Allergenic Potential Research Articles

Peri-wound skin lesions of allergic nature

Peri-wound dermatoses are a fairly common occurrence in clinical practice. In general, they are all allergic in nature and occur on the skin around the surface area of both primary and postoperative wounds. Peri-wound skin lesions can develop as paratraumatic eczema, simple contact or allergic dermatitis. All these dermatoses can be complicated by a secondary bacterial or mycotic infection, both exogenous and endogenous, which significantly complicates the course of the dermatitis itself and wound healing. The patient is exposed to a fairly large number of potential allergens in the course of surgical care provided at all stages: both in the pre- and postoperative period, and during the surgical intervention. Among them may be drugs and antiseptics, surgical sutures, implants, and even latex gloves of healthcare practitioners in some cases. When it comes to potential allergens, foci of chronic infection in the patient’s body, as well as secondary wound infections should be noted as a separate matter. The presence of peri-wound dermatoses is the most common cause of delayed surgical debridement, and can also become an obstacle to surgical treatment and healing of the wound surface. In addition, pre-existing paratraumatic eczema can progress to a chronic course and contribute to the further spread of the inflammatory process. Thus, peri-wound dermatoses are a pressing interdisciplinary issue. Patients with peri-wound dermatoses require a personalized selection of combination therapy and additional consultative assistance from highly specialized doctors. Fixed-dose topical glucocorticoids combined with antibiotics and antimycotics may be the drugs of choice for patients with peri-wound eczematous process, with due account for complex pathogenetic effects and ease of use. The article describes clinical cases of dermatoses developed in surgical patients.

Allergenicity and structural properties of new Cor a 1 isoallergens from hazel identified in different plant tissues

The hazel allergen Cor a 1 is a PR-10 protein, closely related to the major birch pollen allergen Bet v 1. Hazel allergies are caused by cross-reactive IgE antibodies originally directed against Bet v 1. Despite the importance of PR-10 proteins in allergy development, their function and localization in the plant remain largely elusive. Therefore, the presence of Cor a 1 mRNA and proteins was investigated in different tissues, i.e., the female flower, immature and mature nuts, catkins, and pollen. Four yet unknown Cor a 1 isoallergens, i.e., Cor a 1.0501–1.0801, and one new Cor a 1.03 variant were discovered and characterized. Depending on the isoallergen, the occurrence and level of mRNA expression varied in different tissues, suggesting different functions. Interestingly, Cor a 1.04 previously thought to be only present in nuts, was also detected in catkins and pollen. The corresponding Cor a 1 genes were expressed in Escherichia coli. The purified proteins were analysed by CD and NMR spectroscopy. Immunoblots and ELISAs to determine their allergenic potential showed that the new proteins reacted positively with sera from patients allergic to birch, hazel and elder pollen and were recognized as novel isoallergens/variants by the WHO/IUIS Allergen Nomenclature Sub-Committee.

Shotgun proteomics and in silico analysis of potential allergens in mature seeds and sprouts of purple winged bean

Winged bean (Psophocarpus tetragonolobus (L.) DC.) is a tropical legume crop found in Southeast Asian countries including Thailand. The mature seeds have high protein content and have been targeted as a protein source, and germination has been used to increase the value of nutrition. We used nanoLC/timsTOF Pro 2 combined with PEAKS® studio Xpro software to explore the proteomes of mature seeds and sprouts of purple winged bean. This study is the first report on the allergenic proteins in mature seeds and sprouts of purple winged bean. In silico analysis using Allergen Nomenclature search and the Allermatchtm program, 37 allergens were found. Conglutin beta 5 and late embryogenesis abundant protein (3 and D-29) were identified only in mature seeds, while 4 types of major pollen allergen Bet V, profilin and isoflavone reductase, were identified only in sprouts. Examples of allergens in both samples include basic 7S globulin, beta-conglycinin alpha/beta subunit (1,2), convicilin, defensin-like protein, 7 types of non-specific lipid-transfer protein, P24 oleosin isoform B. Since food allergy and airway allergy are found in sprouts, we used shotgun proteomics and in silico analysis for detecting the profiles of allergens. With regards to food safety, purple winged beans may also induce cross-reactivity in patients who are allergic to peanuts or other legumes. Therefore, identifying the proteomes and potential allergens in mature seeds and sprouts of purple winged beans could assist researchers in studying plant-based food safety.

