Host-Parasite Interaction: Parasite-Derived and -Induced Proteases That Degrade Human Extracellular Matrix

Abstract

<jats:p>Parasitic protozoa are among the most important pathogens worldwide. Diseases such as malaria, leishmaniasis, amoebiasis, giardiasis, trichomoniasis, and trypanosomiasis affect millions of people. Humans are constantly threatened by infections caused by these pathogens. Parasites engage a plethora of surface and secreted molecules to attach to and enter mammalian cells. The secretion of lytic enzymes by parasites into host organs mediates critical interactions because of the invasion and destruction of interstitial tissues, enabling parasite migration to other sites within the hosts. Extracellular matrix is a complex, cross-linked structure that holds cells together in an organized assembly and that forms the basement membrane lining (basal lamina). The extracellular matrix represents a major barrier to parasites. Therefore, the evolution of mechanisms for connective-tissue degradation may be of great importance for parasite survival. Recent advances have been achieved in our understanding of the biochemistry and molecular biology of proteases from parasitic protozoa. The focus of this paper is to discuss the role of protozoan parasitic proteases in the degradation of host ECM proteins and the participation of these molecules as virulence factors. We divide the paper into two sections, extracellular and intracellular protozoa.</jats:p>

Functional Characterization of Anopheles Matrix Metalloprotease 1 Reveals Its Agonistic Role during Sporogonic Development of Malaria Parasites

“…This assumption was based on previous reports showing that infection by several pathogens (parasites, viruses, or bacteria) is associated with increased MMP activity in the invaded tissue, facilitating pathogen migration and/or the establishment of systemic infections (7,62,63,72,73). Indeed, the number of oocysts developing in the midguts of AgMMP1 dsRNA-treated mosquitoes was severely reduced (in some cases 7-fold compared to the value for the control [see Table S1 in the supplemental material]).…”

A Possible Mechanism behind Autoimmune Disorders Discovered By Genome-Wide Linkage and Association Analysis in Celiac Disease

“…The ECM represents a major barrier to parasites like amoebas and leishmania. Parasites produce a wide variety of proteases to break down the ECM in order to access essential nutrients and invade host tissue [37]. A different situation when the ECM is degraded is during nutrient deprivation.…”

The biology of Trichomonas vaginalis in the light of urogenital tract infection

“…The secretion of lytic enzymes enables parasites to migrate to other locations within the host or to make direct contact and fuse with the host cells' plasma membrane. Therefore, one branch of host-parasite research focuses on the characterisation of parasitederived proteases [2]. Piña-Vázquez and colleagues reviewed the current status of identified proteases -discussed in the further course of the text -for nine different species, and which includes the extracellular parasite T. vaginalis.…”

“…Cell-surface sugars part of the parasite's glycocalyx necessary for attachment; lipophosphoglycan is reported to bind to human galectin-1Cysteine proteaseDegradation of human ECM and apoptosis of VECs in vitro[2,40,41] …”