Cx3c Chemokines

1.4.2 Role of chemokines in inflammation

The chemokines are categorised into several subclasses, of which the C, CC, CXC and CX3C chemokines are the main classes of chemotactic cytokines (Fig. 3). The chemokines are thought to be involved in the process of cell transmigration (Fig. 4). Therefore, it is essential to explore the molecular mechanisms underlying leukocyte transmigration processes and the involvement of the chemokines to gain a more complete understanding of the inflammatory disorders of the liver. Moreover, the chemokines are critical participants in tissue injury and healing, and in the progression of fibrosis (Marra 2002). Furthermore, they play key roles in adaptive and innate immunity (Fig. 5). The chemokines attract specific populations of leukocytes, and, of these, the CXC chemokines are considered specific for neutrophils. The chemokines are classified according to their structural differences; hence, CXC chemokines can be differentiated from the other chemokine classes because of their glycine­leucine­arginine (ELR) motifs (Lin et al. 2007; Proudfoot 2002). Furthermore, structural differences between human and murine

They can mobilise and attract more than one cell population, for example, neutrophils and T- lymphocytes (Harris et al. 1996; Moriconi et al. 2008; Proudfoot 2002). In addition to attracting inflammatory cells such as basophils, monocytes, dendritic cells, T lymphocytes and natural killer cells to the injured area, the CC chemokines, for example, monocyte chemoattractant protein (MCP)-1/CCL2, MIP-1 alpha/CCL3, MIP-1 beta/CCL4, MIP-3 alpha/CCL20 and MIP-3 beta/CCL19, also attract a minor proportion of neutrophils (Ajuebor et al. 1998; Moriconi et al. 2008; Proudfoot