Decreased FoxP3 gene expression in the nasal secretions from patients with allergic rhinitis

Objective: To determine whether patients with allergic rhinitis have altered FoxP3 gene expression and/or mutations. Study Design and Methods: We collected nasal secretions from 14 volunteers (five of whom have allergic rhinitis) and five ENT allergy patients. Total RNA was isolated from these nasal secretions. The gene expression levels of FoxP3 were quantified by both semi-quantitative RT-PCR and real-time PCR using Actin as a housekeeping gene. The cDNA fragments amplified by RT-PCR were analyzed by DNA sequencing. Results: We found that patients with allergic rhinitis had significantly lower FoxP3 mRNA compared to nonallergic controls (P < 0.01). In addition, we found a point mutation in the FoxP3 gene from a patient who not only has severe allergic rhinitis, but also has asthma. This mutation locates in a highly conserved region of FoxP3 gene and partially impaired FoxP3 functions. Conclusion: Our data indicate that either reduced FoxP3 gene expression or impaired FoxP3 functions are involved in the development of allergic disease in humans.