vCCL2/vMIP-II, the viral master KEYmokine.

Viral CC motif chemokine or viral macrophage inflammatory protein-II is 1 of the 3 chemokines encoded by the human herpesvirus-8 to interfere with the host chemokine receptor network, facilitate the immune escape, and promote its survival. Viral CC motif chemokine 2 binds to a broad spectrum of viral and human chemokine receptors of all 4 classes and, depending on the receptor, acts either as an agonist or an antagonist, inducing or blocking the recruitment of specific immune cell subsets. These atypical binding and signaling properties make this viral chemokine not only a useful tool to investigate the complexity of the chemokine-receptor interaction network or the virus-host interplay but also for the development of receptor inhibitors. This mini-review summarizes the knowledge currently available on viral CC motif chemokine 2 binding, signaling, and structural mimicry and discusses its role and importance for the virus, the therapeutic potential, and the open questions regarding the biology of this fascinating chemokine. © Society for Leukocyte Biology.