Genetic characterization of the complete genome of a highly divergent simian T-lymphotropic virus (STLV) type 3 from a wild Cercopithecus mona monkey.
BACKGROUND
The recent discoveries of novel human T-lymphotropic virus type 3 (HTLV-3) and highly divergent simian T-lymphotropic virus type 3 (STLV-3) subtype D viruses from two different monkey species in southern Cameroon suggest that the diversity and cross-species transmission of these retroviruses are much greater than currently appreciated.


RESULTS
We describe here the first full-length sequence of a highly divergent STLV-3d(Cmo8699AB) virus obtained by PCR-based genome walking using DNA from two dried blood spots (DBS) collected from a wild-caught Cercopithecus mona monkey. The genome of STLV-3d(Cmo8699AB) is 8913-bp long and shares only 77% identity to other PTLV-3s. Phylogenetic analyses using Bayesian and maximum likelihood inference clearly show that this highly divergent virus forms an independent lineage with high posterior probability and bootstrap support within the diversity of PTLV-3. Molecular dating of concatenated gag-pol-env-tax sequences inferred a divergence date of about 115,117 years ago for STLV-3d(Cmo8699AB) indicating an ancient origin for this newly identified lineage. Major structural, enzymatic, and regulatory gene regions of STLV-3d(Cmo8699AB) are intact and suggest viral replication and a predicted pathogenic potential comparable to other PTLV-3s.


CONCLUSIONS
When taken together, the inferred ancient origin of STLV-3d(Cmo8699AB), the presence of this highly divergent virus in two primate species from the same geographical region, and the ease with which STLVs can be transmitted across species boundaries all suggest that STLV-3d may be more prevalent and widespread. Given the high human exposure to nonhuman primates in this region and the unknown pathogenicity of this divergent PTLV-3, increased surveillance and expanded prevention activities are necessary. Our ability to obtain the complete viral genome from DBS also highlights further the utility of this method for molecular-based epidemiologic studies.
Sintasath
David M
DM
Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore MD 21205, USA. d.sintasath@malariaconsortium.org
Wolfe
Nathan D
ND
Zheng
Hao Qiang
HQ
LeBreton
Matthew
M
Peeters
Martine
M
Tamoufe
Ubald
U
Djoko
Cyrille F
CF
Diffo
Joseph L D
JL
Mpoudi-Ngole
Eitel
E
Heneine
Walid
W
Switzer
William M
WM
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002521:Cercopithecus / Q000821:virology*; D016386:Chromosome Walking; D016000:Cluster Analysis; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics*; D006800:Deltaretrovirus Infections / Q000662:veterinary*; D016679:Genome, Viral; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D056185:Simian T-lymphotropic virus 3 / Q000235:genetics* / Q000302:isolation & purification; D014412:Tumor Virus Infections / Q000662:veterinary*
D004279:DNA, Viral