Researchers design tools to develop vaccines more efficiently for African swine fever virus (ASFV)

The reverse-genetics system developed for ASFV may be adapted for other viruses, including lumpy skin disease, Zika, chikungunya, and Ebola viruses

International Livestock Research Institute

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An electron micrograph of an African swine fever virus particle

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Credit: Kati Franzke, Friedrich Loeffler Institute

Rockville, Maryland—March 26, 2024—Researchers from the J. Craig Venter Institute (JCVI), the Friedrich-Loeffler-Institut (FLI), and the International Livestock Research Institute (ILRI) have developed a reverse genetics system for African swine fever virus (ASFV). This new system will aid researchers in developing vaccines and in studying the pathogenesis and biology of ASFV, a highly contagious, deadly viral disease affecting domesticated and wild pigs, especially prevalent in Africa, Europe, Asia, and the Caribbean. A recent study estimates if ASFV reached the United States it could result in economic losses exceeding $50 billion over a ten-year period.

JCVI Professor Sanjay Vashee, Ph.D., senior author on the paper remarked, “By developing a synthetic genomics-based reverse genetics system for ASFV, we are not only advancing our understanding of this virus but also creating tools that can be applied to other emerging viral threats. This research has the potential to significantly reduce the economic losses caused by ASFV in the global swine industry, providing much-needed solutions to control and prevent the spread of the disease.”

The reverse genetic system allows scientists to quickly generate genetically modified versions of ASFV and involves several steps. First, scientists construct synthetic DNA, which is a lab-made version of the virus’s genetic material. Fragments of ASFV are modified and then assembled into full-length genomes in yeast using its recombination machinery. The modified genomes are then transferred to E. coli which makes isolating them in larger amounts possible.

The synthetic DNA is then transfected (or artificially introduced) into mammalian host cells which are subsequently infected with a self-helper virus. This self-helper virus is an inhibited version of ASFV which has been modified using CRISPR/Cas9 technology, a powerful gene-editing tool that can precisely cut DNA at specific locations. The alterations ensure that the self-helper virus cannot replicate on its own. Despite this inhibition, the self-helper virus still provides the necessary proteins and machinery required for the synthetic DNA to replicate and assemble into new virus particles.

This process results in the production of live recombinant viruses that contain the specific genetic modifications introduced in the synthetic DNA. These recombinant viruses can then be used for further study or vaccine development.

"Globally, ASF outbreaks have caused devastating economic losses amounting to billions of dollars, severely impacting the pork industry, food security, and livelihoods. In Africa, the impact could be dire given the presence of multiple genotypes of the virus and the widespread lack of adequate biosecurity measures to control the disease,” said Dr. Hussein Abkallo, a researcher at ILRI and one of the authors of the paper. “This platform gives hope of developing new, targeted vaccines that can protect animal health to reduce mortality as well as the environmental footprint of the livestock sector by preventing unnecessary losses."

The synthetic genomics-based reverse genetics system developed for ASFV can be applied to other viruses with non-infectious genomes, offering significant potential for research and vaccine development. For example, it could be applied to lumpy skin disease virus, a double-stranded DNA virus that primarily affects cattle causing significant economic harm.

This methodology could also be adapted for emerging RNA viruses such as Zika, chikungunya, Mayaro, and Ebola viruses, which have caused significant outbreaks and pose serious threats to global health. By leveraging synthetic genomics, researchers can rapidly develop reverse genetics tools for these and new emerging viruses, facilitating the study of their biology and the creation of effective vaccines and treatments.

In addition to Dr. Vashee, the study team included senior author Lucilla Steinaa, Ph.D. (ILRI) and first authors Walter Fuchs, Dr. rer. nat. (FLI) and Nacyra Assad-Garcia (JCVI). The complete study, “A synthetic genomics-based African swine fever virus engineering platform,” may be found in the journal Science Advances. Funding for this work was provided by the International Development Research Centre (IDRC) Livestock Vaccine Innovation Fund (LVIF), phase I 108514 and phase II 109212.

 

About J. Craig Venter Institute

The J. Craig Venter Institute (JCVI) is a not-for-profit research institute in Rockville, Maryland and La Jolla, California dedicated to the advancement of the science of genomics; the understanding of its implications for society; and communication of those results to the scientific community, the public, and policymakers. Founded by J. Craig Venter, Ph.D., JCVI is home to approximately 120 scientists and staff with expertise in human and evolutionary biology, genetics, bioinformatics/informatics, information technology, high-throughput DNA sequencing, genomic and environmental policy research, and public education in science and science policy. JCVI is a 501(c)(3) organization. For additional information, please visit www.jcvi.org.

