Vascular endothelium and infectious diseases: Trick and treat

In the past, infectious diseases caused by viruses, bacteria and parasites were shown to be associated with functional and structural disturbances of the cardiovascular system particularly involving the endothelium. This includes, for example, acute haemorrhagic fevers caused by Ebola and Lassa viruses, inflammatory diseases of the central nervous system via meningococcae, staphylococci, pneumococci, or infections of the gut via enterohaemorrhagic Escherichia coli. Chronic degenerative diseases such as atherosclerosis have also been suggested to be associated with infections by human cytomegalie virus or the bacterial pathogen Chlamydia pneumoniae. In contrast to these degenerative disease situations, the development of vascular tumors can be initiated by human immunodeficiency virus (HIV) leading to the Kaposi Sarcoma, or by Bartonella henselae, a bacterium first discovered in 1992, that causes a bacillary angiomatosis. Due to its strategic location within the vascular tree and its accessibility via tissue injury, the vascular endothelium in particular is a central target for pathogen adherence, spread and replication, and numerous bacterial mechanisms to circumvent or knock-down the defense mechanisms of the host have been described (1). Furthermore, inflammatory mediators play a critical role in infectious diseases as well, due to their indirect effects on endothelial cells in a local or systemic manner.