Maintaining the Immunological Balance in Parasitic Infections: A Role for TGF-β?

Abstract
Transforming growth factor β (TGF-β) is an important regulator of inflammation, being proinflammatory at low concentrations and anti-inflammatory at high concentrations. As such, TGF-β might be important in maintaining the balance between control and clearance of infectious organisms on the one hand and prevention of immune-mediated pathology on the other. In this article, Fakhereldin Omer, Jørgen Kurtzhals and Eleanor Riley review the immunoregulatory properties of TGF-β in the context of parasitic infections. Data from murine malaria infections suggest that TGF-β modifies the severity of the disease, and a number of potential protective mechanisms are discussed. Evidence is accumulating that TGF-β is important for the regulation of other host–parasite interactions and that parasites might directly influence TGF-β-dependent pathways via the synthesis of TGF-β or TGF-β-receptor homologues.