Investigation into potential allergenicity of DBD plasma-treated casein digestion products based on immunoglobulin E linear epitopes and the sensitized-cell model

The study aimed to investigate the allergenicity change in casein treated with dielectric barrier discharge (DBD) plasma during in vitro simulated digestion, focusing on the immunoglobulin E (IgE) linear epitopes and utilizing a sensitized-cell model. Results indicated that prior treatment with DBD plasma treatment (4 min) before simulated digestion led to a 10.5% reduction in the IgE-binding capacity of casein digestion products. Moreover, the release of biologically active substances induced from KU812 cells, including β-HEX release rate, human histamine, IL-4, IL-6, and TNF-α, decreased by 2.1, 28.1, 20.6, 11.6, and 17.3%, respectively. Through a combined analysis of LC-MS/MS and immunoinformatics tools, it was revealed that DBD plasma treatment promoted the degradation of the IgE linear epitopes of casein during digestion, particularly those located in the α-helix region of αs1-CN and αs2-CN. These findings suggest that DBD plasma treatment prior to digestion may alleviate casein allergic reactions.

The allergenic potential of green urban areas in the Macaronesian islands: The case of Funchal City (Madeira)

Public gardens are elements that constitute the urban green infrastructure. Such units provide ecosystem services that are becoming a key concern in urban planning strategies.In this survey the allergenic potential of two public gardens in Funchal, a city exhibiting sub-tropical and Mediterranean climatic features, was assessed. Different allergenic risk scenarios were considered, and the Allergenicity Indexes recalculated. Results show that the Municipal Garden exhibits an IUGZA (Index of Urban Green Zone Allergenicity) of 0,39 and Santa Catarina Park an IUGZA of 0,16, which are considered spaces of moderate and low allergenicity level, respectively. Among the tested scenarios that could aggravate the IUGZA values, the worst would be an extension of the pollen season for all species. This might represent an issue considering the overall trend towards an earlier start and later end of the pollen season from important allergenic plants in Europe. The assessment of the IUGZA should include all plant biotypes of an urban green area in subtropical regions as they allow us to infer more precisely on the real risk population is exposed to. It seems that increasing species diversity can improve the allergenic indexes, but novel invasive species should be studied to assess their allergenicity level.

Prevalence of potential contact allergens in best-selling baby cleansers.

Many baby cleansers are promoted as hypoallergic products; however, these claims are not typically validated. This study assessed the 50 best-selling baby cleansers from online retailer Amazon for potential allergens. We found that the presence of most marketing claims, including "hypoallergenic" or "allergy-tested," did not correlate with the number of potential allergens in a cleanser. Furthermore, the total number of marketing claims of a cleanser was positively correlated with the number of allergens, highlighting the discordance between marketing claims and allergen content in baby cleansers.

Analysis of unintended open reading frame ORF-130 expression in maize event MZIR098 by LC-MS as part of the allergenicity risk assessment of genetically modified crops

