Small proteins with molecular weights from 8-12 kDa.
More than 50 chemokines and 20 receptors in human chemokine system.
Divided into inflammatory and homeostatic functions.
Homeostatic ;chemokine receptors are expressed and act to guide lymphocyte traffic.
Inflammatory chemokine receptors expressed on antigen exposure and regulate lymphocyte migration in response to inflammation.
Chemokines are a family of small, structurally related cytokines that play a crucial role in the migration and activation of leukocytes.
These proteins are primarily known for their ability to induce chemotaxis, guiding the movement of immune cells to sites of inflammation, infection, and injury.
Chemokines are categorized into four main subfamilies based on the arrangement of conserved cysteine residues: CXC, CC, C, and CX3C.
The trafficking of lymphocytes is important for induction of adaptive immune responses: T and B cells migrate into the secondary lymphoid organs (SLOs), such as peripheral lymph nodes (PLNs), spleen and Peyer’s patches, via the blood.
The trafficking of lymphocytes process is regulated by homeostatic chemokines CXCL13, CCL19 and CCL21 that fulfill two major functions.
Each subfamily interacts with specific G protein-coupled receptors (GPCRs) on the surface of target cells, named CXCR, CCR, XCR, and CX3CR, respectively.
Chemokines are involved in various physiological and pathological processes, including angiogenesis, hematopoiesis, and immune surveillance.
Chemokines also play significant roles in tumor biology, influencing tumor growth, metastasis, and the tumor microenvironment.
They are integral to both innate and adaptive immune responses.
They regulate the release and positioning of immune cells during homeostasis and in response to inflammatory stimuli, thereby linking innate and adaptive immunity.
Chemokines and their receptors are considered potential therapeutic targets for a range of conditions, including autoimmune diseases, cancer, and infectious diseases.