XCL1

Chemokine (C motif) ligand (XCL1) is a small cytokine belonging to the C chemokine family that is also known as lymphotactin. Chemokines are known for their function in inflammatory and immunological responses. This family C chemokines differs in structure and function from most chemokines.^[5][6] There are only two chemokines in this family and what separated them from other chemokines is that they only have two cysteines; one N-terminal cysteine and one cysteine downstream. These both are called Lymphotactin, alpha and beta form, and claim special characteristics only found between the two. Lymphotactins can go through a reversible conformational change which changes its binding shifts.^[7]

In normal tissues, XCL1 is found in high levels in

XCL1's gene is found on the long arm of chromosome 1, located on cytogenetic band q24.2 as seen in the infobox. The encoding gene is made of 6,017 DNA bases to encode for the protein XCL1.[15] This gene contains three exons and two introns as well as several transcription initiation sites.^[8] This gene encodes for the 114-amino acid protein called XCL1 which is similar to other chemokines except that it lacks the first and third cysteine characteristics. This means that XCL1 only contains one cysteine creating a disulfide bond instead of two or three like the other chemokines.^[5]

The genetic differences between XCL1 and

The pair of XCL1 and XCR1 are known to be involved in cross-presentation, antigen uptake, and induction of innate as well as adaptive cytotoxic immunity.^[12] XCR1, the receptor for XCL1, is exclusively expressed in conventional dendritic cells.^[12] XCL1 is secreted by NK cells and by antigen-specific CD8+ T-cells, along with other chemokines including IFN-gamma.^[12] This process likely facilitates the cross-presentation of antigens by the dendritic cells.

XCL1 is also known to increate T cells in joints that are effected with rheumatoid arthritis.^[6] They are also expressed on RA synovial lymphocytes.^[6]

References