Immunotherapies based on PD-1/PD-L1 pathway inhibitors in ovarian cancer treatment.

Immunotherapies based on anti-programmed death 1/programmed death ligand 1 (PD-1/PD-L1) pathway inhibitors may turn out effective in ovarian cancer (OC) treatment. They can be used in combination with standard therapy and are especially promising in recurrent and platinum-resistant OC. There is growing evidence that the mechanism of the PD-1/PD-L1 pathway can be specific for a particular histological cancer type. Interestingly, the data have shown that the PD-1/PD-L1 pathway blockade may be effective, especially in the endometrioid type of OC. It is important to identify the cause of anti-tumor immune response suppression and exclude its other mechanisms in OC patients. It is also necessary to conduct subsequent studies to confirm in which OC cases the treatment is effective and how to select patients and combine drugs to improve patient survival.

Influence of ovarian cancer type I and type II microenvironment on the phenotype and function of monocyte-derived dendritic cells

PURPOSE. The aim of this study was to evaluate the influence of ovarian cancer cell lysates isolated from type I or type II ovarian cancer (OC) on the phenotype of monocyte-derived dendritic cells (Mo-DCs) and the cytokine profile. We also determined whether the Mo-DCs and tumor microenvironment, reflected by peritoneal fluid (PF) from type I or II ovarian cancer, could promote regulatory T cell (Tregs) differentiation from naive CD4+ lymphocytes in vitro. RESULTS. Our results show a significant role of the ovarian cancer microenvironment reflected by PF from type I or II OC in the inhibition of the DC differentiation process. Interestingly, the percentage of cells co-expressing CD45 and CD14 antigens in the cultures stimulated with PF from both type I and type II OC was higher than in the control. Furthermore, the percentage of cells expressing CD1a, i.e., a marker of immature DCs, was significantly reduced in the cultures stimulated with PF from type I and type II OC. The results obtained show that ovarian cancer type II lysates induce differentiation of monocytes into macrophage-like cells with a CD1a+/HLA-DR+/CD83− phenotype and significantly higher CD86/HLA-DR expression. We show that ovarian cancer type II Mo-DCs are able to prevent an immune response by release of IL-10, whereas OC type I Mo-DCs can promote the generation of Tregs. CONCLUSIONS. We demonstrate that each type of ovarian cancer can induce a unique phenotype of DCs and differentiation of Tregs, both associated with immune-suppressive function, which may be an obstacle while developing effective anticancer dendritic cell vaccination (AU)

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Influence of ovarian cancer type I and type II microenvironment on the phenotype and function of monocyte-derived dendritic cells.

PURPOSE: The aim of this study was to evaluate the influence of ovarian cancer cell lysates isolated from type I or type II ovarian cancer (OC) on the phenotype of monocyte-derived dendritic cells (Mo-DCs) and the cytokine profile. We also determined whether the Mo-DCs and tumor microenvironment, reflected by peritoneal fluid (PF) from type I or II ovarian cancer, could promote regulatory T cell (Tregs) differentiation from naive CD4+ lymphocytes in vitro. RESULTS: Our results show a significant role of the ovarian cancer microenvironment reflected by PF from type I or II OC in the inhibition of the DC differentiation process. Interestingly, the percentage of cells co-expressing CD45 and CD14 antigens in the cultures stimulated with PF from both type I and type II OC was higher than in the control. Furthermore, the percentage of cells expressing CD1a, i.e., a marker of immature DCs, was significantly reduced in the cultures stimulated with PF from type I and type II OC. The results obtained show that ovarian cancer type II lysates induce differentiation of monocytes into macrophage-like cells with a CD1a+/HLA-DR+/CD83- phenotype and significantly higher CD86/HLA-DR expression. We show that ovarian cancer type II Mo-DCs are able to prevent an immune response by release of IL-10, whereas OC type I Mo-DCs can promote the generation of Tregs. CONCLUSIONS: We demonstrate that each type of ovarian cancer can induce a unique phenotype of DCs and differentiation of Tregs, both associated with immune-suppressive function, which may be an obstacle while developing effective anticancer dendritic cell vaccination.

Macrophage-derived chemokine CCL22 and regulatory T cells in ovarian cancer patients.

