The discovery of two new divergent STLVs has implications for the evolution and epidemiology of HTLVs.
We have isolated and characterised two divergent simian T-lymphotropic viruses (STLV), not belonging to the established human and simian T-lymphotropic virus lineages HTLV-1/STLV-1 and HTLV-2. STLV-L, from an Eritrean sacred baboon (Papio hamadryas), has been typed as a third type of simian T-lymphotropic virus, distinct from HTLV-1/STLV-1 and HTLV-2. The other virus, isolated from Congolese bonobos (Pan paniscus), is a distinct member of the HTLV-2 clade and has been designated STLV-2. The isolation of these two simian viruses shows that the spectrum of HTLVs/STLVs is larger than previously expected. Our data indicate that the two lineages STLV-L and HTLV-2/STLV-2 are of African origin, while the HTLV-1/STLV-1 lineage has been shown to be of Asian origin. These data, together with our phylogenetic analyses, suggest an African origin of the HTLV/STLV ancestor, which provides new clues about virus dissemination. Furthermore, the atypical serological profiles exhibited by STLV-L or STLV-2 infected animals in western blot, raise questions about the efficiency of current screening methods to type highly divergent HTLVs/STLVs. Considering the growing interest in xenotransplantations, more epidemiological and biological knowledge of simian and human T-lymphotropic viruses is necessary to estimate the risk of interspecies transmissions.
Van Brussel
M
M
Rega Institute for Medical Research and University Hospitals, Leuven, Belgium.
Salemi
M
M
Liu
H F
HF
Goubau
P
P
Desmyter
J
J
Vandamme
A M
AM
D000818:Animals; D004279:DNA, Viral / Q000737:chemistry; D015368:Human T-lymphotropic virus 1 / Q000145:classification / Q000235:genetics; D015367:Human T-lymphotropic virus 2 / Q000145:classification / Q000235:genetics; D006801:Humans; D019974:Pan paniscus; D010215:Papio; D010641:Phenotype; D015303:Simian T-lymphotropic virus 1 / Q000145:classification* / Q000235:genetics
D004279:DNA, Viral