This would invove the genetic modification of Amoeba cells and/or primate animal cells, that is Lymphocytes to make new cells. These new cells would attack Aids virus cells and perhaps others but not human cells. They would on the surface be alike human cells, free from attack of the hosts immune system. They would also be chosen or modified to move through human tissues effectively. That is the brain the blood vessels etcetera. For other animals have better immune systems than ours...