[1] Scripps Res Inst, Dept Mol Biol, La Jolla, CA 92037 USA
[2] Torrey Pines Inst Mol Studies, San Diego, CA 92121 USA
[3] Natl Inst Communicable Dis, ZA-2131 Johannesburg, South Africa
[4] Scripps Res Inst, Dept Immunol, La Jolla, CA 92037 USA
[5] Scripps Res Inst, Dept Immunol & Mol Biol, La Jolla, CA 92037 USA
[6] Scripps Res Inst, Dept Mol Biol, La Jolla, CA 92037 USA
[7] Scripps Res Inst, Skaggs Inst Chem Biol, La Jolla, CA 92037 USA