title: Allergenic and immunogenic potential of cow's milk β-lactoglobulin and caseins evidenced without adjuvant in germ-free mice.
abstract: METHODS
  In most animal models of allergy, the development of an IgE response requires the use of an adjuvant. Germ-free (GF) mice exhibit Th2-polarized antibody responses combined with defective immunosuppressive mechanisms. The sensitizing potential of milk proteins was investigated in GF mice in the absence of adjuvant.
  
  
  RESULTS
  β-lactoglobulin (BLG) and whole casein (CAS) allergenicity was evaluated by means of intraperitoneal injections without adjuvant. Injections of BLG induced significant IgE and IgG1 responses in GF mice, while CAS injections provoked the production of IgG1 toward κ- and αS1-caseins. No significant antibody response was evidenced in conventional (CV) mice. After in vitro BLG-reactivation, IL-4, IL-5, IL-13 and IFN-γ productions by splenocytes were higher in GF mice than in CV mice. Heat-treatment decreased BLG allergenicity as indicated by the absence of IgE production in GF mice. However, heat-treatment increased protein immunogenicity and led to the production of anti-BLG and anti-κ-casein IgG1 in both GF and CV mice. This correlated with enhanced productions of IL-4, IL-5 and IL-13 in BLG-reactivated splenocytes from CV mice.
  
  
  CONCLUSIONS
  Gut colonization by commensal bacteria appeared then to significantly reduce the susceptibility of mice toward the intrinsic allergenic and immunogenic potential of milk proteins.
authors: INRA, UR 496, Immuno-Allergie Alimentaire, CEA de Saclay, Gif-sur-Yvette, France. stephane.hazebrouck@cea.fr
authors: Stéphanie
authors: S
authors: Morin
authors: Hervé
authors: H
authors: Bernard
authors: Laetitia
authors: L
authors: Przybylski-Nicaise
authors: Gérard
authors: G
authors: Corthier
authors: Sylvie
authors: S
authors: Rabot
authors: Jean-Michel
authors: JM
authors: Wal
authors: Stéphane
authors: S
authors: Hazebrouck
mesh_terms: D000485:Allergens / Q000009:adverse effects* / Q000737:chemistry; D000818:Animals; D000918:Antibody Specificity; D002364:Caseins / Q000009:adverse effects*; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D004198:Disease Susceptibility; D005260:Female; D005856:Germ-Free Life; D006090:Gram-Negative Bacteria / Q000276:immunology; D006094:Gram-Positive Bacteria / Q000276:immunology; D006358:Hot Temperature; D007132:Immunoglobulin Isotypes / Q000032:analysis; D007422:Intestines / Q000276:immunology / Q000382:microbiology; D007782:Lactoglobulins / Q000009:adverse effects* / Q000737:chemistry; D051379:Mice; D008807:Mice, Inbred BALB C; D016269:Milk Hypersensitivity / Q000276:immunology* / Q000378:metabolism; D011489:Protein Denaturation; D020033:Protein Isoforms / Q000009:adverse effects; D013154:Spleen / Q000276:immunology / Q000378:metabolism / Q000473:pathology
chemical_list: D000485:Allergens; D002364:Caseins; D016207:Cytokines; D007132:Immunoglobulin Isotypes; D007782:Lactoglobulins; D020033:Protein Isoforms