Phenotype and antitumor activity of ascitic fluid monocytes in patients with ovarian carcinoma

Abstract

Monocytes/macrophages (MO/MA) represent a major leukocyte population in the peritoneal cavity of patients with epithelial ovarian cancer (EOC). We examined the phenotypic characteristics and antitumor cell activity of ascitic MO in patients with EOC. MO/MA phenotype was compared with MO in peripheral blood by two- and three-color flow cytometry. Cytotoxic/cytostatic effects of different cytokines on cultured EOC cells were measured by initial labeling or uptake inhibition of [methyl-3H] thymidine. Malignant ascites had higher proportion of MO/MA with the CD14brightCD16+ phenotype than peripheral blood. Cell surface antigen expression of activation and differentiation in peripheral blood and ascites, including CD38, CD40, CD64, and CD86, was higher on CD14brightCD16- and CD14brightCD16+ than on CD14dimCD16- cells. HLA-DR expression was higher on ascitic MO/MA than peripheral blood MO. Significant cytotoxic/cytostatic activity was elicited by treating ascitic MO/MA with interferon-gamma (IFN-gamma) and interleukin-2 (IL-2), but not with interleukin-12, paclitaxel, granulocyte-monocyte colony-stimulating factor (GM-CSF), or tumor necrosis factor-alpha (TNF-alpha). Soluble CD40Lt did not enhance MO/MA cytotoxic activity, and inhibited IFN-gamma or IL-2 induced cytoxicity. We conclude that MO/MA from ascites have elevated proportions of CD14brightCD16+ cells, showing phenotypic features of activation. IFN-gamma induces the cytotoxic and cytostatic activity of MO/MA that is inhibited by CD40Lt.

Neopterin as a biomarker of immune response in cancer patients

“…Tumor-promoting inflammatory response is currently recognized as an essential feature of cancer (31). Macrophages represent an important cell population in the tumor microenvironment, and different subpopulations of monocytes/macrophages can be distinguished in the microenvironment and peripheral blood (15,32).…”

“…T h e m a c r o p h a g e s c a n b e s t u d i e d n o t o n l y b y determining the phenotype of the cells by flow cytometry or immunohistochemistry (15,32). Macrophages are metabolically active and some metabolic pathways are expressed predominantly or almost exclusively in macrophages.…”

Defective Antitumor Function of Monocyte-Derived Macrophages from Epithelial Ovarian Cancer Patients

“…A thymidine release assay modified from the method of Melichar et al (13) was done using the allogeneic ovarian tumor cell line 2774. One million target cells were labeled with 50 ACi thymidine in RPMI plus 5% heat-inactivated FBS in a 37jC shaking water bath for 18 to 22 hours, washed, counted on a hemocytometer, and added in duplicate to wells of activated MDM in U-bottomed plates at an effector-to-target cell ratio of 20:1.…”

“…Because peripheral MO/MA do not undergo sizable increases in MO/MA numbers following exposure to growth factors, such as M-CSF (14), thymidine uptake closely parallels the proliferation response of the tumor cells. The ability of activated MDM to inhibit the growth of tumor cells (cytostasis) was measured in a thymidine incorporation assay modified from the method of Melichar et al (13). Sorted MO/MA were cultured and activated at 1 Â 10 5 cells per well in 96-well U-bottomed plates as described above.…”

Human epididymis protein 4: the start of a post-ROMAn era?

“…The presence of tumor-infi ltrating lymphocytes (TIL) may be determined immunohistochemically and represents an independent prognostic factor in EOC (28) . The phenotype and function of leukocyte populations, including lymphocytes and monocytes/macrophages in the tumor microenvironment may be studied even more easily in malignant ascites that is commonly encountered in patients with advanced EOC (29,30) . Serial measurements of biomarkers of the host response against the tumor may be used for the assessment of response to therapy in the tumor microenvironment (31) .…”