If you're using the msgnr channel and you want to publish someone's reply to the other team members then you'll need to use a little Communicator syntax and smartwords.

The text you need to put at the start of the content is:

\n {msngr} t. [|audience.sender.name|,img(|audience.sender.audience_profile_image|)]  your text goes here

The tells TeamXp to start a new line (\n) and publish a text (t.) from the person who replies (audience.sender.name) and display their profile image (audience.sender.audience_profile_image).
The image below shows and example and the result.