A Virus Dynamics Model Considering The Self Proliferation And Staged Generation Of Immune Cells

The dynamic behavior of immune cells has an important influence on the process and results of virus infection.In this paper,different immune generation mechanisms are considered to establish the corresponding dynamic model of virus infection.Some meaningful results are obtained through theoretical analysis and numerical simulation,which provides some valuable suggestions for recognizing the law of virus infection and treatmentThe first chapter introduces the background knowledge of virus infection,including the characteristics of virus infection and the formation mechanism of human immune system,the research status of virus infection at home and abroad,and summarizes the main content of this paper and the basic theoretical knowledge neededIn Chapter 2,a virus infection model considering the self proliferation of immune cells is established,and the global dynamics of the system is obtained;And we prove that the equilibrium state is globally asymptotically stable when the basic regeneration number is less than a certain threshold value greater than 1,which means that the immune system is still in an activated state when the virus is cleared,which is more in line with clinical practice.At the same time,through numerical simulation,we further find that when the self proliferation rate of immune cells exceeds a critical value,For the fixed immune cell capacity level,a larger or smaller growth rate is helpful to control the infected cell level,which is totally different from the conclusion of a smaller growth rate.The above research conclusion shows that the size of self proliferation of immune cellshas an important influence on the dynamics of the system,which should be paid enough attention in medical practiceIn Chapter 3,a virus infection model considering the self proliferation and delayed activation of immune cells is established to study the influence of delayed activation of immune cells in the process of virus infection.First,we prove the nonnegativity and boundedness of the solution of the model.Second,we obtain the global asymptotic stability of the boundary equilibrium point by constructing the appropriate Lyapunov functional,At the same time,we prove that the introduction of delayed activation of immune cells may cause periodic oscillation of the system through Hopf bifurcation,and find that the system may appear stable switching phenomenon under certain conditions.Finally,the direction of the above-mentioned Hopf bifurcation and the stability of the periodic solution generated by the bifurcation are calculated by using the central manifold theory,and the relevant theoretical results are verified by numerical simulation,The global Hopf bifurcation is obtained.In Chapter 4,a model of HIV infection is established,which considers the immune cells to generate in stages.Firstly,the local stability and global stability of the non infection equilibrium point are proved,and then the local stability of the immune non excitation equilibrium point is obtained,In the end,we discuss the condition of local stability of the equilibrium point of immune stimulation.We find that the introduction of the mechanism of staged immune generation may lead to periodic oscillation of system variables,and verify the above theoretical results by numerical simulation.In the fifth chapter,the conclusion of this paper is briefly summarized,and its biological significance and theoretical value are analyzed.At the same time,the problems and directions for further research are pointed out.