1. Activation of extracellular signaling regulated kinase in natural killer cells and monocytes following IL-2 stimulation in vitro and in patients undergoing IL-2 immunotherapy: analysis via dual parameter flow-cytometric assay.
- Author
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Kondadasula SV, Varker KA, Lesinski GB, Benson DM Jr, Lehman A, Olencki T, Monk JP, Kendra K, and Carson WE 3rd
- Subjects
- CD56 Antigen immunology, Carcinoma, Renal Cell diagnosis, Drug Administration Schedule, Enzyme Activation, Extracellular Signal-Regulated MAP Kinases analysis, Extracellular Signal-Regulated MAP Kinases drug effects, Flow Cytometry methods, Humans, Immunotherapy, Injections, Intraventricular, Interleukin-2 administration & dosage, Kidney Neoplasms diagnosis, Killer Cells, Natural enzymology, Killer Cells, Natural immunology, Lipopolysaccharide Receptors immunology, Melanoma diagnosis, Monocytes enzymology, Monocytes immunology, Recombinant Proteins pharmacology, Recombinant Proteins therapeutic use, Time Factors, Carcinoma, Renal Cell therapy, Extracellular Signal-Regulated MAP Kinases immunology, Interleukin-2 pharmacology, Kidney Neoplasms therapy, Killer Cells, Natural drug effects, Melanoma therapy, Monocytes drug effects
- Abstract
Interleukin-2 (IL-2) activates extracellular signal-regulated protein kinase (ERK) within immune cells. To examine the profile of phosphorylated ERK (p-ERK) in IL-2 stimulated immune cells of normal donors and patients receiving IL-2 therapy, we developed a dual parameter flow-cytometric assay. An analysis of PBMCs stimulated with IL-2 indicated that IL-2 exposure induced p-ERK in CD56bright NK cells and CD14+ monocytes, but not in CD3+ T cells or CD21+ B cells. CD3+ T cells that were induced to express functional high-affinity IL-2R did not exhibit enhanced p-ERK following IL-2 treatment. Measurement of p-ERK within PBMCs from cancer patients 1 h following their first dose of IL-2 revealed a complete absence of circulating NK cells, consistent with earlier observations. However, the total number of circulating CD14+ monocytes increased in these samples and 97% of these cells exhibited ERK activation. p-ERK was not observed in T cells post-IL-2 therapy. Analysis of PBMCs obtained 3 weeks post-IL-2 therapy revealed high-p-ERK levels in CD56bright NK cells in a subset of patients, while levels of p-ERK returned to baseline in monocytes. These studies reveal an effective method to detect ERK activation in immune cells and demonstrate that IL-2 activates ERK in a subset of NK cells and monocytes but not T cells.
- Published
- 2008
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