Rigorous safety assessments are required for genetically modified (GM) crops to support their use as food or feed. These assessments include bioinformatics analysis of the amino acid sequences of all potential open reading frames (ORFs) encoded in the exogenous DNA introduced into the plant through genetic modification. Sequence similarities of potential DNA products to known or potential toxins and allergens trigger subsequent assessments of potential hazards for the consumer or the environment. The bioinformatic analysis of Syngenta maize event MZIR098 insert DNA revealed a total of 415 ORFs. One putative ORF (ORF-130) triggered further risk assessment based on its sequence similarities with known allergens, including peanut allergen Ara h 1, wheat glutenin, and others. We examined the potential expression of ORF-130 at a protein level to exclude the possibility of exposure during consumption of MZIR098 maize. Specifically, we developed and validated a liquid chromatography approach coupled to a tandem mass spectrometry (LC-MS/MS) method, called parallel reaction monitoring (PRM). This measure of expression was quantitative and targeted against the peptides unique to ORF-130. The linear range of the method was 25-5000 amol ORF-130/µl. Both, limit of detection (LOD) and lower limit of quantitation (LLOQ) of the method, were 12 μg ORF-130 per gram of dry MZIR098 maize leaf. The method was accurate and specific to ORF-130. PRM analysis of MZIR098 extracts did not detect putative ORF-130 above the limits of detection/quantitation. Furthermore, the broad proteomic data dependent acquisition (DDA) analysis of the MZIR098 extracts demonstrated no evidence of ORF-130 corroborating the PRM analysis. Our results confirm that ORF-130 is not characterized as a functional gene in Syngenta maize event MZIR098 insert DNA and does not express gene products at detectable levels.

Botanical Impurities in the Supply Chain: A New Allergenic Risk Exacerbated by Geopolitical Challenges.

The supply chains of food raw materials have recently been heavily influenced by geopolitical events. Products that came from, or transited through, areas currently in conflict are now preferentially supplied from alternative areas. These changes may entail risks for food safety. We review the potential allergenicity of botanical impurities, specifically vegetable contaminants, with particular attention to the contamination of vegetable oils. We delve into the diverse types of botanical impurities, their sources, and the associated allergenic potential. Our analysis encompasses an evaluation of the regulatory framework governing botanical impurities in food labeling. Unintended plant-derived contaminants may manifest in raw materials during various stages of food production, processing, or storage, posing a risk of allergic reactions for individuals with established food allergies. Issues may arise from natural occurrence, cross-contamination in the supply chain, and contamination at during production. The food and food service industries are responsible for providing and preparing foods that are safe for people with food allergies: we address the challenges inherent in risk assessment of botanical impurities. The presence of botanical impurities emerges as a significant risk factor for food allergies in the 2020s. We advocate for regulatory authorities to fortify labeling requirements and develop robust risk assessment tools. These measures are necessary to enhance consumer awareness regarding the potential risks posed by these contaminants.

Alphitobius diaperinus larvae (lesser mealworm) as human food – An approval of the European Commission – A critical review

Abstract Due to the increasing threat of climate change and the need for sustainable food sources, human consumption of edible insects or entomophagy has gained considerable attention globally. The larvae of Alphitobius diaperinus Panzer (Coleoptera: Tenebrionidae), also known as the lesser mealworm, have been identified as a promising candidate for mass-rearing as a food source based the on evaluation on several aspects such as the production process, the microbiological and chemical composition, and the potential allergenicity to humans. As a consequence, the European Commission has recently approved the utilization of lesser mealworms as human foods. Lesser mealworms are considered a good source of protein, with a protein content ranging from 50-65% of their dry weight and containing various essential amino acids. Lesser mealworms are also rich in other essential nutrients such as iron, calcium, and vitamins B12 and B6. Furthermore, the hydrolysates of lesser mealworms are known to contain antioxidants, suggesting the therapeutic properties of the insects. To enable and ensure a continuous supply of lesser mealworms, various rearing procedures of the insects and information on optimal environmental rearing conditions have been reported. However, like other edible insects, lesser mealworms are still not commonly consumed in Western countries because of various consumer- and product-related factors. Ultimately, the European Commission’s approval of lesser mealworms as a novel food is a key milestone in the development of the insect food industry. Embracing the consumption of edible insects can help address the challenges of feeding a growing population, mitigate the environmental impact of food production, and promote a more sustainable and resilient food system for the future.

Cosensitization to the 3 Nonhomologous Major Cashew Allergens Ana o 1, Ana o 2, and Ana o 3 Is Caused by IgE Cross-reactivity.

