Skip to main content
. 2022 Feb 2;10(2):e003655. doi: 10.1136/jitc-2021-003655

Figure 1.

Figure 1

Treatment with bispecific antibody leads to platelet activation. (A, B) Association of platelet count and sIL-2R concentration in two patients with prostate cancer receiving bispecific PSMA×CD3 (CC-1) antibody. (C) Time course of platelet activation (CD62P expression) on CC-1 treatment. (D) Platelet activation (CD62P expression) in untreated healthy donors (gray, n=5), untreated patients with prostate cancer (light blue, n=4) and in patients with prostate cancer receiving PSMA×CD3 (dark blue, n=5). Statistical significance was calculated by one-way ANOVA and Tukey’s multiple comparisons test. (E) Association of CD62P expression and total platelet count. Statistical significance was calculated using simple linear regression analysis. (F) Lack of platelet activation on PSMA×CD3 treatment (200 ng/mL) (n=4). Classical platelet agonist TRAP-6 (10 µM) served as a positive control. Statistical significance was calculated by one-way ANOVA and Tukey’s multiple comparisons test. (G) Platelet aggregation (percentage of light transmission during the indicated time interval) was studied in the presence or absence of PSMA×CD3 (200 ng/mL) and TRAP-6. (H) Maximum aggregation levels on PSMA×CD3 and TRAP-6 treatment (n=3). Statistical significance was calculated by one-way ANOVA and Tukey’s multiple comparisons test. (I) Representative immunofluorescence staining of LNCaP cells coincubated with human PBMCs, platelets and PSMA×CD3 (scale bar indicates 100 µm, original magnification ×20). (J) Representative staining for platelet activation (CD62P expression) after incubating platelets for 30 min with LNCaP cells and PBMCs (effector to target ratio of 4:1) and PSMA×CD3 (scale bar indicates 20 µm, original magnification ×63). (K, L) Platelets of healthy donors (n=3) were analyzed for CD62P expression after culturing them for 2 hours in the presence or absence of LNCaP cells alone or in combination with PSMA×CD3 and/or PBMCs of healthy donors. (K) Exemplary plots and (L) pooled data are shown. Statistical significance was calculated by one-way ANOVA and Tukey’s multiple comparisons test. ANOVA, analysis of variance; DAPI, 4′,6-diamidino-2-phenylindole; HD, healthy donor; PBMC, peripheral blood mononuclear cell; sIL-2R, soluble interleukin-2 receptor; TRAP-6, thrombin receptor activator peptide 6.