The family C chemokines — the family to which lymphotactin belongs — differs in structure and function from most other types of chemokines. Chemokines as a whole are known for the role they play in inflammatory and immune responses in the body, but family C chemokines are particularly noteworthy.
There are only two chemokines that belong to the family C of chemokines. They are both called lymphotactin, and appear in alpha and beta form. The main note of significance in both lymphotactin alpha and beta is that they have only two cysteines: a single N-terminal cysteine and an additional cysteine downstream.
It has also been noted that both forms of lymphotactin are able to go through reversible conformational changes, which alters its binding shifts.
As touched on above, the structure of lymphotactin is what makes it so unique.
● Most chemokines have two disulfide bonds
● However, lymphotactin has only one
● There are two components of the lymphotactin protein — Ltn10 and Ltn40. These components interfold and alter the binding structures, making lymphotactin biologically active.
● This metamorphic folding behavior is quite unique to lymphotactin.
● Lymphotactin is found on chromosome 1, unlike other chemokines which are predominantly found on chromosomes 4 and 17
● Lymphotactin causes the migration of cells expressing XCR1
● Lymphotactin is found in high levels of numerous organs in the body. These includes the spleen, thymus, lung, prostate gland, and ovaries.
● The data suggests that lymphotactin produced by T cells may have the ability to regulate T cell-mediated immune responses.
● Lymphotactin binds with GPCR XCR1 to induce CD8 + T cell and NK cell chemotaxis
● As with other chemokines, lymphotactin has also been found to induce intracellular calcium mobilization and chemotaxis. This is achieved by binding with a specific G protein-coupled receptor
● Furthermore, lymphotactin has been found to chemoattract CD4 + T cells with lower efficiency
● It is produced predominantly through T Cell receptor activation in CD4+ and CD8+ T cells
● It is also produced by NK cells, along with other chemokines, during the earlier stages of an infection
● It is also expressed by dendritic cells
● Lymphotactin has been found in T cells that are affected by rheumatoid arthritis, Crohn's Disease, and glomerulonephritis.
● It has therefore been theorized that the suppression of lymphotactin may have a therapeutic value regarding inflammatory and immune disease.
● Lymphotactin has already been used in some cancer immunotherapies, and further research regarding its potential in this area is ongoing.