Re: Re: Re: Show me the photo please 24 June 2004
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Brian T Foley,
HIV Researcher
Los Alamos National Lab, Los Alamos, NM 87545

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Re: Re: Re: Re: Show me the photo please

Chris Tyler wrote:
“…
While those are interesting pictures, they can't be 'HIV' because of the date of publication (1981). In addition, these appear to be cell-culture EMs.
…”

Chris Noble did not say that they were EMs of HIV. He only asked Pennee if those photos would meet her criteria for retroviruses. They are EMs of HTLV-I.

Chris Tyler wrote:
“…
To quote from the Tahi/Montagnier:
DT: When one looks at the published electron microscope photographs, for you as a retrovirologist it is clear it's a retrovirus, a new retrovirus?
LM: No, at that point one cannot say. With the first budding pictures it could be a type C virus. One cannot distinguish.
…”

Correct. That is what I have been attempting to convince the Perth group for several years now; that photographs of viruses are not very useful. It is difficult to tell one retrovirus from another by EM, and impossible to tell one lentivirus from another by EM.

Chris Tyler wrote:
“…
However, since we're talking about a lentivirus, where are the gp120 spikes? We've all scene artistic renditions of 'HIV' showing gp120 spikes studding the surface (which we're told of course are quite necessary for infection). It would be highly beneficial to see pictures of:
…”

Can you explain exactly why you think that looking at photos of viruses is “highly beneficial”?

Chris Tyler wrote:
“…
a: 'HIV' with gp120 spikes.
…”

The gp120 part of the envelope protein is attached to the virus particle by very weak forces. Thus, ultracentrifugation tears the gp120 off from most of the viruses. Gp120 spikes are seen in many EMs of viruses in cell culture, such as those shown by Hans Gelderblom in his review of HIV structure.
This BMJ site seems to always break my links, so here is the URL:
http://www.hiv.lanl.gov/content/hiv-db/REVIEWS/Gelderblom.html

Chris Tyler wrote:
“…
b. 'HIV' with all the other morphological characteristics said to be that of a lentivirus.
…”

There really are not that many morphological characteristics that distinguish lentiviruses from other complex retroviruses. The dense cone-shaped (not quite cylindrical) core of mature virus particles may not be unique to lentiviruses, there are still thousands of other retroviruses that have never been very carefully studied by EM. Exactly which morphological characteristics of lentiviruses have not been shown by EM? If they were not shown by EM, how were they shown?

Chris Tyler wrote:
“…
b: 'HIV' from the density gradients. Should be no problem considering it's been claimed this is 'purified, labeled virus' material.
…”

See the papers by Bess et al and Gluschankof et al (1,2).

Chris Tyler wrote:
“…
c. 'HIV' from fresh, uncultured (no oxidising agents, PHA, etc.) blood. Since if a person is given a viral load test, and said to have a high viral load, that person is told he has a lot of virus swimming around his blood. Why not take that person's high viral load blood and find these gp120 spiked, 100-120nm with cylindrical core particles with an electron micrograph?
…”

I am not enough of an electron microscopist to know the answer to that. The Spectra papers that the Perth group gets all excited about (3,4) talk about pretty large cell cultures like 80 liters, which is far more than the volume of blood in a single human, but I suppose one could pool all the plasma from several people who have died of AIDS, or a liter from each of 80 living people, to obtain that sort of volume. The Spectra papers also mention that viruses with very high titers were used, and HIV-1 viral loads in plasma would certainly not be considered to be high titer. Plasma viral loads in humans are typically less that 105 virus particles per ml, whereas many retroviruses reach titers of over 100-fold that high in cell cultures (5). If virus concentration is a major factor in this, then maybe 8,000 liters of human plasma is needed, instead of 80 liters.

After the initial peak of viremia that is observed post-infection but pre-seroconversion in HIV-infected people, most of the virus produced by cells is rapidly bound to antibodies and degraded. Virus-antibody complexes would need to be disrupted prior to centrifugation, and this can probably be done in such a way that does not also disrupt the virus envelope, but I am not sure.

But the major answer here is that photographs of viruses just don’t tell us much about the virus. The pBJ series of SIV-SMMs look exactly like the parental strain, but they have extreme ranges of pathogenicity in Rhesus macaques (6). Looking at the virus tells us nothing, only by swapping genes from clones of the highly pathogenic viruses for genes from clones of the less pathogenic viruses, can we begin to understand which genomic regions contribute to the observed pathogenicity (7).

REFERENCES:

1: Bess JW, Gorelick RJ, Bosche WJ, Henderson LE, Arthur LO.
Microvesicles are a source of contaminating cellular proteins found
in purified HIV-1 preparations.
Virology 1997;230:134-144.

2: Gluschankof P, Mondor I, Gelderblom HR, Sattentau QJ.
Cell membrane vesicles are a major contaminant of gradient-enriched
human immunodeficiency virus type-1 preparations.
Virology 1997;230:125-133.

3: Sinoussi F, Mendiola L, Chermann JC.
Purification and partial differentiation of the particles of murine sarcoma
virus (M. MSV) according to their sedimentation rates in sucrose density
gradients.
Spectra 4: 237-243 (1973).

4: Toplin I.
Tumor Virus Purification using Zonal Rotors.
Spectra 4: 225-235 (1973).

5: Hlavaty J, Stracke A, Klein D, Salmons B, Gunzburg WH, Renner M.
Multiple modifications allow high-titer production of retroviral vectors
carrying heterologous regulatory elements.
J Virol. 2004 Feb;78(3):1384-92.
PMID: 14722293

6: Fultz PN, McClure HM, Anderson DC, Switzer WM.
Identification and biologic characterization of an acutely lethal variant
of simian immunodeficiency virus from sooty mangabeys (SIV/SMM).
AIDS Res Hum Retroviruses. 1989 Aug;5(4):397-409.
PMID: 2765298

7: Novembre FJ, Johnson PR, Lewis MG, Anderson DC, Klumpp S,
McClure HM, Hirsch VM.
Multiple viral determinants contribute to pathogenicity of the acutely
lethal simian immunodeficiency virus SIVsmmPBj variant.
J Virol. 1993 May;67(5):2466-74.
PMID: 8474153

Competing interests: None declared