Adhesins adhesion mechanisms

Many bacterial adhesins and host receptors have been identified and studied in great depth, as described in Section VII. Therefore, with every new adhesin or receptor discovered, a new opportunity arises to develop an anti-adherence mechanism that may inhibit or block the adhesin-receptor interaction, which is the ultimate aim of anfi-adhesion therapy (Kahane and Ofek, 1996 Moricouf et ah, 1990 Ofek and Doyle, 1994). In actual practice, there are several t) es of anfi-adhesive mechanisms including adhesin-based vaccines, innafe hosf-derived anti-adhesives, probiotics, adhesin analogs, and receptor analogs. 

Research aimed at imderstanding bacterial pathogenesis has established the importance of bacterial adherence in disease. This research has led to the identification of a number of both bacterial adhesins and potential host cell receptors. By imderstanding the detailed interactions between a bacterial adhesin and host receptor, it is possible to develop new mechanisms to prevent bacterial adhesion, thereby averting disease. Many promising anti-adhesion mechanisms have been developed and studied, but much more work is needed, both in vitro and in vivo, to establish the feasibility of these mechanisms. 

A bacterial infection starts in general with the adhesion of a bacterium onto a host cell. The adhesion mechanism has turned out to be far more complex than anticipated. For example, bacteria that express their adhesins directly on the cell wall are susceptible to shear forces. A shear flow will apply a torque onto the bacteria that will induce a successive breakage of bonds and result in bacterial rolling [f,2]. This often implies that the bacteria detach from the host cell, which, in turn, makes it less likely that they can pursue their infectious task. 

Some of this variety of adhesion may be straightforward double layer effects (see Chapter 10) but there is no doubt that more complicated mechanisms may be involved and that particular polyma- molecules, now identified as adhesins, integrins, lectins, etc., can be influential. The purpose of this chapter is to outline the basic adhesion principles, starting from a definition of cell surface structure, moving on to measurement methods, then finally discussing the peculiar molecular influences. 

E. V. Sokurenko and W. E. Thomas, Structural basis for mechanical force regulation of the adhesin FimH via finger trap-like P sheet twisting. Cell, 2010, 141, 645-655 (b) M. M. Sauer, R. P. Jakob, J. Eras, S. Baday, D. Eris, G. Navarra, S. Bemeche, B. Ernst, T. Maier and R. Glockshuber, Catch-bond mechanism of the bacterial adhesin FimH, Nat. Common., 2016, 7, 10738. N. Sharon, Carbohydrates as future anti-adhesion drugs for infectious diseases, Biochim. Biophys. Acta, 2006, 1760, 527-537. 

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