Signalling heterogeneity as a contributing factor in macrophage functional diversity.

Macrophages are involved in a variety of different functions in host defence and immunity yet they derive from a relatively homogeneous population of precursor cells. This article will focus on the mechanisms that contribute to functional heterogeneity in monocyte-derived macrophages and how specific stimuli, especially cytokines, act alone or in combination to regulate macrophage functions in an adaptive fashion. In particular, the thesis will be developed that macrophage functional heterogenity may arise as a consequence of heterogeneity in transmembrane and intracellular signalling events thereby leading to diversity in gene expression.