1. Division of Cytokine Signaling, Graduate School of Medical Sciences, Nagasaki University, Nagasaki, Japan
2. Department of AIDS Research, Institute of Tropical Medicine, G-COE, Nagasaki University, Nagasaki, Japan
3. Department of Immunology, Graduate School and Faculty of Medicine, University of the Ryukyus, Okinawa, Japan
4. Present address: Department of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA