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Contributions of the N-terminal flanking residues of an antigenic peptide from the Japanese cedar pollen allergen Cry j 1 to the T-cell activation by HLA-DP5

Cry j 1 is a major allergen present in Japanese cedar (Cryptomeria japonica) pollens. Peptides with the core sequence of KVTVAFNQF from Cry j 1 (‘pCj1’) bind to HLA-DP5 and activate Th2 cells. In this study, we noticed that Ser and Lys at positions −2 and −3, respectively, in the N-terminal flanking...

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Detalles Bibliográficos
Autores principales: Kusano, Seisuke, Ueda, Sho, Oryoji, Daisuke, Toyoumi, Aya, Hashimoto-Tane, Akiko, Kishi, Hiroyuki, Hamana, Hiroshi, Muraguchi, Atsushi, Jin, Hui, Arase, Hisashi, Miyadera, Hiroko, Kishikawa, Reiko, Yoshikai, Yasunobu, Yamada, Hisakata, Yamamoto, Ken, Nishimura, Yasuharu, Saito, Takashi, Sasazuki, Takehiko, Yokoyama, Shigeyuki
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10478803/
https://www.ncbi.nlm.nih.gov/pubmed/37418020
http://dx.doi.org/10.1093/intimm/dxad024
Descripción
Sumario:Cry j 1 is a major allergen present in Japanese cedar (Cryptomeria japonica) pollens. Peptides with the core sequence of KVTVAFNQF from Cry j 1 (‘pCj1’) bind to HLA-DP5 and activate Th2 cells. In this study, we noticed that Ser and Lys at positions −2 and −3, respectively, in the N-terminal flanking (NF) region to pCj1 are conserved well in HLA-DP5-binding allergen peptides. A competitive binding assay showed that the double mutation of Ser(–2) and Lys(–3) to Glu [S(P–2)E/K(P–3)E] in a 13-residue Cry j 1 peptide (NF-pCj1) decreased its affinity for HLA-DP5 by about 2-fold. Similarly, this double mutation reduced, by about 2-fold, the amount of NF-pCj1 presented on the surface of mouse antigen-presenting dendritic cell line 1 (mDC1) cells stably expressing HLA-DP5. We established NF-pCj1-specific and HLA-DP5-restricted CD4(+) T-cell clones from HLA-DP5 positive cedar pollinosis (CP) patients, and analyzed their IL-2 production due to the activation of mouse TG40 cells expressing the cloned T-cell receptor by the NF-pCj1-presenting mDC1 cells. The T-cell activation was actually decreased by the S(P–2)E/K(P–3)E mutation, corresponding to the reduction in the peptide presentation by this mutation. In contrast, the affinity of NF-pCj1·HLA-DP5 for the T-cell receptor was not affected by the S(P–2)E/K(P–3)E mutation, as analyzed by surface plasmon resonance. Considering the positional and side-chain differences of these NF residues from previously reported T-cell activating sequences, the mechanisms of enhanced T-cell activation by Ser(–2) and Lys(–3) of NF-pCj1 may be novel.