Posted on 04/06/2020 8:57:47 AM PDT by Biggirl
The answer begins at 23:00 in that video I just sent you...
Yeah that’s all very interesting. But the S-spike that can infect human ACE2 receptors has been found occuring naturally in pangolins. Which is why they are thought to be the origin of the SARS-2 virus. Pangolins were a popular delicacy in the Wuxan fish market. The Horseshoe bats that carry a similar SARS virus don’t have all of the features of the pangolin virus spike and they aren’t found in Wuxan anyway.
https://www.virology.ws/2020/02/20/pangolins-and-the-origin-of-sars-cov-2-coronavirus/
Pangolins and the origin of SARS-CoV-2 coronavirus
A coronavirus related to SARS-CoV-2 has been isolated from Malayan pangolins illegally imported into Guangdong province. It is not the precursor of SARS-CoV-2, but comparison of viral genome sequences provides further evidence that the virus currently infecting humans was not produced in a laboratory.
There are two important sequences in the viral spike glycoprotein (pictured) that are important for tracing the origin of SARS-CoV-2: a furin cleavage site (discussed last week) and the receptor binding domain (RBD).
The results of experiments in cells in culture have shown that the SARS-CoV-2 spike glycoprotein binds the cell receptor ACE2. Six amino acids in the RBD are critical for binding to this receptor. Five of these six amino acids differ in the RBD of SARS-CoV-2 compared with sequence from the bat virus RaTG13, the most closely related virus. The SARS-CoV-2 spike glycoprotein binds ACE2 with high affinity, an outcome not predicted by computational analysis of the RBD sequence. If someone were to engineer an RBD into a bat SARS-like CoV to allow efficient infection of human cells, they would not use the amino acid sequence in the SARS-CoV-2 spike. Rather the specific sequence was likely selected during replication in cells with human-like ACE2.
As discussed previously, the furin cleavage site in the SARS-CoV-2 spike is not present in the bat virus RaTG13. Its acquisition could allow enhanced infection of human cells. In addition to the furin cleavage site, an extra proline is also present, a change predicted to lead to the addition of O-linked glycans in the vicinity. If someone were to engineer the furin cleavage site into the spike, it is not likely that the extra proline would have been included. Furthermore, the addition of such glycans typically occurs under immune selection.
The genome sequences of CoVs recently isolated from pangolins are not close enough to SARS-CoV-2 to have been its immediate progenitor. However, the RBD of these pangolin CoVs are identical to that of SARS-CoV-2 at 6 of 6 of the key amino acids discussed above. This observation indicates that passage of CoV in a host with human-like ACE2 could select for a RBD with high-affinity binding. Such passage could also select for insertion of the furin cleavage site, which is not present in pangolin CoVs. Once a virus with the appropriate RBD and furin cleavage site arose in an animal – a bat or intermediate host – it would then replicate once introduced into humans.
Another possibility is that viruses with the correct RBD have been repeatedly jumping into humans, but efficient human to human transmission was not established until the acquisition of the furin cleavage site. Such is the scenario with MERS-CoV, which has jumped multiple times from camels to humans, but each chain of infection is short and soon ends. The virus has never become established in humans because the required mutations have not entered the viral genome. Serological surveys specific for SARS-CoV-2 might test this hypothesis for its emergence.
Could laboratory passage of a bat SARS-like virus lead to isolation and accidental emergence of SARS-CoV-2? This scenario would require starting with a virus that is very close to the current isolates. Passage in cell culture might have selected for the RBD amino acid changes to enable high affinity ACE2 binding. However this virus would have had to be very similar to SARS-CoV-2, and no such isolate is known to be present in any laboratory. Selection of viruses with a furin cleavage site would likely have taken extensive passaging in cells. Finally, it is unlikely that the O-linked glycan addition site would have emerged without immune pressure, which is absent in cell cultures.
Proving or disproving any of these hypotheses for the emergence of SARS-CoV-2 might never be possible. Nevertheless, isolation of SARS-like viruses from a variety of animals might help to clarify the steps to emergence in humans. For MERS-CoV, a priority should be to prevent human infections, perhaps by immunizing camels, to avoid the emergence of another epidemic CoV with sustained transmission in humans.
Forget pangolins, civets, etc; that may be where it originated — still not clear as China controls the data — but it’s been recombined in the Wuhan P4 Lab, strengthened and loosed on the world. The animals are in the distant past now. It’s Bio Warfare.
“but it’s been recombined in the Wuhan P4 Lab”
There is zero evidence for that. No American bioweapons professional has made that claim. It’s coming entirely from the amateur rumor mill.
You either missed it from the expert testimony, or you didn’t watch the video all the way thru. Watch it again; the statement is around the 23:00 mark.
You need to stop worshiping at the Hatfill Shrine.
I trust the International Experts, in that video, much more than the dummy Hatfill, who let himself stupidly get taken-in by the FBI during the Anthrax Scare in 2001-02.
“You need to stop worshiping at the Hatfill Shrine.”
Yeah why pay attention to someone who worked with bioweapons at Ft Detrick? What could he know compared to ... who is it that you are citing as your go-to expert?
“I trust the International Experts, in that video, much more than the dummy Hatfill, who let himself stupidly get taken-in by the FBI during the Anthrax Scare in 2001-02.”
Of course you do. And it sounds more like you need to stop worshipping the FBI and DOJ:
“In 2008, the government settled Hatfill’s lawsuit with a $4.6 million annuity totaling $5.8 million in payment.. The government officially exonerated Hatfill of any involvement in the anthrax attacks, and the Justice Department identified another military scientist, Bruce Edward Ivins, as the sole perpetrator of the anthrax attacks”
Oops.
Judy A/Mikovits, PhD, who preceded Hatfill at Ft Dietrich, in Bio R&D, in 1980. She’s light years ahead of him.
Watch the video and learn something.
I don’t trust the FBI or DoInjustice, but they buffaloed the Hatfill chump, even though he was eventually exonerated.
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