1. Immunology Laboratory, Vaccine Research Center, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Bethesda, MD 20892, USA.
2. Humoral Immunology Section, Vaccine Research Center, NIAID, NIH, Bethesda, MD 20892, USA.
3. Laboratory of Molecular Microbiology, NIAID, NIH, Bethesda, MD 20892, USA.
4. Human Immunology Section, Vaccine Research Center, NIAID, NIH, Bethesda, MD 20892, USA.
5. Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
6. Cellular Immunology Section, Vaccine Research Center, NIAID, NIH, Bethesda, MD 20892, USA.
7. AIDS and Cancer Virus Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA.