NATURAL ENDOGENOUS REVERSE TRANSCRIPTION OF SIMIAN IMMUNODEFICIENCY VIRUS

It has been demonstrated that human immunodeficiency virus type I (HIV -I) virions are biochemically active particles, within which reverse t ranscription can take place even in physiological microenvironments. T his process has been termed ''natural endogenous reverse transcription '' (NERT). In this report, we demonstrate that purified virions of sim ian Immunodeficiency virus (SIV) also contain virus-specific DNA, whic h resulted from partial reverse transcription. Further, viral DNA synt hesis could be initiated in SIV virions in the presence of polyamines and deoxyribonucleoside triphosphates (dNTPs), at physiological concen trations. The viral infectivity upon initially quiescent cells was sig nificantly increased, when the levels of intravirion reverse transcrip ts were modulated. These data suggest that NERT of SIV may play an imp ortant role for SIV pathogenesis and transmission. in contrast to HIV- l,these hypotheses may be further directly investigated by in vivo mod el systems. (C) 1997 Academic Press