1. Kihara Institute for Biological Research and Graduate School of Integrated Science, Yokohama City University, Totsuka-ku, Yokohama 244-0813,1 and
2. Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-75252
3. Departments of Bioactive Molecules3 and
4. Bacteriology,4 National Institute of Infectious Diseases, Toyama 1-23-1, Shinjuku-ku, Tokyo 162-8640, Japan, and