[1] Erasmus Univ, Dept Immunol, NL-3000 DR Rotterdam, Netherlands
[2] TNO, PG, Div Immunol & Infect Dis, Prevent & Hlth, NL-2301 CE Leiden, Netherlands
[3] UCL Natl Hosp Neurol & Neurosurg, Inst Neurol, London WC1N 3BG, England
[4] Univ Basel, Kantonsspital, Neurol Klin, CH-4031 Basel, Switzerland