ISOLATION OF SOOTY MANGABEY SIMIAN T-CELL LEUKEMIA-VIRUS TYPE-I [STLV-I(SM)] AND CHARACTERIZATION OF A MANGABEY T-CELL LINE COINFECTED WITHSTLV-I(SM) AND SIMIAN IMMUNODEFICIENCY VIRUS SIVSMMPBJ14

It has been postulated that dual infections of humans with human immun odeficiency Virus (HIV) and human T-cell leukemia! lymphotropic virus (HTLV) may potentiate disease progression. Counterparts of both of the se pathogenic human retroviruses have been identified in various simia n species indigenous to Asia and Africa, including sooty mangabey monk eys (Cercocebus atys). Using peripheral blood mononuclear cells (PBMC) from a mangabey naturally infected with both SIV and STLV-I, T-cell l ines were established and maintained continuously for more than 3 year s; these cell lines harbored only a newly identified mangabey STLV-I(s m) or both STLV-I(sm) and the acutely lethal variant SIVsmmPBj14. The dually infected cell line (FEd-P14) was established by de novo infecti on of mangabey PBMC with SIVsmmPBj14. This cell line was characterized by multiple assays which showed that structural proteins encoded by b oth viruses were produced in large quantities, but that the predominan t viral glycoprotein on the cell surface was the STLV-I(sm) Env. Unusu al interactions of the two retroviral glycoproteins were suggested by the formation of syncytia between Raji and the FEd-P14 cells, but not between Raji and simian cells infected with only one retrovirus or hum an cells infected with HTLV-I. The STLV-I(sm) strain obtained from the sooty mangabey was transmitted to normal macaque and mangabey PBMC an d was shown to be unique by sequencing of the entire env gene. STLV-I( sm) from this African species was more closely related to ''cosmopolit an'' HTLV-I strains than to the prototypic STLV-I from an Asian pig-ta iled macaque. In vitro and in vivo studies of STLV-I(sm) and SIVsmm, b oth isolated from a naturally infected mangabey monkey, may provide in sight into disease induction and manifestations associated with coinfe ction by their human counterparts. (C) 1997 Academic Press.