Comparative proteomic analysis of two wasps venom, Vespa tropica and Vespa affinis

Unwrapping the structural and functional features of antimicrobial peptides from wasp venoms

The study of wasp venoms has captured attention due to the presence of a wide variety of active compounds, revealing a diverse array of biological effects. Among these compounds, certain antimicrobial peptides (AMPs) such as mastoparans and chemotactic peptides have emerged as significant players, characterized by their unique amphipathic short linear alpha-helical structure. These peptides exhibit not only antibiotic properties but also a range of other biological activities, which are related to their ability to interact with biological membranes to varying degrees. This review article aims to provide updated insights into the structure/function relationships of AMPs derived from wasp venoms, linking this knowledge to the potential development of innovative treatments against infections.

Stings on wings: Proteotranscriptomic and biochemical profiling of the lesser banded hornet (Vespa affinis) venom

Distinct animal lineages have convergently recruited venoms as weaponry for prey capture, anti-predator defence, conspecific competition, or a combination thereof. Most studies, however, have been primarily confined to a narrow taxonomic breadth. The venoms of cone snails, snakes, spiders and scorpions remain particularly well-investigated. Much less explored are the venoms of wasps (Order: Hymenoptera) that are infamous for causing excruciating and throbbing pain, justifying their apex position on Schmidt's pain index, including some that are rated four on four. For example, the lesser banded wasp (V. affinis) is clinically important yet has only been the subject of a few studies, despite being commonly found across tropical and subtropical Asia. Stings from these wasps, especially from multiple individuals of a nest, often lead to clinically severe manifestations, including mastocytosis, myasthenia gravis, optic neuropathy, and life-threatening pathologies such as myocardial infarction and organ failure. However, their venom composition and activity remain unexplored in the Indian subcontinent. Here, we report the proteomic composition, transcriptomic profile, and biochemical and pharmacological activities of V. affinis venom from southern India. Our findings suggest that wasp venoms are rich in diverse toxins that facilitate antipredator defence. Biochemical and pharmacological assessments reveal that these toxins can exhibit significantly higher activities than their homologues in medically important snakes. Their ability to exert potent effects on diverse molecular targets makes them a treasure trove for discovering life-saving therapeutics. Fascinatingly, wasp venoms, being evolutionarily ancient, exhibit a greater degree of compositional and sequence conservation across very distant populations/species, which contrasts with the patterns of venom evolution observed in evolutionarily younger lineages, such as advanced snakes and cone snails.

Bioactive Peptides and Proteins from Wasp Venoms

Wasps, members of the order Hymenoptera, use their venom for predation and defense. Accordingly, their venoms contain various constituents acting on the circulatory, immune and nervous systems. Wasp venom possesses many allergens, enzymes, bioactive peptides, amino acids, biogenic amines, and volatile matters. In particular, some peptides show potent antimicrobial, anti-inflammatory, antitumor, and anticoagulant activity. Additionally, proteinous components from wasp venoms can cause tissue damage or allergic reactions in organisms. These bioactive peptides and proteins involved in wasp predation and defense may be potential sources of lead pharmaceutically active molecules. In this review, we focus on the advances in bioactive peptides and protein from the venom of wasps and their biological effects, as well as the allergic reactions and immunotherapy induced by the wasp venom.

Dipeptidyl peptidase IV of the Vespa velutina nigrithorax venom is recognized as a relevant allergen

BACKGROUND

Vespa velutina nigrithorax (VVN), commonly known as "the Asian yellow-legged wasp," has been one of the most significant invasive species in western Europe since 2010. Currently, VVN has become the most prevalent cause of Hymenoptera anaphylaxis in north and northwestern Spain. For this reason, it is crucial to diagnose anaphylaxis cases in the acute moment for carrying out the best available treatment as soon as possible.

OBJECTIVE

To achieve a complete understanding of the venom allergen composition that will help to develop efficient diagnostics and immunotherapy treatments based on this venom.

