoreductases, ligases, lyases and isomerases. The hydrolases identified in the T . nigriceps venom glands included proteases, peptidases and glycosidases, reported as common components of venom from several parasitoid species. Taken together, the identified proteins included factors that could potentially inhibit the host immune system, manipulate host physiological processes and host development, as well as provide nutrients to the parasitoid progeny, degrading host tissues by specific hydrolytic enzymes. The venom decoding provides us with information about the identity of candidate venom factors which could contribute to the success of parasitism, together with other maternal and embryonic factors. [ABSTRACT FROM AUTHOR]

Wasp venom characterization is of interest across multiple disciplines such as medicinal chemistry and evolutionary biology. A simple method is described herein to milk wasp venom without undue risks to the researcher. The wasps were immobilized by cooling for safe handling, restrained, and their venom was collected on parafilm. Bradykinin from Hemipepsis ustulata was identified by LC-MS/MS during method verification. [ABSTRACT FROM AUTHOR]

We have recently characterized bicarinalin as the most abundant peptide from the venom of the ant Tetramorium bicarinatum . This antimicrobial peptide is active against Staphylococcus and Enterobacteriaceae. To further investigate the antimicrobial properties of this cationic and cysteine-free peptide, we have studied its antibacterial, antifungal and antiparasitic activities on a large array of microorganisms. Bicarinalin was active against fifteen microorganisms with minimal inhibitory concentrations ranging from 2 and 25 μmol L −1 . Cronobacter sakazakii , Salmonella enterica , Candida albicans , Aspergilus niger and Saccharomyces cerevisiae were particularly susceptible to this novel antimicrobial peptide. Resistant strains of Staphylococcus aureus , Pseudomonas aeruginosa and C. albicans were as susceptible as the canonical strains. Interestingly, bicarinalin was also active against the parasite Leishmania infantum with a minimal inhibitory concentrations of 2 μmol L −1 . The bicarinalin pre-propeptide cDNA sequence has been determined using a combination of degenerated primers with RACE PCR strategy. Interestingly, the N-terminal domain of bicarinalin pre-propeptide exhibited sequence similarity with the pilosulin antimicrobial peptide family previously described in the Myrmecia venoms. Moreover, using SYTOX green uptake assay, we showed that, for all the tested microorganisms, bicarinalin acted through a membrane permeabilization mechanism. Two dimensional-NMR experiments showed that bicarinalin displayed a 10 residue-long α-helical structure flanked by two N- and C-terminal disordered regions. This partially amphipathic helix may explain the membrane permeabilization mechanism of bicarinalin observed in this study. Finally, therapeutic value of bicarinalin was highlighted by its low cytotoxicity against human lymphocytes at bactericidal concentrations and its long half-life in human serum which was around 15 h. [ABSTRACT FROM AUTHOR]

To increase in the depth characterization of venom proteome of Apis mellifera the hyphenated LC–MALDI–ToF/ToF–MS (liquid chromatography–matrix-assisted laser desorption/ionization–time of flight/time of flight tandem mass spectrometry) and LC–ESI–QToF–MS (liquid chromatography–electrospray ionization–quadrupole time of flight tandem mass spectrometry) techniques combined with combinatorial peptide ligand library enrichment method is proposed in this study. The novel approach simplifies pretreatment protocol in venom investigation. By using the protein preparation kit with sequential multi-step elution, the honeybee venom was dispensed into four different fractions. In total 269 proteins were detected, among these 49 honeybee toxins, allergens and components involved in mechanism of envenoming belonging to venom enzyme classes of esterases, proteases/peptidases, protease inhibitors, hydrolases and major royal jelly proteins. Moreover 5 additional putative toxins were identified. Their role in envenoming process was discussed. We concluded that different mass spectrometry techniques increased the detection of the honeybee venom proteins, underscoring the complementary character of analytical methods. The combination of MALDI and ESI ionization has resulted in numerous proteins identifications, not possible to reach with single proteomic technique. The study will contribute to broadening the knowledge about the complexity of honeybee venom. The newly identified proteins may serve not only as toxins and allergens, but also as substances with potential pharmacological activity. Although, the most detected proteins belong to trace elements of honeybee venom without toxic activity or action on vital system of victims, they should be taken into account in characterization of living organism response on Apis mellifera sting. [ABSTRACT FROM AUTHOR]

