Immunophenotype of dendritic cell differentiation markers in breast cancer in in-vitro conditions

BACKGROUND: During maturation, dendritic cells begin to synthesize peptides that include the major histocompatibility complex MHC-II molecules, costimulatory molecules CD40⁺, CD80⁺, and CD86⁺, as well as CD83⁺ proteins. In cancer patients, dendritic cells dysfunction can lead to serious consequences in the form of deficiency of antitumor immunity, tumor progression, and decreased response to immunotherapy. All this is important to take into account to rethink the tumor immunotherapy strategy. Thus, approaches aimed at enhancing the viability of dendritic cells and preventing their dysfunction and polarization should be considered as a necessary step in order to increase the effectiveness of dendritic cell vaccines.

AIM: To evaluate the expression characteristics of differentiation markers of dendritic cell maturation obtained from peripheral blood monocytes under culture conditions in patients with breast cancer.

MATERIALS AND METHODS: With informed voluntary consent, 19 patients diagnosed with breast cancer were examined. Mononuclear cells were isolated on a Ficoll density gradient. For adhesion of monocytes to the bottom of 75 cm² culture flasks, they were pre-incubated for 1.5 hours in conditions of 5% CO₂ at 37 ℃. Growth and differentiation factors — GM-CSF (40 µl) and IL-٤ (٤٠ µl) — were added to the attached monocytes on the 1^st, 3^rd and 5^th days of cultivation. Immunophenotyping of dendritic cells was carried out on days 7 and 9 of cultivation using flow cytometry.

RESULTS: Flow cytometry data indicate that the viability of cultured dendritic cells in cancer patients is significantly reduced on day 9 compared to day 7 of cultivation. On day 9, there was a significant increase in CD80⁺ expression (2.40, p=0.028) and a decrease in CD83⁺ (1.65, p=0.036) compared to day 7.

CONCLUSION: In general, significant signs of maturation were observed: loss of the monocyte marker CD14⁺, increased expression of CD80⁺, CD83⁺, CD86⁺ — the main markers. A decrease in CD83⁺ can be considered as a suppression of excessive activation of immune responses. In the future, a more in-depth study of the characteristics of maturation and activation of cultured dendritic cells is necessary to understand the mechanisms and factors influencing the decrease in the effectiveness of immunotherapy with an autologous dendritic cell vaccine.