The Sukhumi Primate Monkey Model for Viral Lymphomogenesis: High Incidence of Lymphomas with Presence of STLV-I and EBV-like Virus

T-cell leukemia virus-like proviral sequences (STLV-I) as well as EBV-like sequences were detected in PBLs and tissues of non-human primates (Papio hamadryas baboons, Green monkeys and Macaca arctoides; Sukhumi Primate Center/Georgia) by PCR. Surprisingly, two different types of STLV-I within Papio hamadryas baboons were found. One of its represents the baboon prototype STLV-I-Su described earlier, present in lymphomatous baboons from the "high-lymphoma stock", which shows about 83% homology to HTLV-I and 85% to STLV-I in the env and tax genes. The inter-individual variability within this subtype is very low (about 1% in the tax gene). The second subtype was mainly found in asymptomatic animals from the control colony and showed in the env gene 95% homology to HTLV-I, but only 82% to the prototype baboon sequence. The presence of two subtypes within the Sukhumi baboon population might be interesting in respect to the inoculation experiments with human leukemic blood and to possible interspecies transmissions. The nature of the Herpes Papio-virus was elucidated as EBV-like and the homology to the human EBV was > 90% in the polymerase gene. The homologies between different monkey species were between 92 and 96% and also here two subtypes within the baboons were detected. This is the first direct demonstration by sequencing that the Herpes Papio virus is closely related to EBV. For further studies of this animal model, rabbits were inoculated with cells originated from lymphomatous baboons and macaques. The rabbits developed generalized lymphomas lethal within 1-2 months. EBV-like and STLV-I-like sequences could be detected by PCR and sequencing showed 99-100% identity to the inoculum, indicating in fact the transmission from monkey to rabbit. These animal models seem to be very suitable for the elucidation of the pathogenesis of human HTLV-I associated T-cell leukemia/lymphoma and might be further on used for therapeutical and preventative studies.