Complement receptor 2 and IL-8 production identify in humans naïve T cells recently emigrating from the thymus and a Th8-like subset of memory T cells

ABSTRACT The adaptive immune system utilizes multiple mechanisms linked to innate immune cell functions to respond appropriately to pathogens and commensals. Here we discover further aspects of this connectivity by demonstrating that naive T cells as they emerge from the thymus express complement receptor 2 (CR2), the bacterial pathogen recognition receptor TLR1 and an enzyme that deactivates bacterial lipopolysaccharide (AOAH) and following activation during tissue immunesurveillance secrete the anti-microbial cytokine IL-8. CR2+ naive cells and a novel subset of IL-8-producing CR2+ memory cells are abundant in children but decrease with age. The ability of CR2, which is also a receptor for Epstein-Barr Virus (EBV), to identify recent thymic emigrants will facilitate assessment of thymic function during aging and aid investigations of multiple clinical areas including generation of T cell lymphomas caused by EBV.