Development of Oligoclonal Nanobodies for Targeting the Tumor-Associated Glycoprotein 72 Antigen

作者：Sharifzadeh Zahra; Rahbarizadeh Fatemeh^*; Shokrgozar Mohammad Ali; Ahmadvand Davoud; Mahboudi Fereidoun; Jamnani Fatemeh Rahimi; Bakhtiari Seyed Hamid Aghaee

来源：Molecular Biotechnology, 2013, 54(2): 590-601.

DOI：10.1007/s12033-012-9601-0

• Camel
• Nanobody
• Oligoclonal
• Phage display
• Single domain antibody
• TAG-72

The tumor-associated glycoprotein 72 (TAG-72) is a membrane mucin whose over-expression is correlated with advanced tumor stage and increased invasion and metastasis. In this study, we identified a panel of four nanobodies, single variable domains of dromedary heavy-chain antibodies that specifically recognize the TAG-72 antigen. All selected nanobodies were shown to selectively bind to this cancer-related molecule with low-nanomolar affinities and do not cross-react with other antigens, such as MUC1 or HER2. Furthermore, they can detect TAG-72 in concentrations as low as 5 U/ml which is valuable in sensitive detection of this molecule in cancerous patients. Cell ELISA experiments proved their ability for binding to the native target antigen on TAG-72 expressing cells while not showing any reactivity to HT-29 cells, a TAG-72-negative cell line. Using competition studies, we found that each nanobody recognizes a distinct epitope on the TAG-72 antigen that is different from the one recognized by the mouse anti-TAG-72 antibody, CC49. Considering their high specificity, reduced immunogenicity and multi-targeting behavior, these oligoclonal nanobodies represent a promising tool to target TAG-72 over-expressing tumor cells.

• 出版日期2013-6