A Novel, Divergent Simian T-Cell Lymphotropic Virus Type 3 In A Wild-Caught Red-Capped Mangabey (Cercocebus Torquatus) From Nigeria.

We present here a novel, distinct simian T-cell lymphotropic virus (STLV) found in a red-capped mangabey (Cercocebus torquatus) (CTO-NG409), wild-caught in Nigeria, that showed an HTLV-2-like Western blot (WB) seroreactivity. The complete genome (8920 bp) of CTO-NG409 STLV was related to but different from STLV-3/PHA-PH969 (13(.)5%) and STLV-3/PPA-F3 (7(.)6 %), and STLV-3/CTO604 (11(.)3 %), found in Eritrean and Senegalese baboons, and red-capped mangabeys from Cameroon, respectively. Phylogenetic analysis of a conserved tax (1180 bp) sequence and the env gene (1482 bp) confirmed the relatedness of STLV-3/ CTO-NG409 to the STLV-3 subgroup. Molecular clock analysis of env estimated that STLV-3/CTO-NG409 diverged from East and West/Central African STLV-3s about 140 900 +/- 12 400 years ago, suggesting an ancient African origin of STLV-3. Since phylogenetic evidence suggests multiple interspecies transmissions of STLV-1 to humans, and given the antiquity and wide distribution of STLV-3 in Africa, a search for STLV-3 in human African populations with HTLV-2-like WB patterns is warranted.