title: Activated T cells from umbilical cord blood armed with anti-CD3 × anti-CD20 bispecific antibody mediate specific cytotoxicity against CD20+ targets with minimal allogeneic reactivity: a strategy for providing antitumor effects after cord blood transplants.
abstract: BACKGROUND
  In this study, we asked whether anti-CD3-activated T cells (ATCs) from cord blood (CB) could be expanded and targeted to solid tumors or hematologic malignancies for infusions after unrelated CB stem cell transplant and whether cord blood ATCs (CBATCs) could reduce alloresponsiveness.
  
  
  METHODS
  CB mononuclear cells (MNCs) were activated with anti-CD3 (20 ng/mL) and expanded for 14 days in interleukin-2 (100 IU/mL). CBATCs were armed with anti-CD3 × anti-CD20 (CD20Bi) or anti-CD3 × anti-Her2 (Her2Bi) bispecific antibodies (CBaATCs) and tested for specific cytotoxicity, cytokine secretion, and alloresponsiveness.
  
  
  RESULTS
  Our results show the mean expansion of CBATCs to be 37-fold after 14 days of culture from either frozen (n=4) or fresh (n=4) CB units. Cytotoxicity was optimal when CBATCs were armed with 50 ng of CD20Bi/10(6) cells. Cytotoxicity peaked between Day 8 and Day 10 for both bispecific antibodies. At an effector-to-target ratio of 25:1, the mean cytotoxicities of CBATCs armed with Her2Bi or CD20Bi were 40% (n=4) and 30% (n=4), respectively. CBaATCs exhibited peak specific interferon-γ enzyme-linked immunosorbent spots on Day 10. CBATCs and CBaATCs suppressed responsiveness to alloantigens by 20% to 50% when compared with normal allogeneic peripheral blood MNC response.
  
  
  CONCLUSIONS
  We showed that armed CBATCs mediate specific cytotoxicity, secrete low levels of cytokines and chemokines, and demonstrate attenuated response to alloantigens.
authors: Department of Oncology, Wayne State University School of Medicine and Barbara Ann Karmanos Cancer Institute, Detroit, Michigan 48201, USA. thakur@karmanos.org
authors: Archana
authors: A
authors: Thakur
authors: Carly
authors: C
authors: Sorenson
authors: Oxana
authors: O
authors: Norkina
authors: Dana
authors: D
authors: Schalk
authors: Voravit
authors: V
authors: Ratanatharathorn
authors: Lawrence G
authors: LG
authors: Lum
mesh_terms: D018033:Antibodies, Bispecific / Q000276:immunology*; D018951:Antigens, CD20 / Q000276:immunology*; D017252:CD3 Complex / Q000276:immunology*; D002460:Cell Line; D016207:Cytokines; D004797:Enzyme-Linked Immunosorbent Assay; D005312:Fetal Blood / Q000166:cytology*; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology*; D010641:Phenotype; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D018033:Antibodies, Bispecific; D018951:Antigens, CD20; D017252:CD3 Complex; D016207:Cytokines; D007371:Interferon-gamma