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The food enzyme β‐galactosidase (β‐d‐galactoside galactohydrolase; EC 3.2.1.23) is produced with the genetically modified Bacillus licheniformis strain DSM 34099 by Kerry Group Services International, Ltd. (KGSI). The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. The production strain met the requirements for the qualified presumption of safety (QPS) approach. The food enzyme is intended to be used in two food manufacturing processes. Dietary exposure was estimated to be up to 7.263 mg total organic solids/kg body weight per day in European populations. Given the QPS status of the production strain and the absence of concerns resulting from the food enzyme manufacturing process, toxicity tests, other than an assessment of allergenicity, were considered unnecessary by the Panel. A search for the identity of the amino acid sequence of the food enzyme to known allergens was made and one match with a food allergen from kiwi fruit was found. The Panel considered that a risk of allergic reactions upon dietary exposure to this food enzyme, particularly in individuals sensitised to kiwi fruit, cannot be excluded. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use. [ABSTRACT FROM AUTHOR]

The food enzyme glucan 1,4‐α‐maltohydrolase (4‐α‐d‐glucan α‐maltohydrolase; EC 3.2.1.133) is produced with the genetically modified Saccharomyces cerevisiae strain LALL‐MA+ by Danstar Ferment AG. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used in the processing of cereals and other grains for production of baked products. Dietary exposure was estimated to be up to 0.014 mg TOS/kg body weight per day in European populations. Given the QPS status of the production strain and the absence of concerns resulting from the food enzyme manufacturing process, toxicity tests were considered unnecessary by the Panel. A search for the identity of the amino acid sequence of the food enzyme to known allergens was made and four matches were found, three with respiratory allergens and one with an allergen from mosquito (injected). The Panel considered that the risk of allergic reactions upon dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use. [ABSTRACT FROM AUTHOR]

The food enzyme oryzin (EC 3.4.21.63) is produced with the non‐genetically modified Aspergillus ochraceus strain AE‐P by Amano Enzyme Inc. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in nine food manufacturing processes. Subsequently, the applicant has requested to extend its use to one additional process, to withdraw two food processes and to revise the use levels. In this assessment, EFSA updated the safety evaluation of this food enzyme when used in a total of eight food manufacturing processes. The dietary exposure to the food enzyme‐total organic solids (TOS) was calculated to be up to 0.354 mg TOS/kg body weight (bw) per day in European populations. When combined with the no observed adverse effect level reported in the previous opinion (1862 mg TOS/kg bw per day, the highest dose tested), the Panel derived a margin of exposure of at least 5260. Based on the data provided for the previous evaluation and the revised margin of exposure in the present evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use. [ABSTRACT FROM AUTHOR]

The food enzyme α‐amylase (4‐α‐d‐glucan glucanohydrolase i.e. EC 3.2.1.1) is produced with the non‐genetically modified Cellulosimicrobium funkei strain AE‐AMT by Amano Enzyme Inc. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that the food enzyme did not give rise to safety concerns when used in seven food manufacturing processes. Subsequently, the applicant has requested to extend its use to include three additional processes. In this assessment, EFSA updated the safety evaluation of this food enzyme when used in a total of ten food manufacturing processes. As the food enzyme‐total organic solids (TOS) are removed from the final foods in one food manufacturing process, the dietary exposure to the food enzyme‐TOS was estimated only for the remaining nine processes. The dietary exposure was calculated to be up to 0.049 mg TOS/kg body weight (bw) per day in European populations. When combined with the no observed adverse effect level previously reported (230 mg TOS/kg bw per day, the highest dose tested), the Panel derived a margin of exposure of at least 4694. Based on the data provided for the previous evaluation and the revised margin of exposure in the present evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use. [ABSTRACT FROM AUTHOR]

The food enzyme pullulanase (pullulan 6‐α‐glucanohydrolase; EC 3.2.1.41) is produced with the non‐genetically modified Pullulanibacillus naganoensis strain AE‐PL by Amano Enzyme Inc. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in one food manufacturing process. Subsequently, the applicant has requested to extend its use to include seven additional processes and to revise the previous use level. In this assessment, EFSA updated the safety evaluation of this food enzyme when used in a total of eight food manufacturing processes. As the food enzyme‐total organic solids (TOS) are not carried into the final foods in two food manufacturing processes, the dietary exposure was estimated only for the remaining six processes. The dietary exposure was calculated to be up to 0.004 mg TOS/kg body weight (bw) per day in European populations. The Panel evaluated the repeated dose 90‐day oral toxicity study in rats submitted in the previous application and identified a no observed adverse effect level of 643 mg TOS/kg bw per day, the highest dose tested. When compared with the calculated dietary exposure, this resulted in a margin of exposure of at least 160,750. Based on the data provided for the previous evaluation and the revised margin of exposure in the present evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use. [ABSTRACT FROM AUTHOR]

