Ligase Pellino3 Regulates Macrophage Action and Survival in Response to VSV Infection in RIG-I-Dependent Path.

Sensing of viral particles and elements that initiate mechanisms of immune response is an intrinsic ability of mammalian cells. Regulatory cytokines and antiviral mediators are released after triggering of complex signaling cascades in response to interaction of pathogen particles with pattern recognition receptors (PRRs) leading to the production of interferons (IFN) and proinflammatory cytokines. Viral RNA in the cytoplasm constitute a potent danger molecule that recognition is performed by RIG-I-like receptors, the most common group of receptors in mammalian cells, capable to recognize a foreign RNA. It is known that the E3 ubiquitin ligase Pellino3 plays an important role in antibacterial and antiviral response, but its involvement in the RLR pathways remains poorly understood. In this study, we investigate the molecular mechanisms of the innate immune response in BMDMs (immortalized macrophages from mouse bone marrow) during VSV infection. Here, we present evidence that the activation of the RIG-I/Pellino3/ERK1/2 pathway in BMDMs is crucial for the protection against VSV. We demonstrate that during infection, viral particles replicate in Pellino3 knockout BMDMs more effectively than in wild-type cells. Increased viral replication resulting in cell lysis and death is aid by impaired synthesis of IFN-I and inflammatory cytokines as a consequence of disturbances in the ERK1/2 pathway regulation.