Anxiety disorders are major health problems in terms of costs stemming from sick leave, disabilities, healthcare and premature mortality. Despite the availability of classic anxiolytics, some anxiety disorders are still resistant to treatment, with higher rates of adverse effects. In this respect, several toxins isolated from arthropod venoms are useful in identifying new compounds to treat neurological disorders, particularly pathological anxiety. Thus, the aims of this study were to identify and characterize an anxiolytic peptide isolated from the venom of the social wasp Polybia paulista . The peptide was identified as Polisteskinin R, with nominal molecular mass [M + H] + = 1301 Da and primary structure consisting of Ala-Arg-Arg-Pro-Pro-Gly-Phe-Thr-Pro-Phe-Arg-OH. The anxiolytic effect was tested using the elevated plus maze test. Moreover, adverse effects on the spontaneous behavior and motor coordination of animals were assessed using the open field and rotarod tests. Polisteskinin R induced a dose-dependent anxiolytic effect. Animals treated with the peptide and diazepam spent significantly more time into the open arms when compared to the groups treated with the vehicle and pentylenetetrazole. No significant differences in spontaneous behavior or motor coordination were observed between the groups, showing that the peptide was well tolerated. The interaction by agonists in both known BK receptors induces a variability of physiological effects; Polisteskinin R can act on these receptors, inducing modulatory activity and thus, attenuating anxiety behaviors. The results of this study demonstrated that the compound Polisteskinin R exerted potent anxiolytic effects and its analogues are promising candidates for experimental pharmacology. [ABSTRACT FROM AUTHOR]

The larval endoparasitoid Cotesia chilonis injects venom and bracoviruses into its host Chilo suppressalis during oviposition. Here we study the effects of the polydnavirus (PDV)-carrying endoparasitoid C. chilonis (Hymenoptera: Braconidae) parasitism, venom and calyx fluid on host cellular and humoral immunity, specifically hemocyte composition, cellular spreading, encapsulation and melanization. Total hemocyte counts (THCs) were higher in parasitized larvae than in unparasitized larvae in the late stages following parasitization. While both plasmatocyte and granulocyte fractions and hemocyte mortality did not differ between parasitized and unparasitized hosts, in vitro spreading behavior of hemocytes was inhibited significantly by parasitism throughout the course of parasitoid development. C. chilonis parasitism suppressed the encapsulation response and melanization in the early stages. Venom alone did not alter cellular immune responses, including effects on THCs, mortality, hemocyte composition, cell spreading and encapsulation, but venom did inhibit humoral immunity by reducing melanization within 6 h after injection. In contrast to venom, calyx fluid had a significant effect on cell spreading, encapsulation and melanization from 6 h after injection. Dose–response injection studies indicated the effects of venom and calyx fluid synergized, showing a stronger and more persistent reduction in immune system responses than the effect of either injected alone. [ABSTRACT FROM AUTHOR]

The main insects causing allergy reactions to stinging insect in humans are Apidae (bees), Vespidae (wasps, yellow jackets and hornets) and Formicidae (ants). Their venom stings are composed of various biologically active peptides and protein components, some of which can cause toxicity or anaphylaxis in humans. The protein venom demonstrate some common allergenic activity such as for fire ants and vespids, which have two common allergens that are phospholipase A 1 (enzymatic activity) and antigen 5 with unknown biological activity. The common allergens seem to share some degree of immunological cross-reactivity, particularly when the sequence homology is above 70%. Therefore immunotherapeutic approaches targeting more than one specific species are of interest. Recent widespread increases of various ant species in many countries have resulted in higher number of reported about serious allergic reactions to stings. Most insect-allergy related cases have been reported for species from Solenopsis , Myrmecia and Pachycondyla genera, and their stings can often result in human fatalities. In addition, stinging ants can have serious health effects on livestock, agricultural damage adversely affecting the biodiversity of the region. This review discusses the impact of important ant species on human health in the Asia-Pacific region along with the molecular immunological aspects of the identified venoms and current status of diagnostics and therapeutics. [ABSTRACT FROM AUTHOR]

Vespid phospholipase A 1 (vPLA 1 ) from the black-bellied hornet ( Vespa basalis ) catalyzes the hydrolysis of emulsified phospholipids and shows potent hemolytic activity that is responsible for its lethal effect. To investigate the mechanism of vPLA 1 towards its function such as hemolysis and emulsification, we isolated vPLA 1 from V. basalis venom and determined its crystal structure at 2.5 Å resolution. vPLA 1 belongs to the α/β hydrolase fold family. It contains a tightly packed β-sheet surrounded by ten α-helices and a Gly-X-Ser-X-Gly motif, characteristic of a serine hydrolyase active site. A bound phospholipid was modeled into the active site adjacent to the catalytic Ser-His-Asp triad indicating that Gln95 is located at hydrogen-bonding distance from the substrate's phosphate group. Moreover, a hydrophobic surface comprised by the side chains of Phe53, Phe62, Met91, Tyr99, Leu197, Ala167 and Pro169 may serve as the acyl chain-binding site. vPLA 1 shows global similarity to the N-terminal domain of human pancreatic lipase (HPL), but with some local differences. The lid domain and the β9 loop responsible for substrate selectivity in vPLA 1 are shorter than in HPL. Thus, solvent-exposed hydrophilic residues can easily accommodate the polar head groups of phospholipids, thereby accounting for the high activity level of vPLA 1 . Our result provides a potential explanation for the ability of vPLA 1 to hydrolyze phospholipids of cell membrane. [ABSTRACT FROM AUTHOR]

