How the first contact of the virus influences the immune response to new SARS-CoV-2 variants
2023-12-07
(Press-News.org)
Although SARS-CoV-2 is no longer a stranger to the immune system, new virus variants still pose a challenge. The working group led by Professor Dr Florian Klein, Director of the Institute of Virology at the University Hospital Cologne and the Faculty of Medicine, has now published two studies investigating how the antibody response to SARS-CoV-2 changes over time and how the immune system is preparing itself for new variants with clever strategies. The work has been published under the title ‘Enhanced SARS-CoV-2 humoral immunity following breakthrough infection builds upon the preexisting memory B cell pool’ in Science Immunology and under ‘Somatic hypermutation introduces bystander mutations that prepare SARS-CoV-2 antibodies for emerging variants" in Immunity.
In a process known as affinity maturation, antibodies can mature over time through the exchange (mutations) of individual amino acids, thus enabling them to better detect infectious pathogens. The working group led by Professor Klein has now been able to show that an Omicron infection induces a renewed immune response in vaccinated persons, which is primarily based on the reactivation of so-called memory B cells. Interestingly, the maturation process of the antibodies produced by these cells had already taken place long before Omicron emerged – so the immune system was already prepared. The results of the two studies show how strongly the first contact with SARS-CoV-2 influences the immune system and indicate the possibility that it is also prepared for future variants.
“Our first goal was to investigate how the antibody response in healthy subjects changes through a third vaccination against the original SARS-CoV-2 strain,” reports Svea Rose, a doctoral candidate and a first author. “We were initially surprised by the results. Although the third vaccination significantly increased the SARS-CoV-2 immune response overall, there was hardly any further maturation at the level of individual antibodies.” However, people who – like many – became infected with the Omicron variants BA.1 and BA.2 after vaccination were also examined. The re-analysis showed that memory B cells which were able to form antibodies neutralizing SARS-CoV-2 omicron now proliferate. “Interestingly, the immune cells directed against the Omicron variant were already present before contact with Omicron and were not induced by Omicron,” adds first author Dr Timm Weber. But that's not all: At an early stage, the researchers found so-called broad neutralizing antibodies that can neutralize all new variants which have been tested.
At the same time, the working group looked at the molecular mechanism of affinity maturation. The clock was turned back and individual antibodies, which were isolated throughout the world in the first year of the pandemic, were restored to their original state, report the two lead authors Michael Korenkov and Dr Matthias Zehner in the study published in Immunity. As a result, the researchers were able to show that some of the modifications during affinity maturation are not deliberate, but happen randomly. Surprisingly, it was precisely these random modifications that were essential for the neutralization of Omicron variants. “The immune system expands the arsenal of existing antibodies by inserting arbitrary mutations and thus increases the likelihood of having a suitable antibody in the repertoire when a new virus variant appears,” explains Dr Christoph Kreer, who led the study together with Professor Klein. The group was able to use the new biological findings to modify a therapeutic antibody that was ineffective against Omicron in such a way that it could effectively neutralize Omicron variants again.
In summary, the work shows how the human immune system reacts to a new virus and its emerging variants. The newly isolated broad neutralizing antibodies are so effective that they could also be used therapeutically and preventively against newer Omicron variants.
Publications:
https://pubmed.ncbi.nlm.nih.gov/37976348/
https://pubmed.ncbi.nlm.nih.gov/38035879/
END
ELSE PRESS RELEASES FROM THIS DATE:
2023-12-07
Sage has launched a tool to empower researchers to discover the real-world impact of their work on policy. Sage Policy Profiles lets researchers easily see specific citations of their work in policy documents and then illustrate and share that work’s impact graphically. The tool is powered by Overton, which hosts an extensive repository of global policy documents, guidelines, think-tank publications, and working papers.
The free-of-charge, browser-based tool shows researchers where their work appears in evidence-based policies, offering insights into how policymakers make use of their research. Sage Policy Profiles presents these results ...
2023-12-07
ITHACA, N.Y. – Cornell University researchers have released a new, open-source platform called Cascade that can run artificial intelligence models in a way that slashes expenses and energy costs while dramatically improving performance.
Cascade is designed for settings like smart traffic intersections, medical diagnostics, equipment servicing using augmented reality, digital agriculture, smart power grids and automatic product inspection during manufacturing – situations where AI models must react within a fraction of a second.
With the rise of AI, many companies are eager to leverage new capabilities but worried about the associated computing ...
