Re: Retrovirologists, retroviruses and purification 2 July 2004
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Brian T Foley,
HIV Researcher
Los Alamos National Lab, Los Alamos, NM 87545

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Re: Re: Retrovirologists, retroviruses and purification

The Perth group wrote:
“…
As in any other branch of science, in retrovirology there are scientific principles and methods and rules under which retrovirology is practised. According to one of them, which is nothing more than commonsense, to claim that a protein is a retroviral protein or a fragment of RNA is the genome of a retrovirus, evidence must exist that the protein or RNA originated from viral particles.
…”

This is true, and everyone agrees with it. Where we disagree, is the exact methods by which one “proves” that the proteins are derived from viral particles.

The Perth group wrote:
“…
Until the advent of density gradient ultracentrifugation, the electron microscope and certain advances in immunology and lately molecular biology, retroviruses were defined by filtration and their biological properties. The latter were the induction of tumours by the filtrates hence their name oncoviruses or “filtrable agents”.
…”

Only a very small subset of retroviruses are oncoviruses. Most of the oncoviruses are defective and cannot replicate without the aid of a non-defective helper virus.

There are many agents that can pass through a filter and cause cancer. For example, many chemical carcinogens can pass through a filter. It was always clear that the oncogenic retroviruses differed from chemical agents, in that they can reproduce themselves, whereas chemicals cannot. A very small aliquot of supernatant from one culture can cause cancer in a new cell culture, the passage of the virus does not result in dilution, because the virus replicates in each culture.

The Perth group wrote:
“…
As far back as 1957 one well known retrovirologist, J W Beard, pointed out that the use of filtration as a method to purify retroviruses was less than satisfactory.
…”

Correct. And in later times, molecular cloning and other techniques became available which brought further improvements in the classification and other studies of viruses.

The Perth group wrote:
“…
To claim that some of the proteins in the "purified" preparations were HIV proteins and some of the RNA, "HIV" RNA ("HIV genome"), defies not only scientific reasoning but commonsense.
…”

No. You are wrong. Just because you fail to understand molecular biology, does not mean that it is not understandable.

Competing interests: None declared