. Scientific Frontline: Virology
Showing posts with label Virology. Show all posts
Showing posts with label Virology. Show all posts

Saturday, October 7, 2023

SARS-CoV-2 Caused More, Deadlier Cases of Sepsis Than Thought

Life-threatening systemic inflammation known as sepsis can follow infection with SARS-CoV-2 (shown in green in this colorized electron micrograph), the virus that causes COVID-19.
Image Credit: National Institute of Allergy and Infectious Diseases

New research suggests that the virus responsible for COVID-19 was a more common and deadly cause of sepsis early in the pandemic than previously assumed — accounting for about one in six cases of sepsis from March 2020 to November 2022.

The results, published online in JAMA Network Open, suggest that clinicians should rethink how they treat sepsis while also providing a framework for future surveillance of viral sepsis.

Sepsis is a serious, sometimes fatal overreaction of the immune system to an infection. Doctors and researchers don’t know as much about sepsis that occurs in response to viral infection as they do about sepsis that arises from bacterial infection.

“Most people, including medical professionals, equate sepsis with bacterial infections,” said first author Claire Shappell, HMS instructor in medicine at Brigham and Women’s Hospital. “This is reflected in treatment guidelines and quality measures that require immediate antibiotics for patients with suspected sepsis.”

Friday, October 6, 2023

Vulnerability to different COVID-19 mutations depends on previous infections and vaccination, study suggests

Image Credit: Alexandra Koch

A new study has found that people differ in how vulnerable they are to different mutations in emerging variants of SARS-CoV-2.

This is because the variant of SARS-CoV-2 a person was first exposed to determines how well their immune system responds to different parts of the virus, and how protected they are against other variants.

It also means that the same COVID-19 vaccine might work differently for different people, depending on which variants of SARS-CoV-2 they have previously been exposed to and where their immune response has focused.

The discovery underlies the importance of continuing surveillance programs to detect the emergence of new variants, and to understand differences in immunity to SARS-CoV-2 across the population.

It will also be important for future vaccination strategies, which must consider both the virus variant a vaccine contains and how immune responses of the population may differ in their response to it.

Monday, October 2, 2023

Heavily mutated SARS-CoV-2 variant BA.2.86 not as resistant to antibodies as first feared

Image Credit: Fusion Medical Animation

Researchers at Karolinska Institutet who studied SARS-CoV-2 variant BA.2.86, found that the new variant was not significantly more resistant to antibodies than several other variants that are circulating. The study also showed that antibody levels to BA.2.86 were significantly higher after a wave of XBB infections compared to before, suggesting that the vaccines based on XBB should provide some cross-protection to BA.2.86.

"We engineered a spike gene that matches that of the BA.2.86 variant and tested the blood of Stockholm blood donors (specifically those donations made very recently) to see how effective their antibodies are against this new variant. We found that although BA.2.86 was quite resistant to neutralizing antibodies, it wasn't significantly more resistant than a number of other variants that are also circulating", says Daniel Sheward, lead author of the study and Postdoctoral researcher in Benjamin Murrell's team at the Department of Microbiology, Tumor and Cell Biology at Karolinska Institutet.

Wednesday, September 27, 2023

Tiny CRISPR tool could help shred viruses

Model of a minimal CRISPR-Cas13bt3 molecule generated with a cryo-electron microscope. The RNA to be recognized and cleaved is colored in light blue, while the scissor is formed by the magenta and cyan colored domains. The two loops for controlling the CRISPR-Cas13bt3 are shown in green and red.
 Illustration Credit: Courtesy of the Yang Gao lab/Rice University

Small and precise: These are the ideal characteristics for CRISPR systems, the Nobel-prize winning technology used to edit nucleic acids like RNA and DNA.

Rice University scientists have described in detail the three-dimensional structure of one of the smallest known CRISPR-Cas13 systems used to shred or modify RNA and employed their findings to further engineer the tool to improve its precision. According to a study published in Nature Communications, the molecule works differently than other proteins in the same family.