Loxosceles spiders are responsible for serious human envenomations worldwide. The collection of symptoms found in victims after accidents is called loxoscelism and is characterized by two clinical conditions: cutaneous loxoscelism and systemic loxocelism. The only specific treatment is serum therapy, in which an antiserum produced with Loxosceles venom is administered to the victims after spider accidents. Our aim was to improve our knowledge, regarding the immunological relationship among toxins from the most epidemiologic important species in Brazil ( Loxosceles intermedia , Loxosceles gaucho and Loxosceles laeta ). Immunoassays using spider venoms and L. intermedia recombinant toxins were performed and their cross-reactivity assessed. The biological conservation of the main Loxosceles toxins (Phospholipases-D, Astacin-like metalloproteases, Hyaluronidase, ICK-insecticide peptide and TCTP-histamine releasing factor) were investigated. An in silico analysis of the putative epitopes was performed and is discussed on the basis of the experimental results. Our data is an immunological investigation in light of biological conservation throughout the Loxosceles genus. The results bring out new insights on brown spider venom toxins for study, diagnosis and treatment of loxoscelism and putative biotechnological applications concerning immune conserved features in the toxins. [ABSTRACT FROM AUTHOR]

It was described the morphology and histological composition of the structures related to production, storage and distribution of Bracon vulgaris venom, a wasp that parasite their hosts after the inoculation of a venom which causes irreversible paralysis. Were found 22 glandular filaments, coated with secretory epithelium associated with a reservoir coated internally by a chitin layer and externally by striated muscular fibers. A valve mediates the passage of the toxin to venom duct towards the parasitoids sting. [ABSTRACT FROM AUTHOR]

Most crude venom from Polybia paulista is composed of short, linear peptides; however, only five of these peptides are structurally and functionally characterized. Therefore, the peptides in this venom were profiled using an HPLC-IT-TOF/MS and MS n system. The presence of type - d and - w ions that are generated from the fragmentation of the side chains was used to resolve I/L ambiguity. The distinction between K and Q residues was achieved through esterification of the α- and ε-amino groups in the peptide chains, followed by mass spectrometry analysis. Fourteen major peptides were detected in P . paulista venom and sequenced; all the peptides were synthesized on solid-phase and submitted to a series of bioassays. Five of them had been previously characterized, and nine were novel toxins. The novel peptides correspond to two wasp kinins, two chemotactic components, three mastoparans, and two peptides of unknown function. The seven novel peptides with identified functions appear to act synergistically with the previously known ones, constituting three well-known families of peptide toxins (wasp kinins, chemotactic peptides, and mastoparans) in the venom of social wasps. These multifunctional toxins can cause pain, oedema formation, haemolysis, chemotaxis of PMNLs, and mast cell degranulation in victims who are stung by wasps. [ABSTRACT FROM AUTHOR]

A new method is developed to investigate functions of venom components, using venom gene RNA interference knockdown in the venomous animal coupled with RNA sequencing in the envenomated host animal. The vRNAi/eRNA-Seq approach is applied to the venom calreticulin component ( v-crc ) of the parasitoid wasp Nasonia vitripennis . Parasitoids are common, venomous animals that inject venom proteins into host insects, where they modulate physiology and metabolism to produce a better food resource for the parasitoid larvae. vRNAi/eRNA-Seq indicates that v-crc acts to suppress expression of innate immune cell response, enhance expression of clotting genes in the host, and up-regulate cuticle genes. V-crc KD also results in an increased melanization reaction immediately following envenomation. We propose that v-crc inhibits innate immune response to parasitoid venom and reduces host bleeding during adult and larval parasitoid feeding. Experiments do not support the hypothesis that v-crc is required for the developmental arrest phenotype observed in envenomated hosts. We propose that an important role for some venom components is to reduce (modulate) the exaggerated effects of other venom components on target host gene expression, physiology, and survival, and term this venom mitigation. A model is developed that uses vRNAi/eRNA-Seq to quantify the contribution of individual venom components to total venom phenotypes, and to define different categories of mitigation by individual venoms on host gene expression. Mitigating functions likely contribute to the diversity of venom proteins in parasitoids and other venomous organisms. [ABSTRACT FROM AUTHOR]

Jingzhaotoxin-II (JZTX-II) is a 32-residue peptide from the Chinese tarantula Chilobrachys jingzhao venom, and preferentially inhibits the fast inactivation of the voltage-gated sodium channels (VGSCs) in rat cardiac myocytes. In the present study, we elucidated the action mechanism of JZTX-II inhibiting hNav1.5, a VGSC subtype mainly distributed in human cardiac myocytes. Among the four VGSC subtypes tested, hNav1.5 was the most sensitive to JZTX-II (EC 50 = 125 ± 4 nM). Although JZTX-II had little or no effect on steady-state inactivation of the residual currents conducted by hNav1.5, it caused a 10 mV hyperpolarized shift of activation. Moreover, JZTX-II increased the recovery rate of hNav1.5 channels, which should lead to a shorter transition from the inactivation to closed state. JZTX-II dissociated from toxin–channel complex via extreme depolarization and subsequently rebound to the channel upon repolarization. Mutagenesis analyses showed that the domain IV (DIV) voltage-sensor domain (VSD) was critical for JZTX-II binding to hNav1.5 and some mutations located in S1–S2 and S3–S4 extracellular loops of hNav1.5 DIV additively reduced the toxin sensitivity of hNav1.5. Our data identified the mechanism underlying JZTX-II inhibiting hNav1.5, similar to scorpion α-toxins, involving binding to neurotoxin receptor site 3. [ABSTRACT FROM AUTHOR]

