Brain Tumors in Predominating the Macrophages of Stem Cell MediatorsAuthor(s): Lingyun Li
Macrophages originate from blood monocytes that leave the circulation to differentiate in different tissues. There is a substantial heterogeneity among each macrophage population, which most probably reflects the required level of specialisation within the environment of any given tissue. This heterogeneity is reflected in their morphology, the type of pathogens they can recognise, as well as the levels of inflammatory cytokines they produce (i.e. IL-1, IL-6, tumour necrosis factor alpha). In addition, macrophages produce reactive oxygen species, such as nitric oxide, that can kill phagocytosed bacteria.The heterogeneous nature of these cells may not solely be the result of their differentiation process, but it is likely to be inherited from their monocyte precursors.