Optimized conjugation ratios lead to allergen immunostimulatory oligodeoxynucleotide conjugates with retained immunogenicity and minimal anaphylactogenicity.
BACKGROUND
Immunotherapy has gradually fallen out of favor for the treatment of many allergic diseases because of the overall convenience, safety, and efficacy of medications. However, investigations suggest that allergen/immunostimulatory sequence oligodeoxynucleotide (ISS-ODN) conjugates (AICs) might have improved safety and efficacy compared with allergen extracts.


OBJECTIVE
We determined whether changes in the ISS-ODN conjugation ratio would effect the immunogenicity and allergenicity of AIC.


METHODS
Immunogenicity was determined by means of AIC vaccination of mice, followed by analysis of antigen-specific antibody and cytokine responses. The allergenicity of AIC was determined in mast cell release studies and in murine models of anaphylaxis and the Arthus reaction.


RESULTS
AIC induced a stronger immune response than allergen alone or allergen mixed with ISS-ODN, but higher-level ISS-ODN conjugation reduced its immunogenicity modestly. In mast cell degranulation studies AIC was approximately 100-fold less allergenic than native allergen, with stepwise increases in the ODN conjugation ratio leading to stepwise decreases in allergenicity. In anaphylaxis studies death rates were reduced from 100% with native allergen challenge to as low as 0% with high-ratio ISS-ODN AIC challenge. Similar results were obtained in an Arthus reaction model.


CONCLUSIONS
These investigations establish that AIC is both significantly more immunogenic and less allergenic than native allergens and the techniques used might have further utility for the standardization and optimization of AIC formulations for use in allergic patients.
Horner
Anthony A
AA
Department of Medicine, and The Sam and Rose Stein Institute for Aging, University of California, San Diego, La Jolla 92093, USA.
Takabayashi
Kenji
K
Beck
Lucinda
L
Sharma
Bhavya
B
Zubeldia
Jose
J
Baird
Stephen
S
Tuck
Stephan
S
Libet
Lev
L
Spiegelberg
Hans L
HL
Liu
Fu-Tong
FT
Raz
Eyal
E
D000276:Adjuvants, Immunologic / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology; D000485:Allergens / Q000737:chemistry / Q000276:immunology*; D000707:Anaphylaxis / Q000209:etiology* / Q000401:mortality / Q000517:prevention & control; D000828:Animal Population Groups; D000818:Animals; D001183:Arthus Reaction / Q000209:etiology / Q000473:pathology; D001666:Binding Sites, Antibody; D015550:Cell Degranulation; D002478:Cells, Cultured; D000939:Epitopes / Q000276:immunology; D005260:Female; D007167:Immunotherapy / Q000379:methods; D008407:Mast Cells / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009838:Oligodeoxyribonucleotides / Q000009:adverse effects / Q000737:chemistry / Q000494:pharmacology; D010047:Ovalbumin / Q000276:immunology; D051381:Rats; D016019:Survival Analysis; D014407:Tumor Cells, Cultured
D000276:Adjuvants, Immunologic; D000485:Allergens; C408982:CPG-oligonucleotide; D000939:Epitopes; D009838:Oligodeoxyribonucleotides; D010047:Ovalbumin