This review highlights some of the research advances in anaphylaxis; hypersensitivity reactions to foods, drugs, and insects; and allergic skin diseases that were reported in the Journal in 2014. Studies on food allergy suggest worrisomely high rates of peanut allergy and food-induced anaphylaxis-related hospitalizations. Evidence is mounting to support the theory that environmental exposure to peanut, such as in house dust, especially with an impaired skin barrier attributed to atopic dermatitis (AD) and loss of function mutations in the filaggrin gene, is a risk factor for sensitization and allergy. Diagnostic tests are improving, with early studies suggesting the possibility of developing novel cellular tests with increased diagnostic utility. Treatment trials continue to show the promise and limitations of oral immunotherapy, and mechanistic studies are elucidating pathways that might define the degree of efficacy of this treatment. Studies have also provided insights into the prevalence and characteristics of anaphylaxis and insect venom allergy, such as suggesting that baseline platelet-activating factor acetylhydrolase activity levels are related to the severity of reactions. Advances in drug allergy include identification of HLA associations for penicillin allergy and a microRNA biomarker/mechanism for toxic epidermal necrolysis. Research identifying critical events leading to skin barrier dysfunction and the polarized immune pathways that drive AD have led to new therapeutic approaches in the prevention and management of AD. [ABSTRACT FROM AUTHOR]

We aimed to determine whether the nesting habits of ants have influenced their venom toxicity and composition. We focused on the genus Pseudomyrmex (Pseudomyrmecinae) comprising terrestrial and arboreal species, and, among the latter, plant-ants that are obligate inhabitants of myrmecophytes (i.e., plants sheltering ants in hollow structures). Contrary to our hypothesis, the venom of the ground-dwelling species, Pseudomyrmex termitarius , was as efficacious in paralyzing prey as the venoms of the arboreal and the plant-ant species, Pseudomyrmex penetrator and Pseudomyrmex gracilis . The lethal potency of P. termitarius venom was equipotent with that of P. gracilis whereas the venom of P. penetrator was less potent. The MALDI-TOF MS analysis of each HPLC fraction of the venoms showed that P. termitarius venom is composed of 87 linear peptides, while both P. gracilis and P. penetrator venoms (23 and 26 peptides, respectively) possess peptides with disulfide bonds. Furthermore, P. penetrator venom contains three hetero- and homodimeric peptides consisting of two short peptidic chains linked together by two interchain disulfide bonds. The large number of peptides in P. termitarius venom is likely related to the large diversity of potential prey plus the antibacterial peptides required for nesting in the ground. Whereas predation involves only the prey and predator, P. penetrator venom has evolved in an environment where trees, defoliating insects, browsing mammals and ants live in equilibrium, likely explaining the diversity of the peptide structures. [ABSTRACT FROM AUTHOR]

In the wasp venom apparatus, the convoluted gland is the tract of the thin secretory unit, i.e. filament, contained in the muscular reservoir. Previous transmission electron microscope investigation on Stenogastrinae disclosed that the free filaments consist of distal and proximal tracts, from/to the venom reservoir, characterized by class 3 and 2 gland patterns, respectively. This study aims to extend the ultrastructural analysis to the convoluted tract, in order to provide a thorough, subcellular representation of the venom gland in these Asian wasps. Our findings showed that the convoluted gland is a continuation of the proximal tract, with secretory cells provided with a peculiar apical invagination, the extracellular cavity, collecting their products. This compartment holds a simple end-apparatus lined by large and ramified microvilli that contribute to the processing of the secretory product. A comparison between previous and present findings reveals a noticeable regionalization of the stenogastrine venom filaments and suggests that the secretory product acquires its ultimate composition in the convoluted tract. [ABSTRACT FROM AUTHOR]

Abstract: To date, there are no allergenic extracts or components available in Brazil to diagnosis and treatment of patients with venom allergy from social wasp (Vespidae Family; Polistinae Subfamily) despite of the great number of existing species. We evaluated the immunogenic potential of the Hyal recombinant protein (Pp-Hyal-rec) which was expressed in an insoluble form in comparison with the allergenic native protein (Pp-Hyal-nat) for recognition of immunoglobulin E (IgE) in the serum of allergic patients to venom of the endemic social wasp Polybia paulista from São Paulo State, Brazil. Hyal cDNA from the venom of the social wasp P. paulista (Pp-Hyal) (GI: 302201582) was cloned into the expression vector pET-28a in Escherichia coli DE3 (BL21) cells. Solubilization and purification of Pp-Hyal-rec from inclusion bodies were performed using Ni2+ affinity chromatography (Ni-NTA-Agarose) under denaturing conditions. Both the native (Pp-Hyal-nat) and the recombinant (Pp-Hyal-rec) purified allergens were used for Western blotting to assess the levels of Pp-Hyal-IgE specific in the serum of 10 patients exclusively reactive to the venom of the social wasp P. paulista. The immune sera specifically recognized the band corresponding to the Pp-Hyal-rec protein (40 kDa) at a higher intensity than the native allergen (39 kDa). The sera recognized other proteins in P. paulista crude venom extract to a lesser extent, likely corresponding to other venom allergens such as phospholipase (34 kDa), Antigen 5 (25 kDa), and proteases. The recognition pattern of the immune sera to the Pp-Hyal-rec allergen strongly suggests that this recombinant antigen could be used for developing a diagnostic allergy test as well as for specific immunotherapy (IT). [Copyright &y& Elsevier]