“There are different types of CRISPR systems, and the one our research was focused on for this study is called CRISPR-Cas13bt3,” said Yang Gao, an assistant professor of biosciences and Cancer Prevention and Research Institute of Texas Scholar who helped lead the study. “The unique thing about it is that it is very small. Usually, these types of molecules contain roughly 1200 amino acids, while this one only has about 700, so that’s already an advantage.”

Monday, June 12, 2023

Gentle cleansers kill viruses as effectively as harsh soaps

Photo Credit: Maria Lin Kim

Gentle cleansers are just as effective in killing viruses – including coronavirus – as harsh soaps, according to a new study from scientists at the University of Sheffield 

Healthcare professionals often substitute alcohol-based hand sanitizers and harsh soaps for skin-friendly cleansers in order to treat or prevent irritant contact dermatitis, which develops when chemical or physical agents damage the skin surface faster than the skin can repair

Incidence and severity of irritant contact dermatitis increased from 20 per cent to 80 per cent amongst healthcare professionals during the Covid-19 pandemic

Researchers also found non-enveloped viruses such as norovirus were resistant to all hand wash products tested, and were only killed with bleach disinfectants, which aren’t a feasible option for washing hands 

Gentle cleansers are just as effective in killing viruses – including coronavirus – as harsh soaps, a new study by University of Sheffield experts has found.

Friday, June 9, 2023

Bat-Borne Sarbecoviruses Spilled Over in Southeast Asia Pre-Pandemic

Elephant loggers bring in a timber harvest in Myanmar.
Photo Credit: Tierra Smiley Evans/UC Davis

A virus previously found only in bats was detected in the antibodies of people screened for exposure to sarbecoviruses between 2017 and 2020 in rural Myanmar in Southeast Asia, according to a study from the University of California, Davis and collaborators in Myanmar and Singapore. The work is published in the International Journal of Infectious Diseases.

Sarbecoviruses are a group of coronaviruses. This study found exposure to diverse sarbecoviruses, including some known to be closely related to SARS-CoV-2, such as RaTG13.

The study found that people were significantly more likely to have been exposed to sarbecoviruses if their livelihood involved working directly with or close to bats, such as logging, hunting or harvesting bat guano.

“This study provides new evidence that bat-borne coronaviruses can and do spill over to people, underscoring the importance of surveillance in high-risk rural areas, where humans and wildlife closely interact,” said lead author Tierra Smiley Evans, an epidemiologist and research faculty with the One Health Institute in the UC Davis School of Veterinary Medicine.

Thursday, June 8, 2023

Long Covid can impact fatigue and quality of life worse than some cancers

Photo Credit: engin akyurt

Fatigue is the symptom that most significantly impacts the daily lives of long Covid patients, and can affect quality of life more than some cancers, finds a new study led by researchers at UCL and the University of Exeter.

The research, published in BMJ Open and funded by the National Institute for Health and Care Research (NIHR), examines the impact of long Covid on the lives of over 3,750 patients who were referred to a long Covid clinic and used a digital app as part of their NHS treatment for the condition.

Patients were asked to complete questionnaires on the app about how long Covid was affecting them – considering the impact of long Covid on their day-to-day activities, levels of fatigue, depression, anxiety, breathlessness, brain fog, and their quality of life.

The researchers found that many long Covid patients were seriously ill and on average had fatigue scores worse or similar to people with cancer-related anemia or severe kidney disease. Their health-related quality of life scores were also lower than those of people with advanced metastatic cancers, like stage IV lung cancer.

Overall, the team found that the impact of long Covid on the daily activities of patients was worse than that of stroke patients and was comparable to that of patients with Parkinson’s Disease.

COVID-19 can cause brain cells to ‘fuse’

Fused neurons in yellow, expressing Spike S fusogen from the SARS-CoV-2 virus and the human receptor hACE2.
Image Credit: Courtesy of University of Queensland

Researchers at The University of Queensland have discovered viruses such as SARS-CoV-2 can cause brain cells to fuse, initiating malfunctions that lead to chronic neurological symptoms.

