Evaluation of Myeloid and Lymphoid Dendritic Cells in Peritoneal Fluid in Women with Non-malignant Ovarian Tumors

Clinical Relevance and Immunosuppressive Pattern of Circulating and Infiltrating Subsets of Myeloid-Derived Suppressor Cells (MDSCs) in Epithelial Ovarian Cancer

Myeloid-derived suppressor cells (MDSCs) expansion is a hallmark of cancer. Three major MDSC subsets defined as monocytic (M)-MDSCs, polymorphonuclear (PMN)-MDSCs and early stage (e)MDSCs can be revealed in human diseases. However, the clinical relevance and immunosupressive pattern of these cells in epithelial ovarian cancer (EOC) are unknown. Therefore, we performed a comprehensive analysis of each MDSC subset and immunosupressive factors in the peripheral blood (PB), peritoneal fluid (PF), and the tumor tissue (TT) samples from EOC and integrated this data with the patients' clinicopathological characteristic. MDSCs were analyzed using multicolor flow cytometry. Immunosuppressive factors analysis was performed with ELISA and qRT-PCR. The level of M-MDSCs in the PB/PF/TT of EOC was significantly higher than in healthy donors (HD); frequency of PMN-MDSCs was significantly greater in the TT than in the PB/PF and HD; while the level of eMDSCs was greater in the PB compared with the PF and HD. Elevated abundance of tumor-infiltrating M-MDSCs was associated with advanced stage and high grade of EOC. An analysis of immunosuppressive pattern showed significantly increased blood-circulating ARG/IDO/IL-10-expressing M- and PMN-MDSCs in the EOC patients compared with HD and differences in the accumulation of these subsets in the three tumor immune microenvironments (TIME). This accumulation was positively correlated with levels of TGF-β and ARG1 in the plasma and PF. Low level of blood-circulating and tumor-infiltrating M-MDSCs, but neither PMN-MDSCs nor eMDSCs was strongly associated with prolonged survival in ovarian cancer patients. Our results highlight M-MDSCs as the subset with potential the highest clinical significance.

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.