The proteolytic activity of the major dust mite allergen Der p 1 enhances the IgE antibody response to a bystander antigen.
BACKGROUND
We have recently demonstrated that immunization of mice with proteolytically active Der p 1, the major dust mite allergen, results in a significant enhancement in total and Der p 1-specific IgE synthesis compared to mice immunized with Der p 1 that has been irreversibly blocked with the cysteine protease inhibitors E-64 and iodoacetamide. Thus, the demonstration that the proteolytic activity of Der p 1 enhances total IgE production, apart from increasing Der p 1-specific IgE, suggests that this allergen may have an IgE-specific adjuvant effect.


OBJECTIVE
To determine if the proteolytic activity of Der p 1 has an IgE-specific adjuvant effect.


METHODS
We have examined this concept in experiments whereby ovalbumin, used as a bystander antigen, was injected alone or coinjected with either proteolytically active or inactive Der p 1 into groups of mice and IgE and IgG antibody responses were measured.


RESULTS
Here we demonstrate for the first time that the proteolytic activity of Der p 1, when given at 10-fold higher concentration, enhances the IgE antibody response to ovalbumin.


CONCLUSIONS
These findings show that the proteolytic activity of Der p 1 leads to the augmentation of IgE antibody responses to itself and to other allergens present in the microenvironment.
Gough
L
L
Division of Molecular and Clinical Immunology, Faculty of Medicine and Health Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, UK.
Sewell
H F
HF
Shakib
F
F
D000485:Allergens / Q000276:immunology* / Q000378:metabolism*; D000818:Animals; D000917:Antibody Formation / Q000276:immunology; D000941:Antigens / Q000276:immunology; D039741:Antigens, Dermatophagoides; D024201:Bystander Effect / Q000276:immunology*; D015853:Cysteine Proteinase Inhibitors / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000378:metabolism; D006023:Glycoproteins / Q000276:immunology* / Q000378:metabolism*; D007114:Immunization; D007073:Immunoglobulin E / Q000096:biosynthesis* / Q000187:drug effects / Q000276:immunology*; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000187:drug effects / Q000276:immunology; D007460:Iodoacetamide / Q000378:metabolism; D051379:Mice; D008808:Mice, Inbred CBA; D008925:Mites / Q000276:immunology; D023421:Models, Animal; D010047:Ovalbumin / Q000276:immunology*
D000485:Allergens; D000941:Antigens; D039741:Antigens, Dermatophagoides; D015853:Cysteine Proteinase Inhibitors; D004791:Enzyme Inhibitors; D006023:Glycoproteins; D007074:Immunoglobulin G; D007073:Immunoglobulin E; D010047:Ovalbumin; D007460:Iodoacetamide