1. Immunopathology Section, Laboratory of Immunobiology, National Cancer Institute, Frederick Cancer Research and Development Center, Frederick, MD 21702, USA.
2. INSERM U211, Institut de Biologie-CHR, 44035 Nantes Cedex 01, France.
3. Laboratoire d'Hematologie Experimentale, Faculte de Medecine, 87025 Limoges Cedex, France.