A colony assay for in vitro transformation by human T cell leukemia viruses
type I and type II
M Aboud, DW Golde, N Bersch, JD Rosenblatt and IS Chen
We report here the development of a rapid and quantitative method for
measuring in vitro T cell transformation by human T cell leukemia viruses
type I (HTLV-I) and type II (HTLV-II). This method is based on our finding
that cocultivation of lethally irradiated HTLV-producing cells with
peripheral blood lymphocytes (PBLs) preactivated for 24 hours with
phytohemagglutinin and interleukin-2 (IL-2) induces colony formation in
methylcellulose-containing medium. Colonies of about 200 cells can be
clearly distinguished from background aggregates within four to six days
after cocultivation. These colonies gradually increase in size and reach
300 to 1,000 cells within 14 days after cocultivation. Cells of these
colonies were infected, as evidenced by expression of viral p19 antigen and
the presence of HTLV proviral sequences. These cells proved to be
transformed in terms of IL-2- independent continuous growth in liquid
medium. Colony formation was found to depend in a linear fashion upon the
percentage of the infected cells present in the irradiated cell population
and is sufficiently sensitive to detect as few as 1% of virus-producing
cells.
Volume 70,
Issue 2,
pp. 432-436,
08/01/1987
Copyright © 1987 by The American Society of Hematology