Healthy pigs at ILRI’s Clinical Research Facility.

Credit

ILRI

About ILRI

The International Livestock Research Institute (ILRI) is a non-profit institution working with partners worldwide to enhance the roles that livestock play in food security and poverty alleviation, principally in Africa and Asia. ILRI’s mission is to improve food and nutritional security and to reduce poverty in developing countries through research for efficient, safe and sustainable use of livestock—ensuring better lives and planet through livestock. www.ilri.org

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Journal

Science Advances

DOI

10.1126/sciadv.adu7670 

Article Title

A synthetic genomics-based African swine fever virus engineering platform

Article Publication Date

26-Mar-2025

 

How survivors spanned the globe after Earth’s biggest mass extinction

Stanford University

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Scientists don’t call it the “Great Dying” for nothing. About 252 million years ago, upward of 80% of all marine species vanished during the end-Permian mass extinction – the most extreme event of its kind in Earth’s history. 

What followed was a mysterious, multimillion-year span that could be called the “Great Dulling,” when marine animal communities looked remarkably alike all over the planet, from the equator to the poles. Researchers have long sought an explanation for this so-called taxonomic homogenization – a scene that played out after other mass extinctions over the past half-billion years.

Now, Stanford researchers have shown that profound environmental change likely provided the means for select survivors of the end-Permian extinction to dramatically expand their ranges. The researchers focused on the marine animal fossil record – the most complete evidence of the extinction’s aftermath – and created a model that predicted how creatures like clams, oysters, snails, and slugs flourished in suddenly warmer, less-oxygenated waters. The findings – published in Science Advances on March 26 – offer insight into life’s recovery not only in bygone eras but also for the present, ongoing mass extinction wrought by human activity.

“For us in the paleobiology field, this model is the equivalent to climate scientists getting computerized climate models to make quantitative predictions of how the world should change based on some simple mathematical representations,” said senior study author Jonathan Payne, the Dorrell William Kirby Professor of Earth and Planetary Sciences in the Stanford Doerr School of Sustainability. “We are now able to study big biogeographic changes of mass extinctions in a new way and get a better sense of why some animal groups made it through while others perished.”

Reconstructing the past

In addition to the fossil record, scientists understand ancient oceans based on naturally occurring chemical markers that reveal past temperatures and environmental conditions. Toward the end of the Permian period, the planet was reeling from cataclysmic volcanic activity in modern-day Siberia, which ushered in intense global warming, oxygen depletion, and ocean acidification that killed most marine organisms 252 million years ago. 

But the extinction alone doesn’t explain the bizarre presence of its surviving species – previously constrained to certain specific locations – in every ocean across the globe in the millions of years that followed, known as the earliest Triassic geological period. To convey the surreal concept of taxonomic homogenization on a planetary scale, lead study author Jood Al Aswad, a PhD candidate in Earth and planetary sciences, offered a modern analogy with land animals: 

“If someone asked you today where you’d find kangaroos, you’d say Australia,” she says. “But now imagine some major disaster happened, like a giant volcano erupted, and afterward you’re finding kangaroos in great numbers all over the globe – they’re all the way out in Antarctica, they’re hopping by the pyramids in Egypt, and they’re even in Stanford, California.”

Fossils before and after the end-Permian extinction “go from richly diverse communities to almost boringly alike communities, wherever you look,” Payne said. According to the research, the variety of species across different parts of the world was reduced by more than half after the extinction event.

Setting up shop all over

Researchers have debated the cause of these stark fossil record differences for nearly 200 years and, in recent decades, proposed multiple mechanisms for why different locations had remarkably similar inhabitants following the end-Permian extinction. 

One hypothesis is “ecological release,” where the die-offs of certain predator and competitor creatures allow one surviving group of organisms to go gangbusters. Another common theory is that the climate changes in ways that produce a favorable environment for the same few organism groups just about everywhere.

The study authors put these hypotheses to the test, using geochemical data that provides information about ancient ocean oxygen levels and temperature conditions to build a climate model for end-Permian environmental change in the oceans. 

