Ontology highlight
ABSTRACT: Background
Cow's milk-derived whey hydrolysates are nutritional substitutes for allergic infants. Safety or residual allergenicity assessment of these whey hydrolysates is crucial. Currently, rat basophilic leukemia RBL-2H3 cells expressing the human IgE receptor ?-chain (huFc?RI?-RBL-2H3), sensitized with serum IgE from cow's milk allergic children, are being employed to assess in vitro residual allergenicity of these whey hydrolysates. However, limited availability and inter-lot variation of these allergic sera impede standardization of whey hydrolysate safety testing in degranulation assays.Objective
An oligoclonal pool of chimeric human (chu)IgE antibodies against bovine ?-lactoglobulin (a major allergen in whey) was generated to increase sensitivity, specificity, and reproducibility of existing degranulation assays.Methods
Mice were immunized with bovine ?-lactoglobulin, and subsequently the variable domains of dissimilar anti-?-lactoglobulin mouse IgG antibodies were cloned and sequenced. Six chimeric antibodies were generated comprising mouse variable domains and human constant IgE/? domains.Results
After sensitization with this pool of anti-?-lactoglobulin chuIgEs, huFc?RI?-expressing RBL-2H3 cells demonstrated degranulation upon cross-linking with whey, native 18 kDa ?-lactoglobulin, and 5-10 kDa whey hydrolysates, whereas a 3 kDa whey hydrolysate and cow's milk powder (mainly casein) showed no degranulation. In parallel, allergic serum IgEs were less sensitive. In addition, our pool anti-?-lactoglobulin chuIgEs recognized multiple allergenic immunodominant regions on ?-lactoglobulin, which were also recognized by serum IgEs from cow's milk allergic children.Conclusion
Usage of our 'unlimited' source and well-defined pool of ?-lactoglobulin-specific recombinant chuIgEs to sensitize huFc?RI? on RBL-2H3 cells showed to be a relevant and sensitive alternative for serum IgEs from cow's milk allergic patients to assess safety of whey-based non-allergic hydrolyzed formula.
SUBMITTER: Knipping K
PROVIDER: S-EPMC4143325 | biostudies-literature | 2014
REPOSITORIES: biostudies-literature
PloS one 20140825 8
<h4>Background</h4>Cow's milk-derived whey hydrolysates are nutritional substitutes for allergic infants. Safety or residual allergenicity assessment of these whey hydrolysates is crucial. Currently, rat basophilic leukemia RBL-2H3 cells expressing the human IgE receptor α-chain (huFcεRIα-RBL-2H3), sensitized with serum IgE from cow's milk allergic children, are being employed to assess in vitro residual allergenicity of these whey hydrolysates. However, limited availability and inter-lot variat ...[more]