Human interleukin-7 induces proliferation of neoplastic cells from chronic
lymphocytic leukemia and acute leukemias
W Digel, M Schmid, G Heil, P Conrad, S Gillis and F Porzsolt
Department of Internal Medicine III, University of Ulm, Germany.
The biologic effects of interleukin-7 (IL-7) and the expression of specific
IL-7 membrane receptors on isolated neoplastic cells from previously
untreated patients with chronic lymphocytic leukemia as well as acute
leukemias were investigated in vitro. Leukemic cells were incubated for up
to 6 days with various concentrations of IL-7 (0.01 to 2,000 U/mL).
Neoplastic cells of the T- or B-phenotype from chronic as well as from
acute leukemias proliferated in a dose-dependent manner. Cells from acute
myeloid leukemias also proliferated in response to IL- 7. An optimal
proliferative effect was achieved between 96 and 120 hours with 200 U/mL
IL-7. Combinations of IL-7 with IL-2 and tumor necrosis factor-alpha showed
an additive effect on [3H]TdR incorporation. IL-7 binding assays gave a
value of approximately 33 to 180 high-affinity (kd approximately 20 pmol/L)
binding sites/cell and approximately 241 to 3,280 low-affinity (kd
approximately 600 pmol/L) binding sites/cell. Receptor expression
correlated with the proliferation in response to IL-7. These data indicate
that IL-7 can induce proliferation of relatively mature tumor cells, and
that this effect is not restricted to the lymphoid lineage.
Volume 78,
Issue 3,
pp. 753-759,
08/01/1991
Copyright © 1991 by The American Society of Hematology
