Generation of hypoallergenic DNA vaccines by forced ubiquitination: preventive and therapeutic effects in a mouse model of allergy.
BACKGROUND
Hypoallergenic immunotherapy of type I allergies aims at inducing T-cell immunity while avoiding cross-linking of pre-existing IgE. DNA-based immunotherapy depends on the recruitment of antigen-specific T(H)1 cells and therefore has to provide the whole repertoire of T-cell epitopes. Ubiquitination offers a general approach for the production of hypoallergenic DNA vaccines.


OBJECTIVE
A DNA-based vaccine encoding the major birch pollen allergen Bet v 1 stably linked to ubiquitin was evaluated for its antiallergic potential in a BALB/c mouse model of allergy.


METHODS
Plasmid DNA was applied to mice before (preventive) or after (therapeutic) sensitization with recombinant Bet v 1. In the preventive setting, mice were exposed to aerosolized allergen in addition. Cytokine production was monitored via ELISPOT and Luminex. IgG(1), IgG(2a), and IgE subclass antibody titers were determined by ELISA. In vitro antigen-specific cross-linking of IgE was measured in a degranulation assay. Bronchoalveolar lavages were analyzed for leukocyte subsets as well as for IFN-gamma and IL-5, and paraffin sections of lungs were examined for mucus production and endothelial damage.


RESULTS
Prevaccination with ubiquitinated Bet v 1-stimulated T(H)1-biased immune responses with concomitant suppression of functional IgE, reduction of eosinophil counts in bronchoalveolar lavages, and alleviation of lung pathology, and could also suppress an ongoing IgE response in a therapeutic setting.


CONCLUSIONS
The data clearly demonstrate that hypoallergenic DNA vaccines encoding ubiquitin fusion constructs induce effective antiallergic immune responses.


CONCLUSIONS
Ubiquitination of allergen gene vaccines eliminates the risk of IgE cross-linking, thereby meeting the safety requirements for clinical applications.
Bauer
Roman
R
Department of Molecular Biology, Division of Allergy and Immunology, Hellbrunnerstrasse 34, 5020 Salzburg, Austria.
Scheiblhofer
Sandra
S
Kern
Kerstin
K
Gruber
Christina
C
Stepanoska
Tatjana
T
Thalhamer
Theresa
T
Hauser-Kronberger
Cornelia
C
Alinger
Beate
B
Zoegg
Thomas
T
Gabler
Maximilian
M
Ferreira
Fatima
F
Hartl
Arnulf
A
Thalhamer
Josef
J
Weiss
Richard
R
D000485:Allergens / Q000235:genetics / Q000276:immunology*; D000818:Animals; D052179:Antigens, Plant; D004195:Disease Models, Animal; D005260:Female; D006967:Hypersensitivity / Q000628:therapy*; D007073:Immunoglobulin E / Q000097:blood; D051379:Mice; D008807:Mice, Inbred BALB C; D018417:Th1 Cells / Q000276:immunology*; D025801:Ubiquitin / Q000378:metabolism*; D019444:Vaccines, DNA / Q000276:immunology*
D000485:Allergens; D052179:Antigens, Plant; D025801:Ubiquitin; D019444:Vaccines, DNA; D007073:Immunoglobulin E