Figure 3.

Innate immune evasion mechanisms of HSV. Several countermeasures against the host IFN and proinflammatory response have been established by HSV. For instance, the IRF3 pathway is inhibited by ICP0, ICP27, and ICP34.5, through distinct mechanisms. Also, the HSV L gene products ICP34.5 and Us11 inhibit PKR activation, with Us11 exerting its action by direct binding to dsRNA, for which reason Us11 potentially also blocks activation of TLR3 and RLRs. The 2′–5′-OAS/RNAse L system is inhibited by 2′–5′ A analogs. JAK/STAT signalling and the production of IFN-α/β is counteracted by a mechanism involving ICP27.