TARC Rat

Thymus and Activation Regulated Chemokine (CCL17), also known as TARC, is a member of the CC chemokine family. Chemokines are small cytokines or signaling proteins secreted by cells. They play a crucial role in immune responses by directing the movement of circulating leukocytes to sites of inflammation or injury. CCL17 is particularly significant due to its involvement in various immune responses and its potential therapeutic applications.

CCL17 is encoded by the CCL17 gene located on chromosome 16 in humans . The protein is produced constitutively by thymus cells and transiently by phytohemagglutinin-stimulated peripheral blood mononuclear cells . The recombinant form of CCL17, such as the rat recombinant version, is often used in research to study its functions and interactions.

CCL17 is primarily expressed in the thymus and by antigen-presenting cells like dendritic cells, macrophages, and monocytes . It plays a pivotal role in the immune system by attracting T-helper cells, particularly type 2 helper T cells (Th2), to sites of inflammation. This chemokine binds to the chemokine receptors CCR4 and CCR8, which are expressed on various immune cells .

CCL17 has been implicated in several diseases, particularly those involving immune dysregulation. For instance, elevated levels of CCL17 are associated with eosinophilic disorders, where it contributes to the recruitment of eosinophils to inflamed tissues . Additionally, CCL17 plays a complex role in cancer. It can attract T-regulatory cells, allowing some cancers to evade immune responses, while in other cancers, such as melanoma, increased levels of CCL17 are linked to improved outcomes .

Given its role in immune cell recruitment and activation, CCL17 is a potential target for therapeutic interventions. Modulating CCL17 levels or blocking its interaction with CCR4/CCR8 could be beneficial in treating conditions like allergic diseases, autoimmune disorders, and certain cancers .