TY - JOUR
T1 - Wiskott-Aldrich syndrome protein-mediated actin dynamics control type-I interferon production in plasmacytoid dendritic cells
AU - Prete, Francesca
AU - Catucci, Marco
AU - Labrada, Mayrel
AU - Gobessi, Stefania
AU - Castiello, Maria Carmina
AU - Bonomi, Elisa
AU - Aiuti, Alessandro
AU - Vermi, William
AU - Cancrini, Caterina
AU - Metin, Ayse
AU - Hambleton, Sophie
AU - Bredius, Robbert
AU - Notarangelo, Luigi Daniele
AU - van der Burg, Mirjam
AU - Kalinke, Ulrich
AU - Villa, Anna
AU - Benvenuti, Federica
PY - 2013/2
Y1 - 2013/2
N2 - Mutations in Wiskott-Aldrich syndrome (WAS) protein (WASp), a regulator of actin dynamics in hematopoietic cells, cause WAS, an X-linked primary immunodeficiency characterized by recurrent infections and a marked predisposition to develop autoimmune disorders. The mechanisms that link actin alterations to the autoimmune phenotype are still poorly understood. We show that chronic activation of plasmacytoid dendritic cells (pDCs) and elevated type-I interferon (IFN) levels play a role in WAS autoimmunity. WAS patients display increased expression of type-I IFN genes and their inducible targets, alteration in pDCs numbers, and hyperresponsiveness to TLR9. Importantly, ablating IFN-I signaling in WASp null mice rescued chronic activation of conventional DCs, splenomegaly, and colitis. Using WASp-deficient mice, we demonstrated that WASp null pDCs are intrinsically more responsive to multimeric agonist of TLR9 and constitutively secrete type-I IFN but become progressively tolerant to further stimulation. By acute silencing of WASp and actin inhibitors, we show that WASp-mediated actin polymerization controls intracellular trafficking and compartmentalization of TLR9 ligands in pDCs restraining exaggerated activation of the TLR9-IFN-α pathway. Together, these data highlight the role of actin dynamics in pDC innate functions and imply the pDC-IFN-α axis as a player in the onset of autoimmune phenomena in WAS disease.
AB - Mutations in Wiskott-Aldrich syndrome (WAS) protein (WASp), a regulator of actin dynamics in hematopoietic cells, cause WAS, an X-linked primary immunodeficiency characterized by recurrent infections and a marked predisposition to develop autoimmune disorders. The mechanisms that link actin alterations to the autoimmune phenotype are still poorly understood. We show that chronic activation of plasmacytoid dendritic cells (pDCs) and elevated type-I interferon (IFN) levels play a role in WAS autoimmunity. WAS patients display increased expression of type-I IFN genes and their inducible targets, alteration in pDCs numbers, and hyperresponsiveness to TLR9. Importantly, ablating IFN-I signaling in WASp null mice rescued chronic activation of conventional DCs, splenomegaly, and colitis. Using WASp-deficient mice, we demonstrated that WASp null pDCs are intrinsically more responsive to multimeric agonist of TLR9 and constitutively secrete type-I IFN but become progressively tolerant to further stimulation. By acute silencing of WASp and actin inhibitors, we show that WASp-mediated actin polymerization controls intracellular trafficking and compartmentalization of TLR9 ligands in pDCs restraining exaggerated activation of the TLR9-IFN-α pathway. Together, these data highlight the role of actin dynamics in pDC innate functions and imply the pDC-IFN-α axis as a player in the onset of autoimmune phenomena in WAS disease.
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U2 - 10.1084/jem.20120363
DO - 10.1084/jem.20120363
M3 - Article
C2 - 23337808
AN - SCOPUS:84874577141
VL - 210
SP - 355
EP - 374
JO - Journal of Experimental Medicine
JF - Journal of Experimental Medicine
SN - 0022-1007
IS - 2
ER -