Mathematical Modeling And Analysis Of The Effect Of TGF-? On Tumor Immune System

The growth of tumor cells in tumor immune system is related to the two main influencing factors:anti tumor growth and promote tumor growth factors.Researchs have shown that transforming growth factor ?(TGF-?)will inhibit the prolifera-tion and differentiation of tumor cells in the early stage of tumorigenesis.As tumors develop,tumor cells can secrete TGF-? to promotes tumor cell angiogenesis.At the same time,TGF-? will be expressed in the tumor microenvironment,it can inhib-it immune effector cells in the body and promote tumor migration and metastasis.While the immune system responds to tumor cells in an effective manner,but turnor cells have developed ways to bypass their effects or directly suppress them to escape immune surveillance.Based on the role of TGF-? in the tumor immune system,this dissertation constructs a dynamic model of the interaction between tumor cell,effec-tor cell and TGF-?.This thesis contains four chapters,mainly studying the effect of TGF-? on tumor cell growth and the role of immunotherapy on tumor immune system.The results can help understand the role of TGF-? in the tumor growth,and provide new way for immunotherapy.In Chapter 1,we briefly introduce the role of various cells and cytokines in the tumor microenvironment as well as the research status of tumor cells,immune cells and cytokines interaction models and basic concepts and theories of ordinary differ-ential equations(ODEs).In Chapter 2,we construct a mathematical model based on the role of TGF-? in the immune system.We build a three-dimensional mathe-matical model to study the dynamical properties of interaction between tumor cells,immune cells and TGF-?.Furthermore,we discuss the existence and stability of tumor equilibrium.By performing numerical simulations,we investigate the maxi-mum secretion rate of TGF-?,and study its effects on the dynamical properties of the model.In Chapter 3,Because the monoclonal antibody of TGF-? can neutralize the effect of TGF-? and inhibit the invasion and metastasis of tumor cells,we built a mathematical model of tumor immunotherapy,using numerical simulation to com-pare and analyze the effect of this immunotherapy on tumor growth and its efficacy under different treatment levels.In Chapter 4,we summarize the research results of this thesis and give the future research problem.