Impaired T-cell receptor activation in IL-1 receptor- associated kinase-4-deficient patients

Background: IL-1 receptor-associated kinase 4 (IRAK-4) is an effector of the Toll-like receptor and IL-1 receptor pathways that plays a critical role in innate immune responses. The role of IRAK-4 in adaptive immune functions in human subjects is incompletely understood. Objective: We sought to evaluate T-cell function in IRAK-4 deficient patients. Methods: We compared up regulation of CD25 and CD69 on T cells and production of IL-2, IL-6, and IFN-g after stimulation of PBMCs from 4 IRAK-4-deficient patients and healthy control subjects with anti-CD3 and anti-CD28. Results: Upregulation of CD25 and CD69 on T cells and production of IL-6 and IFN-g, but not IL-2, was significantly reduced in IRAK-4-deficient patients. Conclusions: IRAK-4-deficient patients have defects in T-cell activation. (J Allergy Clin Immunol 2010; 126: 332-7.)