Selection Of Single Chain Antibody That Specifically Recognize Blood Type Antigen Using Phage Display

Personalized medicine is more effective and has fewer side effects than traditional cancer therapy in treating certain types of cancer. Early diagnostic and tumor-specific chemo-drugs, either through cell-specific delivery or cell-specific target, are requisites for personalized therapy. Identification of cancer-specific antibody generated by cancer patients themselves is a key for cancer early detection.This proof-of-concept study is to develop a method to rapidly isolate antibody specifically bind to cell membrane antigen. We used phage display and single chain antibody technology to screen for antibodies specifically bind to red-blood cell membrane from an antibody library generated from B/T cells from a healthy individual. Antibody genes were PCR amplified from peripheral blood lymphocytes (PBMC) isolated from a healthy individual (blood type:O) using combination of31different primers, and were subsequently cloned into an improved phage displayed vector to generate a large size single chain antibody library. This single chain antibody library was panned six rounds against cell membrane prepared from type A or type B red blood cells instead of traditionally used whole cells that are unstable and difficult to store. We optimized the panning conditions, including protein concentration and detergent concentration in the wash and binding buffer, to increase the wash efficiency and minimize the non-specific binding. After this proof-of-concept study, phage displayed-single chain antibody technology we optimized is more mature to be used to identify tumor cell-specific antibodies.