On Thu, 2 Dec 1999 (Pat) email@example.com wrote:
Pat, it makes sense that HIV will be difficult to prepare
in a pure form. HIV (along with Hepatitis B & C) are
"enveloped" viruses. That means that they steal portions
of the cell membrane when they exit the cell and move into the bloodstream. Viral assembly is unlikely to be a perfect process. You may get micro-vessicles budding from cells triggered by incomplete portions of the viral capsid (but they may not contain an HIV genome). It is also highly likely that HIV will carry some of the host's natural cell membrane embedded proteins on the virus particle surface. You would have to use a separation method with antibodies specific to HIV external surface proteins (presumably those required to infect cells) to get relatively pure preparations. Even then there is no guarantee that you would get "perfect" virions. Given how messy HIV is in copying its genome (highly error prone), I suspect it would be equally as sloppy in assembling itself for export.
We would have to go look at the literature in more detail but it seems the arguments you are making about HIV isolates could also be made for HepB & HepC. Are you going to claim that those viruses do not cause their associated liver infections as well?