title: Functional p75 interleukin-2 receptor expression on the fresh blast cells in childhood acute lymphoblastic leukemia with natural killer cell properties.
abstract: Neoplastic cells of childhood acute lymphoblastic leukemia (ALL) with natural killer (NK) cell properties were studied for the expression of p75 interleukin-2 receptors (IL-2R) and the receptor functions. Freshly prepared blast cells from a patient with ALL had NK cell properties: (1) the phenotype such as CD56+, CD2+, E-rosette+, CD3-, and CD19-; and (2) the presence of spontaneous cytotoxicity against NK-sensitive K562 target cells. Although p55 Tac antigen was not detectable, there was the expression of p75 IL-2R on the freshly prepared blast cells: 70% of the cells reacted with Mik-beta 1 monoclonal antibody against p75 IL-2R as determined by flow cytometry. Two-color flow cytometry revealed that the blast cells expressed both p75 IL-2R and NKH-1. NK activity of the blast cells was augmented by their treatment with 1,000 U/ml recombinant IL-2 (rIL-2): the cytotoxicity level as percentage lysis increased to 38.7% from 22.0% when the normal lymphocyte value increased to 62.1% from 46.2%. Although the blast cells possessed no apparent level of proliferative capacity, the addition of 1,000 U/ml rIL-2 yielded a 2.7-fold increase in their thymidine uptake. These results demonstrate the expression of functional p75 IL-2R on the patient's blast cells with NK cell properties.
authors.affiliation: Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ichikawa
authors.forename: H
authors.initials: H
authors.lastname: Kawai
authors.forename: A
authors.initials: A
authors.lastname: Komiyama
authors.forename: M
authors.initials: M
authors.lastname: Tsudo
authors.forename: M
authors.initials: M
authors.lastname: Miyasaka
authors.forename: A
authors.initials: A
authors.lastname: Kinoshita
authors.forename: S
authors.initials: S
authors.lastname: Nakazawa
mesh_terms: D000293:Adolescent; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000378:metabolism / Q000502:physiology; D001752:Blast Crisis / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D002455:Cell Division / Q000187:drug effects; D006651:Histocytochemistry; D006801:Humans; D007694:Killer Cells, Natural / Q000378:metabolism / Q000473:pathology* / Q000502:physiology / Q000648:ultrastructure; D008214:Lymphocytes / Q000473:pathology / Q000502:physiology / Q000648:ultrastructure; D008297:Male; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D015375:Receptors, Interleukin-2 / Q000378:metabolism / Q000502:physiology*; D013936:Thymidine / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D015375:Receptors, Interleukin-2; D013936:Thymidine