They then applied data from physiological experiments on living marine invertebrate animals such as clams and snails that are related to the survivors and victims of the Great Dying to populate a climate model with simulated species. These virtual species were able to respond to environmental changes of the end-Permian era based on their ability to survive alterations in temperature and oxygen availability. In this way, the model provided a “physiology-only” evaluation of how species’ geographical distribution would be expected to change if oxygen and temperature were the main drivers of where species could go. 

The results show that the hardy clique of mollusks monopolizing the marine fossil record in the Great Dying’s aftermath were indeed well suited for the conditions of the changed world. As a result, the model did not even have to consider ecosystem-level factors such as loss of predators and competitors, which might have also played a secondary role.

“Our study has provided a simple environmental explanation, rather than an ecological one, for why certain survivors of the end-Permian extinction prospered and why homogenization happened on a global scale,” Payne said. 

Views into the future

In addition to illuminating the deep past, the new model can also help scientists and policymakers predict and better understand the presently unfolding biodiversity crisis, an impending mass extinction caused by the planet-altering activities of billions of humans.

“The current biodiversity crisis is anticipated to herald changes in ecosystem composition that surpass even those seen in the earliest Triassic, which has been the greatest homogenization event to date,” the study authors wrote.

Al Aswad, Payne, and colleagues are now extending their model to examine other past mass extinctions, such as the end-Cretaceous event that famously wiped out the non-avian dinosaurs. 

“Our model offers a great way of studying how animals respond to extreme changes in the environment,” Al Aswad said. “With anthropogenically spurred climate change, there has been some warning that if we continue, then in the future we’re going to see taxonomic homogenization of organisms in modern oceans as well.”

Other Stanford co-authors of the study are Pedro Monarrez (previously a postdoctoral fellow at Stanford and now an assistant professor at Virginia Tech) and Mohamad Bazzi, a current postdoctoral scholar in Payne’s lab. Justin Penn and Curtis Deutsch from Princeton University are also co-authors. The research was supported by funding from the National Science Foundation.

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Journal

Science Advances

DOI

10.1126/sciadv.adr4199 

Article Title

Physiology and climate change explain unusually high similarity across marine communities after end-Permian mass extinction

Article Publication Date

26-Mar-2025

 

Even in egalitarian Sweden, a "culture of silence" may prevent university staff and students from reporting sexual harassment

PLOS

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Even in egalitarian Sweden, a "culture of silence" may prevent university staff and students from reporting sexual harassment, with just an 8.1% reporting rate for students who had experienced either rape or attempted rape.

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Article URL: https://plos.io/4bW0elh

Article title: What determines the ‘culture of silence’? Disclosing and reporting sexual harassment among university employees and students at a large Swedish public university

Author countries: Sweden

Funding: This work was funded by the Swedish Research Council, grant number 2018-02457, main applicant AA. URL: https://www.vr.se/english.html The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

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Journal

PLOS One

DOI

10.1371/journal.pone.0319407 

 

Data from the Healthy Minds Study of 140 college campuses in the US suggests that religiousness may be protective against symptoms of depression in students, although less so in sexual minorities

PLOS

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Article URL: https://plos.io/3XwiyM6

Article Title: Religiousness, sexual orientation, and depression among emerging adults in U.S. higher education: Findings from the Healthy Minds Study

Author Countries: Spain, United Kingdom, United States

Funding: The authors received no specific funding for this work.

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Journal

PLOS Mental Health

DOI

10.1371/journal.pmen.0000004 

Article Publication Date

26-Mar-2025

 

Cleaning microplastics

New water microcleaners self-disperse, capture microplastics and float up for removal

North Carolina State University

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The system that captures microplastics from water functions in a single cycle.

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Credit: Image courtesy of Orlin Velev, NC State University.

In a new paper, researchers at North Carolina State University show proof of concept for a system that, in a single cycle, actively removes microplastics from water.

The findings, described in the journal Advanced Functional Materials, hold the potential for advances in cleansing oceans and other bodies of water of tiny plastics that may harm human health and the environment. 

“The idea behind this work is: Can we make the cleaning materials in the form of soft particles that self-disperse in water, capture microplastics as they sink, and then return to the surface with the captured microplastic contaminants?” said Orlin Velev, the S. Frank and Doris Culberson Distinguished Professor of Chemical and Biomolecular Engineering at NC State and corresponding author of the paper. 

“We demonstrated how multiple principles can be integrated into a system that works in a single cycle.”

The research starts with soft dendritic colloids – unique, hierarchically-branched soft particles with distinct properties such as the ability to stick to just about any surface – which can be created from a variety of polymers.

