Innate immunity: structure and function of TLRs

被引:113
作者
Delneste, Yves
Beauvillain, Celine
Jeannin, Pascale
机构
[1] Univ Angers, Equipe Avenir, INSERM, U564, F-49933 Angers 9, France
[2] CHU Angers, Lab Immunol & Allergol, F-49100 Angers, France
来源
M S-MEDECINE SCIENCES | 2007年 / 23卷 / 01期
关键词
D O I
10.1051/medsci/200723167
中图分类号
R-3 [医学研究方法]; R3 [基础医学];
学科分类号
1001 ;
摘要
The innate immune system provides the first line of defence against infection. Through a limited number of germline-encoded receptors called pattern recognition receptors (PRRs), innate cells recognize and are activated by highly conserved structures expressed by large group of microorganisms called pathogen-associated molecular patterns (PAMPs). PRRs are involved either in recognition (scavenger receptors, C-type lectins) or in cell activation (Toll-like receptors or TLR, helicases and NOD molecules). TLRs play a pivotal role in cell activation in response to PAMPs. TLR are type I transmembrane proteins characterized by an intracellular Toll/IL1 receptor homology domain that are expressed by innate immune cells (dendritic cells, macrophages, NK cells), cells of the adaptive immunity (T and B lymphocytes) and non immune cells (epithelial and endothelial cells, fibroblasts). In all the cell types analyzed, TLR agonists, alone or in combination with costimulatory molecules, induce cell activation. The crucial role played by TLR in immune cell activation has been detailed in dendritic cells. A TLR-dependent activation of dendritic cells is required to induce their maturation and migration to regional lymph nodes and to activate naive T cells. The ability of different cell types to respond to TLR agonists is related to the pattern of expression of the TLRs and its regulation as well as their intracellular localization. Recent studies suggest that the nature of the endocytic and signaling receptors engaged by PAMPs may determine the nature of the immune response generated against the microbial molecules, highlighting the role of TLRs as molecular interfaces between innate and adaptive immunity. In this review are summarized the main biological properties of the TLR molecules.
引用
收藏
页码:67 / 73
页数:7
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