It doesn't appear that you can have both running at the same time:
Because of Microsoft changes in Windows 8 and Server 2012 and later, the Windows operating system now self-disables when detecting the presence of an anti-malware product. It is now expected behavior on Windows 8 or later that Windows Defender is disabled when installing VSE. With Windows 7 and earlier, Windows Defender was merely an anti-malware application. In Windows 8 and later, Windows Defender is rebranded Microsoft Security Essentials, which is a full anti-virus application that cannot co-exist with VSE.