IgE reactivity and cross-reactivity of Japanese monkeys (Macaca fuscata) to Japanese cedar (Cryptomeria japonica) and cypress (Chamaecyparis obtusa) pollen allergens

Cross-reactivity between major IgE core epitopes on Cry j 2 allergen of Japanese cedar pollen and relevant sequences on Cha o 2 allergen of Japanese cypress pollen

BACKGROUND

Cry j 2 and Cha o 2 are major allergens in Japanese cedar (Cryptomeria japonica; CJ) and Japanese cypress (Chamaecyparis obtusa; CO) pollen, respectively. Here, we assessed the epitopes related to the cross-reactivity between Cry j 2 and Cha o 2 using in vitro analyses.

METHODS

Peptides were synthesized based on Cry j 2 sequential epitopes and relevant Cha o 2 amino acid sequences. Four representative monoclonal antibodies (mAbs) against Cry j 2 were used according to their epitope recognitions. Serum samples were collected from 31 patients with CJ pollinosis. To investigate cross-reactivity between Cry j 2 and Cha o 2, ELISA and inhibition ELISA were performed with mAbs and sera from patients with CJ pollinosis.

RESULTS

Two of four mAbs had reactivity to both Cry j 2 and Cha o 2. Of these two mAbs, one mAb (T27) recognized the amino acid sequence (169)KVVNGRTV(176) on Cha o 2. This is related to the core epitope (169)KWVNGREI(176) on Cry j 2, which is an important IgE epitope. In addition, we found that these correlative sequences and purified allergens showed cross-reactivity between Cry j 2 and Cha o 2 in IgE of CJ patients.

CONCLUSIONS

We demonstrated the importance of (169)KVVNGRTV(176) in Cha o 2 for cross-reactivity with the Cry j 2 epitope (169)KWVNGREI(176), which plays an important role in allergenicity in CJ pollinosis. Our results are useful for the development of safer and more efficient therapeutic strategies for the treatment of CJ and CO pollen allergies.

Characterization of genes for a pollen allergen, Cry j 2, of Cryptomeria japonica

BACKGROUND

Cry j 2 is one of the major pollen allergens of Cryptomeria japonica. The polymorphism of Cry j 2 isoforms and the conservation of the structure of Cry j 2 in coniferous species remain to be analyzed.

METHODS

A cDNA library derived from the pollen of C. japonica was screened using a fragment of Cry j 2 cDNA. Restriction fragment length polymorphism analysis was performed to examine the diversity of Cry j 2 genes. The promoters of Cry j 2 genes were isolated with a commercially available cloning kit. Clonal variations in the expression of Cry j 2 in pollen were examined by RNA gel blot analysis, and the conservation of the structure of the Cry j 2 gene in coniferous species was evaluated by DNA gel blot analysis.

RESULTS

We isolated three cDNA clones encoding novel isoforms of Cry j 2. We also sequenced a total of 16 promoter regions from 10 specimens. The sequences of promoter regions of Cry j 2 genes were highly divergent. The amount of Cry j 2 mRNA also varied considerably. The Cry j 2 gene was found to be conserved among species belonging to Taxodiaceae and Cupressaceae but to vary between Taxodiaceae and Pinaceae.

CONCLUSIONS

The coding and promoter regions of Cry j 2 genes contain large numbers of polymorphisms. Our analysis revealed large variations in the expression of Cry j 2 at the transcriptional level, and we suggest that conserved homologs of Cry j 2 confer cross-allergenicity among Taxodiaceae and Cupressaceae.

IgE reactivity and cross-reactivity to Japanese cedar (Cryptomeria japonica) and cypress (Chamaecyparis obtusa) pollen allergens in dogs with atopic dermatitis

The natural occurrence of Japanese cedar (Cryptomeria japonica) pollinosis has been reported in dogs with atopic dermatitis. However, the reactivity to Japanese cypress (Chamaecyparis obtusa) pollen allergens in these dogs has not been reported. The present study was designed to investigate the reactivity to Japanese cypress pollen allergens in dogs sensitized to Japanese cedar pollen allergens. In 19 dogs with specific IgE to C. japonica pollen allergen, we measured the specific IgE to C. obtusa pollen allergen and examined the reactivity to the allergen by intradermal test. Of the 19 dogs, 18 had specific IgE to crude and purified major allergens (Cha o 1) of C. obtusa pollen. Most of the dogs showed a positive reaction to C. obtusa pollen allergens in the intradermal test. Allergenic cross-reactivity between Cha o 1 and Cry j 1 (a major allergen in C. japonica pollen) was observed by the ELISA inhibition method. Dogs sensitized to Japanese cedar pollen allergens demonstrate reactivity to Japanese cypress pollen allergens.

Sensitization to grass, ragweed, mugwort pollen allergens in Japanese monkeys (Macaca fuscata): preliminary report

BACKGROUND

The natural occurrence of Japanese cedar (CJ, Cryptomeria japonica) pollinosis has been reported in Japanese monkeys (Macaca fuscata). Furthermore, most of these monkeys with CJ pollinosis have immunoglobulin (Ig) E sensitization to Japanese cypress (Chamaecyparis obtusa) pollen. However, specific IgE to other pollens has not yet been reported.

OBJECTIVES

The present study was designed to investigate IgE sensitization of Japanese monkeys to grass, ragweed, and mugwort pollen.

METHODS

Serum samples from 47 monkeys as a general population in one troop were collected at random. We measured specific IgE to grass, ragweed and mugwort pollen. Next, 10 monkeys with CJ pollinosis from the same troop were also examined for their IgE sensitization to grass, ragweed, and mugwort pollen.

RESULTS

Of 47 monkeys, 13 (28%) had specific IgE to CJ pollen, 15 (32%) to grass pollen, five (11%) to ragweed pollen, and three (6%) to mugwort pollen. Furthermore, CJ pollinosis monkeys seemed to be sensitized to these pollen allergens with higher frequency; of 10 monkeys, 10 (100%) had specific IgE to CJ pollen, six (60%) to grass pollen, four (40%) to ragweed pollen, and two (20%) to mugwort pollen.

CONCLUSION

Japanese monkeys had specific IgE to grass, ragweed, and mugwort pollen in addition to CJ pollen.