Leukemic cells from a chronic T-lymphocytic leukemia patient proliferated
in response to both interleukin-2 and interleukin-4 without prior
stimulation and produced interleukin-2 mRNA with stimulation
H Umadome, T Uchiyama, R Onishi, T Hori, H Uchino and N Nesumi
First Division of Internal Medicine, Faculty of Medicine, Kyoto University,
Japan.
Recently, interleukin-4 (IL-4) has been clarified as having T-cell growth
factor activity; therefore, it becomes of interest whether IL-4, as well as
interleukin-2 (IL-2), affects the proliferation of leukemic cells derived
from mature T cells. In the present study, we describe a case of chronic
T-lymphocytic leukemia (T-CLL) with monoclonal proliferation of human
T-lymphotropic retrovirus (HTLV)-I or HTLV-II negative CD3(+)4(+)8(-) T
cell expressing IL-2 receptors without stimulation. Radiolabeled IL-2
binding assay revealed 750 high-affinity and 6,750 low-affinity binding
sites per cell. In accordance with the expression of high-affinity IL-2
receptors, the leukemic cells proliferated in response to exogenous IL-2
without prior stimulation. In addition, exogenous IL-4 also induced their
proliferation. Moreover, IL-2 and IL-4 exerted a synergistic effect on the
leukemic cell proliferation. Although the expression of IL-2 or IL-4 mRNA
was not detected in fresh leukemic cells, the expression of IL-2 mRNA, but
not IL-4 mRNA, was induced by phytohemagglutinin stimulation, and the
leukemic cells proliferated. These findings suggest that not only IL-2, but
also IL-4 are involved in the proliferation of leukemic cells of T- CLL.
Volume 72,
Issue 4,
pp. 1177-1181,
10/01/1988
Copyright © 1988 by The American Society of Hematology
