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.
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.
Umadome
H
H
First Division of Internal Medicine, Faculty of Medicine, Kyoto University, Japan.
Uchiyama
T
T
Onishi
R
R
Hori
T
T
Uchino
H
H
Nesumi
N
N
D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism / Q000494:pharmacology*; D015847:Interleukin-4; D007378:Interleukins / Q000378:metabolism / Q000494:pharmacology*; D015461:Leukemia, Prolymphocytic, T-Cell / Q000276:immunology* / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012333:RNA, Messenger / Q000096:biosynthesis*; D015375:Receptors, Interleukin-2 / Q000302:isolation & purification; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology* / Q000378:metabolism
D007376:Interleukin-2; D007378:Interleukins; D012333:RNA, Messenger; D015375:Receptors, Interleukin-2; D015847:Interleukin-4