mononuclear cell migration

Definition

Target type: biologicalprocess

The movement of a mononuclear cell within or between different tissues and organs of the body. [GOC:mah]

Mononuclear cell migration is a complex process involving a coordinated interplay of multiple factors, including chemotaxis, chemokinesis, and adhesion. Mononuclear cells, such as lymphocytes, monocytes, and macrophages, are essential components of the immune system, and their migration is crucial for immune surveillance, inflammation, and wound healing.

**Chemotaxis:** This is the directed movement of cells along a chemical gradient. Mononuclear cells possess receptors that recognize and bind to specific chemoattractant molecules, which are secreted by cells at the site of inflammation or infection. These chemoattractants include chemokines, cytokines, and complement components. Binding of chemoattractants to their receptors triggers intracellular signaling pathways that activate the cell's cytoskeleton and motility machinery, leading to directed movement towards the source of the chemoattractant.

**Chemokinesis:** This is the random movement of cells in response to a non-directional chemical stimulus. Chemokinesis can enhance the overall migration of mononuclear cells by increasing their motility and facilitating their exploration of the surrounding environment.

**Adhesion:** Mononuclear cells adhere to the extracellular matrix (ECM) and other cells through cell adhesion molecules (CAMs). These interactions provide a stable anchor for the cells, allowing them to exert force on the ECM and move through the tissues. The expression of CAMs on mononuclear cells is regulated by various factors, including chemokines, cytokines, and ECM components.

**Steps in Mononuclear Cell Migration:**

1. **Chemoattractant Recognition and Signal Transduction:** Mononuclear cells detect chemoattractant molecules through specific receptors on their cell surface. This recognition triggers intracellular signaling pathways that activate downstream effector molecules.

2. **Cytoskeletal Rearrangement:** Activated signaling pathways lead to changes in the cytoskeleton, particularly the polymerization of actin filaments. This polymerization forms protrusions called lamellipodia and filopodia, which extend towards the source of the chemoattractant.

3. **Adhesion and Detachment:** Mononuclear cells adhere to the ECM and other cells through CAMs. These interactions provide traction for the cells to move forward. As the cells move, they detach from the ECM and re-adhere to new sites, ensuring continuous migration.

4. **Cell Polarization:** Mononuclear cells become polarized during migration, with the leading edge facing the direction of movement. This polarization is driven by the accumulation of signaling molecules and cytoskeletal components at the leading edge.

5. **Cell Movement:** The coordinated actions of cytoskeletal rearrangements, adhesion, and detachment drive the cell's movement. The leading edge extends towards the chemoattractant, while the trailing edge detaches from the ECM and retracts.

**Regulation of Mononuclear Cell Migration:**

Mononuclear cell migration is tightly regulated by a complex network of signaling pathways, chemokines, cytokines, and ECM components. The regulation of these factors ensures that mononuclear cells migrate in a controlled and directed manner, reaching their intended destinations.

**Consequences of Aberrant Mononuclear Cell Migration:**

Dysregulation of mononuclear cell migration can contribute to various diseases, including autoimmune disorders, chronic inflammation, and cancer. For instance, excessive migration of immune cells into tissues can contribute to inflammatory damage, while deficient migration can impair immune responses to infections.

**Conclusion:**

Mononuclear cell migration is a vital process for immune surveillance, inflammation, and wound healing. This complex process involves a coordinated interplay of chemotaxis, chemokinesis, and adhesion. Understanding the molecular mechanisms that govern mononuclear cell migration is crucial for developing novel therapeutic strategies for various diseases.'
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Proteins (2)

Compounds (50)