Describe the process by which CD4 cells are activated.  Plea…

Describe the process by which CD4 cells are activated.  Please include the other cell involved in the process, type of MHC protein utilized (also write out the full name and define MHC), the source of the antigen, the process by which it is displayed, and what is meant by co-stimulation.  There was a pretty in-depth video link that I posted/taught regarding this entitled CD4 Activation and Co-Stimulation.