PHENOTYPIC PECULIARITIES OF DENDRITIС CELLS DIFFERENTIATED FROM BLOOD MONOCYTES IN PATIENTS WITH KIDNEY CANCER

Abstract

The aim of the study was to investigate the phenotypic features of dendritic cell (DCs) differentiated from peripheral blood monocytes in patients with kidney cancer (KC). The study involved 28 patients with KC (Т3N0М0, clear cell type) before surgical treatment at the age of 40-55 years and 31 healthy age-matched people. Immature DCs (IDCs) were generated from blood monocytes by culturing for 5 days with GM-CSF and IFNα. Activation of the DCs (MDCs) was induced by incubation with tumor cell lysate and TNFα followed by incubation for 48 hours. Phenotyping of DCs at different maturity degrees was carried out by the method of flow cytometry. It was found that the monocytes differentiated into IDCs formed a cellular pool with a high level of costimulatory activity in patients with KC, by increasing number of cells with a high level of CD80 and CD86 receptor expression. In this case, a significant amount of undifferentiated monocytes and cells with an intermediate phenotype (CD14+CD83+) remained in the cell culture. In KC patients, the cell culture formed an increased number of IDCs with the CD83+CD80highCD86highHLA-DR+ phenotype (in comparison with the control values). However, expression level of the HLA-DR receptor on CD83+CD80highCD86high-IDCs in patients with KC was reduced. Therefore, this type of DCs has a high costimulatory and weak antigen-presenting activity. Maturation (activation) of DCs from patients with KC was accompanied by retained amounts of undifferentiated monocytes in cell culture associated with decreased contents of cells with CD14+CD83+ phenotype. Presumably, a part of cells with the CD14+CD83+ phenotype and additional antigenic and cytokine load matured to the level of MDCs. Mature DCs in patients with KC are characterized by weak costimulatory and antigen presenting activity, due to decreased expression of CD83 and CD86 markers. Upon maturation, the amount of DCs with different levels of CD80 expression in cell culture in healthy people and in patients with RP is equalized, but the MDCs with a highly active phenotype (CD83+CD80highCD86high и CD83+CD80highCD86highHLA-DR+) are formed with KC cells to lesser degree. Moreover, MDCs with CD83+CD80highCD86high phenotype in tumor patients show weaker expression of receptors providing costimulatory and antigen-presenting activity. The differences in the IDCs and MDCs phenotype between healthy people and KC patients may be determined by different features of phenotype and functional activity in blood monocyte populations as well as immunosuppressive factors synthesized by the tumor.

Keywords

• dendritic cells
• monocytes
• kidney cancer
• phenotype
• costimulatory molecules
• antigen presentation