ANALYSIS OF IMMUNE CHANGES AND THEIR ROLE IN THE DEVELOPMENT OF ORAL AND OROPHARYNGEAL CANCER

Numerous studies of the immune system in cancer patients at the cellular and molecular levels indicate a persistent violation of natural and acquired mechanisms of immune defense. This article reveals changes in the immune system of patients with cancer of the oral cavity and oropharynx. It was determined that the levels of cytokines IL-6, IL-10, HGF and VEGF in high concentrations in the serum of patients correlate with an unsatisfactory prognosis and are independent indicators of low survival and correlate with relapse. Different immune cells provide a complex defense system with effective communication through cytokines. The inflammatory component of the microenvironment of the tumor of the oral cavity and oropharynx is important in the immune response, because its main component is immunosuppressive cytokines. There is an imbalance of Th1 / Th2 cytokine types and increased levels of Tregs. Among Th1 types of cytokines - IFN-γ, IL-12, TNF-α, the levels of which are reduced, and Th2-cytokines - IL-4, IL-10 - are increased, while the norm is the opposite. The tumor uses various mechanisms to induce changes in the system to avoid an immune response to its development. In fact, a malignant cell of the mouth or oropharynx suppresses the immune response by producing vascular endothelial growth factor (VEGF), prostaglandin E2 (PGE2), TGFβ, IL-6 and IL-10. The tumor environment also releases pro-inflammatory mediators, including a receptor such as IL-15 alpha subunit (IL15RA). It in combination with IL-15 carries out the strengthened synthesis of proinflammatory cytokines - IL-6, TNF-α and IL-17 that influences insufficiency of the immune response and accordingly low prognosis of survival. It was found that the number of NK cells is reduced in patients with oral and oropharyngeal cancer, respectively, there is a low control of iNKT tumor cells in the regional collector, which correlates with low survival rates. Increased concentration of dendritic cells in the blood correlates with a positive prognosis and greater survival of patients with cancer of the oral cavity and oropharynx, reduced metastasis to the cervical lymph nodes. An effective antitumor immune response involves many components of the immune system, but T-cells remain the most important cells involved in antitumor immunity. Therefore, T-cell defects reduce the effectiveness of antitumor immunity. CD4 + CD25 + T-cells play a central role in initiating and maintaining the antitumor immune response. Detection of them and CD4 + CD69 +, CD3 + T cells in large numbers is associated with a good prognosis. More detailed changes in the cellular composition of immunity and the effector link are presented in the article.