Dendritic cell-derived VEGF-A plays a role in inflammatory angiogenesis of human secondary lymphoid organs and is driven by the coordinated activation of multiple transcription factors

Abstract

// Valentina Salvi 1 , William Vermi 1 , Veronica Gianello 1 , Silvia Lonardi 1 , Vincenzo Gagliostro 1 , Antonella Naldini 3 , Silvano Sozzani 1,2,* and Daniela Bosisio 1,* 1 Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy 2 Humanitas Clinical and Research Centre, Rozzano, Italy 3 Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy * These authors have contributed equally to this work Correspondence to: Silvano Sozzani, email: // Keywords : PAMPs, DAMPs, draining lymph node, CD1a+ interdigitating DCs, CD1c+ DCs, Pathology Section Received : March 17, 2016 Accepted : May 20, 2016 Published : May 31, 2016 Abstract Lymph node expansion during inflammation is essential to establish immune responses and relies on the development of blood and lymph vessels. Previous work in mice has shown that this process depends on the presence of VEGF-A produced by B cells, macrophages and stromal cells. In humans, however, the cell types and the mechanisms regulating the intranodal production of VEGF-A remain elusive. Here we show that CD11c + cells represent the main VEGF-A-producing cell population in human reactive secondary lymphoid organs. In addition we find that three transcription factors, namely CREB, HIF-1α and STAT3, regulate the expression of VEGF-A in inflamed DCs. Both HIF-1α and STAT3 are activated by inflammatory agonists. Conversely, CREB phosphorylation represents the critical contribution of endogenous or exogenous PGE 2 . Taken together, these results propose a crucial role for DCs in lymph node inflammatory angiogenesis and identify novel potential cellular and molecular targets to limit inflammation in chronic diseases and tumors.