Journal: Frontiers in Immunology
Article Title: Engineered human B cells targeting tumor-associated antigens exhibit antigen presentation and antibody-mediated functions
doi: 10.3389/fimmu.2025.1621222
Figure Lengend Snippet: Engineered B cells and immune complexes taken up by dendritic cells present E6 antigen to activate E6-specific MHC class II-restricted T cells. (A) Schema depicting the engineered B cell antigen presentation assay. B cells, either non-engineered (EP-only) or engineered to express anti-E6 antibodies (6F4 or C1P5), are loaded with recombinant E6 antigen at multiple concentrations and then incubated with T cells, either engineered (Class II TCR) or non-engineered (UTD) to express an anti-E6 TCR. The concentration of IFNγ in the supernatants is then analyzed by ELISA. (B) ELISA for IFNγ as in (A) Data representative of 2 experiments with 2 donors. Bars and error bars represent mean and SD. ns=pv>0.05, ****=pv<0.0001 for two-way ANOVA with Šídák’s multiple comparisons test. (C) Schema depicting the immune complex-mediated antigen presentation assay. Immune complexes were formed with concentrated antibodies from the supernatants of B cells, either non-engineered or engineered to express anti-E6 antibodies, and recombinant E6 antigen at multiple concentrations. These were then incubated with myeloid-derived dendritic cells and then co-cultured with T cells, either engineered or non-engineered to express an anti-E6 TCR. The concentration of IFNγ in the supernatants is then analyzed by ELISA. (D) ELISA for IFNγ as in (C) Data representative of 2 experiments with 2 donors. Bars and error bars represent mean and SD. ns=pv>0.05, *=pv<0.05, ***=pv<0.001, ****=pv<0.0001 for two-way ANOVA with Šídák’s multiple comparisons test. (E) Schema depicting the flow cytometry-based engineered B cell membrane-bound antigen uptake assay. Engineered or non-engineered B cells are incubated with labeled tumor cells either expressing or not expressing the targeted antigen. The frequency of B cells with the tumor label is then analyzed by flow cytometry. (F) Flow cytometry results as in (E) for B cells engineered to express anti-CLDN6 IMAB206 (blue) or anti-E6 (6F4) antibodies (grey). ns=pv>0.05, ****=pv<0.0001 for two-way ANOVA with Šídák’s multiple comparisons test. (G) Flow cytometry results as in (E) for B cells engineered to express anti-E6 6F4 antibodies (orange), or anti-CLDN6 IMAB206 antibodies (grey). ns=pv>0.05, **=pv<0.01, for two-way ANOVA with Tukey’s multiple comparisons test. (H) Schema depicting a flow cytometry-based engineered B cell antigen presentation assay. B cells, either non-engineered or engineered to express anti-E6 antibodies, were incubated with tumor cells, engineered to express the membrane-bound E6 antigen, and with T cells, either engineered or non-engineered to express an anti-E6 TCR. The frequency of T cells expressing intracellular IFNγ was then analyzed by flow cytometry. (I) Flow cytometry results as in (H) for B cells engineered to express anti-E6 6F4 (orange) antibodies. Data representative of 3 experiments using one donor. Bars and error bars represent mean and SD. ns=pv>0.05, ****=pv<0.0001, for two-way ANOVA with Tukey’s multiple comparisons test.
Article Snippet: Recombinant E6 protein was from R&D Systems.
Techniques: Immunopeptidomics, Recombinant, Incubation, Concentration Assay, Enzyme-linked Immunosorbent Assay, Derivative Assay, Cell Culture, Flow Cytometry, Membrane, Labeling, Expressing