Particles Not Lit with Render to Texture

I’m having trouble lighting particles when inside of a Render to Texture node. I have a particle system and a Directional Light that works as expected when attached to the root:

However, the particles do not show up when connected to a Render to Texture node. If I disable the Directional Light, the particles do show up, but they are not lit.

The intention is to get the lit particles piped into a Video Null. What am I missing?

DFX link - thank you!