About the Authors
Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America
Dipartimento di Medicina Sperimentale e Scienze Biochimiche, Università degli Studi di Perugia, Terni, Italy
The authors have declared that no competing interests exist.
The author(s) have made the following declarations about their contributions: Conceived and designed the experiments: FB PG FC. Performed the experiments: FB PG FM. Analyzed the data: FB PG AS CV FC. Contributed reagents/materials/analysis tools: FC. Wrote the paper: FB FC.