[1] Univ Washington, Dept Lab Med, Seattle, WA 98195 USA
[2] Univ Washington, Dept Microbiol, Seattle, WA 98195 USA
[3] Univ Washington, Dept Pathobiol, Seattle, WA 98195 USA
[4] Univ Lyon 1, IFR128, F-69365 Lyon, France
[5] Univ Lyon 1, Inst Biol & Chim Proteines, UMR 5086, CNRS, F-69365 Lyon, France
[6] Inst Virol, Moscow, Russia