Flow cytometry analysis of ligand binding to cells displaying stereotyped CLL smIgs on HEK 293T cells.
A, general scheme of the cell binding assay with dextran-conjugated multimeric ligands. CLL mAbs from CLL 014, CLL 529, CLL 675, and CLL 1297 and other control CLL IgG were transiently expressed on the HEK 293T cell surface. The cells were incubated with a biotinylated dextran polymer displaying 20–30 copies of the KMS31 or KMS32 and controls followed by staining with phycoerythrin-conjugated streptavidin (sa-PE). B, overlaid flow cytometry histograms showing the binding of dext-KMS31 on the cells expressing stereotyped smIgs from subset 7P and controls. C, overlaid flow cytometry histograms showing the binding of dext-KMS32 on cells expressing stereotyped smIgs from subset 7P and controls.