2023-12-07
Maternal inflammation risk factors may be associated with dysregulation in children, according to a study funded by the Environmental influences on Child Health Outcomes (ECHO) Program at the National Institutes of Health. “Dysregulation” in this context refers to children’s attention, anxiety and depression, and aggression being measurably different from what is typically expected at their age.
While inflammation is a normal bodily response to injury or infection, ECHO investigators wanted to learn whether factors linked ...
2023-12-07
Around 320,000 new cases of leukaemia, a type of blood cancer that can affect all population groups, are diagnosed every year in Europe. In children, cases of leukaemia make up a third of diagnosed cancers. Chemotherapy is the main treatment for leukaemia. Often, the exact cause cannot be identified and the molecular and cellular mechanisms responsible for leukaemia remain shrouded in mystery. Discovering new detection methods and new treatments to eradicate leukaemia is therefore a major challenge in oncology.
Messenger RNA has been in the news in recent months, in connection with COVID-19 vaccinations. In an article published in Molecular Cell, researchers ...
2023-12-07
ITHACA, N.Y. – A new study of paper wasps suggests social interactions may make animals smarter. The research offers behavioral evidence of an evolutionary link between the ability to recognize individuals and social cooperation.
Furthermore, genomic sequencing revealed that populations of wasps that recognized each other – and cooperated more – showed recent adaptations (positive selection) in areas of the brain associated with cognitive abilities such as learning, memory and vision.
The study focused on two distinct populations of paper wasps (Polistes fuscatus): A southern ...
2023-12-07
Key to fatty liver disease and its consequences for billions of people
The global rise in obesity and diabetes is leading to an epidemic in fatty liver disease affecting 20-30 per cent of the world’s population. Almost a third of people with fatty liver disease go on to develop an advanced form of the disease, known as non-alcoholic steatohepatitis (NASH) that can progress to cirrhosis and end-stage liver disease, or even liver cancer, and is a major risk factor for cardiovascular disease.
Why some people remain relatively healthy with fatty liver disease and some go onto potentially life-threatening illness has been a mystery. Until now.
A study ...
2023-12-07
From the 1950s to the 1970s, a Colombian priest named Padre Gustavo Huertas collected rocks and fossils near a town called Villa de Levya. Two of the specimens he found were small, round rocks patterned with lines that looked like leaves; he classified them as a type of fossil plant. But in a new study, published in the journal Palaeontologia Electronica, researchers re-examined these “plant” fossils and found that they weren’t plants at all: they were the fossilized remains of baby turtles.
“It was truly surprising to find these fossils,” says Héctor Palma-Castro, a paleobotany student at the Universidad Nacional de Colombia.
The plants in question ...
2023-12-07
Pancreatic ductal adenocarcinoma (PDAC), that arises from pancreatic epithelial cells, is the most common form of pancreatic cancer, with a very high mortality rate. This elevated mortality is associated with the unique tumor microenvironment (TME), known for increased resistance to chemotherapy and high metastatic potential. TME is characterized by the presence of a complex stromal structure comprising cancer-associated fibroblasts (CAFs), tumor endothelial cells (TECs), and a variety of immune cells.
CAFs are specific cells, primarily involved in the overall aggressiveness and spread of cancer cells. These cells can further be categorized into several types based on their ...
2023-12-07
DALLAS, December 7, 2023 — The Tobacco Endgame — the path to ending tobacco use and nicotine addiction in the U.S. — is within sight, but there has been a sharp increase in electronic cigarette use among high school students, from 1.5% in 2011 to about 27.4% in 2019.[1]
The American Heart Association, the world’s leading nonprofit organization focused on heart and brain health for all, is collaborating with the Association for the Treatment of Tobacco Use and Dependence (ATTUD) to change that. New individual certification as a Certified Professional by the American Heart Association – Tobacco Treatment is ...
2023-12-07
A multidisciplinary study led by the Institute of Evolutionary Biology in Spain (a joint center of the Spanish National Research Council and Pompeu Fabra University), the University of Belgrade in Serbia, the University of Western Ontario in Canada, and Harvard University in the USA, reconstructs the genomic history of the Balkan Peninsula during the first millennium of the common era, a time and place of profound demographic, cultural and linguistic change. The team has recovered and analyzed whole genome data from 146 ancient people excavated primarily from Serbia and Croatia—more than a third of which came from the ...
LAST 30 PRESS RELEASES:
[Press-News.org] How the first contact of the virus influences the immune response to new SARS-CoV-2 variants