Highlights: [•] RNAi was developed in an endoparasitoid wasp species, parasitoid of Drosophila. [•] The expression of a major venom protein was strongly and specifically silenced. [•] The silencing of the venom protein lasted the entire parasitoid lifetime. [ABSTRACT FROM AUTHOR]

This review highlights some of the research advances in anaphylaxis; hypersensitivity reactions to foods, drugs, and insects; and allergic skin diseases that were reported in the Journal in 2013. Studies on food allergy suggest that (1) 7.6% of the US population is affected, (2) a “healthy” early diet might prevent food allergy, (3) the skin might be an important route of sensitization, (4) allergen component testing might aid diagnosis, (5) the prognosis of milk allergy might be predictable through early testing, (6) oral or sublingual immunotherapy show promise but also have caveats, and (7) preclinical studies show promising alternative modes of immunotherapy and desensitization. Studies on eosinophilic esophagitis show a relationship to connective tissue disorders and that dietary management is an effective treatment for adults. Markers of anaphylaxis severity have been determined and might inform potential diagnostics and therapeutic targets. Insights on serum tests for drug and insect sting allergy might result in improved diagnostics. Genetic and immune-mediated defects in skin epithelial differentiation contribute to the severity of atopic dermatitis. Novel management approaches to treatment of chronic urticaria, including use of omalizumab, are being identified. [Copyright &y& Elsevier]

Highlights: [•] A LC–ESI-MS system was used to profile the peptide from P. paulista venom. [•] Surprisingly high level of intra- and inter-colonial variability was observed. [•] From 78 to 108 different peptides were observed in the mass range from 400 to 3000Da. [•] Only 36 and 44 common peptides were observed in inter- and intra-colony comparison. [ABSTRACT FROM AUTHOR]

Abstract: Despite the noxious effects inflicted by Dinoponera ant's envenomation, the information about the biological properties and composition of their venom is still very limited. Ants from the genus Dinoponera are believed to be the world's largest living ants with a body length of 3cm. Their occurrence is restricted to tropical areas of South America. In this work, we study the venom of the giant Dinoponera quadriceps ant collected in 4 different regions of Brazil. By using a combination of complementary mass spectrometric approaches, we aim at: (i) characterizing the venom composition of these ants; (ii) establishing a comparative analysis of the venom from four geographically different regions in Brazil. This approach demonstrates that ant venom is a copious source of new compounds. Several peptides were identified and selected for “de novo sequencing”. Since most of the new peptides showed similarities with antimicrobial peptides (AMPs), antimicrobial assays were performed with the purpose of evaluating their activity. In regard to the comparative study of the four regions, we observed not only major differences in the venom compositions, but also that the venoms collected in closest areas are more similar than the ones collected in distant regions. These observations seem to highlight an adaption of the ant venoms to the local environment. Concerning the biological assays, the peptides called Dq-3162 and Da-3177 showed a wide-ranging antimicrobial activity. The characterization of new AMPs with a broad spectrum of activity and different scaffolds may aid scientists to design new therapeutic agents and understand the mechanisms of those peptides to interact with microbial membranes. The results obtained betoken the biotechnological potential of ant's venom. Biological significance: For the first time this manuscript describes an extensive proteomics characterization of the D. quadriceps venom. In addition this study reports the variation in venom composition of primitive ants from 4 geographically different areas of Brazil. The results reveal the presence of ~335 compounds for each venom/area and inter-colony variations were observed. 16 new peptides were characterized and 2 of them were synthesized and biologically assayed. These findings highlight the considerable and still unexplored diversity of ant's venom which could be used as valuable research tools in different areas of knowledge. [Copyright &y& Elsevier]

Abstract: Apis mellifera venom is one of the best characterized venoms among Hymenoptera, yet relatively little is known about venom belonging to other species in the genus Apis. Melittin, one of the most important bioactive peptides, has been isolated and characterized in A. mellifera, Apis cerana, Apis dorsata and Apis florea, while apamin has been only characterized in A. mellifera and A. cerana. At present, no information is available about the sequence of A. dorsata apamin. Moreover, while the antiseptic properties of melittin and MCD peptides are well documented, the antimicrobial activity of apamin has never been tested. In the present study, we isolated and characterized apamin from the venom of the giant honeybee A. dorsata. We tested the activity of apamin against bacteria and yeasts in a microbiological assay to gain a more complete understanding of the antimicrobial competence of the medium molecular weight venom fraction. We show that A. dorsata apamin toxin has the same primary sequence as apamin in A. mellifera and A. cerana, yet with a different C-terminal amidation. We did not find any antiseptic activity of apamin against any of the tested microorganisms. We discuss the evolutionary processes connected to the ecological context of venom use that drove the generation of Apis venom complexity. [Copyright &y& Elsevier]

