SARS-CoV-2: Infection induces antibodies capable of killing infected cells
SARS-CoV-2 infection induces antibodies capable of killing infected cells regardless of disease severity
2021-04-21
(Press-News.org) Drawing on epidemiological field studies and the FrenchCOVID hospital cohort coordinated by Inserm, teams from the Institut Pasteur, the CNRS and the Vaccine Research Institute (VRI, Inserm/University Paris-Est Créteil) studied the antibodies induced in individuals with asymptomatic or symptomatic SARS-CoV-2 infection. The scientists demonstrated that infection induces polyfunctional antibodies. Beyond neutralization, these antibodies can activate NK (natural killer) cells or the complement system, leading to the destruction of infected cells. Antibody levels are slightly lower in asymptomatic as opposed to symptomatic individuals, but polyfunctional antibodies were found in all individuals. These findings show that infection induces antibodies capable of killing infected cells regardless of the severity of the disease. The research was published in the journal Cell Reports Medicine on April 21, 2021.
Nearly half of those infected with SARS-CoV-2 do not develop symptoms. Yet, the immune response induced by asymptomatic forms of COVID-19 remains poorly characterized. The extent of the antiviral functions of SARS-CoV-2 antibodies is also poorly characterized. Antibodies are capable of both neutralizing the virus and activating "non-neutralizing" functions. The latter include antibody-dependent cellular cytotoxicity (ADCC) and complement activation, which are major components of the immune response and play a key role in the efficacy of some vaccines. ADCC is a two-stage process in which infected cells are first recognized by antibodies, then destroyed by NK cells. The complement system consists of a series of plasma proteins that also enable the elimination of cells targeted by antibodies. The ability of antibodies to activate these non-neutralizing functions has been little described for SARS-CoV-2 infection so far.
The teams from the Institut Pasteur, the CNRS and the VRI (Inserm/University Paris-Est Créteil) initially developed new assays to measure the various antibody functions. They produced assays to study cell death induced by NK cells or by complement in the presence of antibodies. By analyzing cultures in real time using video microscopy, the scientists showed that NK cells kill infected cells in the presence of antibodies, demonstrating new antiviral activity employed by SARS-CoV-2 antibodies.
The scientists then examined the serum of patients with symptomatic or asymptomatic forms of COVID-19 with their new assays. They also used methods previously developed at the Institut Pasteur, such as the S-Flow assay, to detect SARS-CoV-2 anti-spike antibodies, and the S-Fuse assay, to measure the neutralization capacity of these antibodies.
"This study demonstrated that individuals infected with SARS-CoV-2 have antibodies that are capable of attacking the virus in different ways, by preventing it from entering cells (neutralization) or by activating NK cells to kill infected cells (via ADCC). We therefore use the term polyfunctional antibodies," explains Timothée Bruel, co-last author of the study and a scientist in the Institut Pasteur's Virus & Immunity Unit and at the VRI.
By comparing different groups of patients, the scientists then showed that asymptomatic individuals also have polyfunctional antibodies and that their response is slightly weaker than those of patients with moderate forms of COVID-19.
"The study reveals new mechanisms of action of SARS-CoV-2 antibodies and suggests that the protection induced by an asymptomatic infection is very close to that observed after a symptomatic infection," concludes Olivier Schwartz, co-last author of the study, head of the Virus & Immunity Unit and at the VRI.
INFORMATION:
[1] Department of Virology (CNRS/Institut Pasteur)
Watch the video microscopy of antibodies killing infected cells by activating NK cells. Infected cell is shown in green. The NK cell comes into contact with the infected cell, then destroys it. The dying cell turns red.
Link: https://www.youtube.com/watch?v=Elq5KFIUEv0
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
2021-04-21
Creativity--the "secret weapon" of Homo sapiens--constituted a major advantage over Neanderthals and played an important role in the survival of the human species. This is the finding of an international team of scientists, led by the University of Granada (UGR), which has identified for the first time a series of 267 genes linked to creativity that differentiate Homo sapiens from Neanderthals.
This important scientific finding, published today in the prestigious journal Molecular Psychiatry (Nature), suggests that it was these genetic differences linked to creativity that enabled Homo sapiens to eventually replace Neanderthals. It was creativity that gave Homo sapiens the ...
2021-04-21
Children with weakened immune systems have not shown a higher risk of developing severe COVID-19 infection despite commonly displaying symptoms, a new study suggests.
During a 16-week period which covered the first wave of the pandemic, researchers from Southampton carried out an observational study of nearly 1500 immunocompromised children - defined as requiring annual influenza vaccinations due to underlying conditions or medication. The children, their parents or guardians completed weekly questionnaires to provide information about any symptoms they had experienced, COVID-19 test results and the impact of the pandemic on their daily life.