Cashew nuts often cause strong allergic reactions, which are even more severe than those of peanuts. Ana o 1 (vicilin), Ana o 2 (legumin), and Ana o 3 (2S albumin) are major cashew allergens. Cosensitization to all 3 nonhomologous cashew nut allergens has been observed. We hypothesize that this might be due to IgE cross-reactivity. IgE cross-inhibitions were performed with Ana o 1-3 using serum samples from cashew nut-allergic patients. The related hazelnut allergens Cor a 11, 9, and 14 were used as controls. For comparison, IgE cross-reactivity between the hazelnut allergens was investigated using serum samples from hazelnut-allergic patients. The median percentages of cross-inhibition between Ana o 1, 2, and 3 were 84%-99%. In comparison, the median cross- inhibition values between hazelnut allergens were 33%-62%. The IC50 values revealed the highest IgE affinity to be to Ana o 3 and Cor a 14. Hazelnut legumin Cor a 9 inhibited IgE binding to Ana o 1, 2, and 3, with median percentages of 75%, 56%, and 48%, respectively. No cross-reactivity was observed between allergenic vicilins or between 2S albumins from cashew and hazelnut. Potentially cross-reactive peptides of Ana o 3 identified in silico overlapped with previously reported IgE epitopes of all 3 allergens. IgE with high affinity to Ana o 3 that cross-reacts with the other 2 major nonhomologous cashew nut allergens might be responsible for the high allergenic potency of cashew nut. These cross-reactive IgE types comprise the major fraction of specific IgE in cashew-allergic patients and might be responsible for cross-reactivity between unrelated tree nuts.

A novel IgE epitope-specific antibodies-based sandwich ELISA for sensitive measurement of immunoreactivity changes of peanut allergen Ara h 2 in processed foods.

Peanut is an important source of dietary protein for human beings, but it is also recognized as one of the eight major food allergens. Binding of IgE antibodies to specific epitopes in peanut allergens plays important roles in initiating peanut-allergic reactions, and Ara h 2 is widely considered as the most potent peanut allergen and the best predictor of peanut allergy. Therefore, Ara h 2 IgE epitopes can serve as useful biomarkers for prediction of IgE-binding variations of Ara h 2 and peanut in foods. This study aimed to develop and validate an IgE epitope-specific antibodies (IgE-EsAbs)-based sandwich ELISA (sELISA) for detection of Ara h 2 and measurement of Ara h 2 IgE-immunoreactivity changes in foods. DEAE-Sepharose Fast Flow anion-exchange chromatography combining with SDS-PAGE gel extraction were applied to purify Ara h 2 from raw peanut. Hybridoma and epitope vaccine techniques were employed to generate a monoclonal antibody against a major IgE epitope of Ara h 2 and a polyclonal antibody against 12 IgE epitopes of Ara h 2, respectively. ELISA was carried out to evaluate the target binding and specificity of the generated IgE-EsAbs. Subsequently, IgE-EsAbs-based sELISA was developed to detect Ara h 2 and its allergenic residues in food samples. The IgE-binding capacity of Ara h 2 and peanut in foods was determined by competitive ELISA. The dose-effect relationship between the Ara h 2 IgE epitope content and Ara h 2 (or peanut) IgE-binding ability was further established to validate the reliability of the developed sELISA in measuring IgE-binding variations of Ara h 2 and peanut in foods. The obtained Ara h 2 had a purity of 94.44%. Antibody characterization revealed that the IgE-EsAbs recognized the target IgE epitope(s) of Ara h 2 and exhibited high specificity. Accordingly, an IgE-EsAbs-based sELISA using these antibodies was able to detect Ara h 2 and its allergenic residues in food samples, with high sensitivity (a limit of detection of 0.98 ng/mL), accuracy (a mean bias of 0.88%), precision (relative standard deviation < 16.50%), specificity, and recovery (an average recovery of 98.28%). Moreover, the developed sELISA could predict IgE-binding variations of Ara h 2 and peanut in foods, as verified by using sera IgE derived from peanut-allergic individuals. This novel immunoassay could be a user-friendly method to monitor low level of Ara h 2 and to preliminary predict in vitro potential allergenicity of Ara h 2 and peanut in processed foods.

