X-C motif chemokine ligand 1 (XCL1)

X-C motif chemokine ligand 1 (XCL1) is a unique member of the chemokine family, notable for possessing a single disulfide bond and the ability to spontaneously switch between two different protein folds—one that activates its specific G protein-coupled receptor (XCR1), and another that binds glycosaminoglycans and displays antimicrobial activity. XCL1 is predominantly secreted by activated CD8+ T cells and natural killer (NK) cells and plays a key role in directing the migration and activation of conventional dendritic cells subtype 1 (cDC1), a process vital to cross-presentation and activation of cytotoxic lymphocytes against tumors and infection. The XCL1–XCR1 signaling axis is of significant interest in cancer immunotherapy, vaccine development, and broader immune modulation. XCL1 is classified as a metamorphic protein due to its structural versatility, which is rare in biology and critical for its multifaceted biological functions[1][2][3][4][5]

Other names

LymphotactinLTNSCYC1LPTNATACSCM-1aSCM-1SCM-1-alphaSmall-inducible cytokine C1XC chemokine ligand 1cytokine SCM-1lymphotaxinsingle cysteine motif 1asmall inducible cytokine subfamily C, member 1 (lymphotactin)small-inducible cytokine C1

Binding to XCR1 and triggering downstream G protein-mediated signaling. Modulation of antigen presentation in dendritic cells for immunotherapy or vaccine enhancement[1][3][4]