Modelling the interplay between the CD4⁺/CD8⁺T-cell ratio and the expression of MHC-I in tumours

Abstract

<jats:title>Abstract</jats:title><jats:p>Describing the anti-tumour immune response as a series of cellular kinetic reactions from known immunological mechanisms, we create a mathematical model that shows the CD4<jats:sup>+</jats:sup>/CD8<jats:sup>+</jats:sup> T-cell ratio, T-cell infiltration and the expression of MHC-I to be interacting factors in tumour elimination. Methods from dynamical systems theory and non-equilibrium statistical mechanics are used to model the T-cell dependent anti-tumour immune response. Our model predicts a critical level of MHC-I expression which determines whether or not the tumour escapes the immune response. This critical level of MHC-I depends on the helper/cytotoxic T-cell ratio. However, our model also suggests that the immune system is robust against small changes in this ratio. We also find that T-cell infiltration and the specificity of the intra-tumour TCR repertoire will affect the critical MHC-I expression. Our work suggests that the functional form of the time evolution of MHC-I expression may explain the qualitative behaviour of tumour growth seen in patients.</jats:p><jats:sec><jats:title>Mathematics Subject Classification (2010)</jats:title><jats:p>MSC 37C25 · MSC 82C99 · MSC 37N25 · MSC 92B99</jats:p></jats:sec>