1. Medical Research Council Human Immunology Unit, Institute of Molecular Medicine, John Radcliffe Hospital, Oxford OX3 9DS, United Kingdom
2. Aaron Diamond AIDS Research Center, The Rockefeller University, New York, New York 10016
3. Nuffield Department of Medicine, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom
4. University of California at San Diego, La Jolla, California 92093-0679
5. Veterans Administration Research Center for AIDS and HIV Infection, San Diego, California 92063
6. The Caldecot Centre, King's Healthcare National Health Service Trust, London SE5 9RS, United Kingdom