1. Department of Immunology; Kochi Medical School; Nankoku Kochi 783 Japan
2. Internal Medicine; Kochi Medical School; Nankoku Kochi 783 Japan
3. Medical Research Laboratories; Kochi Medical School; Nankoku Kochi 783 Japan
4. Division of Immunology; National Institute of Neuroscience, NCNP; Kodaira Tokyo 187 Japan