Affiliation: | 1. Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA;2. Department of Microbiology and Immunology, Stanford University School of Medicine, 259 Campus Drive, Stanford, CA 94305, USA;3. Departments of Medicine and of Microbiology and Immunology, Stanford University, Stanford, CA 94305-5124, USA;4. Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA |