title: In vitro testing of an anti-CD40 monoclonal antibody, clone 2C10, in primates and pigs.
abstract: BACKGROUND
  The CD40/CD154 and CD28/B7 pathways are important in allo- and xeno-transplantation. Owing to the thrombotic complications of anti-CD154mAb, anti-CD40mAb has emerged as a promising inhibitor of costimulation. Various clones of anti-CD40mAb have been developed against primate species, e.g., clone 2C10 against rhesus monkeys. We have compared the in vitro efficacy of 2C10 to prevent a T cell response in primates and pigs.
  
  
  METHODS
  The binding of 2C10 to antigen-presenting cells (PBMCs [B cells]) of humans, rhesus and cynomolgus monkeys, baboons, and pigs was measured by flow cytometry, and was also tested indirectly by a blocking assay. The functional capacity of 2C10 was tested by mixed lymphocyte reaction (MLR) with polyclonal stimulation by phytohemagglutinin (PHA) and also with wild-type pig aortic endothelial cells (pAECs) as stimulators.
  
  
  RESULTS
  There was a significant reduction in binding of 2C10 to baboon PBMCs compared to rhesus, cynomolgus, and human PBMCs, and minimal binding to pig PBMCs. The blocking assay confirmed that the binding of 2C10 was significantly lower to baboon PBMCs when compared to the other primate species tested. The functional assay with PHA showed significantly reduced inhibition of PBMC proliferation in humans, cynomolgus monkeys, and baboons compared to rhesus monkeys, which was confirmed on MLR with pAECs.
  
  
  CONCLUSIONS
  Since both the binding and functional activity of 2C10 in the baboon is lower than in rhesus monkeys, in vivo treatment using 2C10 in the baboon might require a higher dose or more frequent administration in comparison to rhesus monkeys. It may also be beneficial to develop species-specific clones of anti-CD40mAb.
authors.affiliation: Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Whayoung
authors.initials: W
authors.lastname: Lee
authors.affiliation: Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Vikas
authors.initials: V
authors.lastname: Satyananda
authors.affiliation: Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Hayato
authors.initials: H
authors.lastname: Iwase
authors.affiliation: Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Miyagawa
authors.affiliation: Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Cassandra
authors.initials: C
authors.lastname: Long
authors.affiliation: Revivicor, Blacksburg, VA, USA.
authors.forename: David
authors.initials: D
authors.lastname: Ayares
authors.affiliation: Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: David K C
authors.initials: DK
authors.lastname: Cooper
authors.affiliation: Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA. Electronic address: harah@upmc.edu.
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Hara
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D001402:B-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D019013:CD40 Antigens / Q000276:immunology; D049109:Cell Proliferation / Q000187:drug effects / Q000235:genetics; D002478:Cells, Cultured; D018920:Coculture Techniques; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000276:immunology*; D006084:Graft Rejection / Q000188:drug therapy* / Q000276:immunology; D006801:Humans; D007959:Lymphocyte Culture Test, Mixed; D011323:Primates; D013552:Swine; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D019013:CD40 Antigens
keywords: Anti-CD40 monoclonal antibody; Costimulation blockade; Nonhuman primate; Pig; Transplantation; Xenotransplantation