Identification of IgE-binding components of citrus red mite in sera of patients with citrus red mite-induced asthma.
BACKGROUND
Our previous investigations demonstrated that citrus red mite (CRM) antigen could cause IgE-mediated bronchoconstriction in exposed farmers working on citrus farms.


OBJECTIVE
This study was performed to confirm IgE-binding components and major allergens within the CRM antigens.


METHODS
Ten subjects who had been diagnosed as having CRM-induced asthma were enrolled. Serum-specific IgE antibodies to CRM antigens were measured by using an ELISA. To identify IgE-binding components and major allergens, SDS-PAGE, 2-dimensional PAGE, IgE-immunoblot analysis, and amino acid sequencing of major allergens were performed.


RESULTS
All the asthmatic subjects had high specific IgE antibodies to CRMs. Twelve percent SDS-PAGE analysis showed more than 10 protein bands ranging from 6 to 64 kd. SDS-PAGE and IgE-immunoblot analysis with each individual serum showed 5 IgE-binding components (11, 24, 35, 40, and 64 kd), with 2 (24 and 35 kd) of them bound in more than 50% of the study subjects. Two-dimensional PAGE and IgE-immunoblot analysis demonstrated that the major allergen at 24 kd had 2 bands with different isoelectric points of 4.75 and 5.1. Thirty-five kilodaltons had one band with an isoelectric point of 4.75. All amino acid sequencing of the 2 major allergens was performed, which was not homologous with any previously characterized allergens.


CONCLUSIONS
Five IgE-binding components and 2 major allergens (24 and 35 kd) were identified within the CRM antigen. The N-terminal amino acid sequence of the 2 major allergens (24 and 35 kd) was determined.
Kim
H Y
HY
Department of Allergy and Clinical Immunology, Ajou University School of Medicine, Suwon, Korea.
Park
H S
HS
Kim
Y K
YK
Son
J W
JW
Kim
H A
HA
Suh
J H
JH
Nahm
D H
DH
Cho
S H
SH
Min
K U
KU
Kim
Y Y
YY
D000328:Adult; D000368:Aged; D000485:Allergens / Q000032:analysis; D000595:Amino Acid Sequence; D000818:Animals; D001249:Asthma / Q000097:blood* / Q000469:parasitology*; D002957:Citrus / Q000469:parasitology*; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D005260:Female; D006801:Humans; D015151:Immunoblotting; D007073:Immunoglobulin E / Q000097:blood*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D012882:Skin Tests; D012967:Sodium Dodecyl Sulfate; D014324:Trombiculidae / Q000276:immunology*
D000485:Allergens; D012967:Sodium Dodecyl Sulfate; D007073:Immunoglobulin E