Highlights: [•] Venom of Nasonia vitripennis induces apoptosis in Sf21 cells. [•] Both serine and metalloproteases are cytotoxic venom compounds. [•] The activity of venom metalloproteases differs between adherent and suspension cells. [•] Serine proteases in the venom are able to induce apoptosis. [Copyright &y& Elsevier]

Abstract: One of the most potent insecticidal venom peptides described to date is Aps III from the venom of the trapdoor spider Apomastus schlingeri. Aps III is highly neurotoxic to lepidopteran crop pests, making it a promising candidate for bioinsecticide development. However, its disulfide-connectivity, three-dimensional structure, and mode of action have not been determined. Here we show that recombinant Aps III (rAps III) is an atypical knottin peptide; three of the disulfide bridges form a classical inhibitor cystine knot motif while the fourth disulfide acts as a molecular staple that restricts the flexibility of an unusually large β hairpin loop that often houses the pharmacophore in this class of toxins. We demonstrate that the irreversible paralysis induced in insects by rAps III results from a potent block of insect voltage-gated sodium channels. Channel block by rAps III is voltage-independent insofar as it occurs without significant alteration in the voltage-dependence of channel activation or steady-state inactivation. Thus, rAps III appears to be a pore blocker that plugs the outer vestibule of insect voltage-gated sodium channels. This mechanism of action contrasts strikingly with virtually all other sodium channel modulators isolated from spider venoms that act as gating modifiers by interacting with one or more of the four voltage-sensing domains of the channel. [Copyright &y& Elsevier]

Abstract: Previously, it was determined that the presence of rVPr1 (a recombinant Pimpla hypochondriaca venom protein), in the haemocoel of two lepidopteran larvae, significantly increases their susceptibility to the biological control agents (BCAs), Bacillus thuringiensis (Bt) and Beauveria bassiana (Richards and Dani, 2010; Richards et al., 2011). The current work examines the mechanism of action of rVPr1 and demonstrates that it binds to the surface of some haemocytes and disrupts the organization of the haemocyte cytoskeleton. This binding is associated with a reduction in the ability of haemocytes to extend pseudopods, and to move and form aggregates in vitro over an 18h period. Moreover, rVPr1 exerts these effects after a relatively short incubation period (1.5h) and the haemocytes do not recover their ability to form aggregates after rVPr1 has been removed. In addition, rVPr1 significantly reduces haemocyte-mediated phagocytosis of Bt and B. bassiana in vitro (p <0.05) and, following injection into the insect haemocoel, rVPr1 reduces the number of circulating haemocytes per ml of haemolymph (this being significantly different to the controls 3h after injection [p =0.05]). The finding that rVPr1 has an adverse effect on haemocyte function and number in vivo, supports the hypothesis that this wasp protein significantly increases the susceptibility of lepidopteran larvae to Bt and B. bassiana, by suppressing haemocyte-mediated immune responses in the insects which otherwise would be directed against these BCAs. [Copyright &y& Elsevier]

Abstract: Endoparasitoid wasps develop at the expense of other insects, leading to their death. Eggs deposited inside the host body induce an immune response, which results in the formation of a melanized cellular capsule around the egg. To evade or counteract this response, endoparasitoids have evolved different strategies, the most often reported being injection into the host of immunosuppressive factors, notably venom proteins, along with the egg. The analysis of venom components has been performed independently in species of different taxa, but the present picture is far from complete. Intriguingly, the question of the level of venom variability inside species has been neglected, although it may partly determine the potential for parasitoid adaptation. Here, we present a short review of our present knowledge of venom components in endoparasitoids, as well as of the only well-known example of intraspecific variability in a venom immune suppressive protein being responsible for variation in parasitoid virulence. We then present data evidencing inter-individual variation of venom protein profiles, using a gel electrophoresis approach, both in laboratory strains and field populations of a figitid and a braconid species. Whether occurrence of such variability may permit a selection of parasitoid venom components driven by the host remains to be tested, notably in the context of the production and use of biological control auxiliaries. [Copyright &y& Elsevier]

Abstract: Venoms from Hymenoptera display a wide range of functions and biological roles. These notably include manipulation of the host, capture of prey and defense against competitors and predators thanks to endocrine and immune systems disruptors, neurotoxic, cytolytic and pain-inducing venom components. Recent works indicate that many hymenopteran species, whatever their life style, have also evolved a venom with properties which enable it to regulate microbial infections, both in stinging and stung animals. In contrast to biting insects and their salivary glands, stinging Hymenoptera seem to constitute an under-exploited ecological niche for agents of vector-borne disease. Few parasitic or mutualistic microorganisms have been reported to be hosted by venom-producing organs or to be transmitted to stung animals. This may result from the presence of potent antimicrobial molecules in venoms, histological features of venom apparatuses and selective effects of venoms on immune defenses of targeted organisms. The present paper reviews for the first time the venom antimicrobial potential of solitary and social Hymenoptera in molecular, ecological, and evolutionary perspectives. [Copyright &y& Elsevier]