Professor Massimo Hilliard and Dr Ramon Martinez-Marmol from the Queensland Brain Institute have explored how viruses alter the function of the nervous system.

SARS-CoV-2, the virus that causes COVID-19, has been detected in the brains of people with ‘long COVID’ months after their initial infection.

“We discovered COVID-19 causes neurons to undergo a cell fusion process, which has not been seen before,” Professor Hilliard said.

“After neuronal infection with SARS-CoV-2, the spike S protein becomes present in neurons, and once neurons fuse, they don’t die.”

Tuesday, June 6, 2023

Scientists closing in on long-lasting swine flu vaccine

 A team led by Eric Weaver, associate professor of biological sciences, has developed a robust vaccine against a strain of swine influenza. Framed by a model of nucleic acid proteins is (from left) Weaver; Matt Pekarek, a graduate student in the Weaver Lab; Cedric Wooledge, a technician with the Institutional Animal Care Program; David Steffen, with the Nebraska Veterinary Diagnostic Center; and Nicholas Jeanjaquet and Erika Petro-Turnquist, both doctoral students in the Weaver Lab. Not pictured is Hiep Vu, assistant professor in the Nebraska Center for Virology and Department of Animal Science.
Photo Credit: Craig Chandler | University Communication and Marketing

A successful long-term experiment with live hogs indicates Nebraska scientists may be another step closer to achieving a safe, long-lasting and potentially universal vaccine against swine flu.

The results are not only important to the pork industry, they hold significant implications for human health. That’s because pigs act as “mixing vessels,” where various swine and bird influenza strains can reconfigure and become transmissible to humans. In fact, the 2009 swine flu pandemic, involving a variant of the H1N1 strain, first emerged in swine before infecting about a fourth of the global population in its first year, causing nearly 12,500 deaths in the United States and perhaps as many as 575,000 worldwide, according to the Centers for Disease Control and Prevention.

“Considering the significant role swine play in the evolution and transmission of potential pandemic strains of influenza and the substantial economic impact of swine flu viruses, it is imperative that efforts be made toward the development of more effective vaccination strategies in vulnerable pig populations,” said Erika Petro-Turnquist, a doctoral student and lead author of the study recently published in Frontiers in Immunology.

To Prevent Future Pandemics, Leave Bats Alone

Photo Credit: Clement Kolopp

A new paper in the journal The Lancet Planetary Health makes the case that pandemic prevention requires a global taboo whereby humanity agrees to leave bats alone—to let them have the habitats they need, undisturbed.

Like the SARS coronavirus outbreak of 2003, the COVID-19 pandemic can be traced back to a bat virus. Whether someone handled or ate an infected bat or was exposed to a bat’s bodily fluids in a cave or some other way, or was exposed to another animal that had been infected by a bat, we will quite likely never know. Even a virus released via a lab accident would still have originally come from a bat. But we don’t need to know all of the details in order to act.

Bats are known to be reservoirs for a wide range of viruses that can infect other species, including people. They are a source of rabies, Marburg filoviruses, Hendra and Nipah paramyxoviruses, coronaviruses such as Middle East Respiratory Syndrome (MERS) Coronavirus, and fruit bats are strongly believed to be a source of Ebolaviruses. A new analysis points to the value of a global taboo whereby humanity agrees to leave bats alone—not fear them or try to chase them away or cull them (activities that only serve to disperse them and increase the odds of zoonotic spillover)—but to let them have the habitats they need and live undisturbed.

Researchers Identify Genetic Makeup of New Strains of West Nile

This study shows the variety of strains in circulation and what mosquitoes may be carrying as we head into summer
Photo Credit: Jimmy Chan

Researchers at Connecticut Veterinary Medical Diagnostic Laboratory (CVMDL) located in UConn’s College of Agriculture, Health and Natural Resources identified the genetic makeup of strains of West Nile virus found in an alpaca and a crow.

These findings were published in Frontiers in Veterinary Science.

In 2021, eight cases of West Nile virus were brought to the CVMDL for diagnosis – seven birds, both domestic and wild – and one alpaca.