The study was undertaken to evaluate macrophage-derived chemokine (CCL22) levels in the peritoneal fluid (PF) and plasma of patients with ovarian cancer (n = 93) in relation to regulatory T cells (Tregs; n = 75). The peritoneal fluid CCL22 concentrations were significantly higher in epithelial ovarian cancer (EOC) patients than in patients with benign tumors-serous cystadenoma (n = 32). There was no difference in plasma levels of CCL22 in EOC patients compared with the non-cancer and healthy volunteers (n = 10). There were no significant differences in the plasma and PF CCL22 levels based on tumor grade. However, women with stage IV FIGO (International Federation of Gynecologists and Obstetricians) had significantly higher plasma CCL22 levels than patients with stages I and III. Women with stage I FIGO had significantly higher PF CCL22 levels than patients with stages II and III. Women with endometrioid cystadenocarcinoma had higher PF CCL22 levels than women with undifferentiated carcinoma. The percentage of tumor-infiltrating Tregs (11.06 %) was significantly higher compared to PF (3.05 %) and peripheral blood (PB) (2.01 %). Moreover, the percentage of Tregs was higher in the PF than in the PB of EOC patients. There were no significant differences in the PB, PF, and tumor-infiltrating Tregs percentage based on tumor stage, grade, or histology. Elevated levels of CCL22 found in the ascites could create a chemokine gradient aiding in Treg cells migration. Increased Tregs percentage in the local microenvironment of ovarian cancer might be an important mechanism of immunosuppression.

Phenotype of dendritic cells generated from peripheral blood monocytes of patients with ovarian cancer.

OBJECTIVES: The aim of our study was to generate dendritic cells (DCs) from peripheral blood monocytes (PBMC) of patients suffering from ovarian cancer. MATERIALS AND METHODS: Immature DCs were generated from PBMC cultured in RPMI 1640 medium with 2% human serum albumin (HSA), supplemented with recombinant human (rh) granulocyte macrophage colony stimulating factor (GM-CSF) and rh interleukin (IL)-4. After 5 days of culture, DC maturation was induced by the addition of an ovarian cancer cell line (CAOV3) lysate and after 6 days of rh tumor necrosis factor (TNF)-α for a further 2 days. The phenotype of the generated cells was assessed by flow cytometry for the expressions of human leukocyte antigen (HLA)-DR, costimulatory molecules (e.g., CD86, CD80), CD83, CD1a, and CD14. PBMC cultured in 2% HSA without rhIL-4, rhGM-CSF, rh-TNF-α, or tumor cell lysate formed the control group. RESULTS: The 2.41% (interquartile range, 1.51%-3.52%) of CD45+/CD14+ cells in cultures with rhIL-4, rhGM-CSF, rhTNF-α and tumor cell lysate was significantly lower than in the control group (31.10%; interquartile range, 11.11%-64.06%). Cultures with rhIL-4, rhGM-CSF, rhTNF-α, and tumor cell lysate showed a higher percentage (19.96%; interquartile range, 9.30%-24.42%) of fully mature CD83+/CD1a-/HLA-DR+ DCs compared with control culture (6.02%; interquartile range, 3.01%-7.37%). There was no significant difference in the expression of the immature DC marker (CD1a) between the cultures. The expression of co-stimulatory markers (CD80, CD86, HLA-DR) was greater (24.29%; interquartile range, 18.68%-33.95%) on DCs from cultures with rhIL-4, rhGM-CSF, TNF-α, and tumor cell lysate versus controls (4.93%; interquartile range, 2.67%-9.09%). CONCLUSION: Our data demonstrated that immature and mature DCs can be generated from adherent human PBMC from ovarian cancer patients cultured with rhIL-4, rhGM-CSF, rhTNF-α, and tumor cell lysates.

Dendritic cell subsets in the peritoneal fluid and peripheral blood of women suffering from ovarian cancer.

BACKGROUND: Evaluation of immature myeloid and lymphoid dendritic cells (DCs) in the peritoneal fluid (PF) and peripheral blood (PB) mononuclears of women with ovarian carcinoma (n = 47) and benign ovarian tumors (n = 37). METHODS: Mononuclear cells were isolated from PF and PB, stained with monoclonal antibodies (mAbs) against DC antigens (anti-BDCA-1, anti-BDCA-2), and estimated using flow cytometry. RESULTS: The percentage of PF myeloid DC (MDC) in mononuclears was significantly lower in patients with ovarian cancer in comparison to the group of nonmalignant ovarian tumors (0.65% and 6.95%). The percentage of PF lymphoid DCs (LDCs) was higher in patients with ovarian cancer than in the reference group (0.64% and 0.09%). The percentage of PB MDCs and LDCs did not differ significantly between studied groups. In women suffering from ovarian cancer the percentage of both MDCs and LDCs was higher in the PF than in the PB. In the reference group the percentage of MDCs was higher but that of LDCs was lower in the PF than in the PB. In women with ovarian cancer, PF MDCs/LDCs ratio was lower in comparison to patients with serous cystadenoma. In PB the ratio of MDCs to LDCs did not differ significantly between studied groups. CONCLUSIONS: We concluded that MDCs population may be affected by the presence of malignant disease. LDC subsets may have influence on the local immune response in the PF of women with malignant tumors of the ovary. (c) 2008 Clinical Cytometry Society.