[1] Inst Pasteur, Unite Pathogenie Microbienne Mol, F-75724 Paris 15, France
[2] Inst Pasteur, Unite INSERM 786, F-75724 Paris 15, France
[3] Inst Pasteur, Unite Cytokines & Dev Lymphoide, F-75724 Paris 15, France
[4] Inst Pasteur, Unite INSERM 668, F-75724 Paris 15, France