GENERATION OF HERPES-VIRUS SAIMIRI-TRANSFORMED T-CELL LINES FROM MACAQUES IS RESTRICTED BY REACTIVATION OF SIMIAN SPUMA VIRUSES

Herpes virus saimiri (HVS) transforms human T-cells in vitro to stable growth. These T-cell lines retain their immunological characteristics of the parent cells and do not release infectious virus. Recently, ly mphocytes of Old World monkeys were efficiently transformed by HVS. In parallel to these studies we initiated transformation experiments by infecting peripheral blood cell cultures of 45 monkeys, 35 rhesus and 10 cynomolgus macaques. In only three cases, we obtained transformed T -cell lines. The transformed T-cells were largely double-positive for CD4 and CD8. They responded with increased proliferation to mitogenic or IL-2 stimulation and transcribed mRNA for IL-2, IL-4, and IL-10. Ho wever, most initiated T-cell cultures from macaques developed giant ce lls. The cytopathic agent was identified as simian foamy virus (SFV) a s confirmed by PCR, immunofluorescence, and coculture experiments. Tre atment of the T-cell cultures with AZT- and SFV-specific sera did only shortly prolong the life-span of the cultures. Therefore, the reactiv ation of SFV caused remarkable difficulties in the establishment of ma caque T-cell lines by HVS. This seems to be a general problem since mo st animals from several breeding colonies are SFV-positive. (C) 1997 A cademic Press.