Fish feed composition by high-throughput sequencing analysis: Parasite risk assessment

The use of wild small fish species as feed for aquaculture has clearly an economic incentive by speeding the growth of farmed species. Since feed ingredients are sourced from wild fisheries the farmed species could contain natural contaminants which may introduce food safety concerns. In this study, we used High-Throughput Sequencing (HTS) to explore the whole DNA profile of ten dry commercial feeds commonly used by Spanish fish farming companies. The feeds were mainly made of species within the genus Sprattus, Ammodytes and Clupea, and vegetables of the genus Triticum. In the feeds, DNA sequences of parasitic nematodes of fishes (˂1 % total OTUs) were also identified. A taxonomic assignment of query sequences, using a phylogeny-based approach, estimation of pairwise nucleotide identities within and between sequence groups and haplotype network analysis, allow assign short query sequences to the species Phocanema krabbei (Anisakidae) and Hysterothylacium aduncum (Rhaphidascarididae). Both species were identified as ingredient in two and six fish feeds, respectively. This result is of highly concern regarding dietetic recommendations to sensitized patients to anisakids, considering the growing evidence on the possible allergenic potential of both genera, and the recent data on the transfer of anisakid heat-resistant allergens from fishmeal to farm and aquaculture animals.

Identification and characterization of a novel nematode pan allergen (NPA) from Wuchereria bancrofti and their potential role in human filarial tropical pulmonary eosinophilia (TPE).

Tropical pulmonary eosinophilia (TPE) is a chronic respiratory syndrome associated with Lymphatic Filariasis (LF), a tropical parasitic infection of the human, transmitted by mosquitoes. The larval form of LF (microfilariae) are trapped in the lungs of TPE subjects have a major role in initiating the TPE syndrome. To date, there are no reports on the potential allergen that is responsible for generating parasite-specific IgE in TPE. In this project, we screened a cDNA expression library of the microfilarial stages of Wuchereria bancrofti with monoclonal IgE antibodies prepared from subjects with clinical filarial infections. Our studies identified a novel molecule that showed significant sequence similarity to an allergen. A blast analysis showed the presence of similar proteins in a number of nematodes parasites. Thus, we named this molecule as Nematode Pan Allergen (NPA). Subsequent functional analysis showed that NPA is a potent allergen that can cause release of histamine from mast cells, induce secretion of proinflammatory cytokines from alveolar macrophages and promote accumulation of eosinophils in the tissue, all of which occur in TPE lungs. Based on our results, we conclude that the NPA protein secreted by the microfilariae of W. bancrofti may play a significant role in the pathology of TPE syndrome in LF infected individuals. Further studies on this molecule can help design an approach to neutralize the NPA in an attempt to reduce the pathology associated with TPE in LF infected subjects.

Accelerating the identification of the allergenic potential of plant proteins using a stacked ensemble-learning framework

ABSTRACT: Plant-allergenic proteins (PAPs) have the potential to induce allergic reactions in certain individuals. While these proteins are generally innocuous for the majority of people, they can elicit an immune response in those with particular sensitivities. Thus, screening and prioritizing the allergenic potential of plant proteins is indispensable for the development of diagnostic tools, therapeutic interventions or medications to treat allergic reactions. However, investigating the allergenic potential of plant proteins based on experimental methods is costly and labour-intensive. Therefore, we develop StackPAP, a three-layer stacking ensemble framework for accurate large-scale identification of PAPs. In StackPAP, at the first layer, we conducted a comprehensive analysis of an extensive set of feature descriptors. Subsequently, we selected and fused five potential sequence-based feature descriptors, including amphiphilic pseudo-amino acid composition, dipeptide deviation from expected mean, amino acid composition, pseudo amino acid composition and dipeptide composition. Additionally, we applied an efficient genetic algorithm (GA-SAR) to determine informative feature sets. In the second layer, 12 powerful machine learning (ML) methods, in combination with all the informative feature sets, were employed to construct a pool of base classifiers. Finally, 13 potential base classifiers were selected using the GA-SAR method and combined to develop the final meta-classifier. Our experimental results revealed the promising prediction performance of StackPAP, with an accuracy, Matthew’s correlation coefficient and AUC of 0.984, 0.969 and 0.993, respectively, as judged by the independent test dataset. In conclusion, both cross-validation and independent test results indicated the superior performance of StackPAP compared with several ML-based classifiers. To accelerate the identification of the allergenicity of plant proteins, we developed a user-friendly web server for StackPAP (https://pmlabqsar.pythonanywhere.com/StackPAP). We anticipate that StackPAP will be an efficient and useful tool for rapidly screening PAPs from a vast number of plant proteins. Communicated by Ramaswamy H. Sarma

