Well, yes, but it's an abstraction in that case, and usually acknowledged as such. But when you play the abstraction with prisoners, you're still playing an abstraction... and it's not really, IMHO, all that noteworthy... as opposed to when you ACTUALLY play the Prisoner's Dilemma with actual prisoners who are actually in that situation.
I guess my point is, the fact that when you say "Actual prisoners playing the Prisoners Dilemma" you're sort of setting up for the idea that the fact that they're actually prisoners is relevant, that it's somehow a more real result because they're playing the actual thing. But it's not, and they're not. Just as the other group are people who happen to be college students playing the abstraction, this is a group who happen to be prisoners playing the abstraction. Neither are actually in the situation described in it, though, so their status as prisoners or college students and how they react is really only a slight curiosity rather than being some especially important aspect. (Well, it is important, but not for the same reason: Because the prisoners are more likely to have a non-optional extended interaction with each other, after the game, than the college students... but that's not a part of the Prisoner's Dilemma, as stated... in fact, the opposite might be true, in that, if one cooperates and the other doesn't, the Prisoners might not have to interact with each other at all for years, whereas here, no matter what the case, they're going to be in jail together.)