Fig 2: Niraparib treatment alters the proportion and function of tumor-associated lymphocytes in vivo. A Representative images of immunohistochemistry (IHC) staining for poly ADP-ribose polymerase (PARP1) in human normal ovarian tissues and ovarian cancer samples. Scale bar:100 μm. B Expression of PARP1 its relationship with clinical characteristics in ovarian cancer. C Representative images of IHC staining for programmed cell death ligand (PD-L1) and CD8 in human normal ovarian tissues and ovarian cancer samples. Scale bar:100 μm. D The correlation of CD8a and PD-L1 in GEPIA database. E-K Flow cytometry analysis of CD3+T cells, CD3+CD4+T cells, CD3+CD8+T cells, CD4+IFN-γ+ cells, and CD8+ IFN-γ+ cells of the Niraparib treatment patients. All experiments were repeated three times. Data are presented as the mean ± SD. *P < 0.05, **P < 0.01

Fig 3: DON treatment suppressed T cells activation in vitro. Freshly separated spleen cells were stimulated with 1.5mg/ml ConA with or without treating 2.5μM DON, and cells were analyzed 24h after ConA stimulation. (A, B) The expressions of activation markers CD25 and CD69 in CD4(+) (A) and CD8(+) (B) T cells were examined by flow cytometry. Data were expressed as means ± SEM. **P <0.01, and ***P <0.001.

Fig 4: JHU083 inhibited T cells activation in vivo. Mice of Vehicle-AIH and JHU083-AIH group were intravenously injected with 8ml/kg ConA, and Vehicle-WT group was injected with normal saline of equal volume. JHU083-AIH group was gavaged with 0.3mg/kg JHU083 24h and 1h before ConA injection, and mice of Vehicle-WT and Vehicle-AIH group were treated with equal vehicle at the same time points. (A, B) Flow cytometry was applied to analyze the expression of CD25 and CD69 of CD4(+) (A) and CD8(+) (B) T cells. Data were expressed as means ± SEM. *P < 0.05 and **P <0.01.

Fig 5: Combination of Niraparib with PD-L1 blockade can enhance the proportion and function of T lymphocytes in vivo. A Flow cytometry analysis of CD3+CD4+T lymphocytes from the peripheral blood of mice treated with control (PBS, 100 μl), Niraparib (25 mg/kg, four times a week), PD-L1 blockade (10 mg/kg, twice a week), and the combination. B Flow cytometry analysis of CD3+CD8+T lymphocytes from the peripheral blood of the mice from the four treatment groups. C Flow cytometry analysis of CD4+IFN-γ+T lymphocytes from the peripheral blood of the mice from the four treatment groups. D Flow cytometry analysis of CD8+IFN-γ+T lymphocytes from the peripheral blood of the mice from the four treatment groups. E Quantification of data of lymphocytes with four different treatment groups. F Representative images of immunohistochemistry (IHC) staining for CD8 and IFN-γ staining from resected tumors with different treatments at day 52. Scale bar: 50 μm. G Quantification of lymphocytes and IFN-γ with different treatment groups. All experiments were repeated three times. Data are presented as the mean ± SD. *P < 0.05, **P < 0.01