August 14, 2020 Science Journal Essence.

!-- webeditor: page title -- August 25, 2020 // --- This week, a new issue of Science (August 14, 2020) was published. Let the little editor come with us.
images from the Journal of Science.
1.Science: Revealing the therapeutic antibody binding mechanism of the human CD20 mechanism doi:10.1126/science.abb8008 Since the late 1990s, immunotherapy has been a first-line treatment against lymphoma, using synthetic antibodies to prevent the proliferation of cancerous white blood cells.
, however, little is known about the molecular mechanisms of the therapy, which has been in use for more than 20 years.
new study, researchers from France's National Centre for Scientific Research, the Pasteur Institute and the University of Bordeaux observed for the first time the interaction between therapeutic antibodies and their target proteins.
described these molecular mechanisms, opening the way for the development of new treatments.
study was published in the August 14, 2020 issue of the journal Science under the title "Binding mechanisms of therapeutic antibodies to human CD20".
, they can be divided into two categories, depending on the number of therapeutic antibodies binding to CD20 molecules and the immune response they trigger.
the interaction between the first class of therapeutic antibodies (type 1 therapeutic antibodies) and CD20 molecules is twice that of the second class of therapeutic antibodies (type 2 therapeutic antibodies), which can trigger a cascading immune response called the "complement pathway".
, the molecular mechanism of the differences between the two therapeutic antibodies was unclear.
using cryogenic electroscopy, the researchers were able to observe for the first time at the atomic level the interaction between these two therapeutic antibodies and their target molecules.
they found that, due to the availability of space, the CD20 protein could bind to two therapeutic antibodies, but only to one type 2 therapeutic antibody.
because of the large number of therapeutic antibodies type 1 on the surface of B lymphocytes, they can form clusters.
confirmed that these clusters trigger a complement pathway, which can lead to damage to target B lymphocytes.
, on the other hand, therapeutic antibodies type 2 are sparsely dispersed on the surface of B lymphocytes and therefore do not trigger this cascading immune response.
other independent immune responses can still destroy these cells.
2.Science: Revealed protein BAF prevents cells from attacking their own DNA mechanism doi:10.1126/science.aaw6421 Virus proliferates by injecting its DNA into host cells.
once it enters the cell fluid, the foreign material triggers a defense mechanism called the cGAS-STING pathway.
a protein called cyclic GMP-AMP lysase (cGAS) is also present in liquids, binding to invading DNA to produce a new molecule.
this is then combined with another protein called STING, which induces an inflammatory immune response.
time, the substances contained in the liquid -- and those in contact with the cGAS protein -- come not from the virus, but from the cells themselves, such as after an accidental rupture of the nucleus.
when this happens, the cGAS-STING pathway is not activated.
now, in a new study, researchers from the Federal Institute of Technology (EPFL) in Lausanne, Switzerland, have confirmed how cells react differently to their DNA and genetic material from pathogens to avoid attacking the wrong targets.
their findings provide new insights into the complex processes that occur in the body's inflammatory response.
study was published in the August 14, 2020 issue of the Journal of Science under the title "BAF restricts cGAS on nuclear DNA to prevent innate immune activation".
author of the paper is Professor Andrea Ablasser of the Federal Institute of Technology in Lausanne, Switzerland.
Ablasser and his team have come up with new insights into the key role of a small protein called the Barrier-to-Autointegration Factor (BAF).
found that by binding to harmless DNA, BAF prevents cGAS proteins from binding to DNA, thereby preventing cGAS-STING pathway activation.
3. Two Scientific papers point out that IN rhesus monkeys, DNA vaccines prevent SARS-CoV-2 infections, and previous infections prevent re-infection with doi:10.1126/science.abc6284; doi:10.1126/science.abc4776 There are nearly 5 million confirmed cases and more than 300,000 deaths from COVID-19 worldwide, but there are still many unknowns about the SARS-CoV-2 virus that causes the disease.
two key questions are whether the vaccine can prevent new coronavirus SARS-CoV-2 infections and whether people who have recovered from COVID-19 can avoid re-infection.
two new studies led by researchers at The Beth Israel Deacon Medical Center (BIDMC) provide new inspiration for answering these questions.
the results of the study, published online May 20, 2020 in the journal Science, are titled "DNA vaccine protection against SARS-CoV-2 in rhesus macaques" and "SARS-CoV-2 infect protects against rechallenge in rhesus macaques".
the first study, the researchers confirmed that six candidate DNA vaccines induced a meso-antibody response in rhesus monkeys and prevented them from contracting SARS-CoV-2.
Barouch and his colleagues began working on the COVID-19 vaccine when Chinese scientists released the virus genome in mid-January, developing a series of candidate DNA vaccines that express hedgehog protein variants, among which the hedgehog protein is a key antibody target for the new coronavirus SARS-CoV-2.
these vaccines are designed to train the body's immune system to recognize and respond quickly after exposure to the virus.
