1. Department of Biomedical Sciences, University of Sassari, 07100 Sassari, Italy
2. Division of Immunology, International Institute of Infection and Immunity, Shantou University Medical College, Shantou 515031, China
3. Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy
4. Department of Medicine, Surgery and Pharmacy, University of Sassari, 07100 Sassari, Italy
5. Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
6. Sbarro Institute for Cancer Research and Molecular Medicine, Centre for Biotechnology, College of Science and Technology, Temple University, Philadelphia, PA 19122, USA