Chemokine-binding proteins encoded by herpesviruses

To establish infection, a wide variety of pathogens, including viruses, have evolved a number of strategies to avoid immune elimination. Viruses have acquired and optimized molecules that interact with the host chemokine network in order to disrupt immune surveillance and defense of vertebrates, helping to promote cell entry, facilitating dissemination of infected cells, and evasion the immune response. Viral immunomodulators include ligands, chemokine receptors and chemokine-binding proteins (vCKBPs) functioning as either cell surface receptor mimics, ligand mimics, or secreted chemokine-binding proteins. vCKBPs specifically modulate chemokine gradient formation and ligand-receptor recognition when they have a potential to even completely block chemokine-mediated responses to viral infection. Members of only two virus families (Herpesviridae and Poxviridae) encode vCKBPs capable of sequestering host chemokines through either the chemokine receptor, GAG-binding pocket, or both, which may result in the inhibition of chemotaxis in vivo. Here, we focused on vCKBPs encoded by α-, β-, and γ-herpesviruses, of which several have been experimentally used as anti-inflammatory or anti-immune reagents in animal models. Current results suggest that vCKBPs could be used to regulate the activity of both chemokines and chemokine receptors for the treatment of infections such as AIDS, diseases such as arthritis, neurotrauma, inflammatory CNS disorders, atherosclerosis, transplant rejection, and metastatic spread and angiogenesis. Better understanding of vCKBPs biology will help evaluate, which human diseases related to chemokine network dysregulation might be effectively treated with these novel promising immunomodulatory drugs to enable the manipulation of chemokine functions and leukocyte trafficking. Keywords: herpesviruses; chemokine-binding proteins; chemokines; immunomodulation viral infection, chemokines and viral immunomodulators.