Figure 1.

HMIs can activate, inhibit or shift host signaling pathways. (A) KSHV cytokine mimic vIL6 serves as an agonist to host IL6-R and initiates host inflammatory responses (21). (B) KSHV chemokine mimic K4 antagonizes cellular chemokine receptor CXCR4 and inhibits immune cell recruitment to the infected tissue/cell (22). (C) EBV cytokine mimic vIL10 binds to cellular IL10-R1 with a ~1,000 fold less affinity compared to its host counterpart. While it activates the host anti-inflammatory responses, it cannot activate other immunostimulatory functions, such as stimulation of thymocyte and mast cell proliferation (23). Pink and blue proteins are from virus and human, respectively. Red arrows indicate oncovirus action/impact on a host protein and black arrows are the conventional downstream outcome of the host pathways.