1. Department of Biochemistry and Molecular Biology
2. Department of Microbiology and Immunology, Center for Molecular Virology and Neuroimmunology, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 245 N. 15th Street, Philadelphia, Pennsylvania 19102
3. Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892