Protocol for simultaneous isolation of three important banana allergens

Identification of S-adenosyl-l-homocysteine hydrolase from banana fruit as a novel plant panallergen

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.

Comprehensive Review on Banana Fruit Allergy: Pathogenesis, Diagnosis, Management, and Potential Modification of Allergens through Food Processing

The pulp of the banana fruit is rich in bioactive compounds like dietary fibers, low glycemic carbohydrates, natural sugars, vitamins, minerals and antioxidants. These beneficial compounds are responsible for the proper functioning of immune system and enhance prevention against various deadly diseases like cancer, diabetes and heart diseases. Despite having, positive effects, the fruit are recognized as an important source for causing allergy to 0.6% of people in general population and up to 67 and 46% for people with asthma or atopic dermatitis. Fruit allergy is one of the most common food allergies witnessed worldwide. Banana fruit allergy results from the abnormal immune response to the banana proteins soon after its consumption. Symptoms range from oral allergy syndrome (OAS) to the life-threatening anaphylaxis. IgE reactivity of banana is associated with different proteins of which six proteins have been identified as major allergens, viz., Mus a1 (Profilin-actin binding protein), Mus a 2 (Class 1 chitinase), Mus a 3 (Nonspecific lipid transfer protein), Mus a 4 (Thaumatin like protein), Mus a 5 (Beta 1,3 glucanase) and Mus a 6 (Ascorbate peroxidase). This review focuses on pathogenesis, clinical features, diagnosis, and different food processing methods to mitigate the allergenicity of banana fruit.

Are Dietary Lectins Relevant Allergens in Plant Food Allergy?

Lectins or carbohydrate-binding proteins are widely distributed in seeds and vegetative parts of edible plant species. A few lectins from different fruits and vegetables have been identified as potential food allergens, including wheat agglutinin, hevein (Hev b 6.02) from the rubber tree and chitinases containing a hevein domain from different fruits and vegetables. However, other well-known lectins from legumes have been demonstrated to behave as potential food allergens taking into account their ability to specifically bind IgE from allergic patients, trigger the degranulation of sensitized basophils, and to elicit interleukin secretion in sensitized people. These allergens include members from the different families of higher plant lectins, including legume lectins, type II ribosome-inactivating proteins (RIP-II), wheat germ agglutinin (WGA), jacalin-related lectins, GNA (Galanthus nivalis agglutinin)-like lectins, and Nictaba-related lectins. Most of these potentially active lectin allergens belong to the group of seed storage proteins (legume lectins), pathogenesis-related protein family PR-3 comprising hevein and class I, II, IV, V, VI, and VII chitinases containing a hevein domain, and type II ribosome-inactivating proteins containing a ricin B-chain domain (RIP-II). In the present review, we present an exhaustive survey of both the structural organization and structural features responsible for the allergenic potency of lectins, with special reference to lectins from dietary plant species/tissues consumed in Western countries.

Pomegranate chitinase III: Identification of a new allergen and analysis of sensitization patterns to chitinases

Allergy to pomegranate is often associated with severe symptoms. Two allergens have previously been described: 9k-LTP Pun g 1 and pommaclein Pun g 7. This study describes the isolation of a chitinase III, identified by direct protein sequencing and mass spectrometry. It is a 29-kDa protein showing 69% sequence identity with the latex hevamine and IgE binding in dot blotting, immunoblotting and FABER^®test. Chitinase-specific IgE were detected in 69 of 357 patients sensitized to one or more pomegranate allergenic preparations present on the FABER^®test. Using this test, 19.2% of the patients sensitized to kiwifruit chitinase IV were also sensitized to pomegranate chitinase III, rather than to latex chitinase I (7.2%) with which it shares the N-terminal hevein-like domain. In conclusion, a new allergen has been identified, contributing to improving food allergy diagnosis. This study reveals the important role of chitinases III and IV as allergy sensitizers and prompts further investigations.

Bioanalytical methods for food allergy diagnosis, allergen detection and new allergen discovery

For effective monitoring and prevention of the food allergy, one of the emerging health problems nowadays, existing diagnostic procedures and allergen detection techniques are constantly improved. Meanwhile, new methods are also developed, and more and more putative allergens are discovered. This review describes traditional methods and summarizes recent advances in the fast evolving field of the in vitro food allergy diagnosis, allergen detection in food products and discovery of the new allergenic molecules. A special attention is paid to the new diagnostic methods under laboratory development like various immuno- and aptamer-based assays, including immunoaffinity capillary electrophoresis. The latter technique shows the importance of MS application not only for the allergen detection but also for the allergy diagnosis.