actor state is meant to be read and modified only by the actor itself, which operates off of its own message mailbox (e.g. event queue).

I would expect actors to operate on their own state and on immutable data, and things such as transactional data coordination to be separate.

That said, I don't have nearly the experience with actors as many on HN - are you thinking of a particular actor-based system w.r.t touched state?