[1] Univ Perugia, Dept Expt Med & Biochem Sci, Microbiol Sect, I-06122 Perugia, Italy
[2] Univ Roma Tor Vergata, Dept Expt Med & Biochem Sci, Microbiol Sect, Rome, Italy
[3] R&D Coley Pharmaceut, Langenfield, Germany
[4] Tech Univ Munich, Inst Med Microbiol Immunol & Hyg, D-8000 Munich, Germany
[5] Med Coll Wisconsin, Div Allergy Immunol, Milwaukee, WI 53226 USA
[6] Vet Affairs Med Ctr, Milwaukee, WI 53295 USA