Detection and isolation of type C retrovirus particles from fresh and cultured lymphocytes of a patient with cutaneous T-cell lymphoma

Bernard Poiesz, Robert Gallo and colleagues found retrovirus particles with type C morphology in two T-cell lymphoblastoid cell lines, HUT 102 and CTCL-3, and in fresh peripheral blood lymphocytes from a patient with mycosis fungoides. The cell lines produced the virus continuously, collectively called HTLV.

The characterisation was careful because the claim was large. Mature particles measured 100 to 110 nanometres, banded at a density of 1.16 grams per millilitre on a sucrose gradient, and contained 70S RNA and a DNA polymerase activity typical of a viral reverse transcriptase. That reverse transcriptase preferred magnesium to manganese, unlike the cellular DNA polymerases purified from human lymphocytes, and antibodies to cellular DNA polymerase gamma and to reverse transcriptases from several animal retroviruses did not react with it. Six major proteins of roughly 10,000, 13,000, 19,000, 24,000, 42,000 and 52,000 daltons were found in disrupted particles, a count consistent with a retrovirus but with sizes distinct from the known primate retroviruses.

The following year Hinuma's group in Japan independently detected an antigen in a cell line from a patient with adult T-cell leukaemia and antibodies to it in all 44 patients with that disease. The two lines of work converged on one virus, now called human T-lymphotropic virus type 1.