Journal: Immunotherapy Advances
Article Title: Targeting intratumoral regulatory T cells by CD137 aptamer-shRNA chimeras
doi: 10.1093/immadv/ltaf037
Figure Lengend Snippet: Selective, dose-dependent binding and uptake of murine CD137 aptamer by CD137-expressing cells. A total of 2 × 10 5 A20 or A20-CD137 cells prefixed with 1% paraformaldehyde were treated with fluorescein maleimide (FAM)-labeled murine CD137 aptamer at different concentrations (50, 100, and 500 nM). (a) The size of murine aptamer (222 nt) and the successful labeling of the aptamer with fluorescein maleimide (FAM) were detected using agarose gel electrophoresis. (b) CD137 expression on A20 and A20-CD137 cells. (c) Histograms showing the binding of CD137 aptamer to A20 (upper panel) or A20-CD137 (bottom panel) cells when given at different concentrations. (d) Comparisons of CD137 aptamer binding across different concentrations in A20 or A20-CD137 cells. (e) Comparisons of the % population between A20 and A20-CD137 cells that had bound to the CD137 aptamer at a given concentration. A total of 5 × 10 5 CD137-expressing (A20-CD137 or B16-CD137) or control (A20 or B16) cell lines were incubated with murine CD137 aptamer (0.5, 1, or 2 μg) for 2 h at 37°C. Comparisons between the amount of CD137 aptamer internalized by (f) A20 and A20-CD137 or (g) B16 and B16-CD137 cells. Comparisons of CD137 aptamer uptake when given at different amounts for (h) A20-CD137 and (i) B16-CD137 cells. The extent of CD137 aptamer internalization was expressed as fold change relative to control cells treated with 0.5 μg aptamer, or as absolute copy number per 1 μg total RNA. Dashed lines at a ratio of 1 represent the normalization reference. Data are shown as means ± SEM. Numbers above the brackets indicate P -values. * P < .05, ** P < .01, and *** P < .001 using unpaired Students’ t -test for (e), (f), and (g), while using one-way ANOVA with Bonferroni’s multiple comparison test for (d), (h), and (i).
Article Snippet: Murine B lymphoma cell line A20, melanoma cell line B16, and hepatoma cell line Hepa1-6 were purchased from American Type Cell Culture (ATCC; Manassas, VA, USA).
Techniques: Binding Assay, Expressing, Labeling, Agarose Gel Electrophoresis, Concentration Assay, Control, Incubation, Comparison