1. Department of Host Defense and Biochemical Research, Juntendo University Graduate School of Medicine, Tokyo 113‑8421, Japan
2. Atopy (Allergy) Research Center, Juntendo University Graduate School of Medicine, Tokyo 113‑8421, Japan
3. Division of Oral Microbiology, Tohoku University Graduate School of Dentistry, Sendai‑shi, Miyagi 980‑8575, Japan
4. Endotoxin Test Service, Microcoat Biotechnologie GmbH, D‑82347 Bernried, Germany