Trim69 is a microtubule regulator that acts as a pantropic viral inhibitor

ABSTRACT To identify novel cellular modulators of HIV-1 infection in IFN-stimulated myeloid cells, we have carried out a screen that combines functional and evolutionary analyses in THP-1-PMA cells that led us to the Tripartite Motif Protein 69 (Trim69), a poorly studied member of the Trim family of innate immunity regulators. Trim69 inhibits HIV-1, primate lentiviruses and the negative and positive-strand RNA viruses VSV and SARS-CoV2, overall indicating it is a broad-spectrum antiviral factor. Trim69 binds directly to microtubules and its antiviral activity is intimately linked to its ability to promote the accumulation of stable MTs, a specialized subset of microtubules. By analyzing the behavior of primary blood cells, we provide evidence that a program of MT stabilization is commonly observed in response to IFN-I in cells of the myeloid lineage and Trim69 is the key factor behind this program. Overall, our study identifies Trim69 as the first antiviral innate defense factor that regulates the properties of microtubules to limit viral spread, highlighting the possibility that the cytoskeleton may be a novel unappreciated fighting ground in the host-pathogen interactions that underlie viral infections.