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Forschungsdatenbank PMU-SQQUID

Immune responses after immunization with plasmid DNA encoding Bet v 1, the major allergen of birch pollen.
Hartl, A; Kiesslich, J; Weiss, R; Bernhaupt, A; Mostböck, S; Scheiblhofer, S; Ebner, C; Ferreira, F; Thalhamer, J;
J Allergy Clin Immunol. 1999; 103(1 Pt 1):107-113
Originalarbeiten (Zeitschrift)

PMU-Autor/inn/en

Hartl Arnulf Josef

Abstract

BACKGROUND
Immunization with plasmid DNA encoding various antigens is a promising method in vaccine research. Recent studies also indicate that DNA-based immunization might represent a potential approach in allergen-specific immunotherapy.
In this study we have characterized the immune responses induced by recombinant Bet v 1a and plasmid DNA encoding for Bet v 1a, the major allergen of birch pollen in a mouse system.
Balb/c mice were injected intraperitoneally with recombinant Bet v 1a and intradermally with plasmid DNA encoding for the gene of Bet v 1a (pCMV-Bet). In addition, the effect of immunostimulatory DNA sequences was investigated by appending CpG motifs to the gene of Bet v 1a, coinjecting CpG-oligodeoxynucleotides together with the pCMV-Bet construct, or both. IgE and IgG antibody responses, as well as IgG subclasses, were measured by ELISA in sera after each immunization. IFN-gamma and IL-4 levels were also measured by ELISA in sera and supernatants of allergen-stimulated spleen cells.
The primary humoral response to a single treatment with pCMV-Bet was very weak, but the reaction could be boosted to higher levels by 2 additional injections. On the other hand, proliferation assays of spleen cells and measurements of cytokine levels already indicated a cellular response after the first injection of plasmid DNA. After 2 immunizations with pCMV-Bet, the ratio of IgG1 to IgG2a pointed to a TH1 subclass profile. IgE was not detectable in any group at any time during the immune reaction. Accordingly, IL-4 levels were markedly reduced in the serum, as well as in the supernatants, of stimulated spleen cells. Animals immunized with pCMV-Bet containing appended CpG motifs at the 3" end of the Bet v 1a gene and/or with the CpG-ODN GCTAGACGTTAGCGT plus pCMV-Bet displayed reduced humoral responses against Bet v 1a when compared with animals injected with pCMV-Bet alone. The levels of IFN-gamma measured after allergen stimulation of isolated spleen cells were significantly higher in animals immunized with pCMV-Bet plus CpG motifs than with pCMV-Bet alone. Immunization with recombinant Bet v 1a protein elicited a strong TH2 -type response, including IgE production, a high titer of IgG1, and IL-4 production in both serum and supernatants of proliferation cultures.
In contrast to immunization with protein, DNA immunization induces a strong TH1 -type response against a relevant inhalant allergen. Our data support the concept of developing a novel type of allergen immunotherapy based on plasmid DNA immunization.


Useful keywords (using NLM MeSH Indexing)

Allergens/genetics

Allergens/immunology

Animals

Antibody Formation/drug effects

Antigens, Plant

Cell Division

CpG Islands/physiology

Cytokines/blood

DNA/immunology*

Female

Immunization

Immunotherapy*

Mice

Mice, Inbred BALB C

Plant Proteins/genetics*

Plant Proteins/immunology*

Plasmids/genetics*

Spleen/cytology

Th1 Cells/physiology


Find related publications in this database (Keywords)

Bet v 1a
DNA immunization
birch pollen allergen
immunotherapy
Balb/c