Global Analysis of r3LCMV Cancer Immunotherapy Model

An attenuated lymphocytic choriomeningitis virus (r3LCMV) has shown safety and efficacy in treating cancer. This paper develops a within-host r3LCMV cancer immunotherapy model. The model considers the interconnection between nutrient, normal cells, tumor cells, infected tumor cells, viral vector, and virus-specific CTLs. The nonnegativity and boundedness of the solutions are verified. The equilibrium points with the biological acceptance conditions are calculated. The global stability of each point is demonstrated. Numerical simulations are implemented to ratify the theoretical results. It is found that the equilibria exhibit four main states: a healthy individual who does not have cancer, a cancer patient who does not receive any treatments, a cancer patient who receives r3LCMV cancer therapy with inactive immunity, and a cancer patient who receives r3LCMV therapy with active virus-specific CTLs. The parameters that control the transition between these states need to be carefully chosen. Increasing the stimulation rate of CTLs induced by r3LCMV viral vector reduces the concentration of infected tumor cells. The attenuation rate of the viral vector affects its ability to eliminate tumor cells from the body. Therefore, these rates need to be cautiously selected and tested.