[1] Vet Adm Med Ctr, Mucosal & Vaccine Res Ctr, Minneapolis, MN 55417 USA
[2] Univ Minnesota, Dept Med, Minneapolis, MN 55455 USA
[3] Univ Buffalo, VA Med Ctr, Buffalo, NY USA
[4] Univ Buffalo, Dept Med, Buffalo, NY USA
[5] Univ Buffalo, Dept Microbiol, Buffalo, NY USA
[6] Univ Buffalo, Witebsky Ctr Microbial Pathogenesis & Immunol, Buffalo, NY USA