PIPE‐cloned human IgE and IgG4 antibodies: New tools for investigating cow's milk allergy and tolerance

Abstract

To the Editor, Cow's milk (CM) allergy (CMA) is defined as an immune-mediated adverse response to CM proteins. 2% to 3% of children are suffering from CMA, but many develop natural tolerance after 3-4 years. 1,S01 Food allergen immunotherapy (FA-AIT) applying increasing antigen doses (oral immunotherapy, OIT) can contribute to improvement of CMA, S02 with variable clinical efficacy, 2,S03 but immunologically often resulting in decreased specific IgE levels and increased specific IgG4 levels S04,S05 . IgG4 is (a)anti-inflammatory as it does not activate the complement system; (b) bi-specific due to fab-arm exchange and, thus, has less crosslinking capacity than IgE, but has (c) blocking capacity. 3 The interplay of IgE and IgG4 may hence be decisive for the immune balance in CMA.Antibodies of different isotypes with the same variable region could be essential in molecular studies of the mechanism underlying CMA and might shed light onto the function of specific IgG4 antibodies during the acquisition of tolerance.Polymerase Incomplete Prime Extension (PIPE) cloning is a cutting-edge technique to engineer antibodies against various targets and facilitates simple exchange of the constant regions to increase the range of subtypes of antibodies. [4][5][6] In this study, we combined variable regions from the high-affinity IgE antibody "D1" 7 (KD = 1.4 × 10 −9 M; k on = 1.4 × 10 6 , k off = 1.54 × 10 −3 ) S06 specific for the major CM allergen beta-lactoglobulin (BLG), with the constant domains of IgE or IgG4 antibodies (Figure 1A). Correct antibody assembly was confirmed by SDS-PAGE in comparison with commercialThis is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Oral Immunotherapy in Food Allergy: A Critical Pediatric Perspective

“…It has been shown a reduction of specific IgE levels (after an initial raise) followed by an increase in specific immunoglobulin G4 (IgG4), reaching a balance in the achievement of tolerance. IgG4 compete with sIgE for allergen binding, suppressing the reactivity of mast cell and basophils, which are deprived of their preformed mediators through continuous degranulation ( 42 , 43 ) ( Figure 2 ).…”

Secretory protein beta‐lactoglobulin in cattle stable dust may contribute to the allergy‐protective farm effect

“…BALB/c mice (5-7 weeks old) were treated intranasally on 2 consecutive days for 5 times with 14 days interval (A) with stable dust extract (SDE+, containing 200 ng BLG/ml extract; n = 5), (B) with SDE depleted of BLG via magnetic beads (Protein G Magnetic Beads, Pierce™, ThermoFischer) coupled with human IgG1 and IgG4 antibodies specific for bovine BLG19 acc. to manufacturer's instructions (SDE-; BLG content below detection limit in ELISA; n = 5), or (C) with MQ water (n = 4; FigureS1A).…”