Do these characters from Sherlock Holmes appear as part of the story?

I'm currently playing AJ. I'm on the third case and that's definitely... something. Well, at least Trucy is around, so I'm enjoying it.

Anyway, I would like to clarify something about the Great Ace Attorney. I don't know much about it, but as far as I understand, Sherlock Holmes and Tobias Gregson plays important role there. I'm a big fan of the original Holmes stories, so I'd like to ask which characters from the stories appear in these games? Is Irene Adler in it? Moriarty? Mycroft? What references to OF stories it has?

Preferably without spoilers. Thank you for answers!