Isolation and characterization of the mountain cedar (Juniperus ashei) pollen major allergen, Jun a 1.
BACKGROUND
Cedar pollens are important causes of seasonal allergic disease in diverse geographic areas.


OBJECTIVE
A major allergen from mountain cedar (Juniperus ashei) pollen, termed Jun a 1, was isolated and characterized.


METHODS
Water-soluble pollen glycoproteins were extracted, salt precipitated, and purified with use of concanavalin A affinity chromatography or HPLC. The purified fractions were characterized by SDS-PAGE, immunoblotting, and N-terminal amino acid sequence analysis. Binding of allergen-specific IgE from the sera of cedar-hypersensitive patients was detected by ELISA and antigen-specific responses of peripheral blood T cells by tritiated thymidine incorporation.


RESULTS
The major extractable cedar pollen glycoprotein had a molecular weight and N-terminal amino acid sequence that was similar to that of the major allergen Cha o 1, from Japanese cypress (Chamaecyparis obtusa), and Cry j 1, from Japanese cedar (Cryptomeria japonica). IgE from cedar-hypersensitive patients' sera bound to the isolated glycoprotein.


CONCLUSIONS
The predominance of Jun a 1 in the soluble proteins of mountain cedar pollen and its high degree of homology with Cha o 1 and Cry j 1 make it likely to be the major allergen of this pollen. Amino acid sequence conservation also makes Jun a 1 a potential target for cross-reactivity between these pollen allergens. The observed reactivity of IgE from the sera of Japanese cedar-sensitive patients with Jun a 1 is consistent with this proposition.
Midoro-Horiuti
T
T
Department of Pediatrics, University of Texas Medical Branch at Galveston, 77555-0366, USA.
Goldblum
R M
RM
Kurosky
A
A
Goetz
D W
DW
Brooks
E G
EG
D000485:Allergens / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification; D052179:Antigens, Plant; D002455:Cell Division; D002478:Cells, Cultured; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D007526:Isoelectric Point; D018653:Juniperus; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology; D008970:Molecular Weight; D010940:Plant Proteins / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification; D011058:Pollen / Q000276:immunology*; D006255:Rhinitis, Allergic, Seasonal / Q000097:blood / Q000209:etiology* / Q000276:immunology; D017421:Sequence Analysis
D000485:Allergens; D052179:Antigens, Plant; D010940:Plant Proteins; C121951:jun a 1 protein, Juniperus ashei; D007073:Immunoglobulin E