Cell adhesion receptors - signaling capacity and exploitation by bacterial pathogens

Cell adhesion receptors play an essential role in multicellular organisms by mediating the direct association of cells with each other and with proteins of the extracellular matrix. Members of different protein families such as integrins, cadherins, immunoglobulin superfamily cell adhesion molecules (IgCAMs), selectins, and syndecans not only support the structural integrity of cells and tissues, but also contribute to the transduction of signals. Interestingly, several of these molecules are exploited by bacterial pathogens to establish tight contact with eukaryotic cells. Using the example of integrins, cadherins, and IgCAMs, this review illustrates the signaling capacity of cell adhesion receptors and highlights a number of bacterial adhesins that are known to engage these receptors. Where applicable, the role of the receptor-adhesin interaction in the course of the infection is discussed.