Knapp Sylvia, Wieland Catharina W, van 't Veer Cornelis, Takeuchi Osamu, Akira Shizuo, Florquin Sandrine, van der Poll Tom
Laboratory of Experimental Internal Medicine, Department of Pathology, Tropical Medicine and AIDS, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
J Immunol. 2004 Mar 1;172(5):3132-8. doi: 10.4049/jimmunol.172.5.3132.
Toll-like receptors (TLR) are crucial pattern recognition receptors in innate immunity. The importance of TLR2 in host defense against Gram-positive bacteria has been suggested by the fact that this receptor recognizes major Gram-positive cell wall components, such as peptidoglycan and lipoteichoic acid. To determine the role of TLR2 in pulmonary Gram-positive infection, we first established that TLR2 is indispensable for alveolar macrophage responsiveness toward Streptococcus pneumoniae. Nonetheless, TLR2 gene-deficient mice intranasally inoculated with S. pneumoniae at doses varying from nonlethal (with complete clearance of the infection) to lethal displayed only a modestly reduced inflammatory response in their lungs and an unaltered antibacterial defense when compared with normal wild-type mice. These data suggest that TLR2 plays a limited role in the innate immune response to pneumococcal pneumonia, and that additional pattern recognition receptors likely are involved in host defense against this common respiratory pathogen.
Toll样受体（TLR）是天然免疫中至关重要的模式识别受体。TLR2可识别主要的革兰氏阳性菌细胞壁成分，如肽聚糖和脂磷壁酸，这一事实表明了TLR2在宿主抵御革兰氏阳性菌中的重要性。为了确定TLR2在肺部革兰氏阳性菌感染中的作用，我们首先证实TLR2对于肺泡巨噬细胞对肺炎链球菌的反应性是不可或缺的。尽管如此，与正常野生型小鼠相比，经鼻接种不同剂量（从非致死性剂量（感染被完全清除）到致死性剂量）肺炎链球菌的TLR2基因缺陷小鼠，其肺部炎症反应仅适度降低，抗菌防御未改变。这些数据表明，TLR2在对肺炎球菌肺炎的天然免疫反应中作用有限，并且可能有其他模式识别受体参与宿主对这种常见呼吸道病原体的防御。
