Impaired TH2 response in patients with Vav1-deficient common variable immunodeficiency with T-cell defects.

Based on these background studies, here we investigated the effect of the defect in Vav1 expression observed in 4 of 32 patients with CVID on TH1/TH2 differentiation. We measured IL-4 and IFN-γ T-cell production, as well as expression of GATA-3, c-Maf, and T-bet, in 4 patients with CVID with defective Vav1 expression (T-CVID1, T-CVID2, T-CVID3, and T-CVID4)6 and 5 healthy control subjects. The present study indicates that Vav1 deficiency and impaired expression of the TH2 lineage–specific transcription factors c-Maf and GATA-3 underlie the T-cell defects harbored by a proportion of patients with CVID and suggests a potential future therapeutic intervention strategy based on restoring normal Vav1 levels in the defective patient's T cells.