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Banana allergy is often associated with the pollen and latex allergies, which led us to the hypothesis that some yet unidentified banana allergen could provide a basis of the latex-pollen-fruit syndrome. S-adenosyl-L-homocysteine hydrolase (SAHH) was recently identified in the literature as a novel plant allergen. This study aimed to assess the allergenic potential of the naturally occurring banana SAHH (nSAHH) and its recombinant homolog produced in E. coli (rSAHH). nSAHH showed IgE reactivity with a serum pool of twelve banana-allergic persons, while rSAHH displayed IgE reactivity in ten out of the twelve tested patients. Five linear B-cell epitopes were identified on the rSAHH surface, exhibiting ≥ 90 % sequence homology with relevant plant SAHH allergens. Our findings have elucidated SAHH as a novel plant panallergen, underlying the cross-reactivity between plant derived food and respiratory allergens, confirming our initial hypothesis.

Supplementary Table S2: A)List of T-cell epitopes in kiwifruit SAHH. B)List of T cell epitopes in latex SAHH.C)List of T-cell epitopes in ryegrass SAHH

Food allergies mediated by specific IgE (sIgE) have a significant socioeconomic impact on society. Evaluating the IgE cross-reactivity between allergens from different allergen sources can enable the better management of these potentially life-threatening adverse reactions to food proteins and enhance food safety. A novel banana fruit allergen, S-adenosyl-L-homocysteine hydrolase (SAHH), has been recently identified and its recombinant homolog was heterologously overproduced in E. coli. In this study, we performed a search in the NCBI (National Center for Biotechnology Information) for SAHH homologs in ryegrass, latex, and kiwifruit, all of which are commonly associated with pollen-latex-fruit syndrome. In addition, Western immunoblot analysis was utilized to identify the cross-reactive IgE to banana SAHH in the sera of patients with a latex allergy, kiwifruit allergy, and ryegrass allergy. ClustalOmega analysis showed more than 92% amino acid sequence identity among the banana SAHH homologs in ryegrass, latex, and kiwifruit. In addition to five B-cell epitopes, in silico analysis predicted eleven T-cell epitopes in banana SAHH, seventeen in kiwifruit SAHH, twelve in ryegrass SAHH, and eight in latex SAHH, which were related to the seven-allele HLA reference set (HLA-DRB1*03:01, HLA-DRB1*07:01, HLA-DRB1*15:01, HLA-DRB3*01:01, HLA-DRB3*02:02, HLA-DRB4*01:01, HLA-DRB5*01:01). Four T-cell epitopes were identical in banana and kiwifruit SAHH (positions 328, 278, 142, 341), as well as banana and ryegrass SAHH (positions 278, 142, 96, and 341). All four SAHHs shared two T-cell epitopes (positions 278 and 341). In line with the high amino acid sequence identity and B-cell epitope homology among the analyzed proteins, the cross-reactive IgE to banana SAHH was detected in three of three latex-allergic patients, five of six ryegrass-allergic patients, and two of three kiwifruit-allergic patients. Although banana SAHH has only been studied in a small group of allergic individu

Allergen immunotherapy (AIT) is currently the only disease-modifying treatment forallergies. Pre-clinical models for the evaluation of novel therapeutics are crucial forensuring their efficacy and safety. While cell culture models are cost-effective andefficient, they cannot fully replicate the cellular interactions in vivo. Therefore, it isessential to use more sophisticated model systems, such as co-cultures, to assess thepotential of new therapeutics more accurately. Immunomodulatory protein banana lectin(BLwt) is an attractive candidate for adjuvant in AIT. Its mutant BLH84T was developed toreduce its potential mitogenicity. The aim of this study was the development of the coculture model system for testing the immunomodulatory effect of chimeras composed ofthe major birch pollen allergen (Bv1a) and BLwt (Bv1a-BLwt, Cwt), the hypoallergenicisoform of Bv1a (Bv1l) and BLH84T (Bv1l-BLH84T, C1 and BLH84T-Bv1l, C2). Chimericstructures were designed in silico, fully minimized, and relaxed without van der Waalsatomic clashes. Afterward, proteins were successfully expressed in Escherichia coli andpurified by IMAC yielding around 0.4 mg per 1L of expression medium. The IgE bindingcapacity was assessed using ELISA inhibition with birch pollen allergic patients’ sera.Caco-2 intestinal epithelial cells and THP-1 differentiated macrophages were used for theco-culture model system development. After protein application on the apical side of theco-culture, the integrity of the epithelial monolayer was not disturbed. Theimmunomodulatory potential of antigens was tested by measuring the gene expressionlevels for pro- and anti-inflammatory cytokines in both cell lines from co-culture. Theobtained results indicate that the best anti-inflammatory response was favored aftertreatment with Cwt. Additionally, to further confirm the immunomodulatory effect of therecombinant chimeras, PBMCs obtained from individuals allergic to birch pollen wereemployed and treated with recombinant prote

Ovalbumin (OVA) is the most abundant egg white protein. It is a globular, acidic phosphorylated glycoprotein of the serpin family with a molecular weight of 45 kDa. OVA is rich in essential amino acids and upon proteolytic digestion yields bioactive peptides (BAPs), recognized nutraceuticals with hypotensive, antimicrobial, antioxidant, and anticancer properties that contribute to the overall nutritional and health benefits of eggs. OVA is a common choice in the food, biomedical, and pharmaceutical industries due to its useful properties during food processing, capacity to form biocompatible gels, and special properties as an effective transporter for a variety of nutraceuticals and pharmaceuticals. Cellular agriculture is an innovative interdisciplinary approach that bypasses conventional animal husbandry in the production of animal proteins. OVA expressed in Trichoderma reesei (T. reesei) most closely mimics the structural and functional properties of its natural homolog and is therefore considered a sustainable alternative to chicken egg white protein powder. Egg allergy poses serious concerns for food safety and an important socioeconomic burden to the food sector and public health. OVA has been extensively studied as an important egg allergen in mice and in vitro experimental models, providing fundamental insights into the molecular mechanisms of allergy and identifying new therapeutic targets. This chapter focuses on providing a comprehensive overview of the state-of-the-art of OVA in human nutrition and the food industry. After presenting the structure underlying the functional properties of OVA, we provide a critical perspective on cellular agriculture as a non-poultry production of OVA. Additionally, the detailed nutritional and biotechnological significance of OVA is elaborated. The final part of this chapter provides a comprehensive insight into OVA as a model antigen and food allergen from a food safety perspective.

Diagnostic evaluation of specific antibodies against the SARS-CoV-2 virus is mainly based on spike (S) and nucleocapsid (N) proteins. Despite the critical functions in virus infection and contribution to the pattern of immunodominance in COVID-19, exploitation of the most abundant membrane (M) protein in the SARS-CoV-2 serology tests is minimal. This study investigated the recombinant M protein’s immunoreactivity with the sera from COVID-19 convalescents. In silico designed protein was created from the outer N-terminal part (19 aa) and internal C-terminal tail (101–222 aa) of the M protein (YP_009724393.1) and was recombinantly produced and purified. The designed M protein (16,498.74 Da, pI 8.79) revealed both IgM and IgG reactivity with serum samples from COVID-19 convalescents in Western blot. In ELISA, more than 93% (28/30) of COVID-19 sera were positive for IgM detection, and more than 96% (29/30) were positive for specific IgG detection to M protein. Based on the capacity to provoke an immune response and its strong antigenic properties, as shown here, and the fact that it is also involved in the virion entry into host cells, the M protein of the SARS-CoV-2 virus as a good antigen has the potential in diagnostic purposes and vaccine design.