1. Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037
2. Core Microscopy, La Jolla Institute for Immunology, La Jolla, CA 92037
3. Department of Chemistry, The Scripps Research Institute, Jupiter, FL 33458
4. Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX 75390