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

Thursday, February 15, 2024

Targeting inflammation to tackle long covid

Illustration Credit: Gerd Altmann

Overactivation of the immune system leading to circulation of inflammatory proteins around the body contributes to the development of long covid, and could be targeted to provide treatments for patients, finds new research.

Cardiff University research has uncovered biological markers that could be targeted by repurposing medication to treat long covid.

The research conducted extensive analysis of plasma samples obtained from a large cohort of healthy post-covid individuals and non-hospitalized patients with long covid. They found that the complement system – a system that plays a crucial part of the immune system, consisting of a group of proteins that work together to enhance the function of antibodies and immune cells – was commonly overactivated in those with long covid.

“The covid-19 pandemic has left a global legacy of ill health, with long covid estimated to affect up to 1.9 million people in the UK. Long covid can last for months or years after the triggering infection and is associated with diverse symptoms including brain fog, chest pain, breathlessness, fatigue, and sensory problems. The causes of this disease remain largely unknown, emerging evidence suggests an important role for chronic inflammation."
Professor Paul Morgan 'Professor of complement biology, Division of Infection and Immunity

Sunday, December 24, 2023

New COVID vaccine induces good antibody response to mutated viral variants

Photo Credit: CDC

Researchers at Karolinska Institutet and Danderyd Hospital have followed recipients of the new updated COVID-19 vaccine and analyzed the antibody response to different SARS-CoV-2 variants. The results show a surprisingly strong response to the now dominant and highly mutated Omicron variants.

The ongoing COMMUNITY study, which was launched in the spring of 2020 with the regular testing of 2,149 members of the Danderyd Hospital staff, has recently published the results of this autumn’s leg of the study. Twenty-four participants were recorded in this study, the majority of whom were over 64 and had received four or five previous vaccine doses. The article has been peer-reviewed and accepted for publication in the scientific journal The Lancet Infectious Diseases, and is accessible prior to publication on the preprint server, bioRxiv.

Friday, December 15, 2023

Deadly chicken disease: ancient DNA reveals evolution of virulence

With the increase in poultry farming, Marek's disease virus evolved
Photo Credit: Heidi-Ann Fourkiller

Using genetic analyses, an international team led by LMU paleogeneticist Laurent Frantz has revealed the evolutionary history of the pathogen of a fatal disease in chickens.

A notifiable animal disease in Germany, Marek’s disease is caused by the globally distributed Marek’s disease virus (MDV). Over the past century, the virus, which causes tumors in chickens and has a high mortality rate, has become increasingly aggressive. Combating the disease costs the poultry industry over a billion dollars every year. With the help of ancient DNA, an international team of scientists led by LMU paleogenomicist Professor Laurent Frantz and Professor Greger Larson and Professor Adrian Smith from the University of Oxford has now decoded the evolution of MDV and shed light on what is behind the growing virulence.

The international team from the fields of paleogenetics, archeology, and biology isolated viral genomes from chicken bones up to 1,000 years old from 140 archeological sites in Europe and the Near East. “Our data shows that the virus was already widely distributed at least 1,000 years before the first description of the disease in 1907,” says Frantz. When the disease was first described, it was said to produce only mild symptoms in older chickens. With the dramatic increase in poultry farming in the 1950s and 1960s, the virus evolved and has become increasingly virulent despite the development of several vaccines.

Thursday, December 14, 2023

How the Immune System Fights to Keep Herpes at Bay

These microscope images show how interferon in the nucleus raises levels of the protective protein IFI16 (stained green) from low background levels (left) to the higher levels needed to resist herpes infection (right).
Image Credit: HMS MicRoN core imaging facility/Nicolas Romero Rata

Herpes simplex virus (HSV) is extremely common, affecting nearly two-thirds of the world’s population, according to the World Health Organization.

Once inside the body, HSV establishes a latent infection that periodically awakens, causing painful blisters on the skin, typically around the nose and mouth. While a mere nuisance for most people, HSV can also lead to dangerous eye infections and brain inflammation in some people and cause life-threatening infections in newborns.

