Parietaria judaica–specific T-cell clones from atopic patients: Heterogeneity in restriction, Vβ usage, and cytokine profile

Abstract

The pollen of Parietaria spp. is one of the most clinically relevant sources of allergens in the Mediterranean area. CD4 + T-lymphocyte clones specific for Parietaria allergens were isolated from peripheral blood of atopic donors, and their phenotype, HLA restriction, Vβ usage, and cytokine profile were determined. All the T-cell clones expressed the α/β T-cell receptor and were induced to express CD40 ligand after activation with phorbol-myristate-acetate plus ionomycin. When the proliferative response to three chromatographic fractions of the extract was analyzed, distinct reactivity patterns were found. Interestingly, most of the clones responded to the fraction that was the most enriched for the major allergen Par j 1. The clones were either HLA-DR– or HLA-DQ–restricted and did not show any preferential usage of T-cell receptor Vβ segments. Five of the 17 clones tested produced only IL-4 and no interferon-γ, thus displaying a T H 2 phenotype. The other clones displayed a T H 0 phenotype in that they produced both IL-4 and interferon-γ. These results show that in atopic patients T-cell response against Parietaria judaica allergen involves different T-cell subsets in terms of restriction, Vβ usage, and cytokine profile. (J A LLERGY C LIN I MMUNOL 1996;97:627-37.)