Intranasal tolerance induction with polypeptides derived from 3 noncross-reactive major aeroallergens prevents allergic polysensitization in mice.
BACKGROUND
Specific immunotherapy is less effective in patients with multiple allergic sensitizations compared with monosensitized patients.


OBJECTIVE
We therefore established a mouse model of polysensitization to the major birch and timothy grass pollen allergens to test whether allergic polysensitization can be prevented by multiple allergen application via the mucosal route.


METHODS
Female BALB/c mice were immunized intraperitoneally with recombinant (r) Bet v 1, rPhl p 1, and rPhl p 5. For intranasal tolerance induction, a mixture of the complete allergens was compared with allergen-derived immunodominant peptides applied either as a mixture or as a synthetic hybrid peptide composed of the T-cell epitopes of the 3 allergens.


RESULTS
Intranasal application of the mixture of the complete allergen molecules did not prevent polysensitization to the same allergens. In contrast, pretreatment with a mixture of the immunodominant peptides or the hybrid peptide led to significantly reduced allergen-specific IgE responses in sera, IL-4 production in vitro, and suppressed airway inflammation. TGF-beta mRNA levels did not change, and IL-10 production was significantly suppressed after the pretreatment. The fact that the reduction of IL-10 was not abrogated after IL-10 receptor neutralization and that tolerance was not transferable with splenocytes indicates that the suppression of T(H)2 responses in polysensitized mice might not be mediated by immunosuppressive cytokines.


CONCLUSIONS
Our study demonstrates that it is possible to suppress allergic immune responses simultaneously to several clinical important allergens. Thus, mucosal coapplication of selected peptides/hybrid peptides could be the basis of a mucosal polyvalent vaccine to prevent multiple sensitivities in atopic patients.
Hufnagl
Karin
K
Department of Specific Prophylaxis and Tropical Medicine, Center for Physiology and Pathophysiology, Medical University of Vienna, Vienna, Austria.
Winkler
Birgit
B
Focke
Margit
M
Valenta
Rudolf
R
Scheiner
Otto
O
Renz
Harald
H
Wiedermann
Ursula
U
D000485:Allergens / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D052179:Antigens, Plant; D003429:Cross Reactions; D018604:Epitope Mapping; D018984:Epitopes, T-Lymphocyte; D005260:Female; D006967:Hypersensitivity / Q000628:therapy*; D007108:Immune Tolerance; D007114:Immunization; D016056:Immunodominant Epitopes; D016753:Interleukin-10 / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009297:Nasal Mucosa / Q000276:immunology*; D010455:Peptides / Q000276:immunology*; D010940:Plant Proteins / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D016212:Transforming Growth Factor beta / Q000502:physiology
D000485:Allergens; D052179:Antigens, Plant; D018984:Epitopes, T-Lymphocyte; D016056:Immunodominant Epitopes; D010455:Peptides; C076049:Phl p V protein, Phleum pratense; D010940:Plant Proteins; D016212:Transforming Growth Factor beta; C061312:Bet v 1 allergen, Betula; D016753:Interleukin-10