title: Protective effects of anti-ricin A-chain antibodies delivered intracellularly against ricin-induced cytotoxicity.
abstract: OBJECTIVE
  To evaluate the ability of anti-ricin A-chain antibodies, delivered intracellularly, to protect against ricin-induced cytotoxicity in RAW264.7 cells.
  
  
  METHODS
  Anti-deglycosylated ricin A-chain antibody and RAC18 anti-ricin A-chain monoclonal antibody were delivered intracellularly by encapsulating in liposomes or via conjugation with the cell-penetrating MTS-transport peptide. RAW264.7 cells were incubated with these antibodies either before or after ricin exposure. The changes in cytotoxicity were estimated by MTT assay. Co-localization of internalized antibody and ricin was evaluated by fluorescence microscopy.
  
  
  RESULTS
  Internalized antibodies significantly increased cell viability either before or after ricin exposure compared to the unconjugated antibodies. Fluorescence microscopy confirmed the co-localization of internalized antibodies and ricin inside the cells.
  
  
  CONCLUSIONS
  Intracellular delivery of antibodies to neutralize the ricin toxin after cellular uptake supports the potential use of cell-permeable antibodies for post-exposure treatment of ricin intoxication.
authors.affiliation: Feng Wu, Shaoan Fan, Kam-Meng Tchou-Wong, Department of Environmental Medicine, New York University School of Medicine, 57 Old Forge Road, Tuxedo, NY 10987, United States.
authors.forename: Feng
authors.initials: F
authors.lastname: Wu
authors.forename: Shaoan
authors.initials: S
authors.lastname: Fan
authors.forename: Frank
authors.initials: F
authors.lastname: Martiniuk
authors.forename: Seth
authors.initials: S
authors.lastname: Pincus
authors.forename: Sybille
authors.initials: S
authors.lastname: Müller
authors.forename: Heinz
authors.initials: H
authors.lastname: Kohler
authors.forename: Kam-Meng
authors.initials: KM
authors.lastname: Tchou-Wong