[1] NCI, CELL BIOL LAB, BETHESDA, MD 20892 USA
[2] US FDA, CTR BIOL EVALUAT & RES, DIV VIROL, BETHESDA, MD 20892 USA
[3] NIAID, IMMUNOL LAB, BETHESDA, MD 20892 USA
[4] KITASATO UNIV, DEPT DERMATOL, SAGAMIHARA, KANAGAWA 228, JAPAN
[5] UNIV MURCIA, DEPT BIOCHEM, MURCIA, SPAIN