[1] Royal Vet & Agr Univ, Dept Vet Virol & Immunol, DK-1870 Frederiksberg C, Denmark
[2] CISA, INIA, Valdeolmos 28130, Madrid, Spain
[3] Massachusetts Gen Hosp, Transplantat Biol Res Ctr, Charlestown, MA 02129 USA
[4] Cent Vet Inst, CDI, NL-8200 AB Lelystad, Netherlands
[5] Babraham Inst, Dept Immunol, T Cell Lab, Cambridge CB2 4AT, England
[6] Pig Res Inst Taiwan, Chunan 35099, Taiwan
[7] Washington State Univ, Dept Vet Microbiol & Pathol, Pullman, WA 99164 USA
[8] AFRC, Inst Anim Hlth, Pirbright Lab, Woking GU24 0NF, Surrey, England
[9] Univ Bristol, Sch Med, Dept Vet Med, Bristol BS18 7DV, Avon, England
[10] Finch Univ Hlth Sci Chicago Med Sch, Dept Microbiol & Immunol, N Chicago, IL 60064 USA
[11] Univ L Rotvos, Dept Immunol, H-2131 God, Hungary
[12] Fed Res Ctr Virus Dis Anim, D-72001 Tubingen, Germany
[13] Univ Greifswald, Inst Immunol & Transfus Med, D-17487 Greifswald, Germany
[14] Natl Inst Anim Hlth, Oho, Ibaraki 305, Japan
[15] Univ Illinois, Dept Vet Pathobiol, Urbana, IL 61801 USA