Abstract: As the frequent emergence of the resistant bacteria, the development of new agents with a new action mode attracts a great deal of interest. It is now widely accepted that antimicrobial peptides (AMPs) are promising alternatives to conventional antibiotics. In this study, antimicrobial peptide polybia-MPI and its analogs were synthesized and their antibacterial activity was studied. Our results revealed that polybia-MPI has potent antibacterial activity against both Gram-positive and Gram-negative bacteria. Its ability to make PI permeate into bacteria and lead to the leakage of calcein from model membrane LUVs, suggests a killing mechanism involving membrane perturbation. SEM and TEM microscopy experiments verified that the morphology of bacteria was changed greatly under the treatment of polybia-MPI. Compared with the conventional chemotherapy, polybia-MPI targets the cell membrane rather than entering into the cell to exert its antibacterial activity. Furthermore, molecular dynamics (MD) simulations were employed to investigate the mechanism of membrane perturbation. The results indicated that the α-helical conformation in the membrane is required for the exhibition of antibacterial activity and the membrane disturbance by polybia-MPI is a cooperative process. In conclusion, with the increasing resistance to conventional antibiotics, there is no doubt that polybia-MPI could offer a new strategy to defend the resistant bacteria. [Copyright &y& Elsevier]

This review highlights some of the research advances in anaphylaxis; hypersensitivity reactions to foods, drugs, and insects; and allergic skin diseases that were reported in the Journal in 2012. Studies support an increase in peanut allergy prevalence in children and exposure to the antibacterial agent triclosan and having filaggrin (FLG) loss-of-function mutations as risk factors for food sensitization. The role of specific foods in causing eosinophilic esophagitis is elucidated by several studies, and microRNA analysis is identified as a possible noninvasive disease biomarker. Studies on food allergy diagnosis emphasize the utility of component testing and the possibility of improved diagnosis through stepped approaches, epitope-binding analysis, and bioinformatics. Treatment studies of food allergy show promise for oral immunotherapy, but tolerance induction remains elusive, and additional therapies are under study. Studies on anaphylaxis suggest an important role for platelet-activating factor and its relationship to the need for prompt treatment with epinephrine. Insights on the pathophysiology and diagnosis of non–IgE-mediated drug allergy are offered, with novel data regarding the interaction of drugs with HLA molecules. Numerous studies support influenza vaccination of persons with egg allergy using modest precautions. Evidence continues to mount that there is cross-talk between skin barrier defects and immune responses in patients with atopic dermatitis. Augmentation of the skin barrier with reduction in skin inflammatory responses will likely lead to the most effective intervention in patients with this common skin disease. [ABSTRACT FROM AUTHOR]

Abstract: Toxic agents, derived from bee or hornet venoms and from fungi – melittin, mastoparan, and alamethicin are able to permeabilize biological membranes. We studied the initial steps of pore formation by these peptides in rat liver mitochondria preparations (RLM) generating transmembrane potential (ΔΨ). RLM has been used as a potassium transmembrane current (PTC) sensor. The PTC induced in RLM depends linearly on the degree of steady-state activation of RLM respiration. The concentration order of such activation by melittin in a “potassium” incubation medium containing 6mM Mg2+ was 2.01±0.15. In the case of mastoparan, the reaction order was 1.83±0.23. The first steady-state phase of activation of RLM respiration by alamethicin was not detected in “Tris” incubation medium; it appeared only after addition of KCl. The order of the reaction limiting such activation was 1.92±0.07. It is suggested that PTC in this phase is determined by the channels with the lowest degree of oligomerization formed by “dimers”. The ratio of equally active membrane concentrations of peptides obviously reflects the ratio of average lifetimes (ALT) for corresponding “dimers” (alamethicin and melittin, 38.5; mastoparan and melittin, 0.32). It is concluded that the results of this investigation may be useful for comparative testing of perspective pharmaceuticals. [Copyright &y& Elsevier]

This review highlights some of the research advances in anaphylaxis; hypersensitivity reactions to foods, drugs, and insects; and allergic skin diseases that were reported in the Journal in 2011. Food allergy appears to be increasing in prevalence and carries a strong economic burden. Risk factors can include dietary ones, such as deficiency of vitamin D and timing of complementary foods, and genetic factors, such as filaggrin loss-of-function mutations. Novel mechanisms underlying food allergy include the role of invariant natural killer T cells and influences of dietary components, such as isoflavones. Among numerous preclinical and clinical treatment studies, promising observations include the efficacy of sublingual and oral immunotherapy, a Chinese herbal remedy showing promising in vitro results, the potential immunotherapeutic effects of having children ingest foods with baked-in milk if they tolerate it, and the use of anti-IgE with or without concomitant immunotherapy. Studies of allergic skin diseases, anaphylaxis, and hypersensitivity to drugs and insect venom are elucidating cellular mechanisms, improved diagnostics, and potential targets for future treatment. The role of skin barrier abnormalities, as well as the modulatory effects of the innate and adaptive immune responses, are major areas of investigation. [ABSTRACT FROM AUTHOR]

