Cadherins

Definition

Cadherins are a family of calcium-dependent cell-cell adhesion molecules that play a crucial role in the virulence mechanisms of eukaryotic pathogens. They are responsible for maintaining the structural integrity of tissues and regulating cell-cell interactions, which pathogens often exploit to facilitate their invasion and spread within the host.

5 Must Know Facts For Your Next Test

1. Cadherins are essential for maintaining the integrity of epithelial and endothelial barriers, which pathogens often target to breach host defenses.
2. Certain pathogens, such as Listeria monocytogenes and Helicobacter pylori, produce virulence factors that can directly interact with and disrupt cadherin-mediated cell-cell adhesion.
3. The disruption of cadherin-mediated cell-cell junctions can lead to increased permeability of host tissues, facilitating the invasion and dissemination of eukaryotic pathogens.
4. Some pathogens, like Candida albicans, can induce the internalization of cadherins, causing the disassembly of cell-cell junctions and promoting their own entry into host cells.
5. Pathogens may also exploit cadherin-mediated cell-cell adhesion to facilitate their own cell-to-cell spread within the host, as seen with the movement of Toxoplasma gondii between neighboring cells.

Review Questions

• Explain how eukaryotic pathogens can target cadherin-mediated cell-cell adhesion to facilitate their invasion and spread within the host.
  • Eukaryotic pathogens often target cadherin-mediated cell-cell adhesion as a virulence mechanism to breach host barriers and disseminate within the body. Some pathogens, like Listeria monocytogenes and Helicobacter pylori, produce virulence factors that can directly interact with and disrupt cadherin-mediated junctions, leading to increased permeability of host tissues. Other pathogens, such as Candida albicans, can induce the internalization of cadherins, causing the disassembly of cell-cell junctions and promoting their own entry into host cells. Additionally, pathogens may exploit cadherin-mediated cell-cell adhesion to facilitate their own cell-to-cell spread within the host, as seen with the movement of Toxoplasma gondii between neighboring cells.
• Describe the role of the extracellular matrix and tight junctions in the context of cadherin-mediated cell-cell adhesion and eukaryotic pathogen virulence.
  • The extracellular matrix and tight junctions are closely related to cadherin-mediated cell-cell adhesion and play important roles in the virulence mechanisms of eukaryotic pathogens. The extracellular matrix provides structural and biochemical support to surrounding cells, and pathogens may target this network to gain access to host tissues. Tight junctions, on the other hand, create a barrier to the movement of molecules between cells, which pathogens may disrupt to breach host defenses. The disruption of cadherin-mediated cell-cell adhesion can lead to the breakdown of these barriers, facilitating the invasion and dissemination of eukaryotic pathogens within the host.
• Analyze how the disruption of cadherin-mediated cell-cell adhesion by eukaryotic pathogens can impact the overall pathogenesis and disease progression within the host.
  • The disruption of cadherin-mediated cell-cell adhesion by eukaryotic pathogens can have significant impacts on the overall pathogenesis and disease progression within the host. By targeting and dismantling the structural integrity of epithelial and endothelial barriers, pathogens can gain easier access to host tissues and facilitate their invasion and dissemination. This breakdown of cell-cell junctions can lead to increased permeability, allowing pathogens to cross barriers and spread to new sites within the body. Furthermore, the disruption of cadherin-mediated adhesion can promote the internalization of pathogens into host cells, enabling them to evade immune responses and establish persistent infections. Ultimately, the exploitation of cadherin-mediated cell-cell adhesion by eukaryotic pathogens is a critical virulence mechanism that can profoundly influence the course and severity of the resulting disease.

Related terms

Cell Adhesion: The process by which cells attach to each other or to the extracellular matrix, mediated by various cell adhesion molecules like cadherins.

Extracellular Matrix: The complex network of macromolecules, such as collagen and proteoglycans, that provide structural and biochemical support to surrounding cells.

Tight Junctions:

Specialized cell-cell adhesion complexes that create a barrier to the movement of molecules between cells, which pathogens may disrupt to gain access to host tissues.