Copyright © 2009 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We formulate the dynamical model for the anti-tumour immune response based on intercellular cytokine-mediated interactions with the interleukin-2 (IL-2) taken into account. The analysis shows that the expression level of tumour antigens on antigen presenting cells has a distinct influence on the tumour dynamics. At low antigen presentation, a progressive tumour growth takes place to the highest possible value. At high antigen presentation, there is a decrease in tumour size to some value when the dynamical equilibrium between the tumour and the immune system is reached. In the case of the medium antigen presentation, both these regimes can be realized depending on the initial tumour size and the condition of the immune system. A pronounced immunomodulating effect (the suppression of tumour growth and the normalization of IL-2 concentration) is established by considering the influence of low-intensity electromagnetic microwaves as a parametric perturbation of the dynamical system. This finding is in qualitative agreement with the recent experimental results on immunocorrective effects of centimetre electromagnetic waves in tumour-bearing mice.