Structural and allergenic properties of the fatty acid binding protein from shrimp Litopenaeus vannamei.

Abstract

BACKGROUND:

The shrimp Litopenaeus vannamei is an important source of food allergens but its allergenic repertoire is poorly characterized. Cross-reactivity between crustacean and mites has been reported, with tropomyosin, the most relevant allergen involved. The aim of this study was to investigate the structural and immunological properties of a recombinant Fatty Acid Binding Protein (FABP) family from L. vannamei (LvFABP).

METHODS:

ELISA, skin prick test (SPT) and basophil activation assays were performed to determine IgE reactivity and allergenic activity of LvFABP. LC-MS/MS and Circular Dichroism experiments were done for structural analysis. B-cell epitope mapping with overlapping peptides, and cross-inhibition studies using human sera were done to identify antigenic regions and cross-reactivity.

RESULTS:

The recombinant LvFABP bound serum IgE from 27% of 36 shrimp allergic patients and showed allergenic activity when tested for basophil activation and SPT in a selected number of them. CD-spectroscopy of LvFABP revealed that the protein is folded with a secondary structure composed of mainly β-strands and a smaller fraction of α helices. This is consistent with molecular modelling results, which exhibit a typical β barrel fold with two α-helices and ten β-strands. Epitope mapping identified two IgE-binding antigenic regions and inhibition assays found high cross-reactivity between LvFABP and Blo t 13, mediated by the antigenic region involving amino acids 54 to 72.

CONCLUSIONS:

Our results show that LvFABP is a shrimp allergen that cross reacts with the house dust mite allergen Blo t 13 and has allergenic activity, which suggest that it could be clinically relevant in case of shellfish allergy. This new allergen, named Lit v 13, will also help to understand basic mechanisms of sensitization to shrimp.

• Authors: Marlon Múnera, Dalgys Martínez, Judith Wortmann, Josefina Zakzuk, Walter Keller, Luis Caraballo, Leonardo Puerta
• Journal: Allergy (Allergy) Vol. 77 Issue 5 Pg. 1534-1544 (05 2022) ISSN: 1398-9995 [Electronic] Denmark
• PMID: 34695231 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2021 European Academy of Allergy and Clinical Immunology and John Wiley & Sons Ltd.

Chemical References

• Allergens
• Fatty Acid-Binding Proteins
• Immunoglobulin E

Topics

• Allergens
• Animals
• Chromatography, Liquid
• Cross Reactions
• Fatty Acid-Binding Proteins
• Food Hypersensitivity (diagnosis)
• Humans
• Immunoglobulin E
• Penaeidae
• Tandem Mass Spectrometry