Researchers have long known that the virus and the host immune system are in a perpetual competition, but why does this battle reach a stasis in most people while causing serious infections in others?

More important, precisely how does the battle unfold at the level of cells and molecules? This question has continued to bedevil scientists and hamper the quest for treatments that prevent or cure infections.

A recent study by researchers at Harvard Medical School, conducted using lab-engineered cells and published in PNAS, unveils the precise maneuvers used by host and pathogen in the fight for dominance of the cell.

Wednesday, November 8, 2023

Temperature increase triggers viral infection

Illustration of phage virus injecting its DNA into a cell
Illustration Credit: Alex Evilevitch and Ting Liu

Researchers at Lund University, together with colleagues at the NIST Synchrotron Facility in the USA, have mapped on an atomic level what happens in a virus particle when the temperature is raised.

"When the temperature rises, the virus's genetic material changes its form and density, becoming more fluid-like, which leads to its rapid injection into the cell," says Alex Evilevitch who led the study.

Viruses lack their own metabolism and the ability to replicate independently; they are entirely dependent on a host cell to multiply. Instead, the virus hijacks the internal machinery of the infected cell to produce new virus particles, which are then released and spread to infect other cells.

In most cases, the virus's genetic material, DNA, is enclosed within a protective protein shell called a capsid. A research group at Lund University is working to understand the process by which the virus ejects its genetic material from the capsid and into cells and what causes the virus's DNA to be released.

It all began with a study published in 2014, where the Lund University researchers observed that there seems to be a sudden change in the virus's genetic material when exposed to the infection temperature, around 37 degrees.

Monday, November 6, 2023

Success of Wolbachia-infected mosquitoes in fighting dengue may be underestimated

Alex Perkins, associate professor of biological science
Photo Credit: Courtesy of University of Notre Dame

The fight against dengue fever has a new weapon: a mosquito infected with the bacteria Wolbachia, which prevents the spread of the virus. These mosquitoes have now been deployed in several trials demonstrating their potential in preventing disease transmission.

Now, researchers at the University of Notre Dame have conducted an analysis of the World Mosquito Program’s randomized control trial of Wolbachia-infected mosquitoes in Indonesia, looking at how excluding transmission dynamics impacted the original interpretation of the trial’s results.

“Randomized controlled trials are the gold standard for evaluating the efficacy of any medical or public health intervention. That is very difficult for vector interventions against dengue because incidence of the disease can be somewhat unpredictable and sporadic, requiring very large-scale trials,” said Alex Perkins, associate professor of biological sciences at Notre Dame and senior author on the study.

Wednesday, November 1, 2023

The Unraveling of a Protist Genome Could Unlock the Mystery of Marine Viruses

Light-microscopy image of clusters of Aurantiochytrium limacinum cells. The marine protist is prevalent in the world’s oceans.
Image Credits: Laura Halligan, Joshua Rest and Jackie Collier

Viruses are the most prevalent biological entities in the world’s oceans and play essential roles in its ecological and biogeochemical balance. Yet, they are the least understood elements of marine life. By unraveling the entire genome of a certain marine protist that may act as a host for many viruses, an international research team led by scientists from Stony Brook University sets the stage for future investigations of marine protist genomes, marine microbial dynamics and the evolutionary interplay between host organisms and their viruses — work that may open doors to a better understanding of the “invisible” world of marine viruses and offers a key to the ecology and health of oceans worldwide. The research is published early online in Current Biology.

Food webs of the oceans provide humanity with essential food sources as well as the wonderment of sea creatures from polar bears to penguins. This wellspring of life is supported mainly by microscopic organisms, including the wide presence of viruses. Learning more about the viruses through DNA research and other forms of investigation is essential to scientists’ understanding of the sea. Novel groups of viruses are still being discovered, such as the recently discovered “mirusvirues” featured in a Nature paper earlier this year.

