title: Targeting and killing of glioblastoma with activated T cells armed with bispecific antibodies.
abstract: BACKGROUND
  Since most glioblastomas express both wild-type EGFR and EGFRvIII as well as HER2/neu, they are excellent targets for activated T cells (ATC) armed with bispecific antibodies (BiAbs) that target EGFR and HER2.
  
  
  METHODS
  ATC were generated from PBMC activated for 14 days with anti-CD3 monoclonal antibody in the presence of interleukin-2 and armed with chemically heteroconjugated anti-CD3 × anti-HER2/neu (HER2Bi) and/or anti-CD3 × anti-EGFR (EGFRBi). HER2Bi- and/or EGFRBi-armed ATC were examined for in vitro cytotoxicity using MTT and 51Cr-release assays against malignant glioma lines (U87MG, U118MG, and U251MG) and primary glioblastoma lines.
  
  
  RESULTS
  EGFRBi-armed ATC killed up to 85% of U87, U118, and U251 targets at effector:target ratios (E:T) ranging from 1:1 to 25:1. Engagement of tumor by EGFRBi-armed ATC induced Th1 and Th2 cytokine secretion by armed ATC. HER2Bi-armed ATC exhibited comparable cytotoxicity against U118 and U251, but did not kill HER2-negative U87 cells. HER2Bi- or EGFRBi-armed ATC exhibited 50--80% cytotoxicity against four primary glioblastoma lines as well as a temozolomide (TMZ)-resistant variant of U251. Both CD133- and CD133+ subpopulations were killed by armed ATC. Targeting both HER2Bi and EGFRBi simultaneously showed enhanced efficacy than arming with a single BiAb. Armed ATC maintained effectiveness after irradiation and in the presence of TMZ at a therapeutic concentration and were capable of killing multiple targets.
  
  
  CONCLUSIONS
  High-grade gliomas are suitable for specific targeting by armed ATC. These data, together with additional animal studies, may provide the preclinical support for the use of armed ATC as a valuable addition to current treatment regimens.
authors: Department of Neurosurgery, Wayne State University, Karmanos Cancer Institute, Detroit, MI, USA.
authors: Ian M
authors: IM
authors: Zitron
authors: Archana
authors: A
authors: Thakur
authors: Oxana
authors: O
authors: Norkina
authors: Geoffrey R
authors: GR
authors: Barger
authors: Lawrence G
authors: LG
authors: Lum
authors: Sandeep
authors: S
authors: Mittal
mesh_terms: D000704:Analysis of Variance; D018033:Antibodies, Bispecific / Q000276:immunology / Q000627:therapeutic use*; D001932:Brain Neoplasms / Q000276:immunology / Q000378:metabolism / Q000628:therapy*; D017252:CD3 Complex / Q000276:immunology; D019070:Cell Lineage; D016207:Cytokines / Q000378:metabolism; D003601:Cytotoxicity Tests, Immunologic; D005909:Glioblastoma / Q000276:immunology / Q000378:metabolism / Q000628:therapy*; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D008213:Lymphocyte Activation; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
chemical_list: D018033:Antibodies, Bispecific; D017252:CD3 Complex; D016207:Cytokines