title: [Expression of IL-2 receptors on the surfaces of L1210 cells and bioactivity assay for IL-2-toxin fusion proteins].
abstract: OBJECTIVE
  To confirm that L1210 cells surfaces express IL-2 receptors (IL-2R) and to establish experimental models for studying the cytotoxic effect of IL-2-toxin fusion protein in vivo and in vitro.
  
  
  METHODS
  IL-2R on mouse leukemia L1210 cells was analyzed with immunofluorescence stain and FACS. The cytotoxic effects in vitro of these fusion proteins IL-2-PEZNM and IL-2-K-PEZNM were assayed by MTT method; mice ascitic L1210 leukemia was induced by i.p. L1210 cells and the therapeutic effect of IL-2-K-PEZNM was observed.
  
  
  RESULTS
  86.3% of L1210 cells expressed IL-2R on their surfaces and the relative fluorescence intensity was 51.55. Two fusion proteins IL-2-PEZNM and IL-2-K-PEZNM showed dose-related cytotoxicities to L1210 cells in vitro with the IC50 of 0.51 and 0.67 microgram/ml respectively. IL-2-K-PEZNM (5 micrograms/d) showed significantly inhibitory effect on L1210 cells and prolonged the survival time of mice by 78.6%.
  
  
  CONCLUSIONS
  L1210 cells as a model system to measure the cytotoxic activity of IL-2-toxin fusion proteins both in vitro and in vivo is simpler, stabler, and safer model than those with other cells such as Hut102 and activated T lymphocytes.
authors.affiliation: Department of Pharmacology, Institute of Medicinal Biotechnology, CAMS, PUMC, Beijing 100050, China. zhanglili@netease.com
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.forename: L
authors.initials: L
authors.lastname: Nie
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: S
authors.initials: S
authors.lastname: Li
authors.forename: S
authors.initials: S
authors.lastname: Lu
mesh_terms: D000818:Animals; D007376:Interleukin-2 / Q000494:pharmacology*; D007939:Leukemia L1210 / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D015375:Receptors, Interleukin-2 / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000494:pharmacology*; D014118:Toxins, Biological / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D011993:Recombinant Fusion Proteins; D014118:Toxins, Biological