“We decided to pursue some research avenues through these diagnostic cases because we had an interesting cohort of West Nile cases that had come through that fall,” says Natalie Tocco ’23 (CAHNR), a resident in anatomic pathology the Department of Pathobiology and Veterinary Science.

Of the eight cases, the alpaca from Massachusetts and a crow from Connecticut had the highest amount of virus in their systems at the time of diagnosis.

Focusing on these two cases, the researchers were interested in seeing if there were genetic differences between the viruses because they occurred in different species in different states.

Wednesday, May 17, 2023

New study explains how a common virus can cause multiple sclerosis

Olivia Thomas and Mattias Bronge
Photo Credit: Erik Holmgren

Researchers at Karolinska Institutet have found further evidence for how the Epstein-Barr virus can trigger multiple sclerosis or drive disease progression. A study published in Science Advances shows that some individuals have antibodies against the virus that mistakenly attacks a protein in the brain and spinal cord.

The Epstein-Barr virus (EBV) infects most people early in life and then remains in the body, usually without causing symptoms. The link between EBV and the neurological disease multiple sclerosis (MS) was discovered many years ago and has puzzled researchers ever since. Increasing evidence, including two papers published in Science and Nature last year, suggests that EBV infection precedes MS and that antibodies against the virus may be involved. However, the molecular mechanisms seem to vary between patients and remain largely unknown.

“MS is an incredibly complex disease, but our study provides an important piece in the puzzle and could explain why some people develop the disease,” says Olivia Thomas, postdoctoral researcher at the Department of Clinical Neuroscience, Karolinska Institutet and shared first author of the paper. “We have discovered that certain antibodies against the Epstein-Barr virus, which would normally fight the infection, can mistakenly target the brain and spinal cord and cause damage.”

Tuesday, May 16, 2023

Monkeypox viruses relatively stable on surfaces

Cleaning surfaces with alcohol-based disinfectant is a good protection against infection.
Photo Credit: © RUB, Marquard

The virus remains infectious on steel surfaces for up to 30 days, but can be effectively deactivated by alcoholic disinfectants.

Pockenviruses are known to remain infectious in the area for a very long time. A study by the Molecular and Medical Virology Department at the Ruhr University Bochum showed that the temperature is very important: at room temperature, it can take up to eleven days until there is no longer a reproductive monkeypox virus on a stainless-steel surface, at four degrees Celsius even up to a month. Accordingly, it is particularly important to disinfect surfaces. According to the study, alcoholic disinfectants work well against monkeypox viruses. However, hydrogen peroxide-based disinfectants are not sufficiently effective. The team reports in Journal of infectious diseases.

Weekly observation

Since 2022, the monkey pox virus has been spreading from person to person. Even if the infection is primarily due to direct physical contact, it is possible to infect yourself via contaminated surfaces, for example in the household or in hospital rooms. "Pockenviren is known to remain infectious in the area for a very long time," explains Dr. Toni Meister from the Department of Molecular and Medical Virology at Ruhr University. “So far we have not known the exact times for monkey pox."

Monday, May 15, 2023

Phage structure captured for the first time, to benefit biotech applications

Phage image
Image Credit: Dr Vicki Gold et al, Nature Communications

New insights into the structure of phages will enable researchers to develop new uses for viruses in biotechnology.

Phages are viruses that infect bacteria, which enables them to be exploited as tools in biotechnology and medicine. Now, for the first time, researchers at the University of Exeter, in collaboration with Massey University and Nanophage Technologies, New Zealand, have mapped out what a commonly-used form of phage looks like, which will help researchers design better uses in future.

One common use for phage is phage display, which is a useful tool in drug discovery. Phage display works by linking a gene fragment of interest to a phage gene that makes one of the phage coat proteins. The new coat protein with the linked protein of interest appears on the surface of the phage, where it can be assayed and tested for biological activity.

