mast cell chemotaxis

Definition

Target type: biologicalprocess

The movement of a mast cell in response to an external stimulus. [GOC:add, PMID:11292027, PMID:12789214, PMID:16448392]

Mast cell chemotaxis is a complex biological process that involves the migration of mast cells towards a chemical gradient. This process is critical for immune responses, as mast cells are key players in allergic reactions and inflammation.

Here's a detailed description of the process:

1. **Chemoattractant Release:** Mast cells are attracted to various chemoattractants released by other cells or present in the environment. These chemoattractants can include:
* **Cytokines:** Interleukin-8 (IL-8), eotaxin, CCL2, CCL3, CCL5
* **Leukotrienes:** Leukotriene B4 (LTB4)
* **Complement proteins:** C5a
* **Histamine:** Released by other mast cells or other immune cells
* **Platelet-activating factor:** Released by activated platelets
* **Inflammatory mediators:** Released by damaged tissues

2. **Chemoattractant Binding:** The chemoattractant molecules bind to specific receptors on the surface of mast cells. These receptors are typically G protein-coupled receptors (GPCRs).

3. **Signal Transduction:** Binding of the chemoattractant triggers a cascade of intracellular signaling events. This includes:
* **Activation of G proteins:** The bound GPCR activates G proteins, which are intracellular signaling molecules.
* **Production of second messengers:** G proteins activate downstream signaling pathways that generate second messengers, such as cyclic adenosine monophosphate (cAMP), diacylglycerol (DAG), and inositol trisphosphate (IP3).
* **Activation of kinases:** Second messengers activate protein kinases, which phosphorylate and activate other proteins involved in cell migration.

4. **Cytoskeletal Rearrangement:** The activated kinases trigger a series of changes in the mast cell's cytoskeleton, including:
* **Polymerization of actin filaments:** Actin filaments are assembled at the leading edge of the cell, creating a protrusive force that drives the cell forward.
* **Depolymerization of actin filaments:** Actin filaments are disassembled at the trailing edge of the cell, allowing the cell to move forward.
* **Regulation of microtubules:** Microtubules, another component of the cytoskeleton, are also regulated to ensure proper cell orientation and migration.

5. **Cell Polarization:** The mast cell becomes polarized, with the leading edge of the cell facing the higher concentration of chemoattractant. This is driven by the asymmetric distribution of actin filaments and other cytoskeletal components.

6. **Cell Migration:** The mast cell moves towards the chemoattractant source by extending its leading edge and retracting its trailing edge, a process known as chemotaxis.

7. **Mast Cell Activation:** Once the mast cell reaches the source of the chemoattractant, it can become activated and release various inflammatory mediators, such as histamine, leukotrienes, and cytokines. These mediators contribute to the inflammatory response and can attract other immune cells to the site of injury or infection.

In summary, mast cell chemotaxis is a tightly regulated process that involves chemoattractant binding, signal transduction, cytoskeletal rearrangement, cell polarization, and migration. This process is essential for the recruitment of mast cells to sites of inflammation, where they can play a crucial role in immune defense and allergic reactions.'
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Proteins (2)

Compounds (193)