Interleukin-15 + thioredoxin induce DNA synthesis in B-chronic lymphocytic leukemia cells but not in normal B cells.
We have previously shown that Staphylococcus aureus Cowan strain 1 particles (SAC) + thioredoxin (Trx) + IL-2 may induce B-chronic lymphocytic leukemia (B-CLL) cells to proliferate. In this paper we have examined IL-15, which has activities similar to IL-2, for its ability to stimulate B-CLL cells and compared its activity with that of IL-2. We found that B-CLL cells could be induced to DNA synthesis upon treatment with IL-15 + Trx. The presence of Trx was essential for the IL-15-induced DNA synthesis. This contrasts to the effect of IL-15 + Trx on normal CD5+ and CD5- B cells, where IL-15 + Trx alone only induced limited DNA synthesis. IL-15 was as effective in the induction of DNA synthesis in B-CLL cells as IL-2, but about 100-fold less potent with an EC50 of 200 ng/ml. In addition we found that the IL-15 + Trx-induced proliferation was inhibited by CD40 stimulation. We conclude that IL-15 together with a proper costimulus can induce B-CLL cells to proliferate in vitro.
Söderberg
O
O
Department of Pathology, University of Uppsala, University Hospital, Sweden.
Christiansen
I
I
Nilsson
G
G
Carlsson
M
M
Nilsson
K
K
D001402:B-Lymphocytes / Q000166:cytology*; D019013:CD40 Antigens / Q000502:physiology; D002453:Cell Cycle / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D004247:DNA / Q000096:biosynthesis*; D006801:Humans; D019409:Interleukin-15 / Q000008:administration & dosage*; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000473:pathology*; D008213:Lymphocyte Activation; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D013879:Thioredoxins / Q000008:administration & dosage*; D014407:Tumor Cells, Cultured
D019013:CD40 Antigens; D019409:Interleukin-15; D015375:Receptors, Interleukin-2; D013879:Thioredoxins; D004247:DNA