METHODS

In this work, autochthonous VVN venom was obtained and characterized by SDS-PAGE, isoelectric focusing, followed by a mass spectrometry analysis. In addition, the allergenic sensitization profile of patients diagnosed with allergy to VVN in the Allergology Service of Navarra University Hospital between the years 2017-2020 was studied by immunoblotting and specific IgE (ImmunoCAP).

RESULTS

Two new allergens (dipeptidyl peptidase IV and serin protease) were identified in the autochthonous VVN venom, and their identity was confirmed by LC-MS analysis. The study by ImmunoCAP using sera from 12 patients who suffered a systemic reaction after a VVN sting revealed group 5 and group 1 as predominant allergens (92% and 34%, respectively). Furthermore, the immunoblotting assay showed a recognition of the dipeptidyl peptidase IV (50%) by the sera of these patients.

CONCLUSION

A serin protease and the dipeptidyl peptidase IV are components of the VVN venom, and this last one is an allergen recognized in the studied population.

In Silico and In Vitro Structure-Activity Relationship of Mastoparan and Its Analogs

Antimicrobial peptides are an important class of therapeutic agent used against a wide range of pathogens such as Gram-negative and Gram-positive bacteria, fungi, and viruses. Mastoparan (MpVT) is an α-helix and amphipathic tetradecapeptide obtained from Vespa tropica venom. This peptide exhibits antibacterial activity. In this work, we investigate the effect of amino acid substitutions and deletion of the first three C-terminal residues on the structure–activity relationship. In this in silico study, the predicted structure of MpVT and its analog have characteristic features of linear cationic peptides rich in hydrophobic and basic amino acids without disulfide bonds. The secondary structure and the biological activity of six designed analogs are studied. The biological activity assays show that the substitution of phenylalanine (MpVT1) results in a higher antibacterial activity than that of MpVT without increasing toxicity. The analogs with the first three deleted C-terminal residues showed decreased antibacterial and hemolytic activity. The CD (circular dichroism) spectra of these peptides show a high content α-helical conformation in the presence of 40% 2,2,2-trifluoroethanol (TFE). In conclusion, the first three C-terminal deletions reduced the length of the α-helix, explaining the decreased biological activity. MpVTs show that the hemolytic activity of mastoparan is correlated to mean hydrophobicity and mean hydrophobic moment. The position and spatial arrangement of specific hydrophobic residues on the non-polar face of α-helical AMPs may be crucial for the interaction of AMPs with cell membranes.

Characterization of the Composition and Biological Activity of the Venom from Vespa bicolor Fabricius, a Wasp from South China

We analyzed, for the first time, the major components and biological properties of the venom of Vespa bicolor, a wasp from South China. Using HPLC and SDS-PAGE, combined with LC–MS/MS, MALDI-TOF-MS, and NMR data to analyze V. bicolor venom (VBV), we found that VBV contains three proteins (hyaluronidase A, phospholipase A1 (two isoforms), and antigen 5 protein) with allergenic activity, two unreported proteins (proteins 5 and 6), and two active substances with large quantities (mastoparan-like peptide 12a (Vb-MLP 12a), and 5-hydroxytryptamine (5-HT)). In addition, the antimicrobial activity of VBV was determined, and results showed that it had a significant effect against anaerobic bacteria. The minimum inhibitory concentration and minimum bactericidal concentration for Propionibacterium acnes were 12.5 µg/mL. Unsurprisingly, VBV had strong antioxidant activity because of the abundance of 5-HT. Contrary to other Vespa venom, VBV showed significant anti-inflammatory activity, even at low concentrations (1 µg/mL), and we found that Vb-MLP 12a showed pro-inflammatory activity by promoting the proliferation of RAW 264.7 cells. Cytotoxicity studies showed that VBV had similar antiproliferative effects against all tested tumor cell lines (HepG2, Hela, MCF-7, A549, and SASJ-1), with HepG2 being the most susceptible. Overall, this study on VBV has high clinical importance and promotes the development of Vespa bicolor resources.

