title: 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.
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.
authors.affiliation: Human Cancer Genetics Program, Department of Molecular Virology, Immunology and Medical Genetics, The Ohio State University, Columbus, OH 43210, USA.
authors.forename: Sri Vidya
authors.initials: SV
authors.lastname: Kondadasula
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Varker
authors.forename: Gregory B
authors.initials: GB
authors.lastname: Lesinski
authors.forename: Don M
authors.initials: DM
authors.lastname: Benson
authors.forename: Amy
authors.initials: A
authors.lastname: Lehman
authors.forename: Thomas
authors.initials: T
authors.lastname: Olencki
authors.forename: J Paul
authors.initials: JP
authors.lastname: Monk
authors.forename: Kari
authors.initials: K
authors.lastname: Kendra
authors.forename: William E
authors.initials: WE
authors.lastname: Carson
mesh_terms: D019002:CD56 Antigen / Q000276:immunology; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000628:therapy*; D004334:Drug Administration Schedule; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000032:analysis / Q000187:drug effects / Q000276:immunology*; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007167:Immunotherapy; D007276:Injections, Intraventricular; D007376:Interleukin-2 / Q000008:administration & dosage / Q000494:pharmacology*; D007680:Kidney Neoplasms / Q000175:diagnosis / Q000628:therapy*; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology; D018950:Lipopolysaccharide Receptors / Q000276:immunology; D008545:Melanoma / Q000175:diagnosis / Q000628:therapy*; D009000:Monocytes / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology; D011994:Recombinant Proteins / Q000494:pharmacology / Q000627:therapeutic use; D013997:Time Factors
chemical_list: D019002:CD56 Antigen; D007376:Interleukin-2; D018950:Lipopolysaccharide Receptors; D011994:Recombinant Proteins; D048049:Extracellular Signal-Regulated MAP Kinases