Low-dose gamma irradiation of food protein increases its allergenicity in a chronic oral challenge

Abstract

Few chronic food protein models have described the relationship between allergenicity and the molecular structure of food protein after physical processing. The effect of γ-radiation on the structure of food protein was measured by fluorescence, circular dichroism and microcalorimetry. BALB/c mice were intraperitoneally sensitized and then given non-irradiated and irradiated Con-A by daily gavage for 28days. The tendency to form insoluble amorphous aggregates and partially unfolded species was observed after irradiation. The administration of non-irradiated and irradiated samples at low-dose significantly increased weight loss as well as plasma levels of eotaxin in animals repeatedly exposed to Con-A. Significant lymphocytic infiltrate filling completely the stroma of microvilli and tubular glands was observed in the small intestinal of the group given Con-A irradiated at a low dose. This phenotype was not observed in animals treated with Con-A irradiated at a high dose.

Effects of Low-pH Treatment on the Allergenicity Reduction of Black Turtle Bean (Phaseolus vulgaris L.) Lectin and Its Mechanism

“…Previous studies 42 Similar to the low pH treated lectin, gamma radiated lectin has also been found to lose the inducing ability for the secretions of IL-4, IL-5, and IL-13, which might be related to the protein conformational changes. 34,43,44 Besides, an up-regulation of Th1-type cytokine IFN-γ in splenocytes was found in the native group compared with the groups administered with low pH treated lectins, PBS, and CFA. In order to keep the balance of the Th1/Th2 ratio to counteract harmful inflammation, 30,40 IFN-γ might be released in a high level in the native lectin group and would also enhance the release of the IgE level and various other mediators that might be responsible for allergic reactions.…”

“…Previous studies demonstrated that several plant-derived lectins, including Con A, P. vulgaris erythroagglutinin (PHA-E), Pisum sativum agglutinin (PSA), Lens culinaris agglutinin (LCA), and Sambucus nigra agglutinin (SNA) could effectively trigger the release of IL-4, and high IL-4 concentration would enhance secretions of IL-13 and histamine . Similar to the low pH treated lectin, gamma radiated lectin has also been found to lose the inducing ability for the secretions of IL-4, IL-5, and IL-13, which might be related to the protein conformational changes. ,, Besides, an up-regulation of Th1-type cytokine IFN-γ in splenocytes was found in the native group compared with the groups administered with low pH treated lectins, PBS, and CFA. In order to keep the balance of the Th1/Th2 ratio to counteract harmful inflammation, , IFN-γ might be released in a high level in the native lectin group and would also enhance the release of the IgE level and various other mediators that might be responsible for allergic reactions .…”

Potential allergenicity response to structural modification of irradiated bovine α-lactalbumin

“…Many researchers have also described similar results in concanavalin A and the soybean trypsin inhibitor. 30,31 In addition, irradiation resulted in important changes in the α-La tertiary structure as demonstrated by UV and fluorescence spectroscopy. The UV spectra of the native α-La reflected the maximum absorption peak at around 280 nm, indicating that the UV absorption spectrum of α-La was mainly dependent on tyrosine (Tyr) and tryptophan (Trp) residue sidechain groups.…”

Bridging the Knowledge Gap for the Impact of Non-Thermal Processing on Proteins and Amino Acids

“…Above 25 kGy, Gly m6 started to decrease and at 100 kGy it was completely destroyed. According to the results of Meinlschmidt et al [46] and Vaz et al [103], γ-irradiation at lower doses (3 kGy and 5 kGy) increased the allergenicity of Gly m5 and Gly m6 in SPI and Con-A, respectively. This might have been due to the partial unfolding and aggregation of species at low doses, which can lead to increased exposure of linear and conformational epitopes.…”