Journal: Frontiers in Immunology
Article Title: Identification of New Antibodies Targeting Malignant Plasma Cells for Immunotherapy by Next-Generation Sequencing-Assisted Phage Display
doi: 10.3389/fimmu.2022.908093
Figure Lengend Snippet: Binding analyses of monoclonal phage antibodies. (A) 1 x 10 6 L‐363 myeloma cells were incubated with 1 x 10 9 colony-forming-units (CFU) from the 41 different VH clonotypes and tested in ELISA experiments. Cell surface bound phages were detected using anti-M13-HRP antibody and absorbance was measured at 405 nm. 17 phages (green) showed a signal above the one obtained for CD7-specific phage (grey; dotted line), which was used as negative control. (B) Results of ELISA experiments performed equally with 1 x 10 6 PBMC from healthy donors are shown. 9 phage antibodies (green) bind low to moderate to PBMC (green) compared to cells alone (grey; dotted line). CD7-specific phage (grey) showed antigen-dependent binding to T cells and NK cells and served as positive control in these experiments. Mean values ± SEM of three independent experiments are shown for these ELISA experiments. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001 monoclonal phage vs. control. (C) The 9 most promising candidates were further tested in whole cell ELISA experiments with plasma cell lines (MM) L-363, U‐266, and INA-6, Raji Burkitt’s lymphoma (BL) cell line, T cell acute lymphoblastic leukemia cell line (T-ALL) CEM, human endothelial cells (endothelial) from healthy donors (HUVEC) and stable transfected CHO cells expressing either CD38, SLAMF7, BCMA, ICAM-1, CD40, CD56, CD70, CD138, FGFR3 or IL-6R. Color bar was set OD 405 nm = 0 (white) to OD 405 nm > 4 (dark green).
Article Snippet: The inhibition of the enzymatic activity of CD38 was measured using the CD38 Inhibitor Screening Assay Kit (Cyclase Activity) from BPS Bioscience (cat. no. 71275).
Techniques: Binding Assay, Incubation, Enzyme-linked Immunosorbent Assay, Negative Control, Positive Control, Transfection, Expressing