1. Department of Microbiology and Immunology and Division of Rheumatology, University of North Carolina, Chapel Hill, NC 27599.
2. Department of Pathology, University of North Carolina, Chapel Hill, NC 27599.
3. Department of Neuropharmacology, Scripps Clinic and Research Institute, La Jolla, CA 92037.
4. Department of Microbiology and Immunology and Lineberger Cancer Research Center, University of North Carolina, Chapel Hill, NC 27599.