The results, published in BMJ Open, showed that symptoms of COVID-19 infection were common in many of the children - with ...
2021-04-21
The effects of the steadily increasing amount of plastic in the ocean are complex and not yet fully understood. Scientists at GEOMAR Helmholtz Centre for Ocean Research Kiel have now shown for the first time that the uptake of microplastics by zooplankton can have significant effects on the marine ecosystem even at low concentrations. The study, published in the international journal Nature Communications, further indicates that the resulting changes may be responsible for a loss of oxygen in the ocean beyond that caused by global warming.
Plastic debris in the ocean is a widely known problem for large marine mammals, fish and seabirds. These ...
2021-04-21
The results, exceptional first time evidence of how early flocks of domesticated sheep fed and reproduced within the Iberian Peninsula, are currently the first example of the modification of sheep's seasonal reproductive rhythms with the aim of adapting them to human needs.
The project includes technical approaches based on stable isotope analysis and dental microwear of animal remains from more than 7,500 years ago found in the Neolithic Chaves cave site in Huesca, in the central Pyrennean region of Spain. The research was coordinated from the Arqueozoology Laboratory of the UAB Department of Antiquity, with the participation of researchers from the University of Zaragoza, the Museum of Natural History of Paris, and the Catalan Institute of Human Palaeocology and Social Evolution (IPHES) ...
2021-04-21
Most battery materials, novel catalysts, and storage materials for hydrogen have one thing in common: they have a structure comprised of tiny pores in the nanometer range. These pores provide space which can be occupied by guest atoms, ions, and molecules. As a consequence, the properties of the guest and the host can change dramatically. Understanding the processes inside the pores is crucial to develop innovative energy technologies.
Observing the filling process
So far, it has only been possible to characterise the pore structure of the substrate materials precisely. The exact structure of the adsorbate inside the pores has remained hidden. To probe this, a team from the HZB together with colleagues ...
2021-04-21
The natural menopause occurs when the menstrual periods cease due to the naturally decreased ovary function. There is a significant interindividual variation in the age at natural menopause but, on average, women undergo it around the age of 51 in Western countries. Furthermore, the length of the preceding menopausal transition, characterized by irregular menstrual cycles and menopausal symptoms, is also known to vary between individuals.
The study revealed that higher estradiol and follicle-stimulating hormone levels, irregular menstrual cycles, and menopausal symptoms are strong indicators of approaching menopause in middle-aged women. Additionally, information related ...
2021-04-21
DALLAS - April 21, 2021 - Food banks should be used more consistently rather than only during emergencies to better address food insecurity and related health issues, a joint study by researchers at UT Southwestern Medical Center and economists at the University of Dallas shows.
"The main discovery in our research is that encouraging clients and making it easier for clients to receive food frequently improves their food security, health, and well-being," says Sandi Pruitt, Ph.D., associate professor of population and data sciences at UT Southwestern, and senior author of the ...
2021-04-21
Perhaps no other ocean creature lives in the human imagination like the great white shark. But while great white sharks might be plentiful in the minds of beachgoers across the country, there are only a handful of places in the world where white sharks can be consistently found. In those areas -- such as Central California, Guadalupe Island Mexico, South Australia and South Africa -- they tend to be found aggregated in small hotspots, often located around seal colonies.
Researchers have estimated that white shark populations are incredibly small, with only hundreds of large adults and a few thousand white sharks total in any of their global ...
2021-04-21
UNIVERSITY PARK, Pa. -- A new approach to gene editing using the CRISPR/Cas9 system bypasses disease-causing mutations in a gene, enabling treatment of genetic diseases linked to a single gene, such as cystic fibrosis, certain types of sickle cell anemia, and other rare diseases. The method, developed and tested in mice and human tissue cultures by researchers at Penn State, involves inserting a new, fully functional copy of the gene that displaces the mutated gene.
A proof-of-concept for the approach is described in a paper appearing online April 20 in the journal Molecular Therapy.
The CRISPR/Cas9 system has allowed promising new gene therapies ...
2021-04-21
The number of solar panels within shortest distance from a house is the most important factor in determining the likelihood of that house having a solar panel, when compared with a host of socio-economic and demographic variables. This is shown in a new study by scientists using satellite and census data of the city of Fresno in the US, and employing machine learning. Although it is known that peer effects are relevant for sustainable energy choices, very high-resolution data combined with artificial intelligence techniques were necessary to single out the paramount importance of proximity. The finding is relevant for policies that aim at a broad deployment of solar panels in order to replace unsustainable ...
LAST 30 PRESS RELEASES:
[Press-News.org] SARS-CoV-2: Infection induces antibodies capable of killing infected cells
SARS-CoV-2 infection induces antibodies capable of killing infected cells regardless of disease severity
