About the Authors
Department of Microbiology, Columbia University Medical Center, New York, New York, United States of America
Departments of Medicine and of Microbiology and Immunology, Howard Hughes Medical Institute, Rosalind Russell Medical Research Center for Arthritis, University of California, San Francisco, California, United States of America
The authors have declared that no competing interests exist.
Conceived and designed the experiments: XC JEG HAS. Performed the experiments: XC JEG MR. Analyzed the data: XC JEG JZ AW HAS. Contributed reagents/materials/analysis tools: JZ AW. Wrote the paper: XC JEG HAS.