Effect of emoxipine on cytotoxicity of peripheral blood mononuclears under cultivation with cytarabine and cyclocytidine

Taking into account the special role of oxidative stress that increases during cancer chemotherapy, the effect of the antioxidant emoxipine on peripheral blood mononuclears was studied under conditions that simulate the cytotoxic effects of antimetabolites of a number of modified cytidine nucleosides in relation to the tumor cell line K562. Lymphoid cells were also a source for subsequent modelling of the immune response to the cancer. It was found that neither the modified nucleosides themselves nor their combination with emoxipine caused changes in IL-2-stimulated cytotoxicity of lymphoid cells in relation to K562 tumor cell line. A study of the expression of the CD107a marker showed a significant stimulating effect of 1 µmol/L of citarabine on the activation of subpopulations of T-lymphocytes (CD3+ ) and cytotoxic T-lymphocytes (CD3+ CD8+ ).

Cytokine Release Ensuing Interaction Between Human Peripheral Blood Mononuclears and Epstein-Barr Virus Transformed B-CLL Cell Line

ABSTRACT Introduction B-cell chronic lymphocytic leukemia (B-CLL) is a common form of leukemia affecting mostly elderly individuals. The course of the disease is usually unremarkable, but because it may proceed with impaired immune defense, B-CLL might be complicated with infections and even death. The leukemic microenvironment containing a number of immune cells, mainly lymphocytes and macrophages capable to produce various molecules including inflammatory cytokines, plays an important role in the development and outcome of the disease. We studied the capacity of Epstein-Barr virus (EBV)-transformed B-cell chronic lymphocytic leukemia (B-CLL) cell line (EHEB) cells, an EBV-transformed line established from a B-CLL patient, to affect the production of inflammatory cytokines by human peripheral blood mononuclear cells (PBMC). Methods PBMC isolated from peripheral blood of healthy donors were incubated either with EHEB cells or with their supernatants and the production of the following cytokines: tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, interferon (IFN)-γ, IL-1ra, and IL-10 were detected using the enzyme-linked immunosorbent assay method. Results Direct contact of PBMC incubated with EHEB cells induced a marked increase of TNFα, IL-1β, IL-6, IFNγ, and IL-10 release by the immune cells. Yet, incubation of PBMC with EHEB cells' supernatant resulted in a mild production of the same cytokines. Conclusions The noticeable increased production of inflammatory cytokines by PBMC following direct contact with EHEB cells and to a lesser degree with their supernatants implies the existence of an immune dialogue between these two types of cells. The results support the concept that not only leukemic cells, but also peripheral blood mononuclears could serve as a therapeutic target for B-CLL.