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Good news!
In the face of the menacing Delta mutation, human beings have the latest scientific research results:
Sinopharm announced that the new monoclonal antibody discovered is effective against the Delta variant strain!
Indicators of effectiveness of reactive antibodies neutralize the activity IC₅₀ up to 5ng/ml.
The lower this value, the better, which is equivalent to the drug suppressing half of the virus at a concentration of only 5 ng/ml.
The paper was published in The Nature sub-journal Cell discovery.
Netizens who heard the news have said: I don't know how to be conscious!
So today, let's sort out what this is all about
<h1 class="pgc-h-arrow-right" data-track="10" >What is a monoclonal antibody? </h1>
Let's start with antibodies, which are proteins secreted by immune cells, and each different antibody is responsible for recognizing the characteristics of a foreign invader (also called an antigen).
Simply put, it is the appearance of a protruding part of the surface of the antigen at one end, encountering just enough to wrap it up, and then notifying the phagocytes to destroy it.
If there is an immune cell that can secrete antibodies against the Delta variant, find a way to get it to continue to secrete this antibody.
This is done by hybridizing immune cells that secrete specific antibodies with a type of myeloma cell that multiplies indefinitely.
The resulting hybridoma cells inherit the ability of the parent cells, and once successfully prepared, they can continuously produce exactly the same monoclonal antibodies.
Monoclonal antibodies, which accurately identify and destroy specific antigens, are also known as "biological missiles" and were seen in the early stages of the pandemic as one of the most promising options for combating COVID-19 infection.
Monoclonal antibodies have their own advantages over vaccines.
Vaccines are injected antigens to stimulate you to produce corresponding antibodies, which can play a long-term effect and preventive effect, but not in time.
Monoclonal antibodies are direct injections of antibodies that have produced a good effective antibody, but the maintenance time is short, suitable for emergency treatment.
<h1 class="pgc-h-arrow-right" data-track="20" > antibody 2B11 is effective against Delta virus</h1>
So in response to this Delta variant, what new discoveries did the Chinese legion make in terms of monoclonal antibodies?
The core technology is the phage display technology.
Bacteriophages are viruses that invade bacteria. Based on the growth characteristics of the phage, the phage display technology is to insert selected gene fragments into the gene region of the phage shell protein in a directional manner.
This allows the selected gene to be expressed with the expression of the coat protein and displayed on the surface of the phage.
The researchers collected serum samples of 8 patients who had recovered from COVID-19 infection, 10 ml each, and isolated peripheral blood mononuclear cell PBMCs.
(Peripheral blood mononuclear cells, that is, any peripheral blood cells that contain nuclei, including lymphocytes and monocytes.) Peripheral blood, on the other hand, is blood that does not include bone marrow. ）
The team used serum samples to determine RBD-specific antibody titers, and donors exhibited RBD-specific antibodies of different titers. Of these, two individuals have a potency of more than 1,000.
(Antibody titer, as an important marker of specific antibody biological activity, reflects the binding ability of specific antibodies to antigens.) ）
On the other hand, two immune libraries were established using PMBC to produce genetic raw materials, and three rounds of screening were carried out using target antigens.
The researchers found that the antibody 2B11 has a strong ability to neutralize the original and three virus variants.
Among them facing the original virus, antibody 2B11 neutralizes the activity IC50 up to 5ng/ml.
The other variants, B.1.1.7, B.1.351, and P.1, were the main variants in South Africa, the United Kingdom, and Brazil, respectively, and the neutralization activity of IC50 was 12.23ng/ml, 5091.00ng/ml, and 2527.00ng/ml, respectively
To further understand the mechanism behind 2B11's powerful neutralization capabilities, the researchers parsed the crystal structure of 2B11-Fab.
Crystal structure analysis data showed that sequence alignment showed that the heavy chain of mAb 2B11 was similar to the heavy chain of other SARS-CoV-2 nAbs previously reported.
Moreover, the RBD epitope recognized by 2B11 overlaps highly with the binding site of ACE2, which can effectively block the binding of the new coronavirus to the ACE-2 on the cell surface, thereby preventing it from infecting cells.
Finally, to assess the prophylactic and therapeutic abilities of this monoclonal antibody, the researchers conducted two sets of controlled trials. One group is mice severely infected with the new coronavirus.
This was achieved by attacking mice with the new coronavirus through intranasal routes, monitoring their body weight and measuring the viral load in the lungs over a 6-day period.
The results showed that the administration of 2B11 before or after attacking the virus significantly reduced the weight loss caused by viral infection and the viral load of the lungs.
It is shown that the administration of 2B11 can significantly reduce the lung inflammation caused by viral infection.
Recent supplementary experiments have shown that 2B11 also has a highly consistent neutralizing activity against The Delta strain, neutralizing the activity IC50 up to 5ng/ml, and even higher than other variant strains.
The researchers said that at present, the clinical declaration of the 2B11 antibody is being promoted in an orderly manner, with a view to using it for the prevention and control of the relevant new crown epidemic in China as soon as possible.
<h1 class="pgc-h-arrow-right" data-track="42" > is expected to replace convalescent plasma therapy</h1>
If the development goes well, then it is expected to replace convalescent plasma therapy in the first place.
By infusing the convalescent plasma of the recovered person, the patient is given antibodies against the new crown virus.
However, this approach has several limitations.
One is the need for blood group matching between patients and convalescents.
Second, the plasma donated by convalescent patients is limited after all, and the patients cured by this method do not have the ability to produce antibodies themselves, so they cannot become the next round of plasma donors, and it is easy to have plasma supply.
It is precisely because of the limitations of these aspects that this method is mainly aimed at patients with severe infection.
Monoclonal antibodies can be mass-produced quickly and are safer than plasma therapy.
< h1 class="pgc-h-arrow-right" data-track="50" > research team</h1>
Finally, let's take a look at the team behind it.
The project was completed by Sinopharm Group member company China Biologics in cooperation with the Shanghai Advanced Research Institute of the Chinese Academy of Sciences and the Wuhan Institute of Virology of the Chinese Academy of Sciences.
The corresponding author of the paper is Yang Xiaoming, a researcher of China Biology, and the first author is Dr. Pan Yongbing, Antibody Research Office of Wuhan Institute of Biological Products.
In addition to the progress in monoclonal antibody research, there is another piece of good news.
Shenzhen Kangtai Biological Products Co., Ltd. also announced the successful isolation of multiple Delta variants of monoclonal poisons.
This will be followed by preparations for the production of an inactivated COVID-19 vaccine against the Delta variant.
Address of thesis:
https://www.nature.com/articles/s41421-021-00295-w
Reference Links:
[1]http://www.detaibio.com/topics/monoclonal-antibody-structure.html
[2]https://mp.weixin.qq.com/s/HYM7IUz7uVujCZwb5HcpVg
[3]http://www.xinhuanet.com/world/2020-08/23/c_1126402161.htm
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