Media conditioned by human leukemic T-cells induce expression of IL2 receptors and proliferation of normal T lymphocytes.
Peripheral blood T-colony-forming cells (T-CFC) from patients with T-cell acute lymphoblastic leukemias (T-ALL) and T-cell non-Hodgkin lymphomas (T-NHL) can generate colonies in methylcellulose in the absence of added growth factors and/or mitogenic stimulation. In the present study, we show that media conditioned (LCM) by unstimulated mononuclear cells (MNC) from these patients can induce proliferation (proliferating inducing activity; PIA) and promote colony growth (T-cell colony promoting activity; T-CPA) of normal T lymphocytes in the absence of any other mitogenic stimulation. Preincubation of normal E+ lymphocytes with some TCPA+, PIA(-)-LCM for 48 hr leads to IL2-induced cell proliferation in the absence of any other stimulation. Moreover, staining of the cells with anti-Tac monoclonal antibody (Mab) reveal 9%-26% Tac+ cells. Both PIA and IL2 receptor-inducing activities were abrogated by treatment of LCM with proteolytic enzymes or by heating at 47 degrees C for 30 min. Modulation of the T3 molecule by OKT3 MAb on normal E+ cells did not abrogate the capacity of LCM to induce expression of IL2-receptors, suggesting that this activity was not mediated by triggering the Ti-T3 molecular complex. These activities were detected in media conditioned by both unfractionated MNC and blast-enriched cell fractions, and their production required DNA and RNA synthesis by actively dividing cells. Taken together, these findings indicate that human leukemic T cells spontaneously release activities which can activate normal resting T lymphocytes.
Kosmatopoulos
C
C
Allouche
M
M
Triebel
F
F
Zanti
M
M
Clemenceau
C
C
Gluckman
J C
JC
Jasmin
C
C
Georgoulias
V
V
D000911:Antibodies, Monoclonal; D002455:Cell Division; D003114:Colony-Forming Units Assay; D003470:Culture Media; D004261:DNA Replication; D006801:Humans; D007938:Leukemia / Q000378:metabolism*; D012313:RNA / Q000096:biosynthesis; D011971:Receptors, Immunologic / Q000378:metabolism*; D015375:Receptors, Interleukin-2; D013601:T-Lymphocytes / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D003470:Culture Media; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D012313:RNA