The food enzyme triacylglycerol lipase (triacylglycerol acylhydrolase; EC 3.1.1.3) is produced with the non‐genetically modified Aspergillus luchuensis strain AE‐L by Amano Enzyme Inc. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in one food manufacturing process. Subsequently, the applicant has requested to extend its use to include four additional processes and to revise the previous use level. In this assessment, EFSA updated the safety evaluation of this food enzyme when used in a total of five food manufacturing processes. The dietary exposure to the food enzyme‐total organic solids (TOS) was calculated to be up to 0.458 mg TOS/kg body weight (bw) per day in European populations. When combined with the no observed adverse effect level previously reported (1726 mg TOS/kg bw per day, the highest dose tested), the Panel derived a revised margin of exposure of at least 3769. Based on the data provided for the previous evaluation and the revised margin of exposure in the present evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use. [ABSTRACT FROM AUTHOR]

The food enzyme triacylglycerol lipase (triacylglycerol acylhydrolase; EC 3.1.1.3) is produced with the non‐genetically modified Rhizopus arrhizus strain AE‐TL(B) by Amano Enzyme Inc. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in two food manufacturing processes. Subsequently, the applicant requested to extend its use to include four additional processes and to revise the use levels. In this assessment, EFSA updated the safety evaluation of this food enzyme when used in a total of six food manufacturing processes. As the food enzyme‐total organic solids (TOS) are removed from one food manufacturing process, the dietary exposure to the food enzyme‐TOS was estimated only for the remaining five processes. Dietary exposure was calculated to be up to 0.086 mg TOS/kg body weight (bw) per day in European populations. When combined with the no observed adverse effect level reported in the previous opinion (1960 mg TOS/kg bw per day, the highest dose tested), the Panel derived a margin of exposure of at least 22,791. Based on the data provided for the previous evaluation and the revised margin of exposure in the present evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use. [ABSTRACT FROM AUTHOR]

The food enzyme lysophospholipase (2‐lysophosphatidylcholine acylhydrolase, EC 3.1.1.5) is produced with the genetically modified Trichoderma reesei strain DP‐Nyc81 by Genencor International B.V. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used in the processing of cereals and other grains for the production of glucose syrups and other starch hydrolysates. Since residual amounts of food enzyme–total organic solids are removed during these food manufacturing processes, dietary exposure was not calculated and toxicological studies were considered unnecessary. A search for the identity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that the risk of allergic reactions upon dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use. [ABSTRACT FROM AUTHOR]

The food enzyme thermolysin (EC. 3.4.24.27) is produced with the non‐genetically modified Anoxybacillus caldiproteolyticus strain AE‐TP by Amano Enzyme Inc. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in eight food manufacturing processes. Subsequently, the applicant has requested to extend its use to one additional process, to withdraw two processes and to revise the use levels. In this assessment, EFSA updated the safety evaluation of this food enzyme for use in a total of seven food manufacturing processes. The dietary exposure to the food enzyme–total organic solids (TOS) was calculated to be up to 0.989 mg TOS/kg body weight (bw) per day in European populations. When combined with the no observed adverse effect level reported in the previous opinion (700 mg TOS/kg bw per day, the mid‐dose tested), the Panel derived a revised margin of exposure of at least 708. Based on the data provided for the previous evaluation and the revised margin of exposure in the present evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use. [ABSTRACT FROM AUTHOR]

