Enzymatic treatment of whey proteins in cow's milk results in differential inhibition of IgE-mediated mast cell activation compared to T-cell activation.
BACKGROUND
Cow's milk (CM) hydrolysates are frequently used as milk substitutes for children with CM allergy. In hydrolysates, allergenic epitopes within CM proteins are diminished by enzymatic treatment. The aim of this study was to examine the allergenic and immunogenic properties of whey proteins during hydrolysis.


METHODS
During hydrolysis, samples were obtained at 0, 10, 15, 30, 45, 60, 75 and 90 min. Degradation was checked by HPLC and SDS-PAGE. Allergenic potential was analyzed by IgE crosslinking capacity of human Fcε receptor type 1-transduced rat basophilic leukemia cells sensitized with serum of CM-allergic patients. Whey-sensitized C3H/HeOuJ mice were ear challenged intracutaneously with the hydrolysates. Immunogenicity was tested using whey-specific human T-cell clones and T-cell lines at the level of proliferation and release of IL-4, IL-10, IL-13 and IFN-γ.


RESULTS
After 15 min of hydrolysis, the majority of the proteins were degraded. Hydrolysis for 15 min resulted in 92% inhibition of mast cell degranulation and in 82% reduction of ear swelling in the mouse model. In contrast, T-cell-stimulatory capacity was less affected by hydrolysis: reduction of human T-cell proliferation was only 9%. This was further reduced to 57 and 74% after 30 and 45 min of hydrolysis, respectively. Cytokine production followed the pattern of T-cell proliferation.


CONCLUSIONS
Via differential analysis of allergenic versus immunogenic properties of the time kinetics of hydrolysis of whey proteins, we have demonstrated specific hydrolysis conditions with reduced IgE-crosslinking responses but retained T-cell activating properties. This approach might be useful in better defining CM hydrolysates.
Danone Research Center for Specialized Nutrition, Wageningen, The Netherlands.
Karen
K
Knipping
Betty C A M
BC
van Esch
Adrie G
AG
van Ieperen-van Dijk
Els
E
van Hoffen
Ton
T
van Baalen
Léon M J
LM
Knippels
Sicco
S
van der Heide
Anthony E J
AE
Dubois
Johan
J
Garssen
Edward F
EF
Knol
D000485:Allergens / Q000737:chemistry / Q000276:immunology* / Q000494:pharmacology; D000818:Animals; D001491:Basophils / Q000187:drug effects / Q000276:immunology; D015550:Cell Degranulation / Q000187:drug effects / Q000276:immunology*; D002478:Cells, Cultured; D002648:Child; D000939:Epitopes / Q000276:immunology; D006801:Humans; D006868:Hydrolysis; D007108:Immune Tolerance; D007073:Immunoglobulin E / Q000276:immunology*; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D008407:Mast Cells / Q000187:drug effects / Q000276:immunology; D051379:Mice; D008809:Mice, Inbred C3H; D008892:Milk / Q000737:chemistry; D016269:Milk Hypersensitivity / Q000276:immunology* / Q000517:prevention & control; D008894:Milk Proteins / Q000737:chemistry / Q000276:immunology* / Q000494:pharmacology; D010447:Peptide Hydrolases / Q000378:metabolism; D051381:Rats; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D000067816:Whey Proteins
D000485:Allergens; D000939:Epitopes; D008894:Milk Proteins; D000067816:Whey Proteins; D007073:Immunoglobulin E; D010447:Peptide Hydrolases