Glycation combined with phosphorylation: Investigating the structure changes and allergenic potential of parvalbumin in silver carp (Hypophthalmichthy molitrix)

This study investigated the effects of glycation combined with phosphorylation on the structure and allergenic potential of parvalbumin (PV) in silver carp (Hypophthalmichthy molitrix). The method increased PV's molecular weight and altered its structure. In vivo, this approach significantly reduced the risk of PV allergy, with decreased serum levels of IgE, IgG, histamine, β-hexosaminidase, and interleukin-4 decreased, while interferon-γ levels increased. Spleen tissue demonstrated increased expression of transforming growth factor-β, interleukin-12, and T-bet. Although the relative abundance of allergy-associated gut microbiota (Firmicutes and Bacteroidetes) changed, the diversity and composition of the gut microbiome in mice remained similar to normal mice at the family and genus taxonomic levels. Allergic mice exhibited imbalanced gut microbiota including Firmicutes, Lactobacillaceae, Staphylococcaceae, and Lactobacillus. Norank_f__Muribaculaceae and Bacteroidetes helped alleviate the allergenic potential. Therefore, glycation combined with phosphorylation can significantly reduce the risk of PV allergy through structural changes and regulation of the gut microbiome.

A cross-sectional review of contact allergens in popular self-tanning products

Background: In recent years, self-tanners have become a well-liked alternative to sun tanning and tanning bed usage, as strikingly similar results can be achieved without the harmful side effects of ultraviolet exposure. Objective: The aim of this study is to investigate the presence and prevalence of potential allergens in the most popular self-tanning products. Methods: Five major retailers in the United States were evaluated, from which 17 different brands and 44 unique self-tanning products were analyzed. The ingredients in each self-tanning product were compared with 80 and 36 notable contact allergens taken from the North American Contact Dermatitis Group and Food and Drug Administration–approved T.R.U.E (Thin-Layer Rapid Use Epicutaneous Patch Test), respectively. Results: We found that contact allergens are frequently present in self-tanning products; allergens especially common are propylene glycol, linalool, polysorbate, d-limonene, benzyl alcohol, tocopherol (vitamin E), fragrances, and other scented botanicals. On average, each self-tanner we analyzed contained 11.86 allergens. Limitations: The limitation is that commercial names could not be eliminated from the analysis, introducing potential bias. Conclusion: While self-tanning products are a safer alternative to tanning bed use or sunbathing, consumers and clinicians alike must be aware that they may cause an allergic reaction of the skin for some users.

Trends in airborne grass pollen in Évora City (Portugal)

Aerobiology could be used as complementary data or proxy for studying phenology, especially in species which usually are not long-distance transported, such as grasses. This 21-year aerobiological study took place in Évora (South Portugal), using a seven-day recording volumetric pollen trap with the aim of analysing the temporal trends of grass pollen seasons. To this end, data were statistically tested for correlation and regression to determine the features and temporal trends of pollen seasons. Main results show that Poaceae pollen has a high representation in pollen spectrum, 20% (min: 7%; max: 44%), with a long season starting in March and lasting till August/September or October. There was an overall, but not statistically significant trend, towards an increase in the annual pollen integral and peak values, and also an overall non-statistically significant trend towards an earlier start and later end of the pollen season. Main and high pollen seasons have been lasting longer, and the days with allergenic potential have been rising in line with the local temperature rising trend. It seems that grass pollen production is being aided by warmer temperatures and increased grassland areas in Alentejo region. This could promote the increase in annual pollen levels and in the number of high pollen days over the years. In clinical terms, it means that grass allergic patients are exposed to longer periods of airborne pollen and to higher counts over a longer time. The climate conditions projected for Alentejo region, including rising temperature, and the changes in local grassland areas may help to clarify the trends of grass pollen seasons in the next decades.

