Protein sequence analysis of a novel 103-kDa Dermatophagoides pteronyssinus mite allergen and prevalence of serum immunoglobulin E reactivity to rDer p 11 in allergic adult patients.
BACKGROUND
House dust mites are regarded as important indoor allergens. While the most studies mite allergens are low molecular weight (mw), a high mw Dermatophagoides farinae mite paramyosin (Der f 11) has recently been cloned. We have also cloned a novel high mw Dermatophagoides pteronyssinus (Dp) mite allergen, Der p 11.


OBJECTIVE
The aim of this study was to isolate and express a cDNA gene coding for a Der p 11 allergen, to compare the sequence of Der p 11 with other antigens and to evaluate the presence of IgE reactivity to the recombinant protein (rDer p 11) in the sera of allergic adult patients.


METHODS
The full-length Der p 11 gene was isolated by cDNA library screening, 5'-3' rapid amplification of cDNA ends and PCR. The cDNA gene was expressed as a glutathione-S-transferase fusion protein in Escherichia coli. The allergenicity of rDer p 11 was tested by human IgE immunodot or immunoblot assay in a large panel of 100 allergic patients with bronchial asthma, allergic rhinitis or eczema.


RESULTS
Der p 11 is a 2965 bp cDNA gene with a 2625 bp open reading frame coding for a 875 amino acid protein. The deduced amino acid sequence of the Der p 11 showed significant homology with various invertebrate paramyosins. The prevalence of serum IgE reactivity to rDer p 11 on immunodot assay ranged from 41.7% to 66.7% in different allergic patient groups, whereas it was rare in non-atopic patients with urticaria (18.8%) and in normal individuals (8%). A high frequency (five out of eight) of MAST(Dp)- allergic serum samples had specific IgE-binding activity to rDer p 11 or its fragments on immunoblot assay, even though their IgE-binding activity to Dp extract was either weak or negative.


CONCLUSIONS
The 103-kDa Der p 11 appears to be major Dp mite allergen with a high frequency of IgE reactivity in sera of patients allergic to mites.
Department of Internal Medicine, Mackay Memorial Hospital, Mackay Junior College of Nursing, and Taipei Medical University, Taipei, Taiwan.
C-S
CS
Lee
L-C
LC
Tsai
P-L
PL
Chao
C-Y
CY
Lin
M-W
MW
Hung
A-I
AI
Chien
Y-T
YT
Chiang
S-H
SH
Han
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000485:Allergens / Q000235:genetics* / Q000276:immunology; D000595:Amino Acid Sequence; D039741:Antigens, Dermatophagoides / Q000235:genetics / Q000276:immunology; D060829:Arthropod Proteins; D001249:Asthma / Q000276:immunology; D001483:Base Sequence; D016022:Case-Control Studies; D040002:Dermatophagoides pteronyssinus / Q000276:immunology*; D004485:Eczema / Q000276:immunology; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D015151:Immunoblotting; D007073:Immunoglobulin E / Q000097:blood*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000276:immunology; D012221:Rhinitis, Allergic, Perennial / Q000276:immunology; D020539:Sequence Analysis, Protein; D014581:Urticaria / Q000276:immunology
D000485:Allergens; D039741:Antigens, Dermatophagoides; D060829:Arthropod Proteins; C451160:Dermatophagoides farinae antigen f 2; C451163:Dermatophagoides pteronyssinus antigen p 2; D011994:Recombinant Proteins; D007073:Immunoglobulin E