Abstract: The honey bee colonies, with the relevant number of immature brood and adults, and stable, high levels of humidity and temperatures of their nests, result in suitable environments for the development of microorganisms including pathogens. In response, honey bees evolved several adaptations to face the increased risks of epidemic diseases. As the antimicrobial venom peptides of Apis mellifera are present both on the cuticle of adult bees and on the nest wax it has been recently suggested that these substances act as a social antiseptic device. Since the use of venom by honey bees in the context of social immunity needs to be more deeply investigated, we extended the study of this potential role of the venom to different species of the genus Apis (A. mellifera, Apis dorsata, Apis cerana and Apis andreniformis) using MALDI-TOF mass spectrometry techniques. In particular we investigated whether (similarly to A. mellifera) the venom is spread over the body cuticle and on the comb wax of these three Asian species. Our results confirm the idea that the venom functions are well beyond the classical stereotype of defence against predators, and suggest that the different nesting biology of these species may be related to the use of the venom in a social immunity context. The presence of antimicrobial peptides on the comb wax of the cavity-dwelling species and on the cuticle of workers of all the studied species represents a good example of “collective immunity” and a component of the “social immunity “ respectively. [Copyright &y& Elsevier]

Abstract: Mastoparan-B is a peptide toxin isolated from the venom of Vespa basalis, the most dangerous hornet found in Taiwan. This study is aimed to evaluate the antioxidative activities of several amino acid substitutions on MP-B, and examined the influences of mast cell degranulation and hemolytic activities in parallel with antioxidative activities. The correlations between the biological function and amino acid sequence were assessed. Our study shows original MP-B is a valuable antioxidant at low concentration in competing with nitric-oxide for oxygen molecules and possesses good antioxidative enzyme activities resembled to superoxidase dismutase and glutathione peroxidase. And there are no predominant rates of mast cell degranulation and hemolytic effects in such condition. With proper substitutions, the reducing power, DPPH scavenging activity and glutathione reductase-like enzyme activity of MP-B can increase clearly. The results demonstrate that MP-B analogs are very potential to be applicable antioxidants for other antioxidative usages. [Copyright &y& Elsevier]

Abstract: Mastoparans, a family of small peptides, are isolated from the wasp venom. In this study, six mastoparans were identified in the venom of six Vespa species in Taiwan. The precursors of these mastoparans are composed of N-terminal signal sequence, prosequence, mature mastoparan, and appendix glycine at C-terminus. These mature mastoparans all have characteristic features of linear cationic peptides rich in hydrophobic and basic amino acids without disulfide bond. Therefore, these peptides could be predicted to adopt an amphipathic α-helical secondary structure. In fact, the CD (circular dichroism) spectra of these peptides show a high content α-helical conformation in the presence of 8mM SDS or 40% 2,2,2-trifluoroethanol (TFE). All mastoparans exhibit mast cell degranulation activity, antimicrobial activity against both Gram-positive and -negative bacteria tested, various degree of hemolytic activity on chicken, human, and sheep erythrocytes as well as membrane permeabilization on Escherichia coli BL21. Our results also show that the hemolytic activity of mastoparans is correlated to mean hydrophobicity and mean hydrophobic moment. [Copyright &y& Elsevier]

Abstract: When searching for prospective novel peptides, it is difficult to determine the biological activity of a peptide based only on its sequence. The “trial and error” approach is generally laborious, expensive and time consuming due to the large number of different experimental setups required to cover a reasonable number of biological assays. To simulate a virtual model for Hymenoptera insects, 166 peptides were selected from the venoms and hemolymphs of wasps, bees and ants and applied to a mathematical model of multivariate analysis, with nine different chemometric components: GRAVY, aliphaticity index, number of disulfide bonds, total residues, net charge, pI value, Boman index, percentage of alpha helix, and flexibility prediction. Principal component analysis (PCA) with non-linear iterative projections by alternating least-squares (NIPALS) algorithm was performed, without including any information about the biological activity of the peptides. This analysis permitted the grouping of peptides in a way that strongly correlated to the biological function of the peptides. Six different groupings were observed, which seemed to correspond to the following groups: chemotactic peptides, mastoparans, tachykinins, kinins, antibiotic peptides, and a group of long peptides with one or two disulfide bonds and with biological activities that are not yet clearly defined. The partial overlap between the mastoparans group and the chemotactic peptides, tachykinins, kinins and antibiotic peptides in the PCA score plot may be used to explain the frequent reports in the literature about the multifunctionality of some of these peptides. The mathematical model used in the present investigation can be used to predict the biological activities of novel peptides in this system, and it may also be easily applied to other biological systems. [Copyright &y& Elsevier]