Expression and purification of two anti-CD19 single chain Fv fragments for targeting of liposomes to CD19-expressing cells.

• Abstract: Antibody-targeted liposomal anticancer drugs combine the specificity of antibodies with large payloads of entrapped drugs. We previously showed that liposomal doxorubicin (DXR) targeted via anti-CD19 monoclonal antibodies (mAb) or their Fab' fragments against the B-cell antigen CD19 led to improved therapeutic effects in murine B-cell lymphoma models relative to non-targeted liposomal DXR. We now are examining the use of anti-CD19 single chain fragments of the antibody variable region (scFv) as a targeting moiety, to test the hypothesis that scFv have advantages over full-sized mAb or Fab' fragments. We expressed two different anti-CD19 scFv constructs, HD37-C and HD37-CCH in E. coli, and purified the scFvs using two different methods. The HD37-CCH construct was selected for coupling studies due to its relative stability and activity in comparison to HD37-C. When coupled to liposomes, the HD37-CCH scFv showed increased binding in vitro to CD19-positive Raji cells, compared to non-targeted liposomes. Cytotoxicity data showed that HD37-CCH scFv-targeted liposomes loaded with DXR were more cytotoxic than non-targeted liposomal DXR. Our results suggest that anti-CD19 scFv constructs should be explored further for their potential in treating B-lymphoid leukemias and lymphomas.
• Authors: W W K Cheng, D Das, M Suresh, T M Allen (Affiliation: Dept. of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada T6G 2H7.)
• Journal: Biochimica et biophysica acta (Biochim Biophys Acta) Vol. 1768 Issue 1 Pg. 21-9 (Jan 2007) ISSN: 0006-3002 [Print] Netherlands
• PMID: 17046711 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibiotics, Antineoplastic
• Antibodies, Monoclonal
• Antigens, CD19
• Antigens, Neoplasm
• Binding Sites, Antibody
• Immunoglobulin Fab Fragments
• Immunoglobulin Variable Region
• Liposomes
• Doxorubicin

Topics

• Antibiotics, Antineoplastic (pharmacology)
• Antibodies, Monoclonal (biosynthesis, genetics, isolation & purification)
• Antibody Affinity
• Antigens, CD19 (immunology, metabolism)
• Antigens, Neoplasm (immunology, metabolism)
• Binding Sites, Antibody
• Burkitt Lymphoma (immunology, metabolism, pathology)
• Cell Line, Tumor
• Cell Survival (drug effects)
• Chemistry, Pharmaceutical
• Cloning, Molecular
• Doxorubicin (pharmacology)
• Drug Compounding
• Drug Delivery Systems
• Humans
• Immunoglobulin Fab Fragments (immunology)
• Immunoglobulin Variable Region (immunology, metabolism)
• Inhibitory Concentration 50
• Liposomes