Modulation of CRT h2 expression on allergen‐specific T cells following peptide immunotherapy

Background Allergen immunotherapy using synthetic peptide T‐cell epitopes (Cat‐PAD) from the major cat allergen Fel d 1 has been shown, in allergen exposure studies, to significantly reduce symptoms of allergic rhinoconjunctivitis in cat‐allergic subjects. However, the immunological mechanisms underlying clinical benefit remain only partially understood. Since previous studies of whole allergen immunotherapy demonstrated a reduction in the frequency of allergen‐specific (MHC II tetramer+) CD4+ T cells expressing the chemokine receptor CRTh2, we assessed the impact of Cat‐PAD on the frequency and functional phenotype of Fel d 1‐specific CD4+ T cells.