Abstract
Cytokine immunotherapy using interleukin (IL)-2 and IL-15 may be beneficial for patients receiving umbilical cord blood (CB) transplantation by ameliorating post-transplant T-cell apoptosis. The present study compares the differential effect of IL-15 and IL-2 on survival of phytohemagglutinin (PHA)-activated CB and adult peripheral blood (APB) T lymphocytes. In comparison with IL-2, IL-15 preferentially enhanced the survival of CB PHA-activated T cells by decreasing the caspase-3+ population and by increasing the Bcl-2+ population. Activated CB T cells were more susceptible to TNF-α-induced apoptosis compared to their adult counterparts. However, the susceptibility could be abrogated by IL-15 but not by IL-2. IL-15 but not IL-2 down-regulated CD28 expression on both activated CB and APB CD8+ T cells, with a much greater effect seen with CB. Western-blot analysis shows that IL-15 Rα is deficient in CB compared to APB immediately after PHA stimulation, while culturing with IL-15 significantly enhanced CB IL-15 Rα expression to levels comparable to that of adults. Thus, IL-15 may provide a better therapeutic choice for immune reconstitution than IL-2 post-CB transplantation due to its preferential survival enhancing effect on CB T cells.
Original language | English |
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Pages (from-to) | 106-112 |
Number of pages | 7 |
Journal | American Journal of Hematology |
Volume | 80 |
Issue number | 2 |
DOIs | |
State | Published - 10 2005 |
Keywords
- Apoptosis
- Cord blood
- Interleukin-15
- Interleukin-2
- T cells
- TNF-α