T cell extravasation
Definition
Target type: biologicalprocess
The migration of a T cell from the blood vessels into the surrounding tissue. [CL:0000084, GOC:BHF, GOC:mah]
T cell extravasation is a critical step in the immune response, allowing T cells to exit the bloodstream and migrate to sites of inflammation or infection. This process is highly regulated and involves a complex interplay of adhesion molecules, chemokines, and signaling pathways.
The first step in T cell extravasation is **tethering and rolling**, mediated by selectins. Selectins are adhesion molecules expressed on both endothelial cells and leukocytes. L-selectin on T cells binds to GlyCAM-1 and CD34 on the endothelial cells, allowing the T cells to slow down and roll along the vessel wall.
Next, the T cells undergo **activation**, triggered by chemokines. Chemokines are small, chemoattractant proteins that are produced by cells at the site of inflammation or infection. They bind to specific receptors on T cells, activating signaling pathways that lead to the upregulation of integrins.
Integrins are another class of adhesion molecules that play a key role in T cell extravasation. They are composed of two subunits, α and β, and their activation leads to strong adhesion to the endothelium.
The activated T cells then undergo **firm adhesion**, mediated by integrins. The most important integrin for T cell extravasation is LFA-1 (αLβ2). LFA-1 binds to ICAM-1 (Intercellular Adhesion Molecule-1) on the endothelium, providing a strong adhesive force that prevents the T cells from being washed away by the blood flow.
Finally, the T cells **transmigrate**, squeezing between the endothelial cells to enter the tissue. This process is facilitated by the chemokine gradient that guides the T cells toward the site of inflammation.
In summary, T cell extravasation is a multi-step process that involves tethering and rolling, activation, firm adhesion, and transmigration. This process is carefully regulated by adhesion molecules, chemokines, and signaling pathways, ensuring that T cells reach the correct location in the body to mount an effective immune response.'
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Proteins (1)
| Protein | Definition | Taxonomy |
|---|---|---|
| Intercellular adhesion molecule 1 | An intercellular adhesion molecule 1 that is encoded in the genome of human. [PRO:WCB, UniProtKB:P05362] | Homo sapiens (human) |
Compounds (13)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| indole | indole; polycyclic heteroarene | Escherichia coli metabolite | |
| 1,4-benzodioxan | 1,4-benzodioxan: structure in first source | ||
| 1-methylindole | 1-methylindole: SKATOLE refers to 3-methylindole; RN given refers to parent cpd; structure methylindole : Any member of the class of indoles carrying one or more methyl substituents. | ||
| lovastatin | lovastatin : A fatty acid ester that is mevastatin carrying an additional methyl group on the carbobicyclic skeleton. It is used in as an anticholesteremic drug and has been found in fungal species such as Aspergillus terreus and Pleurotus ostreatus (oyster mushroom). Lovastatin: A fungal metabolite isolated from cultures of Aspergillus terreus. The compound is a potent anticholesteremic agent. It inhibits 3-hydroxy-3-methylglutaryl coenzyme A reductase (HYDROXYMETHYLGLUTARYL COA REDUCTASES), which is the rate-limiting enzyme in cholesterol biosynthesis. It also stimulates the production of low-density lipoprotein receptors in the liver. | delta-lactone; fatty acid ester; hexahydronaphthalenes; polyketide; statin (naturally occurring) | anticholesteremic drug; antineoplastic agent; Aspergillus metabolite; prodrug |
| chlorfenethazine | chlorfenethazine: RN given refers to parent cpd; synonym elroquil refers to HCl; structure | phenothiazines | |
| 2-bromohippuric acid | |||
| benzotript | benzotript: anti-gastrinic; active group is amide; structure | ||
| pd 144795 | |||
| birt 377 | |||
| 4-[(4-methylphenyl)thio]-2-thieno[2,3-c]pyridinecarboxamide | aryl sulfide | ||
| a 286982 | A 286982: inhibits the interaction between leukocyte function-associated antigen-1 and intracellular adhesion molecule-1; structure in first source | ||
| bio 1211 | BIO 1211: integrin alpha4beta1 inhibitor; structure in first source | ||
| sar 1118 | lifitegrast : An N-acyl-L-alpha-amino acid obtained by formal condensation of the carboxy group of N-[2-(1-benzofuran-6-carbonyl)]-5,7-dichloro-1,2,3,4-tetrahydroisoquinoline-6-carboxylic acid with the amino group of 3-(methanesulfonyl)-L-phenylalanine. Used for treatment of keratoconjunctivitis sicca (dry eye syndrome). lifitegrast: An LFA-1 (LYMPHOCYTE FUNCTION-ASSOCIATED ANTIGEN-1) antagonist that is used in the treatment of DRY EYE SYNDROMES. | 1-benzofurans; isoquinolines; L-phenylalanine derivative; N-acyl-L-alpha-amino acid; sulfone | anti-inflammatory drug; lymphocyte function-associated antigen-1 antagonist |