Journal: PLoS ONE
Article Title: Selection of scFv Antibody Fragments Binding to Human Blood versus Lymphatic Endothelial Surface Antigens by Direct Cell Phage Display
doi: 10.1371/journal.pone.0127169
Figure Lengend Snippet: A: Western Blot analysis showing molecular size of scFv-Fc fusion antibodies B6-11, B6-112 and B6-117. The scFv-region of the phagemids was cloned into the pFUSE-mIgG2B-vector (see ). Constructs were transfected into HEK293-cells. Cell culture supernatants were loaded on reducing (R) and non-reducing (NR) 10% SDS-PAGE, and nitrocellulose blots were probed with peroxidase-labeled anti-mouseFc antibodies. scFv-Fc fusion antibodies are secreted as approximate 140 kDa dimers, as seen under non-reducing condition (-DTT). Control: Fc only protein, produced from pFUSE vector without scFv insert. B: Immunoprecipitation with scFv-Fc B6-11 reconfirms CD146-binding. G1S1 lysates were incubated with scFv-Fc B6-11 and Fc only as control. Blots of immunoprecipitates were probed with anti-CD146 and anti-mouseFc antibodies. C: scFv-Fc B6-11 binds to recombinant CD146 in ELISA. scFv-Fc B6-11, commercial anti-CD146 antibody and Fc only were used on respective dilutions of recombinant human CD146 or BSA as control antigen coated on 96-well ELISA plates. Absorbance was measured at 450nm. D: scFv-Fc B6-11 fusion antibody binds to cells expressing CD146 in ELISA. Purified scFv-Fc B6-11 (light grey bars), commercial anti-CD146 antibody (dark grey bars) and Fc only (black bars) were added to monolayers of respective cell lines. Bound antibodies were detected using anti-Fc and HRP-conjugated anti-rabbit antibodies, and absorbance was measured at 450nm. Mean and standard deviation of triplicate experiments are given. E: On HDMECs, scFv-Fc B6-11 fusion antibody shows the same reactivity as a commercial anti-CD146 antibody. F: scFv-Fc fusion antibodies (red) reveal diverse membraneous labling patterns in co-immunofluorescent stainings with anti-CD31 antibody (green). Nuclei were counterstained with DAPI. Size bars: 50μm.
Article Snippet: After restriction digest with Nco I and Bgl II, scFv fragments were inserted in correct reading frame between the IL2 secretion signal and the murine Fc sequence of pFUSE-mIgG2B-Fc2 expression vector (Invivogen) ( ).
Techniques: Western Blot, Clone Assay, Plasmid Preparation, Construct, Transfection, Cell Culture, SDS Page, Labeling, Control, Produced, Immunoprecipitation, Binding Assay, Incubation, Recombinant, Enzyme-linked Immunosorbent Assay, Expressing, Purification, Standard Deviation