Recombinant allergen fragments as candidate preparations for allergen immunotherapy.
BACKGROUND
Lately, renewed interest has arisen in the new forms of allergen immunotherapy because they may offer alternatives for drug treatment.


OBJECTIVE
The purpose of this study was to develop a well-characterized preparation of the main respiratory cow dander allergen, Bos d 2, with attenuated allergenic activity.


METHODS
The immunologic characteristics of Bos d 2 preparations were studied by indirect IgE ELISA, ELISA inhibition, Western blotting, histamine release, skin prick tests, and the proliferation tests of allergen-specific T-cell clones.


RESULTS
The complete recombinant Bos d 2 was observed to bind effectively, IgE of cow-allergic patients in indirect ELISA. In other experiments, the IgE-binding capacity of recombinant Bos d 2 proved to be lower compared with native Bos d 2. When the two overlapping recombinant fragments of Bos d 2 (corresponding amino acids 1-131 and 81-172, respectively) covering the whole molecule were compared with the complete recombinant Bos d 2 with several methods, only a low level of residual reactivity was observed. For example, recombinant fragments could not bind antibody at all in ELISA inhibition tests retaining, however, some reactivity in skin prick tests. In contrast, the fragments were able to stimulate vigorously Bos d 2-specific T-cell clones.


CONCLUSIONS
The approach we have taken may offer a simple and reproducible way to produce hypoallergenic preparations for immunotherapy, circumventing simultaneously some of the problems of other experimental methods such as individual T-cell epitope recognition in peptide-based immunotherapy.
Zeiler
T
T
Department of Clinical Microbiology, University of Kuopio, Finland.
Taivainen
A
A
Rytkönen
M
M
Rautiainen
J
J
Karjalainen
H
H
Mäntyjärvi
R
R
Tuomisto
L
L
Virtanen
T
T
D000328:Adult; D000485:Allergens / Q000235:genetics / Q000276:immunology / Q000494:pharmacology; D000818:Animals; D052179:Antigens, Plant; D001249:Asthma / Q000276:immunology / Q000628:therapy; D001667:Binding, Competitive; D015153:Blotting, Western; D002417:Cattle; D002999:Clone Cells / Q000187:drug effects / Q000276:immunology; D003888:Desensitization, Immunologic / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006636:Histamine Release / Q000187:drug effects; D006801:Humans; D007073:Immunoglobulin E / Q000096:biosynthesis / Q000097:blood; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000235:genetics / Q000276:immunology* / Q000627:therapeutic use*; D011506:Proteins; D011994:Recombinant Proteins / Q000276:immunology* / Q000627:therapeutic use*; D012882:Skin Tests; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology
D000485:Allergens; D052179:Antigens, Plant; C099745:BDA20 dander protein, Bos taurus; D010446:Peptide Fragments; D011506:Proteins; D011994:Recombinant Proteins; D007073:Immunoglobulin E