1. Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Rockville, MD 20852, USA.
2. Laboratory of Molecular Structure, NIAID, NIH, Rockville, MD 20852, USA.
3. Neuroimmunology Branch, National Institute of Neurological Diseases and Stroke, NIH, Bethesda, MD 20892, USA.
4. Istituto Nazionale per la Ricerca sul Cancro, 16132 Genova, Italy.
5. Istituto di Istologia e Embriologia Generale, University of Genova, 16132 Genova, Italy.