Screening and identification of anti-KG1a cell ScFvs from a phage display antibody library
Objective Screening and cloning of anti KG1a cell single chain antibodies (ScFvs) from phage display antibody library. Methods A ScFv phage display library from the spleen cells of mice immunized with KG1a cells (acute myelogenous leukemia cell line) was selected by using the immunizing cells. After 4 rounds of panning, 96 individual clones of phage ScFvs were tested by cell ELISA. Three out of the 26 positive clones them were further checked for the distribution of their antigens on different cells by using immunofluorescence flow cytometry. Results Flow cytometry assay showed different distribution of the antigens on different leukemia cells. DNA sequences and deduced amino acid sequences of the two clones analyzed both belong to the same mouse Ig V region subgroup and family: The V H belongs to subgroup Ⅱand family Ⅵ, the Vκ belongs to subgroup Ⅲ and family Ⅸ. Conclusion Intact cells can be used effectively to screen, isolate and clone ScFv genes against cell surface molecules which are usually hard to isolate and purify. The anti KG1a ScFvs we obtained are promising for further studying and isolating the cell surface molecules of leukemia cells.