1Max-Planck Institute for Immunology, Department of Developmental Immunology, D-79108 Freiburg, Germany2Research Center Ospedale Bambino Gesu[Combining Grave Accent], 00165 Roma, Italy3Department of Hematology, Heinrich Heine University, D-40225 Du[Combining Diaeresis]sseldorf, Germany4Fe[Combining Acute Accent]de[Combining Acute Accent]ration des Maladies Infectieuses, CHU Hotel Dieu, 63003 Clermont-Ferrand, France5Division of Rheumatology and Clinical Immunology, University Hospital, D-79106 Freiburg, Germany6University Children's Hospital, D-79106 Freiburg, Germany7Division of Pediatrics and Institute of Molecular Medicine “Angelo Nocivelli, ” University of Brescia, 25123 Brescia, Italy8Department of Clinical Medicine, University of Rome “La Sapienza,” 00165 Roma, Italy