Isolation and characterization of native Cry j 3 from Japanese cedar (Cryptomeria japonica) pollen.
BACKGROUND
Japanese cedar (Cryptomeria japonica) pollinosis is the most prevalent allergy in Japan. Recently, the Japanese cedar pollen allergen Cry j 3 was cloned as a homologue of Jun a 3, which is a major allergen from mountain cedar (Juniperus ashei) pollen. However, native Cry j 3 has not been isolated and there are no reports on its allergenic activity. The aims of this study were to isolate native Cry j 3 and assess its immunoglobulin E (IgE)-binding capacity in patients with Japanese cedar pollinosis.


METHODS
Native Cry j 3 was purified from Japanese cedar pollen by multidimensional chromatography. We assessed the IgE-binding capacity using sera from patients allergic to Japanese cedar pollen by immunoblot analysis and ELISA. Moreover, we assayed the capacity of Cry j 3 to induce histamine release from the patients' leukocytes. We cloned cDNA corresponding to purified Cry j 3 from a cDNA library of Japanese cedar pollen.


RESULTS
We isolated native Cry j 3 as a 27-kDa protein. The IgE-binding frequency of Cry j 3 from the sera of patients allergic to Japanese cedar pollen was estimated as 27% (27/100) by ELISA. Cry j 3 induced the release of histamine from leukocytes. We cloned the cDNA and named it Cry j 3.8. Cry j 3.8 cDNA encoded 225 amino acids and had significant homology with thaumatin-like proteins.


CONCLUSIONS
Cry j 3 is a causative allergen in Japanese cedar pollinosis and may play crucial roles in the cross-reactivity with oral allergy syndrome.
Fujimura
T
T
Graduate School of Medicine, Chiba University, Chiba, Japan.
Futamura
N
N
Midoro-Horiuti
T
T
Togawa
A
A
Goldblum
R M
RM
Yasueda
H
H
Saito
A
A
Shinohara
K
K
Masuda
K
K
Kurata
K
K
Sakaguchi
M
M
D000595:Amino Acid Sequence; D052179:Antigens, Plant / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism; D001483:Base Sequence; D001666:Binding Sites, Antibody; D032485:Cryptomeria / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology / Q000378:metabolism; D007073:Immunoglobulin E / Q000096:biosynthesis / Q000097:blood; D008969:Molecular Sequence Data; D011058:Pollen / Q000737:chemistry / Q000276:immunology*; D011485:Protein Binding / Q000276:immunology; D020033:Protein Isoforms / Q000276:immunology / Q000378:metabolism
D052179:Antigens, Plant; C518869:Cry j 3 allergen, Cryptomeria japonica; D020033:Protein Isoforms; D007073:Immunoglobulin E