[1] La Jolla Inst Allergy & Immunol, San Diego, CA 92109 USA
[2] Univ Wisconsin, Natl Primate Res Ctr, WPRC, Madison, WI 53715 USA
[3] Univ Wisconsin, Sch Med, Dept Pathol & Lab Med, Madison, WI 53706 USA
[4] Calif State Univ, Dept Biol Sci, San Marcos, CA 92096 USA