1. T. Kawano, J. Cui, I. Toura, Y. Kaneko, H. Sato, E. Kondo, H. Koseki, M. Taniguchi, CREST (Core Research for Evolutional Science and Technology) Project, Japan Science and Technology Corporation (JST), and Division of Molecular Immunology, Center for Biomedical Science, School of Medicine, Chiba University, 1-8-1 Inohana, Chuo, Chiba 260, Japan.
2. Y. Koezuka, K. Motoki, H. Ueno, R. Nakagawa, Pharmaceutical Research Laboratory, Kirin Brewery, 3 Miyahara, Takasaki, Gunma 370-12, Japan.