Billions of types of phages exist. Phage display often uses a type of phage known as filamentous, so called because they are long and thin, making the display of many proteins across its surface possible. Although phage display and other applications have proved successful, until now, scientists have not known what this type of phage looks like.

Gene-edited calf may reduce reliance on antimicrobials against cattle disease

 Brian Vander Ley, associate professor in the University of Nebraska–Lincoln’s School of Veterinary Medicine and Biomedical Sciences, works with Ginger, a Gir cow gene-edited with resistance to bovine viral diarrhea virus.
Photo Credit: Craig Chandler | University Communication and Marketing

Cattle worldwide face major health threats from a highly infectious viral disease that decades of vaccinations and other precautions have failed to contain. Federal, private-sector and Husker scientists are collaborating on a new line of defense, by producing a gene-edited calf resistant to the virus.

If follow-up research confirms its efficacy, the gene-editing approach offers long-term potential to reduce antimicrobial and antibiotic use in the cattle industry.

The bovine viral diarrhea virus devastates the bovine immune system and can cause severe respiratory and intestinal harm to infected beef and dairy cattle, said veterinary epidemiologist Brian Vander Ley, an associate professor in the University of Nebraska–Lincoln’s School of Veterinary Medicine and Biomedical Sciences.

In utero calves are especially vulnerable to infection. If they survive, they can remain infected for life, repeatedly spreading the virus to other cattle.

“They show up as normal cattle but really, they’re shedding a tremendous amount of virus. They’re the ‘Typhoid Marys’ of BVDV spread,” said Vander Ley, assistant director of UNL’s Great Plains Veterinary Educational Center in Clay Center.

Thursday, May 11, 2023

A multiomics approach provides insights into flu severity

Photo Credit: Andrea Piacquadio

Have you ever wondered why some people might get sicker than others, even when they catch the same virus? It is not yet clear why this is. Viral factors (such as differences in the strain of a virus) play a role in this variability, but they cannot account for the wide range of responses in different individuals infected by the same virus. A number of host factors have also been considered, including pre-existing immunity, age, sex, weight, and the microbiome.

Another important factor is the molecular biology within your cells. DNA is shown as one long double-helical strand. So, you might expect that the cell would always read genetic information in order, starting at one end and going to the other. But this isn’t the case. DNA contains transposable elements, sometimes called “junk DNA,” which can change the regions of the genome that are being read at a given time.

The work published in Cell Genomics by an international team led by Dr. Guillaume Bourque, who studied the role of these transposable elements on the severity of illness after influenza A virus infection.

Ancestral mitoviruses discovered in mycorrhizal fungi

Arbuscular mycorrhizal (AM) fungi in the Glomeromycotina colonize plant roots (left, micrograph) and deliver water and nutrients from soil (right).
Image Credit: Tatsuhiro Ezawa

A new group of mitochondrial viruses confined to the arbuscular mycorrhizal fungi Glomeromycotina may represent an ancestral lineage of mitoviruses.

Mitochondria are organelles in the cells of almost all eukaryotes — organisms with cells that have a nucleus. They were originally free-living bacteria capable of generating energy in the presence of oxygen; then engulfed by an ancestral eukaryotic cell where they became mitochondria, the site of cellular respiration and many important metabolic processes. In humans, dysfunctions of mitochondria are associated with aging and many diseases.

Bacteriophages are viruses that infect bacteria. As former bacteria, there are also viruses that infect mitochondria, known as mitoviruses, which evolved from bacteriophages. While mitoviruses have been found in fungi, plants, and invertebrates, they are not well studied.

Associate Professor Tatsuhiro Ezawa at Hokkaido University, Professor Luisa Lanfranco at University of Torino, and Dr. Massimo Turina at National Research Council of Italy (CNR) Torino led an international team to discover a new group of mitoviruses, called large duamitoviruses. Their findings were published in the journal mBio.

Monday, May 8, 2023

Study sheds light on how the immune system protects the body

Photo Credit: RDNE Stock project

Researchers explore how patients with a rare and severe immunodeficiency were still able to defend themselves normally against viruses, including COVID-19

The first study of humans with a rare immunodeficiency reveals how the immune system protects the body against pathogens known to cause serious diseases, such as tuberculosis and COVID-19. The research involving McGill University, paves the way for new therapies to treat autoimmune diseases, chronic inflammatory diseases, and new approaches to vaccine development.

