[1] Harvard Univ, Sch Med, Massachusetts Gen Hosp, Dept Pediat,Lab Dev Immunol, Boston, MA 02114 USA
[2] Aarhus Univ, Dept Med Microbiol & Immunol, DK-8000 Aarhus C, Denmark
[3] Harvard Univ, Sch Med, Dept Dermatol, Wellman Lab Photomed, Boston, MA 02114 USA