Clinical effects and factors associated with adverse clinical outcomes of hymenopteran stings treated in a Thai Poison Centre: a retrospective cross-sectional study

OBJECTIVE

To describe clinical effects and outcomes of hymenopteran stings and to explore the non-laboratory factors associated with adverse clinical outcomes, a composite outcome including death, respiratory failure requiring intubation, acute kidney injury (AKI) requiring dialysis and hypotension requiring vasopressor use.

METHODS

A retrospective cross-sectional study was performed at the Ramathibodi Poison Center, a poison centre of a tertiary care hospital in Thailand. All cases of hymenopteran sting consultations from January 2015 to June 2019 were consecutively enrolled, and charts were reviewed. Demographics, initial clinical characteristics and outcomes were collected. Factors associated with adverse clinical outcome were explored.

RESULTS

One hundred and fourteen hymenopteran stings cases (wasp 48%, bee 33%, hornet 14% and carpenter bee 8.8%) were included (median age, 36.5 years (interquartile range 9-55); male 63%). The prevalence of adverse clinical outcomes was 12.3% (95%CI 6.88-12.8). At initial presentation, 100% of cases had local skin reactions, 11.4% were clinical anaphylaxis, and 8% had red urine. Adverse clinical outcomes included death (n = 10), respiratory failure requiring intubation (n = 9), AKI requiring dialysis (n = 6) and hypotension requiring vasopressor use (n = 2). None of the patients with carpenter bee or hornet stings developed adverse clinical outcomes. In univariable analysis, urticaria, wheezing, red urine, wasp sting and sting number > 10 were significantly associated with adverse clinical outcomes. In multivariable analysis, red urine (adjusted OR 11.1 (95% CI 1.57-216)), wheezing (adjusted OR 16.7 (95% CI 1.43-402)) and a number of stings > 10 (adjusted OR 21.5 (95% CI2.13-2557)) were significant.

CONCLUSIONS

Adverse clinical outcomes in hymenopteran stings were not uncommon among cases inquiring to a national Thai poison centre. At initial presentation, red urine, wheezing and a number stings >10 were significantly associated with adverse clinical outcomes. Larger epidemiologic studies are required to confirm these associations.

A Role of Newly Found Auxiliary Site in Phospholipase A1 from Thai Banded Tiger Wasp (Vespa affinis) in Its Enzymatic Enhancement: In Silico Homology Modeling and Molecular Dynamics Insights

Phospholipase A₁ from Thai banded tiger wasp (Vespa affinis) venom also known as Ves a 1 plays an essential role in fatal vespid allergy. Ves a 1 becomes an important therapeutic target for toxin remedy. However, established Ves a 1 structure or a mechanism of Ves a 1 function were not well documented. This circumstance has prevented efficient design of a potential phospholipase A₁ inhibitor. In our study, we successfully recruited homology modeling and molecular dynamic (MD) simulation to model Ves a 1 three-dimensional structure. The Ves a 1 structure along with dynamic behaviors were visualized and explained. In addition, we performed molecular docking of Ves a 1 with 1,2-Dimyristoyl-sn-glycero-3-phosphorylcholine (DMPC) lipid to assess a possible lipid binding site. Interestingly, molecular docking predicted another lipid binding region apart from its corresponding catalytic site, suggesting an auxiliary role of the alternative site at the Ves a 1 surface. The new molecular mechanism related to the surface lipid binding site (auxiliary site) provided better understanding of how phospholipase A₁ structure facilitates its enzymatic function. This auxiliary site, conserved among Hymenoptera species as well as some mammalian lipases, could be a guide for interaction-based design of a novel phospholipase A₁ inhibitor.

