Human CD19 Antibody

Detection of CD19 in Human PBMCs by Flow Cytometry.

Human peripheral blood mononuclear cells (PBMCs) were stained with Mouse Anti-Human CD3e PE-conjugated Monoclonal Antibody (Catalog # FAB100P) and either (A) Mouse Anti-Human CD19 Monoclonal Antibody (Catalog # MAB4867) or (B) Mouse IgG₁Isotype Control (Catalog # MAB002) followed by Allophycocyanin-conjugated Anti-Mouse IgG Secondary Antibody (Catalog # F0101B).

Detection of Human CD19 by Flow Cytometry

Common heavy-chain antibodies are specific and have neutralization potential.(a) Flow cytometry profiles obtained with different IgGs selected against CD19, EpCAM, EGFR and CD47. The profiles on antigen-negative versus -positive cell lines are shown shaded and open, respectively (for CD19: Jurkat/Raji; EpCAM: HEK-293/MCF-7; EGFR: MCF-7/A431; CD47: CHO/CHO-CD47). (b) Dose–response inhibition of SIRP alpha binding to CD47 expressed on cells for the positive control mAb B6H12 (open circles), IgGK1 (closed circles) and IgGK2 (crosses) that were directly isolated from the fixed heavy-chain libraries. (c) Neutralization potential in the SIRP alpha/CD47-binding assay for variants IgGK3 and IgGK4 (closed and open squares, respectively) obtained via optimization of IgGK2 (crosses). (d) Neutralization activity in the MSLN/MUC16 interaction assay for IgGO1 (open circles) and IgGO3 (closed triangles) in comparison with a negative control mAb (closed circles) and the therapeutic antibody Amatuximab (closed squares). (e) Dose–response binding profile measured by flow cytometry on CD19-positive Raji cells for IgG1B7 (open circles) and variants IgGL7-1 (triangles), and IgGL7-2 (closed circles) that were generated by affinity maturation. Error bars in b, c and d represent s.e.m. of two replicates. The data are representative of three independent experiments. Image collected and cropped by CiteAb from the following publication (https://pubmed.ncbi.nlm.nih.gov/25672245), licensed under a CC-BY license. Not internally tested by R&D Systems.

Detection of Human CD19 by Flow Cytometry

Biological activity of bispecific kappa lambda-bodies.(a) Schematic representation of monovalent and bivalent binding of CD19xCD47 kappa lambda-bodies on the surface of CD47+/CD19−DS-1 cells (top) and CD47+/CD19+Raji cells (bottom). (b) Binding of CD47 × EpCAM (left panels) and CD47 × CD19 kappa lambda-bodies (right panels) to DS-1 (top panels) and Raji cells (bottom panels) monitored by FACS. kappa lambda bodies were used at 0.01, 0.1 and 1 mg ml−1, control staining with fluorescently labelled secondary antibody is indicated by the shaded area. (c) Inhibition of SIRP alpha binding to the CD47 on DS-1 (top) and Raji cells (bottom) by increasing concentrations of different antibodies: anti-CD47-positive control mAb B6H12 (grey open circles); CD47 × CD19 K3L7-1 (black open circles, dotted line); CD47 × CD19 K3L7-2 (closed circles); CD47 × EpCAM K3L6-1 (open triangles). Error bars represent s.e.m. of four replicates and the data are representative of three independent experiments. (d) T-cell-mediated killing of EpCAM-positive cells by CD3 × EpCAM kappa lambda-bodies. MCF-7 cells were incubated with purified human T cells in the presence of increasing concentrations of different antibodies. CD3 × EpCAM kappa lambda-bodies: L6-3L3-1 (closed circles), L6-4L3-1 (closed squares), L6-5L3-1 (closed triangles); anti-EpCAM mAbs: L6-3 (open circles), L6-4 (open squares), L6-5 (open triangles); anti-CD3 mAb L3-1 (crosses). Error bars represent s.d. of three replicates and the experiment was repeated with the blood of two independent donors. The isoelectric focusing (IEF) gels and electrophoresis profiles corresponding to the different kappa lambda-bodies and mAbs are shown in Fig. 3 and Supplementary Fig. 1. Image collected and cropped by CiteAb from the following publication (https://pubmed.ncbi.nlm.nih.gov/25672245), licensed under a CC-BY license. Not internally tested by R&D Systems.