Visualization of peptide presentation following oral application of antigen in normal and Peyer's patches-deficient mice.
Orally applied antigens generate systemic unresponsiveness by induction of anergy and deletion of specific T cells at high antigen doses, and induction of regulatory T cells at low doses of antigen. These different immune reactions have been attributed to different types of antigen-presenting cells (APC) and/or different secondary lymphoid organs participating in the induction of the immune response. We used high-sensitivity immunofluorescence to directly identify for the first time the cells presenting orally applied antigen in vivo. At low peptide doses (<1 mg) peptide presentation was exclusively detected on dendritic cells (DC) of the Peyer's patches (PP) and mesenteric lymph nodes (mLN). At high doses (>1 mg) peptides were presented systemically and by all types of APC but presentation was still maximal on DC of the PP (up to 65%). Nevertheless, at limiting antigen doses T cell activation in the gut-associated lymphoid tissue occurs preferentially in the mLN but not in PP. PP-deficient mice have the same frequencies of peptide-presenting cells in mLN, peripheral lymph nodes and spleen and activation of naive T cells in vivo is not affected. Therefore, PP are not critical for antigen presentation as well as for T cell activation in response to orally applied soluble antigens.
Deutsches Rheuma-Forschungszentrum Berlin, Berlin, Germany.
Désirée
D
Kunkel
Dennis
D
Kirchhoff
Shin-Ichi
S
Nishikawa
Andreas
A
Radbruch
Alexander
A
Scheffold
D000284:Administration, Oral; D000818:Animals; D017951:Antigen Presentation; D000938:Antigen-Presenting Cells / Q000502:physiology; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D005434:Flow Cytometry; D007108:Immune Tolerance; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010581:Peyer's Patches / Q000502:physiology*; D013601:T-Lymphocytes / Q000276:immunology