Mass Spectrometry Analysis on the Breakage of Allergens in High-Molecular-Mass Polymer of Roasted Peanuts.

Peanut allergy is a prevalent and concerning food allergy. Roasting can introduce structural changes to peanut allergens, affecting their allergenicity, but the structure on the primary structure is unclear. Here, the breakage sites were identified by mass spectrometry and software tools, and structural changes were simulated by molecular dynamics and displayed by PyMOL software. Results revealed that the appearance frequencies of L, Q, F, and E were high at the N-terminal of the breakage site, while S and E were dominant at the C-terminal. In the conformational structure, breakage sites were found close to disulfide bonds and the Cupin domains of Ara h 1 and Ara h 3. The breakage of allergens destroyed linear epitopes and might change the conformation of epitopes, which could influence peanuts' potential allergenicity.

Identification and semi-quantification of protein allergens in complex mixtures using proteomic and AllerCatPro 2.0 bioinformatic analyses: a proof-of-concept investigation

The demand for botanicals and natural substances in consumer products has increased in recent years. These substances usually contain proteins and these, in turn, can pose a risk for immunoglobulin E (IgE)-mediated sensitization and allergy. However, no method has yet been accepted or validated for assessment of potential allergenic hazards in such materials. In the studies here, a dual proteomic-bioinformatic approach is proposed to evaluate holistically allergenic hazards in complex mixtures of plants, insects, or animal proteins. Twelve commercial preparations of source materials (plant products, dust mite extract, and preparations of animal dander) known to contain allergenic proteins were analyzed by label-free proteomic analyses to identify and semi-quantify proteins. These were then evaluated by bioinformatics using AllerCatPro 2.0 (https://allercatpro.bii.a-star.edu.sg/) to predict no, weak, or strong evidence for allergenicity and similarity to source-specific allergens. In total, 4,586 protein sequences were identified in the 12 source materials combined. Of these, 1,665 sequences were predicted with weak or strong evidence for allergenic potential. This first-tier approach provided top-level information about the occurrence and abundance of proteins and potential allergens. With regards to source-specific allergens, 129 allergens were identified. The sum of the relative abundance of these allergens ranged from 0.8% (lamb’s quarters) to 63% (olive pollen). It is proposed here that this dual proteomic-bioinformatic approach has the potential to provide detailed information on the presence and relative abundance of allergens, and can play an important role in identifying potential allergenic hazards in complex protein mixtures for the purposes of safety assessments.

An In silico Study on B-cell Epitope Mapping of Acinetobacter baumannii Outer Membrane Protein K.

Acinetobacter baumannii is one of the main causes of nosocomial infections. No vaccine has yet been licensed for use in humans, and efforts are still ongoing. In the present study, we have predicted the B-cell epitopes of A. baumannii's outer membrane protein K (OMPK) by using epitope prediction algorithms as possible vaccine candidates for future studies. The linear B-cell epitopes were predicted by seven different prediction tools. The 3D structure of OMPK was modeled and used for discontinuous epitope prediction by ElliPro and DiscoTope 2.0 tools. The final linear epitopes and the discontinuous epitope segments were checked for potential allergenicity, toxicity, human similarity, and experimental records. The structure and physicochemical features of the final epitopic peptide were assessed by numerous bioinformatics tools. Many B-cell epitopes were detected that could be assessed for possible antigenicity and immunogenicity. Also, an epitopic 22-mer region (peptide) of OMPK was found that contained both linear and discontinuous B-cell epitopes. This epitopic peptide has been found to possess appropriate physicochemical and structural properties to be an A. baumannii vaccine candidate. Altogether, here, the high immunogenic B-cell epitopes of OMPK have been identified, and a high immunogenic 22-mer peptide as an A. baumannii vaccine candidate has been introduced. The in vitro/in vivo studies of this peptide are recommended to decide its real efficacy and efficiency.