Cytotoxicity of a cell-reactive immunotoxin containing ricin A chain is potentiated by an anti-immunotoxin containing ricin B chain.
In vitro killing of the human Daudi cell line by either univalent [F(ab')] or divalent (IgG) forms of rabbit anti-human Ig (RAHIg) coupled to ricin A chain can be specifically potentiated by a "piggyback" treatment with ricin B chain coupled to goat anti-rabbit Ig (GARIg). When cells are treated with univalent immunotoxin (IT) [F(ab') RAHIg-A] and then cultured, IT can be detected on the cell surface for at least 5 h, since GARIg-B can still enhance killing at this time. These results provide a strategy for in vivo use of A chain- and B chain-containing IT.
D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D000992:Antitoxins / Q000494:pharmacology*; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D006041:Goats; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000502:physiology; D007700:Kinetics; D011817:Rabbits; D012276:Ricin / Q000276:immunology*
D000276:Adjuvants, Immunologic; D000992:Antitoxins; D007140:Immunoglobulin Fab Fragments; D012276:Ricin