Selective killing of tumor cells in vitro by an immunotoxin composed of ricin and monoclonal antibody against Ia antigen.

Abstract

A monoclonal antibody (MAb-HB55) directed against a HLA class II antigen (Ia), was purified by DE-52 chromatography. The purified MAb contained less than 5% impure protein detected by SDS-PAGE. Ricin was conjugated with the MAb via a disulfide bond to construct an immunotoxin (ricin-HB55). The concentration causing fifty percent growth inhibition (IC50) was 2 x 10(-11)M for the Raji cells. In contrast, the IC50 for Molt-4 and K562 cells was 100 times higher than that for the Raji cells. B lymphocytes separated from peripheral blood lymphocytes by nylon wool were selectively killed by the conjugate, but T lymphocytes were not apparently affected. Our results demonstrate that the immunotoxin is selectively cytotoxic to Raji cells and B-cells, and may have potential for purging malignant cells from bone marrow of patients with B-cell leukemia and lymphoma.

• Authors: M Wu, S L Tang, R J Zang, H Yu
• Journal: International journal of immunopharmacology (Int J Immunopharmacol) Vol. 12 Issue 2 Pg. 235-9 ( 1990) ISSN: 0192-0561 [Print] England
• PMID: 2329015 (Publication Type: Journal Article)

Chemical References

• Antibodies, Monoclonal
• Histocompatibility Antigens Class II
• Immunotoxins
• Ammonium Chloride
• Ricin

Topics

• Ammonium Chloride (pharmacology)
• Animals
• Antibodies, Monoclonal (immunology, therapeutic use)
• Antibody-Dependent Cell Cytotoxicity
• B-Lymphocytes (drug effects)
• Histocompatibility Antigens Class II (immunology)
• Immunotoxins (pharmacology)
• Mice
• Mice, Inbred BALB C
• Ricin (pharmacology, therapeutic use)
• T-Lymphocytes (drug effects)
• Tumor Cells, Cultured (drug effects)