Common antigenicity between Japanese cedar (Cryptomeria japonica) pollen and Japanese cypress (Chamaecyparis obtusa) pollen, II. Determination of the cross‐reacting T‐cell epitope of Cry j 1 and Cha o 1 in mice

Abstract

We have previously detected common antigenicity between Cry j 1 and Cha o 1 in B10.S mice. B10.S mice immunized with Cry j 1‐ or Cha o 1‐generated T cells and antibodies reactive to both allergens. In the present study, we investigated the cross‐reacting and Cry j 1‐specific T‐cell epitopes in B10.S mice. Lymph node cells from B10.S mice immunized with Cry j 1 recognized Cry j 1 p111–130, p211–230, and p310–330 as well as Cha o 1 p209–228. The existence of the cross‐reacting T‐cell epitope in Cry j 1 and Cha o 1 was confirmed by the response of newly established p211–230‐specific and Cha o 1 p209–228‐specific T‐cell lines. The minimum peptide sequence (p213–224) of the cross‐reacting T‐cell epitope was identical in Cry j 1 and Cha o 1. These findings clearly demonstrate that common antigenicity at the T‐cell level between Japanese cedar and cypress pollen allergens was caused by the existence of an identitical‐cell epitope in Cry j 1 and Cha o 1.