Spatial proteomics identifies a novel CRTC-dependent viral sensing pathway that stimulates production of Interleukin-11 (preprint)

Appropriate cellular recognition of viruses is essential for the generation of effective innate and adaptive antiviral immunity. Viral sensors and their signalling components thus provide a crucial first line of host defence. Many exhibit subcellular relocalisation upon activation, triggering expression of interferon and antiviral genes. To identify novel signalling factors we analysed protein relocalisation on a global scale during viral infection. CREB Regulated Transcription Coactivators-2 and 3 (CRTC2/3) exhibited early cytoplasmic-to-nuclear translocation upon a diversity of viral stimuli, in diverse cell types. This movement was depended on Mitochondrial Antiviral Signalling Protein (MAVS), cyclo-oxygenase proteins and protein kinase A. We identify a key effect of transcription stimulated by CRTC2/3 translocation as production of the pro-fibrogenic cytokine interleukin-11. This may be important clinically in viral infections associated with fibrosis, including SARS-CoV-2.

Quantitative temporal analysis of modified vaccinia Ankara, the monkeypox and smallpox vaccine (preprint)

Modified vaccinia Ankara (MVA) immunisation is being deployed to curb the current outbreak of monkeypox in multiple countries1. Originally authorized for vaccination against smallpox, MVA is a vaccinia virus (VACV) strain that does not replicate in human cells or cause serious adverse events. Here, we conducted a highly multiplexed proteomic analysis2 to quantify ~7,500 cellular proteins and ~80% of viral proteins at five time points throughout MVA infection of human cells3. >380 human proteins were down-regulated >2-fold by MVA, revealing a profound remodelling of the host proteome. >25% of these MVA targets, including multiple components of the nuclear pore complex (NPC), were not shared with VACV-Western Reserve4, which is derived from a first generation smallpox vaccine associated with serious adverse events. Using pharmacological inhibition of viral DNA replication and killed virions, we discovered that post-replicative gene expression is necessary for the downregulation of NPC proteins and for elements of MVA antagonism of innate immune sensing. Our approach thus provides the first global view of the impact of MVA infection on the host proteome, offers insights into how MVA interacts with the antiviral defences and identifies cellular mechanisms that may underpin the abortive infection of human cells. These discoveries will prove vital to the rational design of future generations of vaccines.