Abstract: | The kidney needs to defend against microbial pathogens in order to maintain normal structure and function. This is achieved through innate and adaptive components of the immune system. For a long time, immunologists were concentrating on the adaptive immune system, which, as a result, was studied in detail; at the same time, the significance of the innate immune system was underestimated. This gap was partly filled in the recently, when the key role of the innate immune system in fighting microorganisms and in activating and regulating the adaptive immune system was convincingly established. In the first part of the present article, the sense apparatus of the innate immune system (the so-called pattern-recognition receptors) will be reviewed; particular attention will be paid to the toll-like receptors (TLRs), which bear the main burden of microorganism recognition. Signalling pathways that are activated by TLRs and result in the activation of effector mechanisms will also be reviewed. In the second part of the review, we will analyse available data on how these mechanisms of the innate immune system secure defence and normal functioning of the kidney. |