Diversity of compounds in Vespa spp. venom and the epidemiology of its sting: a global appraisal

Poisonous animals imply a risk to human life, because their venom is a complex mixture of low molecular weight components, peptides and proteins. Hornets use the venom for self-defence, to repel intruders and to capture prey, but they can cause poisoning and allergic reactions to people. In particular, they seem to be a health problem in the countries where they are native due to their sting, which in the most severe cases can lead to severe or fatal systemic anaphylaxis. But this situation is being an emerging problem for new countries and continents because hornet incursions are increasing in the global change scenario, such as in Europe and America. Furthermore, 55 detailed cases of hornet sting were found in 27 papers during the current review where 36.4% died due to, mainly, a multi-organ failure, where renal failure and liver dysfunction were the most common complications. Moreover, the great taxonomic, ecological diversity, geographical distribution and the wide spectrum of pathophysiological symptoms of hornets have been the focus of new research. Considering this, the present systematic review summarizes the current knowledge about the components of Vespa venom and the epidemiology of its sting to serve as reference for the new research focused on the development of techniques for diagnosis, new drugs and treatments of its sting.

Heterologous expression and mutagenesis of recombinant Vespa affinis hyaluronidase protein (rVesA2)

Background

Crude venom of the banded tiger waspVespa affinis contains a variety of enzymes including hyaluronidases, commonly known as spreading factors.

Methods

The cDNA cloning, sequence analysis and structural modelling of V. affinis venom hyaluronidase (VesA2) were herein described. Moreover, heterologous expression and mutagenesis of rVesA2 were performed.

Results

V. affinis venom hyaluronidase full sequence is composed of 331 amino acids, with four predicted N-glycosylation sites. It was classified into the glycoside hydrolase family 56. The homology modelling exhibited a central core (α/β)₇ composed of Asp107 and Glu109, acting as the catalytic residues. The recombinant protein was successfully expressed in E. coli with hyaluronidase activity. A recombinant mutant type with the double point mutation, Asp107Asn and Glu109Gln, completely lost this activity. The hyaluronidase from crude venom exhibited activity from pH 2 to 7. The recombinant wild type showed its maximal activity at pH 2 but decreased rapidly to nearly zero at pH 3 and was completely lost at pH 4.

Conclusion

The recombinant wild-type protein showed its maximal activity at pH 2, more acidic pH than that found in the crude venom. The glycosylation was predicted to be responsible for the pH optimum and thermal stability of the enzymes activity.

Diagnosis of Vespa affinis venom allergy: use of immunochemical methods and a passive basophil activation test

Background

Allergy to Vespa affinis venom is common in the Asia Pacific region. Venom preparations for diagnosis are not commercially available for this species.

Methods

The prominent allergens in V. affinis venom were identifiedusing immunochemical methods. Use of ImmunoCAP of Vespula vulgaris crude venom/its components and a passive basophil activation test (BAT) in the diagnosis of patients who had anaphylaxis to V. affinis venom (n = 30) were also accessed. The IgE double-positivity rates (positive to both hornet and honeybee) in ImmunoCAP and the passive BAT were determined.

Results

High IgE reactivity was seen with the five allergens in V. affinis venom; 96% (29/30) for 34 and 24 kDa, 93% (28/30) for 45 kDa and 90% (27/30) reactivity for the 100 and 80 kDa respectively. IgE cross-reactivity was low with ImmunoCAP using V. vulgaris venom (43%; 13/30) and Ves v1 (3%; 1/30), but relatively high with Ves v5 (73%; 22/30). All patients (100%) were positive to V. affinis venom in passive BAT. In ImmunoCAP, a high double-positivity rate (76%; 23/30) was detected while no double-positivity was detected in passive BAT.

Conclusions

High IgE reactivity for five allergens of V. affinis points to the potential of using these allergens in component resolved diagnosis (CRD). The passive BAT has shown its importance as a promising diagnostic tool with high accuracy. It would be particularly useful in cases with doubtful double-positive results of other diagnostic tests.

