Characterization and distribution of nucleic acid sequences of a novel type C retrovirus isolated from neoplastic human T lymphocytes.

Abstract
A type C retrovirus (designated HTLV [human cutaneous T cell lymphoma virus]) recently isolated from a cell line derived from a lymph node and later from peripheral blood of a person with cutaneous T-cell lymphoma (mycosis fungoides) was characterized by nucleic acid hybridization experiments. HTLV [3H]c[complementary]DNA hybridized 90% to its own 70S RNA with kinetics consistent with the genetic complexity of other retroviruses, but it did not hybridize substantially to RNA or proviral DNA from animal retroviruses (types B, C and D), including those from nonhuman primates. [3H]cDNA from other retroviruses did not hybridize to RNA or DNA of the human T-cell line producing HTLV, HTLV proviral sequences were present (2-3 copies per haploid genome) in DNA of these cells, and homologous sequences were present in the cell cytoplasmic RNA (0.3% viral sequences by weight). HTLV-related nuclei acid sequences were not found in DNA from various other human tissues. HTLV is apparently is a new class of type C virus that is not an endogenous (genetically transmitted) retrovirus in man.