Skip to main content
. 2021 Apr 5;9(4):e001292. doi: 10.1136/jitc-2020-001292

Figure 4.

Figure 4

Effect of immunosuppressive ascites fluids on PD-L1-targeting BiTE and tumor cells. (A) PBMC-derived T cells were incubated with CD3/CD28 Dynabeads in normal serum (NS) medium or patient-derived malignant ascites fluids (50% v/v) for 48 hours before measuring for T cell activation (CD69+/CD25+) by flow cytometry. (B) PBMC-derived T cells were cocultured with DLD-1 carcinoma cells (5:1) and incubated with either PD-L1 scFv or PD-L1 NB BiTE in the presence of NS medium or patient-derived ascites fluids (50% v/v) for 48 hours before measuring for CD69+/CD25+ expression by flow cytometry. (C and D) DLD-1 cells were grown in NS medium or 50% (v/v) patient-derived ascites fluid for 48 hours before analysis by flow cytometry for the PD-L1-positive population (C) and geometric mean fluorescence intensity (D). Statistical significance was assessed by two-way analysis of variance followed by Bonferroni post hoc analysis. Significance was assessed versus untreated cells within the relevant group (*p<0.05, **p<0.01 and ***p<0.001). BiTE, bispecific T cell engager; DMEM, Dulbecco’s modified Eagle medium; NB, nanobody; PD-L1, programmed death-ligand 1; PBMC, peripheral blood mononuclear cell; scFv, single-chain variable fragment.