Venom characterization of the bark scorpion Centruroides edwardsii (Gervais 1843): Composition, biochemical activities and in vivo toxicity for potential prey

In this study, we characterize the venom of Centruroides edwardsii, one of the most abundant scorpions in urban and rural areas of Costa Rica, in terms of its biochemical constituents and their biological activities. C. edwardsii venom is rich in peptides but also contains some higher molecular weight protein components. No phospholipase A₂, hemolytic or fibrinogenolytic activities were found, but the presence of proteolytic and hyaluronidase enzymes was evidenced by zymography. Venom proteomic analysis indicates the presence of a hyaluronidase, several cysteine-rich secretory proteins, metalloproteinases and a peptidylglycine α-hydroxylating monooxygenase like-enzyme. It also includes peptides similar to the K⁺-channel blocker margatoxin, a dominant toxin in the venom of the related scorpion C. margaritatus. MS and N-terminal sequencing analysis also reveals the presence of Na⁺-channel-modulating peptides with sequence similarity to orthologs present in other scorpion species of the genera Centruroides and Tityus. We purified the hyaluronidase (which co-eluted with an allergen 5-like CRiSP) and sequenced ~60% of this enzyme. We also sequenced some venom gland transcripts that include other cysteine-containing peptides and a Non-Disulfide Bridged Peptide (NDBP). Our in vivo experiments characterizing the effects on potential predators and prey show that C. edwardsii venom induces paralysis in several species of arthropods and geckos; crickets being the most sensitive and cockroaches and scorpions the most resistant organisms tested. Envenomation signs were also observed in mice, but no lethality was reached by intraperitoneal administration of this venom up to 120 μg/g body weight.

Salivary and serum cystatin SA levels in patients with type 2 diabetes mellitus or diabetic nephropathy

OBJECTIVE

To investigate putative salivary biomarkers for screening and diagnosis of type 2 diabetes mellitus and diabetic nephropathy.

DESIGN

Saliva and serum samples were collected from 29 patients with type 2 diabetes, 20 patients with diabetic nephropathy, eight patients with non-diabetic induced nephropathy, and 25 healthy subjects. Initially, pooled unstimulated saliva samples from six sex- and age-matched healthy subjects and six patients with type 2 diabetes were subjected to two-dimensional gel electrophoresis, followed by mass spectrometry. Protein expression of cystatin SA in the saliva of patients with type 2 diabetes was further examined in saliva and serum using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Two-dimensional gel electrophoresis revealed upregulation of salivary cystatin SA in patients with type 2 diabetes. ELISA showed a weak trend of increasing salivary cystatin SA levels in patients with type 2 diabetes, compared with those levels in healthy subjects. When patients were stratified according to periodontal status, linear regression analyses revealed that salivary cystatin SA levels were associated with Periodontal Screening and Recording (PSR) index (β = 0.297, p <  0.05) when the analysis was adjusted for age, sex, HbA_1C, estimated glomerular filtration rate (eGFR), and number of teeth. Serum cystatin SA levels were negatively associated with eGFR (β = -0.534, p <  0.0001) when the analysis was adjusted for age, sex, HbA_1C, number of teeth, and PSR index.

CONCLUSIONS

Salivary cystatin SA was associated with periodontal disease severity; moreover, serum cystatin SA levels could reflect kidney function.

Buzz Kill: Function and Proteomic Composition of Venom from the Giant Assassin Fly Dolopus genitalis (Diptera: Asilidae)

Assassin flies (Diptera: Asilidae) inject paralysing venom into insect prey during hunting, but their venoms are poorly characterised in comparison to those produced by spiders, scorpions, or hymenopteran insects. Here we investigated the composition of the venom of the giant Australian assassin fly Dolopus genitalis using a combination of insect microinjection assays, calcium imaging assays of mammalian sensory neurons, proteomics and transcriptomics. Injection of venom into blowflies (Lucilia cuprina) produced rapid contractile paralysis (PD₅₀ at 1 min = 3.1 μg per fly) followed by death, and also caused immediate activation of mouse dorsal root ganglion neurons (at 50 ng/μL). These results are consistent with venom use for both prey capture and predator deterrence. Paragon searches of tandem mass spectra of venom against a translated thoracic gland RNA-Seq database identified 122 polypeptides present in the venom, including six linear and 21 disulfide-rich peptides. Some of these disulfide-rich peptides display sequence homology to peptide families independently recruited into other animal venoms, including inhibitor cystine knots, cystine-stabilised α/β defensins, Kazal peptides, and von Willebrand factors. Numerous enzymes are present in the venom, including 35 proteases of the S1 family, proteases of the S10, C1A, M12A, M14, and M17 families, and phosphatase, amylase, hydrolase, nuclease, and dehydrogenase-like proteins. These results highlight convergent molecular evolution between the assassin flies and other venomous animals, as well as the unique and rich molecular composition of assassin fly venom.

