C-C motif chemokine 22 (CCL22)

C-C motif chemokine 22 (CCL22), also known as macrophage-derived chemokine (MDC), is a cytokine belonging to the CC chemokine family, characterized by two adjacent cysteine residues near its amino terminus[1][5]. CCL22 is produced by antigen-presenting cells—including macrophages, dendritic cells, and keratinocytes—primarily in response to various external stimuli such as bacterial or viral components[1][2][3]. It signals chiefly through the chemokine receptor CCR4, which is expressed on Th2 cells, regulatory T cells (Tregs), and other immune cells[2][4]. CCL22 functions as a chemoattractant for monocytes, dendritic cells, natural killer cells, and activated T-lymphocytes, and plays a significant role in orchestrating the migration of immune cells to sites of inflammation or tumors[5]. In cancer, elevated MDC/CCL22 contributes to the recruitment of immunosuppressive cells such as Tregs to the tumor microenvironment, promoting immune evasion, while in allergic and inflammatory diseases, CCL22 mediates Th2-related immune responses and immunoglobulin class switching[1][2]. Experimental therapies (including monoclonal antibodies) targeting CCL22 are in development for malignant and inflammatory conditions[1], but direct clinical inhibitors are not currently available. Elevated CCL22 levels are considered biomarkers in various immune disorders[2], and careful modulation is required given its central role in immune homeostasis and the risk of triggering or worsening inflammatory responses if blocked excessively[2].

Other names

Macrophage-derived chemokine (MDC)MDC/CCL22

Inhibition of immune cell recruitment to tumors (through antagonism or neutralization of CCL22); modulation of T cell trafficking and tumor microenvironment