Top AIDS Team's New Crown Research: A Rare Antibody Repeatedly Suggests Vaccine Clues

The entry of new coronaviruses into cells depends on the virus's S protein (spikeprotein) binding domain (RBD) to human cell receptorsAlthough there is no new coronavaccine, antibodies are critical to global fightagainCurrently, a top AIDS research team has extracted, identified antibodies from the plasma of new coronary healers, and found high school and active, rare but recurrent RBD-specific antibodiesThis suggests that a vaccine based on the antibody may be generally effective in the general publicthe discoveries come from a new coronaantibody study by Rockefeller University, California Institute of Technology, Howard Hughes Medical Institution, Chan Zuckerberg Biohub, published by bioRxiv, a medical preprint website: ConvergentAntibody ResponsestoSARS-CoV-2 Infectionin InfectionsThe paper was published on May 15, local time, by Michel Nussenzweig and Professor Paul Bieniasz, Director of theLaboratory of MolecularImmunology at Rockefeller University in the United Statesas a leading researcher in the field of AIDS, Nussenzweig's research focuses on the molecular mechanisms of the immune system's inherent and adaptive response, combining biochemistry, molecular biology andgeneticHe focuses on B lymphocytes and HIV-1 antibodiesIn response to the COVID-19 outbreak, Nussenzweig has expanded its research to SARS-CoV-2 and isolated and identified effective neutralizing antibodies from the body of recovering patientsanother correspondent, Professor Paul Bieniasz, is also a leading academic in the field of AIDSHis research seeks to define how host genes affect the replication of viruses, focusing on human and primate immunodeficiency virusesIts lab is dedicated to characterizing the host function of virus imitation, manipulation, and other uses, as well as to protect cells from the evolution of virus infectionsMay 13 local time, Mike Ryan, head of the WHO's health emergency program, said the new coronavirus could be a long-term problem, making it difficult to predict when it would be defeated and could become an epidemic that would never go awayCiting AIDS as an example, Ryan points out that while HIV has not gone away, humans have found treatments and prevention, and people are no longer as fearful of AIDS as they used to be Attached: Research methods the S protein of the new coronavirus is responsible for binding to human receptors invasion, which is often an important target for drug development During infection, the S protein is cracked by host protease (e.g TMPRSS2) into N-end S1 subunit and C-side S2 subunit, S1 and S2, respectively, mediated receptor binding and membrane fusion S1 contains the N-end domain (NTD) and the receptor binding domain (RBD), which is critical in determining the tissue-to-host and host range When the virus invades the human body, RBD binds to the human receptor ACE2 (angiotensin conversion enzyme 2) But little is known about the human response to antibodies to SARS-CoV-2 For the study, the team reported 68 COVID-19 rehabilitation patients, none of whom were hospitalized The distribution of plasma collected 30 days after the onset of symptoms varied over the semi-maximum and titer range, ranging from undetectable (18% of the sample) to less than 1:1000 (78% of the sample), with only 3% of the patients being more than 1:5000 antibody clones show edavesed RBD-specific memory B cells (expressions of closely related antibodies) in different individuals Although plasma titer is low, the semi-suppressed concentration of antibodies to unique epitopes on RBD can be neutralised as low as ng/mL levels Thus, most individuals who are not hospitalized and recover from COVID-19 do not contain high levels of moderate activity in their restorative plasma However, rare but recurrent RBD-specific antibodies with effective antiviral activity have been found in all individuals tested, suggesting that vaccines developed based on such antibodies may be generally effective between 1 April and 17 April 2020, 73 eligible participants entered the study Of these, 48 (65.8 per cent) were new coronary patients diagnosed through RT-PCR ("cases") and 25 (34.2 per cent) were close contacts with diagnosed cases ("contacts") Five cases of close contacts with out symptoms were excluded from further analysis by the time samples were collected , the 68 had been without any symptoms for at least 14 days Only one SARS-CoV-2 nucleic acid test was positive for asymptomatic people, and the other 67 participants had an average duration of onset approximately 30 days (17 to 48 days) prior to sample collection In this queue, the symptoms lasted an average of 10 days (0-28 days) and were not hospitalized The most common symptoms were fever (82.4%), cough (64.7%), myalgia (55.9%) and fatigue (54.4%), while combined diseases were rare (8.8%) There was no significant difference between sex, between cases and contacts, the duration or severity of symptoms, or between the time the symptoms struck and the time the sample was collected Of the plasma samples tested , 88% and 66% showed IgG and IgM antibodies against RBD specificity (above at least 2 standard deviations in the control group) However, igG and IgM antibody responses against tripolymer S proteins in plasma samples were only 40% and 21% (higher than at least 2 standard deviations in the control group) There was no significant difference between IgG and IgM antibody levels and how long the samples were collected, age, sex, case or contact after onset In contrast, the binding of IgG antibodies to RBD and S proteins was directly related to the duration of symptoms, but the binding of IgM antibodies to RBD and S proteins was not associated with the duration of symptoms Finally, there was little difference between the sexes in the level of antibodies to the S protein, but the effect of igG binding antibodies on RBD was lower in women than in men To measure the neutralizing activity of restorative plasma, the researchers used a pseudo-viral assay using HIV-1-based virus particles and SARS-CoV-2S proteins that carry nano-
