Characterization of p-phenylenediamine-albumin binding sites and T-cell responses to hapten-modified protein.
J Invest Dermatol
; 130(3): 732-42, 2010 Mar.
Article
en En
| MEDLINE
| ID: mdl-19710686
ABSTRACT
Exposure to p-phenylenediamine (PPD) is associated with the development of T-cell-mediated allergic contact dermatitis. The purpose of this study was to define the nature of the interaction of PPD with the protein and the antigenic determinant that stimulates T cells. Mass spectrometry was employed to show that PPD oxidation products bind irreversibly to cysteine (Cys, position 34) in human serum albumin (HSA). A modified tryptic peptide was characterized with an increase in mass of 106 Da, corresponding to the addition of PPD and not to the secondary products of self conjugation. Lymphocytes from 10 PPD-allergic patients, but not tolerant/naive individuals, were stimulated with PPD and PPD-modified HSA. A total of 70 PPD-specific and 10 PPD-HSA-specific CD4+, CD8+, and CD4+CD8+, Th2-secreting T-cell clones were generated from three allergic patients. In total, 40 clones were stimulated with both PPD and PPD-modified HSA. PPD-modified HSA triggered T-cell responses through a classical hapten mechanism involving processing. Presentation of PPD to several clones was dependent on protein complex formation (42 out of 48) and processing (32 out of 68); however, 12% of clones were triggered with PPD directly. These data identify Cys as the single target for PPD-HSA binding, and show that PPD protein adducts are antigenic determinants in patients with contact dermatitis.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Fenilendiaminas
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Dermatitis Alérgica por Contacto
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Células Th2
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Albúminas
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Haptenos
Límite:
Adult
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Aged
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
J Invest Dermatol
Año:
2010
Tipo del documento:
Article
País de afiliación:
Reino Unido