[1] Univ N Carolina, Dept Microbiol & Immunol, Chapel Hill, NC USA
[2] Univ Chicago, Dept Biochem & Mol Biol, 920 E 58th St, Chicago, IL 60637 USA
[3] Univ Chicago, Dept Microbiol, Chicago, IL 60637 USA
[4] Univ Washington, Dept Microbiol, Dept Immunol, Dept Genome Sci,Dept Med, Seattle, WA 98195 USA
[5] Harvard TH Chan Sch Publ Hlth, Dept Immunol & Infect Dis, Boston, MA USA