Related Experiment Video
Updated: Aug 15, 2026
Ex vivo Expansion of Tumor-reactive T Cells by Means of Bryostatin 1/Ionomycin and the Common Gamma Chain Cytokines Formulation
Published on: January 15, 2011
Interleukin-2-induced lymphoproliferative responses
A Winkelstein1, L D Weaver, N Salva
1Department of Medicine, Montefiore Hospital, University of Pittsburgh School of Medicine, Pa. 15213.
Insights
Interleukin-2 (IL-2) concentration dictates immune cell expansion. Higher IL-2 doses promote CD8+ T cell and CD3+ CD56+ cytotoxic cell growth, while lower doses favor CD4+ T cells.
Area of Science:
- Immunology
- Cell Biology
Background:
- Interleukin-2 (IL-2) is known to stimulate immune responses, including lymphoproliferation and cytotoxicity.
- Conflicting reports exist regarding the specific immune cell phenotypes that respond to IL-2 stimulation.
Purpose of the Study:
- To investigate the impact of varying Interleukin-2 (IL-2) concentrations on the phenotypes of peripheral blood mononuclear cells (PBMCs).
- To clarify the cell populations responsible for IL-2-mediated immune modulation.
Main Methods:
- Peripheral blood mononuclear cells (PBMCs) were isolated using Ficoll/Hypaque density gradient centrifugation.
- PBMCs were cultured with different concentrations of IL-2 (50, 100, or 1000 U/ml) for 1, 3, and 5 weeks.
- Flow cytometry was used to analyze the expression of cell surface markers (CD3, CD4, CD8, CD56, CD16) to determine cell phenotypes.
Main Results:
- All IL-2 concentrations progressively increased CD3+ T cells, exceeding 90% by 3-5 weeks.
- Lower IL-2 concentrations (50-100 U/ml) preferentially expanded CD4+ T cells.
- Higher IL-2 concentration (1000 U/ml) led to a predominance of CD8+ T cells, increasing from 28% to 51% within 3 weeks.
- High-dose IL-2 (1000 U/ml) significantly increased CD56+ cells, mainly the CD3+ CD56+ cytotoxic T cell subset.
- Natural killer (NK) cells (CD16+) declined across all IL-2 concentrations.
Conclusions:
- The concentration of IL-2 critically influences the expansion of specific immune cell subsets.
- High-dose IL-2 promotes the development of CD8+ cytotoxic T cells and CD3+ CD56+ cells.
- The findings clarify the distinct cellular responses to varying IL-2 levels, impacting immune modulation strategies.
Abstract:
Interleukin-2 (IL-2) is capable of both stimulating an in vitro lymphoproliferative response and augmenting non-major-histocompatibility-complex-(MHC)-restricted cytotoxicity. However, there are conflicting reports about the phenotypes of responding cells. In the present studies, we determined phenotypes of Ficoll/Hypaque-separated peripheral blood mononuclear cells stimulated with 50, 100 or 1000 U/ml IL-2; analyses were performed after 1, 3 and 5 weeks. With all concentrations, there was a progressive increase in CD3+ cells: after 3-5 weeks more than 90% of the cells reacted with this antibody. However, the proportions of CD4+ and CD8+ cells proved to be a function of the IL-2 concentration. Cultures containing 50 U/ml or 100 U/ml favored the expansion of the CD4+ subset. By contrast, in cultures stimulated with 1000 U/ml. CD8+ cells predominated. At baseline, CD8+ cells comprised 28 +/- 2%; after 3 weeks, this value increased to 51 +/- 5%. In addition, the proportion of CD56+ (Leu19, NKH-1) cells depended on the amount of IL-2. At 50 U/ml, there was no appreciable change in CD56+ cells. However, at 1000 U/ml, CD56+ cells increased from 17 +/- 1% (day 0) to 39 +/- 4% (3 weeks). This increase was primarily due to an expansion of the CD3+ CD56+ subset (non-NMC restricted cytotoxic T cells). By contrast, natural killer (NK) cells, as measured by the CD16 antibody, steadily declined at all IL-2 concentrations.
