1. School of Medicine, Vita-Salute San Raffaele University, Milan, Italy.
2. AIDS Immunopathogenesis Unit, Division of Immunology, Transplantation and Infectious Diseases, San Raffaele Scientific Institute, Milan, Italy.
3. Pathology Unit, Department of Clinical Sciences, L. Sacco Hospital, Università degli Studi di Milano, Milan, Italy.
4. Department of Clinical Sciences, Centro di Microscopia Elettronica per lo studio delle Nanotecnologie Applicate alla medicina “C.M.E.N.A.,” L. Sacco Hospital, University of Milan, Milan, Italy.