The immune system responds differently to various types of pathogens, like bacteria, parasites, and viruses. However, scientists are still trying to uncover how this complex network functions together and the processes that can go wrong with immunodeficiencies.

“The immune system plays a vital role in protecting the body from harmful germs that make people ill. It’s made up of a complex network of organs, cells, and proteins – like IRF1 or regulatory factor 1, which is key in the regulation of an early immune response to pathogens,” says co-author of the study David Langlais, an Assistant Professor in the Departments of Human Genetics and Microbiology and Immunology at McGill University.

Sunday, April 30, 2023

Scientists Identify Antivirals that Could Combat Emerging Infectious Diseases

Aedes aegypti mosquito.
Photo Credit: Pixabay

A new study has identified potential broad-spectrum antiviral agents that can target multiple families of RNA viruses that continue to pose a significant threat for future pandemics. The study, led by Gustavo Garcia Jr. in the UCLA Department of Molecular and Medical Pharmacology, tested a library of innate immune agonists that work by targeting pathogen recognition receptors, and found several agents that showed promise, including one that exhibited potent antiviral activity against members of RNA viral families.

The ongoing SARS-CoV-2 pandemic, which has claimed nearly seven million lives globally since it began, has revealed the vulnerabilities of human society to a large-scale outbreak from emerging pathogens. While accurately predicting what will trigger the next pandemic, the authors say recent epidemics as well as global climate change and the continuously evolving nature of the RNA genome indicate that arboviruses, viruses spread by arthropods such as mosquitoes, are prime candidates. These include such as Chikungunya virus (CHIKV), Dengue virus, West Nile virus and Zika virus. The researchers write: “Given their already-demonstrated epidemic potential, finding effective broad-spectrum treatments against these viruses is of the utmost importance as they become potential agents for pandemics.”

In their new study, published in Cell Reports Medicine, researchers found that several antivirals inhibited these arboviruses to varying degrees. “The most potent and broad-spectrum antiviral agents identified in the study were cyclic dinucleotide (CDN) STING agonists, which also hold promise in triggering an immune defense against cancer,” said senior author Vaithi Arumugaswami, Associate Professor in the UCLA Department of Molecular and Medical Pharmacology and a member of the California NanoSystems Institute.

Wednesday, April 26, 2023

A 'cocktail' of human antibodies shows promise in fighting severe SARS-CoV-2 infections

Antibody 2A10 (yellow shades) and antibody 1H2 (blue shades) were isolated from a vaccinated research volunteer. The LJI team found these two antibodies can neutralize many SARS-CoV-2 variants.
Illustration Credit: Saphire Lab, La Jolla Institute for Immunology.

An anonymous San Diego resident has become a fascinating example of how the human immune system fights SARS-CoV-2. In a new investigation, scientists from La Jolla Institute for Immunology (LJI) have shown how antibodies, collected from this clinical study volunteer, bind to the SARS-CoV-2 “Spike” protein to neutralize the virus.

Although studies have shown antibodies bound to Spike before, this new research reveals how the original Moderna SARS-CoV-2 vaccine could prompt the body to produce antibodies against the later Omicron variants of SARS-CoV-2. The researchers also captured highly detailed, 3D structures of three promising neutralizing antibodies bound to Spike.

This important work shows exactly where Spike is vulnerable to human antibodies—and how future vaccines and antibody therapeutics might exploit these weaknesses. In fact, studies in mice suggest some of these antibodies may help prevent severe cases of COVID-19.

“To blunt the next pandemic and protect people from seasonal re-emergence of this one, we need antibodies of the broadest possible capacity—ones that are not escaped,” says LJI President and CEO Erica Ollmann Saphire, Ph.D., senior author of the new Cell Reports study. “We found those in a vaccinated San Diegan.”

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