About the Authors
Immunopathogensis Section, Laboratory of Parasitic Diseases, National Institutes of Allergy and Infectious Disease, National Institutes of Health, Bethesda, Marlyand, United States of America
Biomedical Research Institute, Rockville, Maryland, United States of America
The authors have declared that no competing interests exist.
Conceived and designed the experiments: MSW AWC TAW. Performed the experiments: MSW AWC SDW RWT. Analyzed the data: MSW AWC. Wrote the paper: TAW MSW.