I know that Tommy Tedesco tuned his mandolin to DGBE and the mandolin on "Iris" by the Goo-Goo Dolls is actually a sort of 12-string terz, but in general I'm kind of in favour of finding the idiom for the different instruments.

If you have a shortish scale and only 4 strings, you can cover a wider more range tuning in fifths, and you have the benefit of transposable fingering, which the forths and a third tuning on a guitar, or Chicago tuning of tenor , militates against.

I would probably go for Irish tuning, as Jerry suggests.