[1] KYOTO UNIV,INST IMMUNOL,KYOTO 606,JAPAN
[2] UNIV TOKYO,INST MED SCI,TOKYO 113,JAPAN
[3] NAGOYA CITY UNIV,NAGOYA,AICHI 467,JAPAN
[4] KAROLINSKA INST,DEPT TUMOR BIOL,S-10401 STOCKHOLM 60,SWEDEN
[5] KAROLINSKA INST,DEPT MED CELL GENET,S-10401 STOCKHOLM 60,SWEDEN