Bovine α-lactalbumin (α-La) is a major food allergen found in milk and is characterized by high conformational stability because of its four disulfide bridges and being calcium bound. This study aimed to describe the influence of gamma irradiation on the structure and potential allergenicity of α-La. The prepared α-La was irradiated at doses of 1–10 kGy. The changes in structure were characterized through SDS-PAGE, circular dichroism spectroscopy, ultraviolet absorption spectroscopy, and fluorescence spectroscopy. The potential allergenicity of the irradiated α-La was evaluated in vitro through IgG/IgE inhibition ELISA and the human basophil KU812 degranulation assay. The results showed that the secondary and tertiary structures of α-La significantly changed and caused extensive protein denaturation and aggregation. IgG and IgE binding properties remarkably decreased, and the degranulation capacity of basophils weakened. The results suggested that structural damage of α-La induced by irradiation significantly reduces the potential allergenicity of α-La.
12 November 2018 in Journal of Crohn's and Colitis
For women with inflammatory bowel disease [IBD], it is not very well known how IBD or IBD treatment affects their breast milk components. We aimed to investigate whether breast milk composition differs in healthy control [HC] versus IBD mothers in terms of antibodies, cytokines, and metabolite,s to identify potential impact of IBD breast milk on neonatal immune system. Breast milk specimens from HC [n = 17] and IBD [n = 31 for Crohn's disease [CD]; and n = 41 for ulcerative colitis [UC]; were collected at 3 and 6 months postpartum [PP3] and [PP6], respectively. Faecal samples were also collected. Cytokines and immunoglobulins [IgA/IgG/IgE] were analysed by multiplex Meso Scale Discovery [MSD] and commercial kits. Moreover, breast milk metabolites were analysed by 1H nuclear magnetic resonance [NMR]. We found that breast milk from IBD mothers showed significantly lower levels of IgA, sugar metabolite [lactose], and 2-aminobutyrate. In contrast, we observed that breast milk from mothers with IBD had increased levels of pro-inflammatory cytokines and higher energy metabolites [lactate and succinate] than milk from healthy mothers. In addition, we noticed that the type of treatment [5-aminosalicylic acid versus biologics] influenced the milk cytokines and metabolites profile. The reduction in immunoprotective components of IBD breast milk such as sIgA and lactose theoretically may modulate the potential protective effects of breastfeeding. On the other hand, presence of higher levels of pro-inflammatory cytokines, lactate, and succinate may predispose the offspring to an inflammatory condition or impact on the gut microbiome. Better understanding of the role of succinate in infants and its potential effects on microbiome or mucosal immunity merits further investigations.
The reported association of Moringa oleifera seeds and allergic disease clinically resembling occupational asthma in cosmetic manufacturing workers has resultedin the need to identify such components in the manufacturing process. However, Moringa oleifera leaves from the same plant, an important food ingredient, have limited immunotoxicity data. This study aimed to determine if Moringa oleifera leafproteins (MLP) can elicit allergic responses in BALB/c mice. The BALB/c mice were sensitized twice and challenged 10 times to evaluate the potential allergenicityof MLP in vivo. The results showed increased levels of mast cells, total and specific IgE and IgG, severe signs of systemic anaphylaxis, and reduced body temperature compared with controls. The sensitized mice serum observed enhanced levels of histamine and Th-related cytokine release. Compared with the control group, increased levels of interleukins IL-4, IL-9, and IL-17A and enhanced expression and secretion of normal T cells were found in the culture supernatant of splenocytes treated with MLP.This study suggeststhat MLPcanelicit allergic responses; this providesmore comprehensive guidance for identifying new allergen candidates and developing hypoallergenic MLP products.
Bovine α-lactalbumin (BLA) and β-lactoglobulin (BLG) are the most common and severe food allergens in milk and they can bind C18 unsaturated fatty acids (UFAs) and their bioactivities were changed. This study aims to determine the effects of C18 UFAs on the structures of BLA and BLG and their allergic properties, such as antigenicity and allergenicity. We reveal that C18 UFAs can efficiently promote the gradual unfolding of the structures of BLA and BLG and increase their hydrophobicity. Moreover, the IgG binding ability and the expression of IgG-dependent activation marker CD200R3 on basophils were remarkably promoted after C18 UFA treatment. Finally, we also observed that C18 UFAs can enhance the IgE binding ability and the degranulation capacity of human basophil KU812 cells (intracellular Ca2+, histamine, β-Hex, and IL-6). Collectively, these results suggested that C18 UFAs changed the structures of BLA and BLG, which contributed to their increased allergic potential.