1. Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, and
2. Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD;
3. Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark; and
4. Laboratory of Bacterial Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD