Good question MarcD. I've never owned a thru-axle bicycle before but assume you'd want to clean it and use grease as with other skewer style solid rod axles? I'm not a bike mechanic...
I found the Turbo Owner's Manual online and attached it here for reference. At one point on page 21 it says "Clean and grease moving parts (excluding brake surfaces) arrording to instructions from the manufacturer." which must apply to the thru-axle? Might be worth taking it to your local bike shop and asking. If you find out, please report back here, I'd love to know the proper may to maintain it.
Also, page 8 says "Ensure that the wheels are securely fastened in the frame and fork. Check that the wheels and thru axles as well as all important nuts and bolts are secure (see page 24)."