Nitration of the major birch pollen allergen Bet v 1 alters the immune responses toward this protein, but the underlying chemical mechanisms are not yet understood. Here we address the efficiency and site-selectivity of the nitration reaction of recombinant protein samples of Bet v 1.0101 with different nitrating agents relevant for laboratory investigations (tetranitromethane, TNM), for physiological processes (peroxynitrite, ONOO(-)), and for the health effects of environmental pollutants (nitrogen dioxide and ozone, O₃/NO₂). We determined the total tyrosine nitration degrees (ND) and the NDs of individual tyrosine residues (NDY). High-performance liquid chromatography coupled to diode array detection and HPLC coupled to high-resolution mass spectrometry analysis of intact proteins, HPLC coupled to tandem mass spectrometry analysis of tryptic peptides, and amino acid analysis of hydrolyzed samples were performed. The preferred reaction sites were tyrosine residues at the following positions in the polypeptide chain: Y83 and Y81 for TNM, Y150 for ONOO(-), and Y83 and Y158 for O₃/NO₂. The tyrosine residues Y83 and Y81 are located in a hydrophobic cavity, while Y150 and Y158 are located in solvent-accessible and flexible structures of the C-terminal region. The heterogeneous reaction with O₃/NO₂ was found to be strongly dependent on the phase state of the protein. Nitration rates were about one order of magnitude higher for aqueous protein solutions (∼20% per day) than for protein filter samples (∼2% per day). Overall, our findings show that the kinetics and site-selectivity of nitration strongly depend on the nitrating agent and reaction conditions, which may also affect the biological function and adverse health effects of the nitrated protein.

Sublingual immunotherapy (SLIT) is used worldwide to treat house dust mites (HDM) allergy. Epitope specific immunotherapy with peptide vaccines is used far less, but it is of great interest in the treatment of allergic reactions, as it precludes the drawbacks of allergen extracts. The ideal peptide candidates would bind to IgG, blocking IgE-binding. To better elucidate IgE and IgG4 epitope profiles during SLIT, sequences of main allergens, Der p 1, 2, 5, 7, 10, 23 and Blo t 5, 6, 12, 13, were included in a 15-mer peptide microarray and tested against pooled sera from 10 patients pre- and post-1-year SLIT. All allergens were recognized to some extent by at least one antibody isotype and peptide diversity was higher post-1-year SLIT for both antibodies. IgE recognition diversity varied among allergens and timepoints without a clear tendency. Der p 10, a minor allergen in temperate regions, was the molecule with more IgE-peptides and might be a major allergen in populations highly exposed to helminths and cockroaches, such as Brazil. SLIT-induced IgG4 epitopes were directed against several, but not all, IgE-binding regions. We selected a set of peptides that recognized only IgG4 or were able to induce increased ratios of IgG4:IgE after one year of treatment and might be potential targets for vaccines. [ABSTRACT FROM AUTHOR]

Introduction: Considering the likely need for the development of novel effective vaccines adapted to emerging relevant CoV-2 variants, the increasing knowledge of epitope recognition profile among convalescents and afterwards vaccinated with identification of immunodominant regions may provide important information. Methods: We used an RBD peptide microarray to identify IgG and IgA binding regions in serum of 71 COVID-19 convalescents and 18 vaccinated individuals. Results: We found a set of immunodominant RBD antibody epitopes, each recognized by more than 30% of the tested cohort, that differ among the two different groups and are within conserved regions among betacoronavirus. Of those, only one peptide, P44 (S415-429), recognized by 68% of convalescents, presented IgG and IgA antibody reactivity that positively correlated with nAb titers, suggesting that this is a relevant RBD region and a potential target of IgG/ IgA neutralizing activity. Discussion: This peptide is localized within the area of contact with ACE-2 and harbors the mutation hotspot site K417 present in gamma (K417T), beta (K417N), and omicron (K417N) variants of concern. The epitope profile of vaccinated individuals differed from convalescents, with a more diverse repertoire of immunodominant peptides, recognized by more than 30% of the cohort. Noteworthy, immunodominant regions of recognition by vaccinated coincide with mutation sites at Omicron BA.1, an important variant emerging after massive vaccination. Together, our data show that immune pressure induced by dominant antibody responses may favor hotspot mutation sites and the selection of variants capable of evading humoral response. [ABSTRACT FROM AUTHOR]

Within the last decade, the application range of aptamers in biochemistry and medicine has expanded rapidly. More than just a replacement for antibodies, these intrinsically structured RNA‐ or DNA‐oligonucleotides show great potential for utilization in diagnostics, specific drug delivery, and treatment of certain medical conditions. However, what is analyzed less frequently is the process of aptamer identification known as systematic evolution of ligands by exponential enrichment (SELEX) and the functional mechanisms that lie at its core. SELEX involves numerous singular processes, each of which contributes to the success or failure of aptamer generation. In this review, critical steps during aptamer selection are discussed in‐depth, and specific problems are presented along with potential solutions. The discussed aspects include the size and molecule type of the selected target, the nature and stringency of the selection process, the amplification step with its possible PCR bias, the efficient regeneration of RNA or single‐stranded DNA, and the different sequencing procedures and screening assays currently available. Finally, useful quality control steps and their role within SELEX are presented. By understanding the mechanisms through which aptamer selection is influenced, the design of more efficient SELEX procedures leading to a higher success rate in aptamer identification is enabled. [ABSTRACT FROM AUTHOR]

