Journal of Clinical and Cellular Immunology
Open Access

Abstract

Macrophage Polarisation: A collaboration of Differentiation, Activation and Pre-Programming?

Andrew D. Foey

Macrophages (Mϕs) exhibit a sliding scale of functional heterogeneity ranging from pro-inflammatory, immune activatory and anti-tumoral responses to anti-inflammatory, regulatory and pro-tumoral activity. These effector responses are reflected in distinct Mϕ subsets; the M1/classically activated- and M2/alternatively activated subsets. The functional diversity is determined by the combination of Mϕ subset differentiation, activation, signalling and preprogramming in separate monocyte subsets. This diversity in Mϕ subset and functionality is also reflected in mucosal pathologies associated with chronic inflammation (Crohn’s disease, chronic periodontitis) and immunosuppression observed in solid tumours (oral squamous cell carcinoma). The relative functional plasticity between these monocytes and Mϕs represents a realistic therapeutic regimen in the treatment of these Mϕ-driven diseases. This review will discuss the research evidence that is suggestive of the manipulation of Mϕ polarisation plasticity through pre-programming, differentiation, activation and tolerisation in the therapeutic intervention for chronic inflammation and solid tumours.