Velev and Ph.D. student Haeleen Hong, the paper’s first author, say these particles’ sticky nature can attract microplastics and grab them – even in wet and salty conditions, like ocean water.

“The cleansing particles in this research are made from chitosan, a biodegradable polymer originating from chitin, which comes from processed shellfish waste,” Velev said. He adds that using environmentally safe materials that already come from the sea makes the process more sustainable. 

Soft dendritic colloids take the shape of small pellets when dried in droplets suspended over a water-repellent surface. When dropped into water, particles in the pellets separate and spread out to hunt microplastics. But first the researchers infuse a bit of eugenol, a plant-based oil, on one section of the pellet as a dispersant.

“This oil makes the pellets move in the water by the so-called ‘camphor boat effect,’ decreasing the surface tension on one side of the pellet and driving it forward. This allows our microcleaners to spread out across a larger area, capturing microplastics as they move and descend,” Hong said.

To make the return trip to the water’s surface, the microcleaners also contain small particles of magnesium, which makes them bubble up and rise to the surface when reacting with water.

To delay this return trip, the researchers coat the magnesium with an environmentally safe gelatin layer that blocks the magnesium’s reaction with water. Essentially, thicker coats of the gelatin delay the particles from rising to the surface, allowing the microcleaners to pick up more microplastics as they swirl and descend in water.

“As the gelatin dissolves, the magnesium generates bubbles and the microcleaners rise, bringing the captured plastics particles to the surface in a dense, scummy mixture,” Hong said. The paper shows that the particles can “swim” and collect microplastics for up to 30 minutes. The microplastic-laden microcleaners that have floated up to the water surface can then be collected by skimming.

“Potentially, the collected scum can be bioprocessed into more chitosan, which can then be used to create more microcleaners in order to capture more microplastics,” Velev said. Scaling up the process will take further investigations, the researchers say.

Former NC State Ph.D. student Rachel Bang co-authored the paper, along with current NC State Ph.D. student Lucille Verster. 
      
Funding by the National Science Foundation under grants EFMA-2029327, CMMI-2233399 and DMR-2243104 supported the research.

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Note to editors: An abstract of the paper follows.

“Designing of self-dispersing soft dendritic microcleaners for microplastics capture and recovery”

Authors: Haeleen Hong, Rachel S. Bang, Lucille Verster and Orlin D. Velev, North Carolina State University

Published: March 25, 2025, in Advanced Functional Materials

DOI: 10.1002/adfm.202423494

Abstract: The recovery of persistent microplastics (MPs) from aquatic systems is a pressing environmental issue that is hard to address by conventional methods such as filtration or centrifugation. Strategies are investigated for the design of the self-dispersal and collection cycle of a class of active microcleaners comprising soft dendritic colloids (SDCs). The SDCs are made of chitosan and have a hierarchical fibrillar structure which enables adhesive collection of MP particles through van der Waals attraction. Wide-scale dispersion is achieved by agglomerating the SDCs into larger supraparticles, which self-propel on the water surface by the Marangoni effect driven by small amounts of organic oil. The cycle of propulsion, rehydration, and sinking enables efficient MP capture by the sedimenting SDCs. Further, magnesium hydrolysis reaction timed by encapsulation leads to vertical bubble propulsion and collection of the SDC-MPs aggregates on the surface. Overall, the results present a proof of concept of the potential of comprehensive MP cleanup methods based on sustainable self-dispersing microcleaners.

Microcleaners attract and capture microplastics in water.

Credit

Image courtesy of Haeleen Hong, NC State University.

Journal

Advanced Functional Materials

DOI

10.1002/adfm.202423494 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Designing of self-dispersing soft dendritic microcleaners for microplastics capture and recovery

Article Publication Date

25-Mar-2025

New evidence links microplastics with chronic disease

Places with higher concentrations of microplastics see higher rates of hypertension, diabetes, stroke and other noncommunicable diseases

American College of Cardiology

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Tiny fragments of plastic have become ubiquitous in our environment and our bodies. Higher exposure to these microplastics, which can be inadvertently consumed or inhaled, is associated with a heightened prevalence of chronic noncommunicable diseases, according to new research being presented at the American College of Cardiology’s Annual Scientific Session (ACC.25).

Researchers said the new findings add to a small but growing body of evidence that microplastic pollution represents an emerging health threat. In terms of its relationship with stroke risk, for example, microplastics concentration was comparable to factors such as minority race and lack of health insurance, according to the results.

