1. Department of Immunopharmacology, R & D Center, Daewoong Pharmaceutical Co. Ltd., Sungnam 462-120, Korea, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770, Japan, and Department of Immunology, Windeyer Institute of Medical Sciences, University College London Medical School, London W1P 6DB, United Kingdom