Worldwide, pollen of the weed mugwort (Artemisia vulgaris) is a major cause of severe respiratory allergy, with its major allergen, Art v 1, being the key pathogenic molecule for millions of patients. Humanized mice transgenic for a human T-cell receptor specific for the major Art v 1 T-cell epitope and the corresponding HLA have been made. We sought to characterize IgE epitopes of Art v 1–sensitized patients and humanized mice for molecular immunotherapy of mugwort allergy. Four overlapping peptides incorporating surface-exposed amino acids representing the full-length Art v 1 sequence were synthesized and used to search for IgE reactivity to sequential epitopes. For indirect mapping, peptide-specific rabbit antibodies were raised to block IgE against surface-exposed epitopes on folded Art v 1. IgE reactivity and basophil activation studies were performed in clinically defined mugwort-allergic patients. Secondary structure of recombinant (r) Art v 1 and peptides was determined by circular dichroism spectroscopy. Mugwort-allergic patients and humanized mice sensitized by allergen inhalation showed IgE reactivity and/or basophil activation mainly to folded, complete Art v 1 but not to unfolded, sequential peptide epitopes. Blocking of allergic patients' IgE with peptide-specific rabbit antisera identified a hitherto unknown major conformational IgE binding site in the C-terminal Art v 1 domain. Identification of the new major conformational IgE binding site on Art v 1, which can be blocked with IgG raised against non-IgE reactive Art v 1 peptides, is an important basis for the development of a hypoallergenic peptide vaccine for mugwort allergy. [ABSTRACT FROM AUTHOR]

The progressive accumulation of misfolded α-synuclein (α-syn) in the brain is widely considered to be causal for the debilitating clinical manifestations of synucleinopathies including, most notably, Parkinson's disease (PD). Immunotherapies, both active and passive, against α-syn have been developed and are promising novel treatment strategies for such disorders. To increase the potency and specificity of PD vaccination, we created the 'Win the Skin Immune System Trick' (WISIT) vaccine platform designed to target skin-resident dendritic cells, inducing superior B and T cell responses. Of the six tested WISIT candidates, all elicited higher immune responses compared to conventional, aluminum adjuvanted peptide-carrier conjugate PD vaccines, in BALB/c mice. WISIT-induced antibodies displayed higher selectivity for α-syn aggregates than those induced by conventional vaccines. Additionally, antibodies induced by two selected candidates were shown to inhibit α-syn aggregation in a dose-dependent manner in vitro. To determine if α-syn fibril formation could also be inhibited in vivo, WISIT candidate type 1 (CW-type 1) was tested in an established synucleinopathy seeding model and demonstrated reduced propagation of synucleinopathy in vivo. Our studies provide proof-of-concept for the efficacy of the WISIT vaccine technology platform and support further preclinical and clinical development of this vaccine candidate. [ABSTRACT FROM AUTHOR]

Until recently, glycan epitopes have not been documented by the WHO/IUIS Allergen Nomenclature Sub‐Committee. This was in part due to scarce or incomplete information on these oligosaccharides, but also due to the widely held opinion that IgE to these epitopes had little or no relevance to allergic symptoms. Most IgE‐binding glycans recognized up to 2008 were considered to be "classical" cross‐reactive carbohydrate determinants (CCD) that occur in insects, some helminths and throughout the plant kingdom. Since 2008, the prevailing opinion on lack of clinical relevance of IgE‐binding glycans has been subject to a reevaluation. This was because IgE specific for the mammalian disaccharide galactose‐alpha‐1,3‐galactose (alpha‐gal) was identified as a cause of delayed anaphylaxis to mammalian meat in the United States, an observation that has been confirmed by allergists in many parts of the world. Several experimental studies have shown that oligosaccharides with one or more terminal alpha‐gal epitopes can be attached as a hapten to many different mammalian proteins or lipids. The classical CCDs also behave like haptens since they can be expressed on proteins from multiple species. This is the explanation for extensive in vitro cross‐reactivity related to CCDs. Because of these developments, the Allergen Nomenclature Sub‐Committee recently decided to include glycans as potentially allergenic epitopes in an adjunct section of its website (www.allergen.org). In this article, the features of the main glycan groups known to be involved in IgE recognition are revisited, and their characteristic structural, functional, and clinical features are discussed. [ABSTRACT FROM AUTHOR]