“This study provides initial evidence that microplastics exposure has an impact on cardiovascular health, especially chronic, noncommunicable conditions like high blood pressure, diabetes and stroke,” said Sai Rahul Ponnana, MA, a research data scientist at Case Western Reserve School of Medicine in Ohio and the study’s lead author. “When we included 154 different socioeconomic and environmental features in our analysis, we didn’t expect microplastics to rank in the top 10 for predicting chronic noncommunicable disease prevalence.”

Microplastics—defined as fragments of plastic between 1 nanometer and 5 millimeters across—are released as larger pieces of plastic break down. They come from many different sources, such as food and beverage packaging, consumer products and building materials. People can be exposed to microplastics in the water they drink, the food they eat and the air they breathe.

The study examines associations between the concentration of microplastics in bodies of water and the prevalence of various health conditions in communities along the East, West and Gulf Coasts, as well as some lakeshores, in the United States between 2015-2019. While inland areas also contain microplastics pollution, researchers focused on lakes and coastlines because microplastics concentrations are better documented in these areas. They used a dataset covering 555 census tracts from the National Centers for Environmental Information that classified microplastics concentration in seafloor sediments as low (zero to 200 particles per square meter) to very high (over 40,000 particles per square meter). 

The researchers assessed rates of high blood pressure, diabetes, stroke and cancer in the same census tracts in 2019 using data from the U.S. Centers for Disease Control and Prevention. They also used a machine learning model to predict the prevalence of these conditions based on patterns in the data and to compare the associations observed with microplastics concentration to linkages with 154 other social and environmental factors such as median household income, employment rate and particulate matter air pollution in the same areas.

The results revealed that microplastics concentration was positively correlated with high blood pressure, diabetes and stroke, while cancer was not consistently linked with microplastics pollution. The results also suggested a dose relationship, in which higher concentrations of microplastic pollution are associated with a higher prevalence of disease. However, researchers said that evidence of an association does not necessarily mean that microplastics are causing these health problems. More studies are required to determine whether there is a causal relationship or if this pollution is occurring alongside another factor that leads to health issues, they said.

Further research is also needed to determine the amount of exposure or the length of time it might take for microplastics exposure to have an impact on health, if a causal relationship exists, according to Ponnana. Nevertheless, based on the available evidence, it is reasonable to believe that microplastics may play some role in health and we must take steps to reduce exposures, he said. While it is not feasible to completely avoid ingesting or inhaling microplastics when they are present in the environment, given how ubiquitous and tiny they are, researchers said the best way to minimize microplastics exposure is to curtail the amount of plastic produced and used, and to ensure proper disposal.

“The environment plays a very important role in our health, especially cardiovascular health,” Ponnana said. “As a result, taking care of our environment means taking care of ourselves.”

Ponnana will present the study, “Microplastic Concentration, Social, and Environmental Features and Their Association with Chronic Disease Prevalence: An Analysis Across U.S. Census Tracts,” Sunday, March 30, 2025, at 9:00 a.m. CT / 14:00 UTC in Moderated Poster Theater 2.

In a separate study presented at ACC.25, researchers from a different group reviewed the scientific literature and found that studies showed a strong correlation between microplastics in plaques in the heart’s arteries and the risk of adverse cardiovascular events, suggesting that the presence of microplastics could play a role in the onset or exacerbation of serious heart problems. Eesha Nachnani of the University School of Nashville will present the study, “Plastic Perils: The Hidden Threat of Microplastics in Cardiovascular Health,” on Monday, March 31, 2025, at 9:00 a.m. CT / 14:00 UTC in South Hall.

ACC.25 will take place March 29-31, 2025, in Chicago, bringing together cardiologists and cardiovascular specialists from around the world to share the newest discoveries in treatment and prevention. Follow @ACCinTouch, @ACCMediaCenter and #ACC25 for the latest news from the meeting.

The American College of Cardiology (ACC) is the global leader in transforming cardiovascular care and improving heart health for all. As the preeminent source of professional medical education for the entire cardiovascular care team since 1949, ACC credentials cardiovascular professionals in over 140 countries who meet stringent qualifications and leads in the formation of health policy, standards and guidelines. Through its world-renowned family of JACC Journals, NCDR registries, ACC Accreditation Services, global network of Member Sections, CardioSmart patient resources and more, the College is committed to ensuring a world where science, knowledge and innovation optimize patient care and outcomes. Learn more at ACC.org.

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