[1] SCRIPPS RES INST, DEPT IMMUNOL, LA JOLLA, CA 92037 USA
[2] CHIRON CORP, EMERYVILLE, CA 94608 USA
[3] UNIV TEXAS, HLTH SCI CTR, DEPT MED, SAN ANTONIO, TX 78284 USA
[4] UNIV TEXAS, HLTH SCI CTR, DEPT CELLULAR & STRUCT BIOL, SAN ANTONIO, TX 78284 USA