1. Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland.
2. Transgenic Core, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland.
3. Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland.