Journal: Cancer Immunology, Immunotherapy : CII
Article Title: The tumor antigen N -glycolyl-GM3 is a human CD1d ligand capable of mediating B cell and natural killer T cell interaction
doi: 10.1007/s00262-016-1812-y
Figure Lengend Snippet: CD1d interacts with NGcGM3. a NGcGM3 was adsorbed on 96-well microtiter plates that were incubated with either recombinant CD1d-IgG1 fusion or IgG1 isotype control. Detection of immobilized CD1d by NGcGM3-coated surfaces was performed with a biotinylated aIgG1, extravidin alkaline phosphatase, and p-nitrophenyl phosphate. Bars show the mean absorbance at 405 nm ± standard error of the mean (SEM) of 10 wells per treatment. For a control, we used wells that were not coated with NGcGM3 and were only coated with MeOH. **p < 0.01, t test. b Competitive ELISA assays with CD1d-IgG1 fusion that was pre-incubated ON with increasing amounts of NGcGM3 in solution (0, 5, 10, 50, 250 and 500 µg/mL) and subsequently added to the NGcGM3 adsorbed plates. The assays were performed in duplicate. c Competitive ELISA assays with 18:1 Biotinyl PE (2 µg/mL). Plates were coated with goat anti-mouse IgG1 Ab, and CD1d-IgG1 fusion was pre-incubated ON in mixtures containing control lipid (2 µg/mL) in the presence of NGcGM3 (competitor lipid) at the indicated concentrations; the mixtures were subsequently added to the anti-mouse IgG1 adsorbed plates. The assays were performed in duplicate. d Top panel flow cytometry analysis of NGcGM3 expression on the murine myeloma cell line X63. The cell line was stained with isotype-matched control mAb (gray-filled histogram) or 14F7 mAb (black line) followed by PE-conjugated aIgG1. The numbers represent the percentages of NGcGM3-expressing cells. Data are representative of three independent experiments. Lower panels flow cytometry analysis of recombinant CD1d-IgG1 fusion binding to the surface of the murine myeloma cell line X63. The cell line was incubated for 24 hs with isotype-matched control mAb (right panel, IgG1 black line) or CD1d-IgG1 (left panel, black line). Detection of CD1d bound to the X63 cells surface was evidenced by PE-conjugated aIgG1 staining (referred to as aCD1d in the figure). The staining controls were fresh cells stained with PE-conjugated aIgG1 (gray-filled histogram). Data are representative of three independent experiments
Article Snippet: Commercial NGcGM3 (Enzo Life Sciences, catalogue number ALX-302-019, purity ≥98 % according to the product data sheet) was adsorbed by solvent methanol (MeOH) evaporation on the surfaces of 96-well microtiter plates (PolySorp, Nunc) and then washed for removal of unbound ganglioside.
Techniques: Incubation, Recombinant, Competitive ELISA, Flow Cytometry, Expressing, Staining, Binding Assay