{HEAD ~ These previously unseen peptides/proteins} may enter and associate with {TAIL ~ the empty major histocompatibility complex molecules} of the surviving cells to form non naturally occurring species of antigen associated antigen presenting cells, which then could be tested for their ability to confer to the recipient a beneficial immune system response 
associate with
{ HEAD ~ These previously unseen peptides / proteins } may enter and associate with { TAIL ~ the empty major histocompatibility complex molecules } of the surviving cells to form non naturally occurring species of antigen associated antigen presenting cells , which then could be tested for their ability to confer to the recipient a beneficial immune system response
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH