1. INSERM U567, 75014 Paris, France.
2. CNRS UMR8104, 75014 Paris, France.
3. Université René Descartes, 75014 Paris, France.
4. Institut Cochin, Département d′ Immunologie, 75014 Paris, France.
5. Protein Engineering and Research Department, CEA-Saclay, 91191 Gif sur Yvette, France.