Dynamics of tumor immune escape via adaptive change

抄録

Despite of several complementary mechanisms that are inherently equipped with the immune system to eliminate tumor cells, some adaptive change of tumor cells such as down-regulating expression level of Major HistoCompatibility (MHC) class I to evade killing from T cells can be beneficial. Description of complex interactions among tumor and immune cells is useful to understand how some of adaptive change are effective for tumor cells to escape from immunosurveillance. In this paper, we formulate a mathematical model representing tumor killing by two different immune subsets to investigate under what conditions down-regulation of MHC class I expression can be favorable for tumor cells. Mathematical analysis and numerical computation results suggest that tumor cells prefer down-regulation of MHC class I if the killing of tumor cells by T cells is more potent than NK cells. This implication may support empirical observations that tumor escape via down-regulation of MHC class I expression can commonly occur.