The mechanism of Axlmediated Ebola virus infection

We previously reported that expression of the receptor-type tyrosine kinase Axl, which regulates cell survival and activation, enhances both pseudotype and live Ebola virus (EBOV) infection. To clarify the mechanistic basis of this enhancement, we created a series of Axl mutants and identified amino acids/domains necessary for this function, by using a pseudotype virus carrying the EBOV glycoprotein (GP). Analyses of the Axl mutants showed the importance of extracellular and intracellular regions for Axl functions, including ligand binding and signal transduction, in EBOV GP–mediated infection. These data suggest that EBOV uses the physiological functions of Axl to enter cells. Ebola virus (EBOV), a member of the family Filoviridae, causes severe hemorrhagic fever in humans and non-human primates [1]. The virus can be detected in vir-tually all organs of infected primates [1]. Furthermore, pseudotype viruses carrying EBOV glycoproteins (GPs)—the only surface protein of the virus that me-diates viral attachment and entry into cells—infect many types of cells in vitro [2, 3]. Thus, EBOV ha