fluorerase report genes The overall level of mid-to-activity in queues as measured by the semi-maximum median value (NT50) is generally low, at 18% that cannot be detected, and 78% for those below 1000 The geometric average of NT50 is 212 (arithmetic mean s 850), and only 2 people have NT50 above 5000 Studies have found that neutrality activity is associated with the duration of symptoms and the severity of symptoms, but not the time of sample collection associated with the onset of symptoms, age, gender, or case/contact status It is worth noting that the level semen of IgG antibodies combined with RBD and S is closely related to NT50 To determine the nature of antibodies triggered by SARS-CoV-2 infection, the researchers used a flow cytometer to isolate B lymphocytes with binding RBD receptors from the blood of six participants, including two patients with the best antibody neutralization The frequency of antigen-specific B cells was determined by their ability to bind to algal hemoglobin (PE) and BV711-labeled RBD, and the cycle B cell range during COVID-19 recovery was 0.07 to 0.005%, but could not be detected in the control group The researchers obtained 534 pairs of IgG heavy chains and light chains (IGH and IGL) sequences from a single RBD binding B cell from six recovering individuals using reverse transcription and PCR Compared with the human antibody bank, the IGH and IGL genes are significantly out of standard The average number of Nucleotide mutations in iGH and IGL's V gene is 4.2 and 2.8, respectively, which is lower than antibodies cloned from individuals with chronic infections, such as hepatitis B or HIV-1, and similar to antibodies derived from primary malaria infection or non-antigen-rich circulating IgG memory cells , like other human pathogens, there are amplification clones of antigen-binding B-cells in all tested COVID-19 individuals Overall, 32.2% of the restored IGH and IGL sequences came from cloned amplification B cells (range 21.8-57.4%) Antibodies that shared specific combinations of IGHV and IGLV genes in different individuals accounted for 14% of all cloned sequences It is worth noting that some antibodies found in different individuals have almost identical amino acid sequences For example, amino acid sequences of cloned antibodies with IGHV1-58/IGKV3-20 and IGHV3-30-3/IGKV1-39, repeatedly found in different individuals, were as homogenous as 99% and 92% The researchers concluded that igG memory reactions to SARS-CoV-2RBD were highly abundant in the antibody sequence of periodic cloning amplification to examine the binding properties of anti-SARS-CoV-2 antibodies, the researchers expressed 34 representative antibodies, 24 from cloning and 10 from monomers (3 participants found in plasma) ELISA analysis showed that 94% (32 of 34 antibodies) were combined with SARS-CoV-2RBD at a semi-maximum effective concentration of 6.6 ng/mL (EC50) To determine whether these antibodies are neutralizing, the researchers tested the SARS-CoV2-Strunc pseudovirus Of the 32 RBD binding antibodies tested, 20 were found to have a small neutralizing concentration of half-maximum inhibitory concentrations (IC50) of the ng/ml order of magnitude, ranging from 4.4 to 709 ng/ml Effective neutralizing antibodies were found in individuals, independent of plasma NT50 For example, C002 and C121 were obtained from individuals with plasma NT50 values of 5053 and 298, respectively, and C002 and C121, respectively, and IC50 was 8.9 and 6.7 ng/mL, respectively Finally, cloning of antibodies with shared IGHV and IGLV genes is one of the best neutralizing agents, such as the antibody C002 with IGHV3-30/IGKV1-39, both of which have the best plasma neutralization activity The researchers concluded that even people with moderate plasma neutrality had rare IgG memory B cells that produced effective SARS-CoV-2 neutralizing antibodies to determine whether neutralized human anti-SARS-CoV-2 monoclonal antibodies can be combined to different domains on RBD, the researchers conducted a two-layer interferometry experiment in which a pre-formed antibody-RBD immunocompound was exposed to a second monoclonal antibody The antibodies tested consisted of 2 groups, while C002 and C105 were combined with the pre-formed C121-RBD complex, while C104, C110 and C119 did not The conclusion is that, like SARS-CoV, there are at least two different middle and epitopes on the RBD of SARS-CoV-2 through single-cell edmortic cloning, individuals have obtained human monoclonal antibodies that neutralise pathogens such as viruses and parasites in natural infections Several effective protection and treatments have been shown in model biology and early clinical studies, but only one antiviral monoclonal drug is currently being used in clinical use Antibodies are relatively expensive and more difficult to produce than small-molecule drugs However, they differ from the drug in that they can participate in the host immune system through a constant domain of the fc receptor on the host immune cell These interactions can boost immunity and help clear pathogens or infected cells, but they can also lead to increased dengue and coronavirus infections This problem hinders the development of the dengue vaccine, but does not interfere with the clinical application of effective neutralizing antibodies, which can be modified to prevent the interaction of fce receptors and maintain protection against viral pathogens antibodies are essential elements of most vaccines and may be a key component of an effective vaccine against SARS-CoV-2 Observations showthat that most patients with recovery period have low plasma neutrality activity, but antibodies with effective neutralizing activity of anti-SARS-CoV-2RBD recurrence can be found in plasma and patients with abnormal activity, indicating that humans have an intrinsic ability to produce anti-RBD-effective antibodies to neutralise SARS-CoV-2 Therefore, a vaccine that specifically and effectively induces antibodies targeted at SARS-CoV-2RBD may be particularly effective (
Bio valley Bioon.com)