1. Laboratory of Microbiology and Virology, Vita-Salute San Raffaele University, Milan, Italy
2. Laboratory of Microbiology and Virology, IRCCS San Raffaele Scientific Institute, Milan, Italy
3. Harvard Medical School, Boston Children’s Hospital, Division of Immunology, Boston, Massachusetts, USA
4. Department of Rheumatology and Clinical Immunology, Humanitas Clinical and Research Center–IRCCS, Rozzano, Italy
5. Harvard Medical School, Boston Children’s Hospital, Division of Gastroenterology, Boston, Massachusetts, USA