1. Department of Molecular Biology and Biochemistry, Rutgers University, P.O. Box 1059, Piscataway, New Jersey, 08855-1059, SBPM/DBCM CEA AND URA 1290 CNRS, Centre d'etudes de Saclay, 91191 Gif sur Yvette, France, OraVax Inc., 38 Sidney Street, Cambridge, Massachusetts 02139, and KAIROS Scientific Inc., 3350 Scott Boulevard, Santa Clara, California 95054