!--/ewebeditor:page--!--ewebeditor:page-title" -- to assess the efficacy of these vaccines, the researchers immunized 25 adult rhesus monkeys with a research DNA vaccine and 10 other rhesus monkeys were immunized with simulated controls.
monkeys that have been vaccinated have produced antiviral mesobacterial antibodies.
three weeks after the increased vaccination, all 35 rhesus monkeys were exposed to the virus.
follow-up tests showed that the viral load of vaccinated rhesus monkeys decreased significantly compared to the control group.
of the 25 vaccinated rhesus monkeys, eight did not show detectable viruses at any point in time after exposure to the virus, while the remaining 17 had lower viral levels.
in addition, higher antibody levels are associated with lower viral loads, suggesting that the mediated antibody may be a protective factor and may prove to be a benchmark for clinical testing of the SARS-CoV-2 vaccine.
a second study, the researchers confirmed that rhesus monkeys recovered from COVID-19 produce natural protective immunity to prevent re-infection.
An individual recovering from many viral infections usually produces antibodies that prevent re-infection, but not all viral infections produce this natural protective immunity," Barouch said.
the researchers exposed nine adult rhesus monkeys to the SARS-CoV-2 virus and monitored their viral levels as they recovered.
all nine animals recovered and produced antiviral antibodies.
more than a month after the initial infection, they exposed the rhesus monkeys to the virus again.
second exposure, they almost completely prevent re-infection of the virus.
data show that this animal model has a natural protective immunity to COVID-19 after initial infection.
.4.ScienceDaily The Qinchuan team found that monkeys first infected with SARS-CoV-2 developed short-term immunity to the virus: 10.1126/science.abc5343 The new coronavirus SARS-CoV-2 (previously known as 2019-nCoV) caused the 2019 coronavirus disease (COVID-19) and is now raging around the world.
In a new study, researchers from the Institute of Experimental Zoology of the Chinese Academy of Medical Sciences, the Center for Comparative Medicine of the Concord Medical College of Beijing and the Capital Medical University reported that the rhesus monkeys infected with SARS-CoV-2 were not infected for the next 28 days.
results were published online July 2, 2020 in the journal Science under the title "Primary exposure to SARS-CoV-2 protects against the refedation in rhesus macaques".
Chuan of the Institute of Experimental Zoology of the Chinese Academy of Medical Sciences and the Comparative Medical Center of the Concord Medical College of Beijing.
Although these rhesus monkeys show initial immunity, it is not clear how long it will last in humans--- it will take months or even years to know if the millions of people infected at the start of the pandemic are protected from re-infection.
5.Science: Huntington's disease alters human neurodevelopment doi:10.1126/science.aax3338; doi:10.1126/science.abd6215 Huntington's disease (HD) is one of the four leading neurodegenerative diseases that have been studied most widely.
the disease is caused by mutations in the Huntingtin protein (HTT) coding gene.
with HD experience depression, irritability, and other neurological and behavioral problems.
may also have difficulty processing information and controlling body movements.
although HD is a late-stage neurodegenerative disease, both mouse studies and neuroimaging studies of people with pre-symptomatic mutations suggest that the disease may affect neurodevelopment.
to determine whether this was the case, researchers from France studied tissue from human fetuses carrying HD mutations (13 weeks pregnant).
study was published online July 16, 2020 in the journal Science under the title "Huntington's disease alters human neurodevelopment."
These tissues exhibit significant abnormalities in the developing cortical layer, including the misalposition of mutated HTTP proteins and junction complex proteins, defects in the polarity and differentiation of neuroprogenitor cells, abnormal filamentation, and changes in filamentation and cell cycle processes.
6.Science: New study suggests that the threshold for achieving group immunity for neo-coronary pneumonia has dropped by doi:10.1126/science.abc6810 According to a new study, hervid-19 population immunity can be achieved with fewer infections than previously estimated.
the new study, researchers from the University of Nottingham in the UNITED Kingdom and Stockholm University in Sweden designed a simple model that divided people into groups that reflect age and levels of social activity.
when differences in age and social activity were included in this model, group immunization levels decreased from 60 per cent to 43 per cent.
43% should be interpreted as an example, not an exact number, or even the best estimate.
results were published online June 23, 2020 in the journal Science under the title "A mathematical model reveals the influence of people heterogeneity on herd immunity to SARS-CoV-2".
!--/ewebeditor:page--!--ewebeditor:page title"--this study uses a new mathematical method to estimate the population's level of immunity to infectious diseases such as the current COVID-19 pandemic.
levels of immunity are defined as the proportion of the population that must develop immunity in order for the spread of the disease to decline and stop when all preventive measures (e.g. social isolation) are eliminated.
in the case of COVID-19, it is often said that this figure is about 60 per cent, based on the portion of the population that must be vaccinated to prevent large-scale outbreaks (before an epidemic occurs).
co-author of the paper, Frank Ball of the University of Nottingham.