IL-4 and IL-13 alter plasmacytoid dendritic cell responsiveness to CpG DNA and herpes simplex virus-1

Abstract

Human plasmacytoid dendritic cells (pDCs) are found in skin lesions in a wide variety of diseases. The role of the microenvironment in these lesions on the function of human pDCs remains elusive. We sought to determine the effect of T h 2 cytokines on the ability of human pDCs to respond to CpG oligodeoxynucleotides (ODNs) and herpes simplex virus in vitro. In this study, we found that the T h 2 cytokines, IL-4 and IL-13, modulate Toll-like receptor 9 (TLR-9)- and herpes simplex virus-induced pDC phenotype and enhance the ability of these cells to induce allogeneic T-cell responses. Moreover, Th2 cytokines impaired TLR-9-induced secretion of inflammatory cytokines and chemokines. Taken together, these results demonstrate that Th2 cytokines are involved in the modulation of pDC function and responsiveness to bacterial- and viral-derived stimuli. © 2011 The Society for Investigative Dermatology.