Herpesvirus ateles is an oncogenic tumor virus of New World primates, which has sequence homology and biological properties in common with Herpesvirus saimiri. Each causes acute T-cell lymphomas in susceptible species of New World primates, while establishing a latent infection of the T lymphocytes of its normal host. The thesis research consists of characterization of the viral genome, cloning of viral DNA, in vitro immortalization of T cells with the virus, and mapping of viral transcripts within immortalized cells. Additional experiments performed to transfect cloned DNA into immortalized cells were unsuccessful.

Fragments of H. ateles virion DNA were cloned into the vector pHyg, which is selectable in both prokaryotic and mammalian cells. Overlapping clones of >95% of the viral genome were characterized by restriction mapping, and were used to determine restriction maps of H. ateles strains 73 and 810.

Peripheral blood T lymphocytes from several species of New World primate were expanded in medium containing IL-2. T-cells from cottontopped tamarins were immortalized with H. ateles 73, H. saimiri 11, and H. saimiri 484-77, becoming IL-2-independent and growing continuously in culture. Immortalization was highly efficient, occurring reproducibly in cultures of 10⁴-10⁵ cells. Immortalization of IL-2-expanded T-cells of red-bellied tamarins, spider monkeys, and squirrel monkeys was unsuccessful with all strains of virus used.

The right end of H. saimiri DNA is deleted in nononcogenic mutants. It has been found to produce four small RNAs in immortalized cells. Similarly, two small viral RNAs were found to be transcribed in cells immortalized by H. ateles 73. The RNAs, of 115 and 119 nuc1eotides, were mapped in the right end of the viral genome. The RNAs contain two regions of high conservation with H. saimiri RNAs. The genes for the small RNAs contain promoter, internal, and terminator sequences characteristic of cellular U RNAs.