Adhesion molecules

Definition

Adhesion molecules are proteins located on the cell surface that facilitate the binding of cells to other cells or to the extracellular matrix. They play a crucial role in various biological processes, including immune responses, tissue formation, and the maintenance of tissue architecture, and are essential in determining host specificity and tropism for pathogens.

5 Must Know Facts For Your Next Test

1. Adhesion molecules are critical for cell-cell interactions, which influence processes like tissue development, repair, and immune system functioning.
2. Pathogens often exploit adhesion molecules to attach to host cells, making them key players in host specificity and tropism.
3. Different types of adhesion molecules can promote or inhibit cell migration, affecting how cells move within tissues and their ability to respond to infections.
4. Infections can alter the expression of adhesion molecules on host cells, impacting the susceptibility to disease by enhancing or reducing pathogen attachment.
5. Adhesion molecules can also play a role in cancer metastasis, as tumor cells often change their adhesion properties to invade surrounding tissues and spread to other parts of the body.

Review Questions

• How do adhesion molecules contribute to host specificity and tropism in pathogens?
  • Adhesion molecules play a significant role in host specificity and tropism by facilitating the attachment of pathogens to specific cell types. This binding is often mediated through interactions between pathogen surface proteins and host adhesion molecules, which allows pathogens to establish infection in certain tissues. The presence or absence of specific adhesion molecules on host cells can determine whether a pathogen can successfully invade, leading to variations in infection susceptibility among different hosts.
• Discuss the impact of adhesion molecules on cell migration during immune responses.
  • During immune responses, adhesion molecules facilitate the movement of leukocytes from the bloodstream to sites of infection or inflammation. Selectins mediate the initial weak interactions between leukocytes and endothelial cells, allowing them to roll along the vessel wall. Once activated, integrins enhance the firm adhesion of leukocytes, enabling them to exit the bloodstream. This coordinated action is vital for mounting an effective immune response and highlights the importance of adhesion molecules in regulating immune cell behavior.
• Evaluate how changes in adhesion molecule expression can affect disease progression in conditions such as cancer.
  • Changes in adhesion molecule expression can significantly influence disease progression, particularly in cancer. Tumor cells often downregulate certain adhesion molecules to escape normal tissue architecture, enabling them to invade surrounding tissues more easily. Additionally, increased expression of specific adhesion molecules can promote metastasis by allowing tumor cells to adhere to distant sites more effectively. Understanding these mechanisms opens pathways for therapeutic strategies aimed at targeting adhesion molecule interactions to hinder cancer spread and improve treatment outcomes.

Related terms

Integrins: Integrins are a type of adhesion molecule that mediate the attachment between cells and the extracellular matrix, influencing cell signaling and migration.

Selectins: Selectins are a family of adhesion molecules that mediate the interaction between leukocytes and the endothelium during immune responses, playing a role in inflammation.

Extracellular Matrix (ECM): The extracellular matrix is a complex network of proteins and carbohydrates that provides structural and biochemical support to surrounding cells, impacting cell adhesion and communication.