Molecular Basis of IgE-Mediated Shrimp Allergy and Heat Desensitization

Abstract

Crustacean allergy, especially to shrimp, is the most predominant cause of seafood allergy. However, due to the high flexibility of immunoglobulin E (IgE), its three-dimensional structure remains unsolved, and the molecular mechanism of shrimp allergen recognition is unknown. Here a chimeric IgE was built in silico, and its variable region in the light chain was replaced with sequences derived from shrimp tropomyosin (TM)-allergic patients. A variety of allergenic peptides from the Chinese shrimp TM were built, treated with heating, and subjected to IgE binding in silico. Amino acid analysis shows that the amino acid residue conservation in shrimp TM contributes to eliciting an IgE-mediated immune response. In the shrimp-allergic IgE, Glu98 in the light chain and other critical residues that recognize allergens from shrimp are implicated in the molecular basis of IgE-mediated shrimp allergy. Heat treatment could alter the conformations of TM allergenic peptides, impact their intramolecular hydrogen bonding, and subsequently decrease the binding between these peptides and IgE. We found Glu98 as the characteristic amino acid residue in the light chain of IgE to recognize general shrimp-allergic sequences, and heat-induced conformational change generally desensitizes shrimp allergens.

Study on the Sensitization and Antigenic Epitopes of Tropomyosin from Antarctic Krill (Euphausia superba)

“…The physiological state of TM is a highly stable, α-helical coiled-coil homo-dimeric protein, which endows TM heat resistance and retains its allergenicity . The impact of heat treatment on the IgE reactivity of crustacean TM to allergic patients has been discussed previously. − Heat treatment below 100 °C could not reduce the IgE reactivity of AkTM, but higher temperatures (about 100 °C) did cause a reduction of IgE-binding activity (Figure S1), which is similar to the thermal stabilities of TIM and FLN c studied in Procambarus clarkii. Heat treatment could alter the conformational epitopes of TM, impact their intramolecular hydrogen bonding, and subsequently decrease the binding capacity between TM and IgE .…”

“…The impact of heat treatment on the IgE reactivity of crustacean TM to allergic patients has been discussed previously. − Heat treatment below 100 °C could not reduce the IgE reactivity of AkTM, but higher temperatures (about 100 °C) did cause a reduction of IgE-binding activity (Figure S1), which is similar to the thermal stabilities of TIM and FLN c studied in Procambarus clarkii. Heat treatment could alter the conformational epitopes of TM, impact their intramolecular hydrogen bonding, and subsequently decrease the binding capacity between TM and IgE . Although TM is highly heat-stable, some studies have demonstrated that thermal processing enhanced the patient’s IgE-binding to shrimp extracts or purified TM. , …”

Edible algae (Ecklonia cava) bioprocessed with mycelia of shiitake (Lentinula edodes) mushrooms in liquid culture and its isolated fractions protect mice against allergic asthma

“…The high bioactivity of the bioprocessed combinations against foodborne pathogens and hangover biomarkers in rodents are most likely the result of the formation of new bioactive compounds during the fermentation process, an aspect that merits further study. Moreover, although asthma does not seem to increase risk of COVID-19 infection, it would also be of interest to determine if the bioprocessed E. cava food formulation that protected the lungs of mice against inflammatory allergic asthma might also help ameliorate the acute respiratory syndrome associated with the viral infection [31][32][33] as well as allergic manifestations associated with foods [34][35][36][37][38] and drugs [39].…”

Effects of methylglyoxal on shrimp tropomyosin structure and allergenicity during thermal processing

“…TM is a heat-stable protein with 32–38 kDa molecular weight and 4.2 isoelectric points. More than 90 % of shrimp-allergic people contain TM-specific antibodies ( Tsedendorj et al, 2018 , Zhang et al, 2021 , Zhang et al, 2019 ). Therefore, the allergenicity of shrimp should be considered when it is used as a food ingredient.…”