Is it possible to add multiple customers to a ticket?

I have an organization (customer) that has multiple customers. When I create a ticket for them they would like any ticket updates to automatically be sent to the originator and two managers as well. I.e. if the originator emails a response, the managers would like to receive the update as well as me. Or, if I ask the user a question, they'd like to see my replies (to keep abreast of the situation).

I cannot see how to add the managers to a ticket. Is there currently a way to accomplish this?