Microreview: Regulation of mammalian defensin expression by Toll-like receptor-dependent and independent signalling pathways
Article first published online: 8 AUG 2005
Volume 7, Issue 10, pages 1387–1397, October 2005
How to Cite
Froy, O. (2005), Microreview: Regulation of mammalian defensin expression by Toll-like receptor-dependent and independent signalling pathways. Cellular Microbiology, 7: 1387–1397. doi: 10.1111/j.1462-5822.2005.00590.x
- Issue published online: 8 AUG 2005
- Article first published online: 8 AUG 2005
- Received 30 March, 2005; accepted 16 May, 2005.
The immune system consists of innate and adaptive immune responses. The innate immune system confers non-specific protection against a large number of pathogens, hence, serving as the first line of defence. The innate immune system utilizes Toll-like receptors (TLRs) to recognize and bind pathogen-associated molecular patterns (PAMPs). Binding of PAMPs leads to TLR activation, which, in turn, initiates MAPK- or NF-κB-dependent cascades that culminate in a proinflammatory response. This response involves the secretion of cytokines, chemokines and broad-spectrum antibacterial substances, such as defensins. Increased defensin synthesis is also mediated by the activation of receptors other than TLRs, such as NOD2, IL-17R and PAR-2. This review summarizes the recently characterized signalling pathways leading to increased defensin synthesis as well as the pathway by which defensins activate TLRs on immature dendritic and memory T cells. Thus, not only do defensins eliminate pathogens, but they also recruit the adaptive immune system in instances of infection and/or inflammation.