Journal: NPJ Precision Oncology
Article Title: An antibody-drug conjugate designed through clone and isotype selection restricts the growth of CSPG4-expressing triple-negative breast cancer
doi: 10.1038/s41698-026-01341-0
Figure Lengend Snippet: A Putative areas of epitope binding of anti-CSPG4 clones. Variable regions 225.28S are postulated to bind to the D3 domain of CSPG4, variable regions 763.74 bind to the D2 domain, and the precise binding site of variable regions 9.2.27 is not reported in the literature. Created using Biorender . B Production and purity of anti-CSPG4 IgG1 clones. SDS-PAGE indicates intact antibody at 150 kDa under non-reducing conditions (Lanes 1–3), and the presence of bands consistent with the antibody heavy chain (50 kDa) and light chain (25 kDa) under reducing conditions (treatment with β-mercaptoethanol). Lane 1: 225.28S IgG1, Lane 2: 763.74 IgG1, Lane 3: 9.2.27 IgG1, Lane 4: Reduced 225.28S IgG1, Lane 5: Reduced 763.74 IgG1, Lane 6: Reduced 9.2.27 IgG1 (left). Size-exclusion chromatography traces of the three antibody clones are shown. C Identification of CSPG4-expressing TNBC and melanoma cell lines by flow cytometric evaluation using 225.28S IgG1 and FITC-conjugated anti-human IgG secondary antibody. Representative plots of fluorescence intensity compared to cells stained with secondary antibody only (non-specific binding), and quantitation of median fluorescence intensity for each cell line. D Flow cytometric assessment of isotype control (Control IgG1) and Anti-CSPG4 IgG1 clones binding to MDA-MB-231 and A2058 cells using FITC-conjugated secondary antibody. MFI values are normalised to the maximum MFI value for each experiment. K D values and standard deviations are presented. E Investigation of internalisation of FabFluor®-labelled anti-CSPG4 IgG1 clones into MDA-MB-231 and A2058 cells at 24 h (one-way ANOVA with Tukey’s multiple comparisons test). Representative images and quantitation of fluorescence after 24-h incubation for cells treated with 30 nM of FabFluor-labelled antibody. F Generation of MMAE-conjugated ADCs and comparisons of cytotoxicity. Schematic representation of conjugation of IgG1 antibody (150 kDa) to 2 molecules of linker-payload (8 kDa), yielding an ADC product of 166 kDa. SDS-PAGE gel confirming higher molecular weight for anti-CSPG4 IgG1 clones after conjugation to payload. Left panel: Comparisons of cytotoxicity of MMAE payload, antibodies, and ADCs at 30 nM, with treatment over 96 h for MDA-MB-231 and A2058 cells (one-way ANOVA with Tukey’s multiple comparisons test, right panel). Created using Biorender .
Article Snippet: After incubation at 4 °C for 30 min, plates were centrifuged in the previous conditions and supernatants were removed before re-suspension of the cells in 100 μL of FACS Buffer containing Goat Anti-Human IgG-FITC (Native Antigen Company, Cat# 5230-0291) at a concentration of 2 μg/mL.
Techniques: Binding Assay, Clone Assay, SDS Page, Size-exclusion Chromatography, Expressing, Fluorescence, Staining, Quantitation Assay, Control, Incubation, Conjugation Assay, Molecular Weight