T cell migration

Definition

Target type: biologicalprocess

The movement of a T cell within or between different tissues and organs of the body. [CL:0000084, GOC:BHF, GOC:mah]

T cell migration is a complex and highly regulated process that is essential for immune surveillance and the generation of effective immune responses. It involves a series of coordinated steps, including:

**1. Chemotaxis:** T cells are attracted to specific sites in the body by chemoattractant molecules, such as chemokines. These chemokines bind to receptors on the surface of T cells, triggering intracellular signaling pathways that lead to changes in the cytoskeleton and the formation of lamellipodia, which are finger-like protrusions that extend towards the source of the chemokine.

**2. Adhesion:** Once T cells encounter their target, they adhere to the surface of the tissue. This adhesion is mediated by interactions between cell adhesion molecules (CAMs) on the surface of the T cell and their ligands on the surface of the target cells or the extracellular matrix.

**3. Diapedesis:** After adhesion, T cells squeeze through the endothelial cells that line blood vessels to enter the surrounding tissues. This process, known as diapedesis, is facilitated by the action of enzymes that degrade the extracellular matrix and by changes in the shape of the T cells, which allows them to squeeze through tight spaces.

**4. Homing:** Once T cells have entered a tissue, they migrate towards specific locations within the tissue. This homing process is guided by a variety of factors, including chemokine gradients, adhesion molecules, and the expression of tissue-specific antigens.

**5. Activation and Differentiation:** Upon reaching their target location, T cells can be activated and differentiate into effector cells, such as cytotoxic T lymphocytes (CTLs) or helper T cells (Th cells). Activation is triggered by the recognition of antigens presented by antigen-presenting cells (APCs).

**6. Effector Function:** Effector T cells perform their specific functions, such as killing infected cells (CTLs) or activating other immune cells (Th cells).

**7. Memory Formation:** After an immune response, some T cells differentiate into memory T cells, which persist in the body and can rapidly respond to subsequent encounters with the same antigen.

The entire process of T cell migration is tightly regulated by a complex interplay of signaling pathways, transcription factors, and cell surface receptors. Dysregulation of T cell migration can lead to a variety of immune disorders, including autoimmune diseases and immunodeficiency.'
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Proteins (4)

Compounds (132)