Antigen-specific secretory IgA antibodies in the gut are decreased in a mouse model of food allergy.
BACKGROUND
A large body of evidence implicates IgA antibodies in the immune response to pathogens present in the gut. Whether IgA antibodies play a similar role in food allergy remains to be determined.


OBJECTIVE
We sought to characterize beta-lactoglobulin (BLG)-specific serum and secretory IgA antibody production in the gut and to define the role of antigen-induced cytokines in IgA production in a murine model of food allergy.


METHODS
BLG-specific IgA antibodies were measured in the sera and feces of mice anaphylactic or tolerant to BLG. The number of antibody-secreting cells in the spleen and Peyer's patches was determined by means of ELISPOT. Mesenteric lymph node cells and Peyer's patch T cells were transferred to naive mice, and antibody production in the sera and feces in recipient mice, as well as antibody-secreting cell numbers, were measured.


RESULTS
Serum IgA antibody titers were strongly increased in anaphylactic mice. In contrast, BLG-specific IgA antibody titers were increased in feces but not in sera from tolerant mice. These results were correlated with an increased number of BLG-specific IgA-secreting cells in Peyer's patches from tolerant mice. The adoptive transfer of Peyer's patch CD3+ cells from tolerant mice induced an increased number of IgA-secreting cells preferentially in the Peyer's patches of naive recipient mice. Furthermore, an increase of BLG-induced IL-10 and TGF-beta levels was found at IgA production sites.


CONCLUSIONS
These results suggest a role for secretory IgA in tolerance mechanisms to foods. Peyer's patch CD3+ cells are primarily involved by favoring IgA production through the release of IL-10 and TGF-beta.
Department of Pediatrics, University Hospital of Geneva, Switzerland.
Christophe P
CP
Frossard
Conrad
C
Hauser
Philippe A
PA
Eigenmann
D019264:Adoptive Transfer; D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology*; D007108:Immune Tolerance; D007071:Immunoglobulin A, Secretory / Q000032:analysis*; D016753:Interleukin-10 / Q000096:biosynthesis; D007413:Intestinal Mucosa / Q000276:immunology*; D007782:Lactoglobulins / Q000276:immunology*; D051379:Mice; D008809:Mice, Inbred C3H; D010581:Peyer's Patches / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D016212:Transforming Growth Factor beta / Q000096:biosynthesis
D007071:Immunoglobulin A, Secretory; D007782:Lactoglobulins; D016212:Transforming Growth Factor beta; D016753:Interleukin-10