[1] Mayo Clin, Dept Pediat & Adolescent Med, Rochester, MN 55905 USA
[2] Mayo Clin, Dept Biochem & Mol Biol, Rochester, MN 55905 USA
[3] Univ Groningen, Univ Med Ctr Groningen, Dept Pathol & Med Biol, NL-9700 RB Groningen, Netherlands
[4] Mayo Clin, Dept Med, Rochester, MN 55905 USA
[5] Mayo Clin, Dept Immunol, Rochester, MN 55905 USA