Putative salivary protein biomarkers for the diagnosis of oral lichen planus: a case-control study

BACKGROUND

Salivary protein biomarkers for screening and diagnosis of oral lichen planus (OLP) are not well-defined. The objective of this study was to identify putative protein biomarkers for OLP using proteomic approaches.

METHODS

Pooled unstimulated whole saliva was collected from five OLP patients and five healthy control participants. Saliva samples were then subjected to two-dimensional gel electrophoresis, followed by mass spectrometry to identify putative protein biomarkers. Subsequently, a subset of these putative biomarkers were validated in 24 OLP patients and 24 age-matched healthy control subjects, using an enzyme-linked immunosorbent assay (ELISA). Immunoblotting analyses were then performed in 3 pairs of age- and sex-matched OLP patients and healthy controls to confirm results from the ELISA study.

RESULTS

Thirty-one protein spots were identified, corresponding to 20 unique proteins. Notably, fibrinogen fragment D and complement component C3c exhibited increased expression in OLP patients, while cystatin SA exhibited decreased expression in OLP patients, compared with healthy control subjects. ELISA analyses indicated increased expression of fibrinogen fragment D and complement component C3c, and decreased expression of cystatin SA, in the saliva of OLP patients. Statistical differences in the expression of salivary complement C3c were observed between OLP patients and healthy control subjects. Immunoblotting analyses confirmed the results of our ELISA study.

CONCLUSION

Complement C3c, fibrinogen fragment D and cystatin SA may serve as salivary biomarkers for screening and/or diagnosis of OLP.

Cloning, structural modelling and characterization of VesT2s, a wasp venom hyaluronidase (HAase) from Vespa tropica

Background

Wasp venom is a complex mixture containing proteins, enzymes and small molecules, including some of the most dangerous allergens. The greater banded wasp (Vespa tropica) is well-known for its lethal venom, whose one of the major components is a hyaluronidase (HAase). It is believed that the high protein proportion and activity of this enzyme is responsible for the venom potency.

Methods

In the present study, cDNA cloning, sequencing and 3D-structure of Vespa tropica venom HAase were described. Anti-native HAase antibody was used for neutralization assay.

Results

Two isoforms, VesT2a and VesT2b, were classified as members of the glycosidase hydrolase 56 family with high similarity (42–97 %) to the allergen venom HAase. VesT2a gene contained 1486 nucleotide residues encoding 357 amino acids whereas the VesT2b isoform consisted of 1411 residues encoding 356 amino acids. The mature VesT2a and VesT2b are similar in mass and pI after prediction. They are 39119.73 Da/pI 8.91 and 39571.5 Da/pI 9.38, respectively. Two catalytic residues in VesT2a, Asp107 and Glu109 were substituted in VesT2b by Asn, thus impeding enzymatic activity. The 3D-structure of the VesT2s isoform consisted of a central core (α/β)₇ barrel and two disulfide bridges. The five putative glycosylation sites (Asn79, Asn99, Asn127, Asn187 and Asn325) of VesT2a and the three glycosylation sites (Asn1, Asn66 and Asn81) in VesT2b were predicted. An allergenic property significantly depends on the number of putative N-glycosylation sites. The anti-native HAase serum specifically recognized to venom HAase was able to neutralize toxicity of V. tropica venom. The ratio of venom antiserum was 1:12.

Conclusions

The wasp venom allergy is known to cause life-threatening and fatal IgE-mediated anaphylactic reactions in allergic individuals. Structural analysis was a helpful tool for prediction of allergenic properties including their cross reactivity among the vespid HAase.