TY - JOUR

T1 - Lipopolysaccharide contamination of β-lactoglobulin affects the immune response against intraperitoneally and orally administered antigen

AU - Brix, Susanne

AU - Kjær, Tanja M.R.

AU - Barkholt, Vibeke

AU - Frøkiær, Hanne

PY - 2004

Y1 - 2004

N2 - Background: Microbial components in the environment are potent activators of the immune system with capacity to shift the active immune response towards priming of Th1 and/or Th2 cells. Lipopolysaccharide (LPS), a cell-wall component of Gram-negative bacteria, is extensively present in food products like cow's milk. It is not well established, however, how this presence of LPS affects oral tolerance induction. Methods: We studied the effect of LPS contamination in a commercial preparation of the cow milk protein β-lactoglobulin (β-LG) on antigen-specific immune responses. IgG1/IgG2a production upon intraperitoneal immunization without adjuvant was measured, and oral tolerance induction against β-LG after administration of either an aqueous solution or water-in-oil (w/o) emulsion of β-LG was evaluated. Results: LPS contamination of β-LG provoked a β-LG-specific IgG2a response, as well as an enhanced β-LG-specific IgG1 response upon intraperitoneal immunization. Oral tolerance induction to β-LG was induced by aqueous solutions of β-LG with and without LPS administration. Conversely, oral administration of w/o-emulsified β-LG prevented oral tolerance to β-LG only when the β-LG was contaminated with LPS. Conclusions: LPS contamination of an aqueous protein solution does not affect oral tolerance induction, whereas LPS present in emulsion prevents oral tolerance induction towards the food protein.

AB - Background: Microbial components in the environment are potent activators of the immune system with capacity to shift the active immune response towards priming of Th1 and/or Th2 cells. Lipopolysaccharide (LPS), a cell-wall component of Gram-negative bacteria, is extensively present in food products like cow's milk. It is not well established, however, how this presence of LPS affects oral tolerance induction. Methods: We studied the effect of LPS contamination in a commercial preparation of the cow milk protein β-lactoglobulin (β-LG) on antigen-specific immune responses. IgG1/IgG2a production upon intraperitoneal immunization without adjuvant was measured, and oral tolerance induction against β-LG after administration of either an aqueous solution or water-in-oil (w/o) emulsion of β-LG was evaluated. Results: LPS contamination of β-LG provoked a β-LG-specific IgG2a response, as well as an enhanced β-LG-specific IgG1 response upon intraperitoneal immunization. Oral tolerance induction to β-LG was induced by aqueous solutions of β-LG with and without LPS administration. Conversely, oral administration of w/o-emulsified β-LG prevented oral tolerance to β-LG only when the β-LG was contaminated with LPS. Conclusions: LPS contamination of an aqueous protein solution does not affect oral tolerance induction, whereas LPS present in emulsion prevents oral tolerance induction towards the food protein.

KW - β-lactoglobulin

KW - Emulsion

KW - Food allergy

KW - Food protein

KW - Intraperitoneal immunization

KW - Lipopolysaccharide

KW - Oral tolerance

UR - http://www.scopus.com/inward/record.url?scp=10844238800&partnerID=8YFLogxK

U2 - 10.1159/000081306

DO - 10.1159/000081306

M3 - Journal article

C2 - 15475660

AN - SCOPUS:10844238800

VL - 135

SP - 216

EP - 220

JO - International Archives of Allergy and Immunology

JF - International Archives of Allergy and Immunology

SN - 1018-2438

IS - 3

ER -