Selective killing of normal and neoplastic human B cells with anti-CD19- and anti-CD22-ricin A chain immunotoxins.
Monoclonal antibodies directed against two human B cell-restricted antigens, CD19 and CD22, were conjugated to highly purified ricin A chain. These A chain immunotoxins (A-IT) were specifically cytotoxic to Daudi cells and normal human peripheral blood B cells in vitro. The concentration required for 50% inhibition of protein synthesis (IC50) in these cells ranged from 7.5 X 10(-10) M to 4.2 X 10(-9) M. The specific toxicities of these A-ITs for Daudi cells were augmented 2- to 6-fold in the presence of 20mM NH4Cl. These studies demonstrate that A-ITs specific for CD19 and CD22 may be useful in the clinical treatment of B cell malignancies.
D000643:Ammonium Chloride / Q000494:pharmacology; D018941:Antigens, CD19; D000944:Antigens, Differentiation, B-Lymphocyte; D000954:Antigens, Surface / Q000276:immunology*; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D002051:Burkitt Lymphoma / Q000628:therapy*; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D000922:Immunotoxins / Q000494:pharmacology*; D012276:Ricin / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000187:drug effects; D013696:Temperature; D013997:Time Factors
D018941:Antigens, CD19; D000944:Antigens, Differentiation, B-Lymphocyte; D000954:Antigens, Surface; D000922:Immunotoxins; D000643:Ammonium Chloride; D012276:Ricin