title: Preexisting antigen-specific immune responses are modulated by oral KLH feeding in humans.
abstract: Oral tolerance is the antigen-specific inhibition of a systemic immune response after oral antigen uptake and well established in animal models. We recently showed that keyhole limpet hemocyanin (KLH) feeding modulates subsequently induced systemic immune responses in humans as well. In the present study, we investigated whether oral KLH can also modulate preexisting antigen-specific systemic B- and T-cell responses. We induced delayed-type hypersensitivity (DTH) reactions as well as systemic KLH-specific B- and T-cell responses by subcutaneous KLH injections. Subsequent oral KLH administration decreased the small proportion of antigen-specific CD4(+) T cells positive for the cytokine IL-17 at the end of the feeding regimen even further. After reimmunization, there was no difference in DTH reactions and the KLH-specific B-cell responses, but KLH-fed volunteers had an increased proportion of antigen-specific CD4(+) T cells positive for IL-10 and a reduced proportion of antigen-specific CD4(+) T cells positive for the skin-homing receptor cutaneous lymphocyte antigen and IL-2 and IFN-γ. Taken together, oral KLH can modulate a preexisting systemic KLH-specific immune response. These results suggest that feeding antigen may offer therapeutic strategies for the suppression of unwanted immune reactions in humans.
authors.affiliation: Charité-Campus Benjamin Franklin, Medizinische Klinik für Gastroenterologie, Infektiologie und Rheumatologie, Berlin, Germany.
authors.forename: Arwed
authors.initials: A
authors.lastname: Hostmann
authors.affiliation: Charité-Campus Benjamin Franklin, Medizinische Klinik für Gastroenterologie, Infektiologie und Rheumatologie, Berlin, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Meyer
authors.affiliation: Charité-Campus Benjamin Franklin, Medizinische Klinik für Gastroenterologie, Infektiologie und Rheumatologie, Berlin, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Maul
authors.affiliation: Charité-Campus Benjamin Franklin, Medizinische Klinik für Gastroenterologie, Infektiologie und Rheumatologie, Berlin, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Preiss
authors.affiliation: Charité-Campus Benjamin Franklin, Medizinische Klinik für Gastroenterologie, Infektiologie und Rheumatologie, Berlin, Germany.
authors.forename: Bertram
authors.initials: B
authors.lastname: Boortz
authors.affiliation: Charité-Universitätsmedizin Berlin, Berlin-Brandenburg Center for Regenerative Therapies (BCRT) Virchow-Klinikum, Berlin, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Thiel
authors.affiliation: Medizinische Klinik, Hospital zum Heiligen Geist, Frankfurt a. M., Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Duchmann
authors.affiliation: Charité-Campus Benjamin Franklin, Medizinische Klinik für Gastroenterologie, Infektiologie und Rheumatologie, Berlin, Germany.
authors.forename: Reiner
authors.initials: R
authors.lastname: Ullrich
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000284:Administration, Oral; D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D003888:Desensitization, Immunologic / Q000379:methods; D005260:Female; D005434:Flow Cytometry; D006433:Hemocyanins / Q000008:administration & dosage* / Q000276:immunology; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007108:Immune Tolerance / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D000276:Adjuvants, Immunologic; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin
keywords: B- and T-cell response; Cytokines; Human; KLH feeding; Tolerance/immune modulation