Identification of a vicilin-like major allergen from Prosopis juliflora exhibiting cross- reactivity with legume food allergens

Background: Panallergens are proteins that take part in key processes of organisms and, therefore, are ubiquitously distributed with highly conserved sequences and structures. One class of these panallergens is composed of the tropomyosins. The highly heat-stable tropomyosins comprise the major allergens in crustaceans and mollusks, which make them important food allergens in exposed populations. Tropomyosins are responsible for a widespread immunoglobulin E cross-reactivity among allergens from different sources. Allergic tropomyosins are expressed in many species, including parasites and insects. Methods: This panallergen class is divided, according to it capacity of induced allergic symptoms, into allergenic or nonallergenic tropomyosin. Although vertebrate tropomyosins share ∼55% of sequence homology with invertebrate tropomyosins, it has been thought that the invertebrate tropomyosins would not have allergic properties. Nevertheless, in recent years, this opinion has been changed. In particular, tropomyosin has been recognized as a major allergen in many insects. Results: A high grade of homology has been shown among tropomyosins from different species, such as crustaceans and insects, which supports the hypothesis of cross-reactivity among tropomyosins from divergent species. Moreover, the emerging habit of consuming edible insects has drawn the attention of allergists to invertebrate tropomyosin protein due to its potential allergenic risk. Nevertheless, evidence about tropomyosin involvement in clinical allergic response is still scarce and deserves more investigation. Conclusion: This review intended to report allergic reactions associated with different tropomyosins when considering house dust mites, parasites, seafood, and insects, and to summarize our current knowledge about its cross-reactivity because this could help physicians to accurately diagnose patients with food allergy.

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Novel Allergen Discovery through Comprehensive De Novo Transcriptomic Analyses of Five Shrimp Species

International Journal of Molecular Sciences ◽

10.3390/ijms22010032 ◽

2020 ◽

Vol 22 (1) ◽

pp. 32

Author(s):

Shaymaviswanathan Karnaneedi ◽

Roger Huerlimann ◽

Elecia B. Johnston ◽

Roni Nugraha ◽

Thimo Ruethers ◽

...

Keyword(s):

De Novo ◽

Penaeus Monodon ◽

Clinical Importance ◽

Major Allergen ◽

Cross Reactivity ◽

Multiple Sequence ◽

Alpha Tubulin ◽

Shrimp Species ◽

Allergen Sources ◽

Shellfish Allergy

Shellfish allergy affects 2% of the world’s population and persists for life in most patients. The diagnosis of shellfish allergy, in particular shrimp, is challenging due to the similarity of allergenic proteins from other invertebrates. Despite the clinical importance of immunological cross-reactivity among shellfish species and between allergenic invertebrates such as dust mites, the underlying molecular basis is not well understood. Here we mine the complete transcriptome of five frequently consumed shrimp species to identify and compare allergens with all known allergen sources. The transcriptomes were assembled de novo, using Trinity, from raw RNA-Seq data of the whiteleg shrimp (Litopenaeus vannamei), black tiger shrimp (Penaeus monodon), banana shrimp (Fenneropenaeus merguiensis), king shrimp (Melicertus latisulcatus), and endeavour shrimp (Metapenaeus endeavouri). BLAST searching using the two major allergen databases, WHO/IUIS Allergen Nomenclature and AllergenOnline, successfully identified all seven known crustacean allergens. The analyses revealed up to 39 unreported allergens in the different shrimp species, including heat shock protein (HSP), alpha-tubulin, chymotrypsin, cyclophilin, beta-enolase, aldolase A, and glyceraldehyde-3-phosphate dehydrogenase (G3PD). Multiple sequence alignment (Clustal Omega) demonstrated high homology with allergens from other invertebrates including mites and cockroaches. This first transcriptomic analyses of allergens in a major food source provides a valuable resource for investigating shellfish allergens, comparing invertebrate allergens and future development of improved diagnostics for food allergy.

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Immunological Cross-Reactivity of the Major Allergen from Perennial Ryegrass (Lolium perenne), Lol p I, and the Cysteine Proteinase, Bromelain

International Archives of Allergy and Immunology ◽

10.1159/000237489 ◽

1997 ◽

Vol 112 (4) ◽

pp. 412-414 ◽

Cited By ~ 18

Author(s):

Robert N. Pike ◽

Dennis Bagarozzi, Jr. ◽

James Travis

Keyword(s):

Lolium Perenne ◽

Perennial Ryegrass ◽

Cysteine Proteinase ◽

Major Allergen ◽

Cross Reactivity

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Invasive Mesquite (Prosopis juliflora), an Allergy and Health Challenge

Plants ◽

10.3390/plants9020141 ◽

2020 ◽

Vol 9 (2) ◽

pp. 141

Author(s):

M. Iftikhar Hussain ◽

Ross T. Shackleton ◽

Ali El-Keblawy ◽

María Del Mar Trigo Pérez ◽

Luís González

Keyword(s):

Health Risks ◽

Arabian Peninsula ◽

Animal Health ◽

Flowering Phenology ◽

Prosopis Juliflora ◽

Cross Reactivity ◽

Pollen Load ◽

Respiratory Problems ◽

The World ◽

Major Allergens

Mesquite (Prosopis juliflora (Sw.) DC), is an medium-sized tree (family Fabaceae, subfamily Mimosoideae), that has been intorcuded around the world. It is a noxious invasive species in Africa, Asia, and the Arabian Peninsula and a source of highly allergenic pollen in. The present article reviews the adverse allergenic effects of P. juliflora pollen on human and animal health. Several studies have diagnosed that allergenic pollens from Prosopis spp. can provoke respiratory problems. Prosopis pollen extracts have 16 allergenic components of which nine proteins were recognized as major allergens with some of them showing cross-reactivity. Clinically, understanding Prosopis pollen production, flowering seasonality, pollen load, and dispersal in the atmosphere are important to avoid allergic consequences for local inhabitants. Climate change and other pollution can also help to further facilitate allergenic issues. Furthermore, we document other human and animal health problems caused by invasive Prosopis trees. This includes flesh injuries, dental and gastric problems, and the facilitation of malaria. This review summarizes and enhances the existing knowledge about Prosopis flowering phenology, aeroallergen, and other human and animal health risks associated with this noxious plant.

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Common food allergens and cross-reactivity

Journal of Food Allergy ◽

10.2500/jfa.2020.2.200020 ◽

2020 ◽

Vol 2 (1) ◽

pp. 17-21

Author(s):

Olivia L. Francis ◽

Kathleen Y. Wang ◽

Edwin H. Kim ◽

Timothy P. Moran

Keyword(s):

Food Allergy ◽

Protein Stability ◽

Cross Reactivity ◽

Molecular Characteristics ◽

Food Allergens ◽

Tree Nuts ◽

Heat Stable ◽

Systemic Reactions ◽

Hen’S Egg ◽

Fish And Shellfish

The most clinically relevant food allergens are cow’s milk, hen’s egg, peanut, tree nuts, wheat, soy, fish, shellfish, and seeds. Heat-stable food allergens have molecular characteristics that enhance protein stability and gastrointestinal absorption and thus are more likely to cause systemic reactions on ingestion. In contrast, heat-labile food allergens lack these characteristics and do not typically elicit reactions if sufficiently altered by heat or acid. Immunologic cross-sensitization between food allergens is more common than clinical cross-reactivity. However, certain groups of food allergens, such as tree nuts, fish, and shellfish, are associated with high rates of clinical cross-reactivity. Knowing the rates of clinical cross-reactivity is important when providing guidance to patients with food allergy and families on what foods can be safely added to the diet and what foods should be avoided.

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