1. Laboratory of Immunology
2. Medical Research Council Human Immunology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, United Kingdom
3. Infectious Disease Pathology Branch, Division of Viral and Rickettsial Diseases, Center for Disease Control and Prevention, Atlanta, Georgia 30333
4. Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892
5. Department of Epidemiology, School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7435
6. Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892
7. Hammersmith Hospital, Imperial College, London W12 0NN, United Kingdom