Bidirectional regulation of macrophage function by TGF-beta.
The dual role of transforming growth factor-beta (TGF-beta) in modulating macrophage function is an important concept gaining increasing recognition. In addition to its role as a 'macrophage-deactivating' agent, TGF-beta functions as a monocyte activator, inducing cytoke production and mediating host defence. These functions are context-dependent, modulated by the differentiation state of the cell, the local cytokine environment, and the local levels of TGF-beta in itself. In general, during the initial stages of inflammation, TGF-beta locally acts as a proinflammatory agent by recruiting and activating resting monocytes. As these cells differentiate specific immunosuppressive actions of TGF-beta predominate, leading to resolution of the inflammatory response. Increasing our understanding of the bidirectional regulation of macrophage function will facilitate prediction of the ultimate outcome of modulating TGF-beta levels in vivo.
Ashcroft
G S
GS
Oral Infection and Immunity Branch, National Institute of Craniofacial and Dental Research, National Institutes of Health, Bethesda, MD 20892, USA.
D000818:Animals; D006801:Humans; D008262:Macrophage Activation / Q000502:physiology; D008264:Macrophages / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D009000:Monocytes / Q000187:drug effects / Q000502:physiology; D015291:Transforming Growth Factors / Q000494:pharmacology / Q000502:physiology*
D015291:Transforming Growth Factors