1. Department of Human Immunology, Research Institute for Frontier Medicine; Sapporo Medical University School of Medicine; Sapporo Japan
2. Department of Otolaryngology; Sapporo Medical University School of Medicine; Sapporo Japan
3. Department of Pathology; Sapporo Medical University School of Medicine; Sapporo Japan
4. Animal Resource Development Unit; RIKEN Center for Life Science Technologies; Kobe Japan
5. Genetic Engineering Team; RIKEN Center for Life Science Technologies; Kobe Japan