About the Authors
Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
The authors have declared that no competing interests exist.
Conceived and designed the experiments: JY RGM. Performed the experiments: JY RP SR JM. Analyzed the data: JY RP SR JM RGM. Contributed reagents/materials/analysis tools: RGM. Wrote the paper: JY RP RGM.