I believe that I read somewhere that one can and will develop Killer T-Cells for KS. Is this true?

One very important part of the immune system are cells called cytotoxic T-lymphocytes (abbreviated CTL cells). These are cells that are part of the cellular immune system and that target many of the various viruses. Just recently investigators at Harvard, for instance, published that CTLs can be directed against the JC virus, the virus which causes a disease called progressive multifocal leukoencephalopathy. HOWEVER, I am not aware of any study demonstrating that CTLs can be directed against the HHV-8 virus, the virus which causes KS. Many investigators are working in this area, so we should continue seeing interesting articles on the subject. So to answer your question, "is it true?", I would say "no for now, but it may possibly be true in the future".