CXCR

CXCR receptors (C-X-C motif chemokine receptors) are a family of chemokine receptors that belong to the group of G-protein-coupled receptors (GPCRs). Chemokine receptors are transmembrane G protein-coupled receptors that are activated by binding to one or more chemokines.

CXCR receptors play an essential role in the immune system by influencing the migration of immune cells to sites of inflammation or to tissues. Chemokines are signaling molecules produced by various cells. They form a family of chemoattractive molecules, of which more than 50 have been identified to date. Chemokines are categorized into four main groups according to the number and spacing of conserved cysteines: CXC, CC, CX3C and C. They bind to their specific receptors (e.g. CXCR) and thus initiate a signaling cascade that controls the behavior of immune cells, including their movement, activation and differentiation. In individual cases, this can also influence tumor growth.

CXCR chemokine receptors:

• CXCR1: CXCR1 binds to the chemokine interleukin-8 (also known as C-X-C motif ligand 8 or CXCL8).CXCR1 plays a role in the recruitment of neutrophil granulocytes to sites of inflammation.
• CXCR2
• CXCR3
• CXCR4
• CXCR5
• CXCR6
• CXCR7 (was renamed as ACKR3 = atypical chemokine receptor 3)
• CXCR8

CXCR receptors play an important role in cell migration: they promote the movement of immune cells to sites of inflammation or tumors. Here are some details on their function and the mechanisms by which they act:

Chemotaxis: CXCR receptors bind specific chemokines (signaling molecules) and activate intracellular signaling pathways that control the movement of cells towards a chemokine gradient. This is crucial for the recruitment of immune cells to sites of inflammation or infection.

Homeostatic migration: CXCR receptors also play a role in the normal distribution of immune cells in the body, e.g. in the migration of T cells and B cells to lymphoid organs.

Activation and differentiation: By binding to chemokines, CXCR receptors can activate immune cells and promote their differentiation. This is particularly important for T cells, which need to be able to bind to specific antigens and generate an appropriate immunological response.

Production of cytokines: Activated immune cells produce cytokines that amplify the inflammatory response and recruit other immune cells.

Role in inflammatory processes: CXCR receptors are crucial for the recruitment of immune cells during inflammatory reactions. They help to attract neutrophil granulocytes, T cells and other immune cells to the site of inflammation.

Chronic inflammation: Excessive or prolonged activation of CXCR receptors can lead to chronic inflammatory conditions associated with various diseases such as autoimmune diseases and allergies.

Role in tumor biology: Tumor migration and metastasis: Some CXCR receptors, especially CXCR4, are involved in tumor metastasis.

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