DOWN-REGULATION OF ANTI-CD3 ANTIBODY-INDUCED IL-4 PRODUCTION BY BOVINE CASEINS HYDROLYZED WITH LACTOBACILLUS GG-DERIVED ENZYMES

A prerequisite for systemic hyporesponsiveness to dietary antigens is their processing in the gut. This study investigated whether bovine ca seins degraded by enzymes of an intestinal bacterial strain, Lactobaci llus GG (ATCC 53103), could regulate the cytokine production by anti-C D3 antibody-induced peripheral blood mononuclear cells of 14 atopic pa tients, aged 5-29 (mean, 16) months. Purified casein up-regulated the interleukin-4 and interferon-gamma production, P = 0.008 and P = 0.008 , respectively. Conversely, Lactobacillus GG-degraded casein down-regu lated the interleukin-4 production, P = 0.003, with no effect on inter feron-gamma. These results indicate that intestinal bacteria may modif y immunomodulatory properties of native food proteins and introduce a promising tool to provide protection from potentially harmful dietary antigens at a young age.