[1] Univ Manchester, Fac Life Sci, Bill Ford Chair Cellular Immunol, Manchester M13 9PT, Lancs, England
[2] Helmholtz Ctr Infect Res, Dept Expt Immunol, Braunschweig, Germany
[3] Inst Pasteur, Cellular Biol Unit, Montevideo, Uruguay
[4] Rhein Westfal TH Aachen, Fac Med, Dept Pediat, Aachen, Germany