THE ONTOGENY OF CLASS-REGULATION OF CD4(+) T-LYMPHOCYTE POPULATIONS

The differential dass-regulation of CD4(+) T lymphocyte populations is believed to play a major role in determining the qualitative behaviour of the immune system, and in the fate of immune responses in particular. In this article we propose a model for the dynamics of the T(h)1 and T(h)2 subpopulations. We put forward the concept of an 'antigenic niche' which allows us to postulate that the key feature underlying the regulation of T-h differentiation pathways is the population dynamics of the lymphocytes themselves. Using this model we are able to account for a number of established experimental observations which were hitherto apparently unrelated and poorly understood. This suggests that our simplified model might be capturing some essential features of the immune system.