Characterization of folded recombinant Der p 5, a potential diagnostic marker allergen for house dust mite allergy.
BACKGROUND
Der p 5 was reported as an important allergen in Dermatophagoides pteronyssinus, which is particularly recognized by patients suffering from asthma. The aim of this study was to produce, by recombinant DNA technology, a folded Der p 5 allergen for diagnostic, therapeutic and preventive purposes.


METHODS
Der p 5-encoding cDNA was isolated from a lambda gt11 D. pteronyssinus expression cDNA library and expressed in Escherichia coli. rDer p 5 was purified to homogeneity and characterized by mass spectroscopy and circular dichroism. IgE reactivity was tested with sera from 117 mite-allergic patients and in a basophil histamine release experiment. Der p 5-specific rabbit IgG antibodies were produced for the ultrastructural localization of the allergen in mites by immunogold electron microscopy as well as for cross-reactivity studies.


RESULTS
rDer p 5 is a heat-stable protein with predominantly alpha-helical secondary structure which reacted with IgE from 31% of mite-allergic patients' sera and showed no relevant cross-reactivity to group 5 allergens from storage mites and tropical mites. rDer p 5-specific rabbit IgG antibodies inhibited mite-allergic patients' IgE binding to Der p 5 and allowed to localize the allergen in secretory granules of midgut epithelial cells of house dust mites.


CONCLUSIONS
The described rDer p 5 molecule may be useful for diagnosis and immunotherapy of house dust mite-allergic patients.
Division of Immunopathology, Department of Pathophysiology, Center for Physiology and Pathophysiology, Medical University of Vienna, Vienna, Austria.
Margit
M
Weghofer
Monika
M
Grote
Yuliya
Y
Dall'Antonia
Enrique
E
Fernández-Caldas
Maria-Theresa
MT
Krauth
Marianne
M
van Hage
Friedrich
F
Horak
Wayne R
WR
Thomas
Peter
P
Valent
Walter
W
Keller
Rudolf
R
Valenta
Susanne
S
Vrtala
D000485:Allergens / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D000818:Animals; D039741:Antigens, Dermatophagoides / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D060829:Arthropod Proteins; D001491:Basophils / Q000276:immunology; D004926:Escherichia coli / Q000235:genetics; D006636:Histamine Release; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis / Q000276:immunology*; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D017510:Protein Folding; D017433:Protein Structure, Secondary; D039981:Pyroglyphidae / Q000276:immunology*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*
D000485:Allergens; D039741:Antigens, Dermatophagoides; D060829:Arthropod Proteins; C451239:Dermatophagoides pteronyssinus antigen p 5; D011994:Recombinant Proteins; D007073:Immunoglobulin E