Isolation and characterization of a scFv antibody specific for tumor endothelial marker 1 (TEM1), a new reagent for targeted tumor therapy.
Tumor endothelial marker 1 (TEM1) is a protein predominantly expressed on the cell surface of endothelial cells in newly developing blood vessels and on tumor cells. It is therefore ideally suited as a target for anti-angiogenic tumor therapy. Using phage display technology a single chain antibody fragment (scFv-CM6) was isolated that specifically binds to the extracellular part of TEM1. Antibody specificity was determined in ELISA, by Western analysis, fluorescence microscopy and flow cytometry performed with TEM1-expressing cells. ScFv-CM6 was further functionalized and coupled to liposomes. Such immunoliposomes loaded with the cytotoxic drug N4-octadecyl-1-beta-D-arabinofuranosylcytosine-(5'-5')-3'-C-ethinylcytidine showed increased binding affinity and up to 80% higher cytotoxic activity towards TEM1-expressing IMR-32 tumor cells compared with control liposomes.
Marty
Cornelia
C
Paul Scherrer Institut, Biomolecular Research, Molecular Cell Biology, OFLC-102, CH-5232 Villigen, Switzerland.
Langer-Machova
Zuzana
Z
Sigrist
Sandra
S
Schott
Herbert
H
Schwendener
Reto A
RA
Ballmer-Hofer
Kurt
K
D000918:Antibody Specificity; D015703:Antigens, CD; D000951:Antigens, Neoplasm; D002460:Cell Line; D003561:Cytarabine / Q000008:administration & dosage / Q000031:analogs & derivatives; D003562:Cytidine / Q000008:administration & dosage; D006801:Humans; D007128:Immunoglobulin Fragments / Q000008:administration & dosage* / Q000302:isolation & purification; D008081:Liposomes; D008565:Membrane Proteins / Q000276:immunology*; D009363:Neoplasm Proteins / Q000276:immunology*; D009369:Neoplasms / Q000628:therapy*; D019151:Peptide Library; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000302:isolation & purification
D015703:Antigens, CD; D000951:Antigens, Neoplasm; C078203:CD248 protein, human; D007128:Immunoglobulin Fragments; D008081:Liposomes; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D019151:Peptide Library; D011994:Recombinant Proteins; C055966:immunoglobulin Fv; D003561:Cytarabine; C065145:N(4)-oleylcytosine arabinoside; D003562:Cytidine