Tuesday, October 31, 2023

Pinpointing HIV immune response

HIV, the AIDS virus (yellow), infecting a human cell
Image Credit: National Cancer Institute

New research combining computer modeling and experiments with macaques shows the body’s immune system helps control human immunodeficiency virus (HIV) infections largely by suppressing viral production in already infected cells while also killing viral infected cells, but only within a narrow time window at the start of a cell’s infection.

“To eliminate HIV, we have to understand how the immune system attempts to control the infection,” said Ruy M. Ribeiro, a theoretical biologist at Los Alamos National Laboratory who led the development of the model underpinning the research. Ribeiro is the corresponding author of the paper about the findings, published in Nature Communications.

The research team included Los Alamos Senior Fellow Alan S. Perelson and a former Los Alamos postdoctoral researcher now at the Fred Hutchinson Cancer Research Center. Their collaborators at the University of Pittsburg managed the experiments with macaques infected with simian immunodeficiency virus (SIV) to validate the model. SIV infections in monkeys behave the same way as HIV in humans.

Friday, October 27, 2023

Long COVID most prevalent in the most seriously ill

Image Credit: Scientific Frontline

A collaborative study involving researchers from Karolinska Institutet has charted the prevalence of severe physical symptom burden amongst Scandinavians for up to two years after a SARS-CoV-2 infection. Most affected were people who had a severe COVID-19 infection, while the researchers found no elevated prevalence of long COVID in those who had never been bedridden. The study is published in The Lancet Regional Health – Europe.

By mid-October 2023, over 771 million cases of COVID-19 had been reported to the World Health Organization (WHO). An estimated 10 to 20 per cent of the affected have persistent symptoms.

Close to 65,000 participants

In the present study, researchers examined the prevalence of persistent physical symptoms in people with different degrees of COVID-19 severity and compared them with people who had not had a confirmed COVID-19 diagnosis. The study comprised 64,880 adults from Sweden, Denmark, Norway and Iceland with self-reported physical symptoms between April 2020 and August 2022.

Over 22,000 of the participants were diagnosed with COVID-19 during the period, almost 10 per cent of whom were bedridden for at least seven days. The prevalence of chronic symptoms such as shortness of breath, chest pain, dizziness, headaches, and low energy/ fatigue, was 37 per cent higher in those who had had a COVID-19 diagnosis than in those who had not.

Wednesday, October 25, 2023

Zika Infection in Pregnant Macaques Slows Fetal Growth

Female rhesus macaque monkeys and infants at the California National Primate Research Center at UC Davis.
Photo Credit: Courtesy of University of California, Davis

Zika virus infection in pregnant rhesus macaques slows fetal growth and affects how infants and mothers interact in the first month of life, according to a new study from researchers at the California National Primate Research Center at the University of California, Davis. The work, published Oct. 25 in Science Translational Medicine, has implications for both humans exposed to Zika virus and for other viruses that can cross the placenta, including SARS-CoV2, responsible for the COVID-19 pandemic.

“Initially I thought this was a story about Zika, but as I looked at the results, I think this is also a story about how fetal infections in general affect developmental trajectories,” said Eliza Bliss-Moreau, professor of psychology at UC Davis and senior author on the paper.

In most people, Zika virus infection causes mild or no symptoms and leaves long-lasting immunity. But during pregnancy, the virus can cross the placenta and cause damage to the nervous system of the fetus. In extreme cases, it can cause microcephaly in humans.

Scientists uncover cause of mysterious deaths of elephants in Zimbabwe

Photo Credit: Charl Durand

During this unique study, scientists from the Victoria Falls Wildlife Trust, the Animal and Plant Health Agency UK, the University of Surrey and laboratories in South Africa investigated the mysterious deaths of 35 elephants mostly between August and September 2020, in a 40 x 25 km radius of North-Western Zimbabwe. This incident followed the death of approximately 350 elephants in neighboring northern Botswana from May to June 2020, which triggered much international concern. 

African savanna elephants are an endangered species with only 350,000 remaining in the wild and ongoing losses estimated at eight percent annually. This finding is very worrying since elephants are on the International Union for Conservation of Nature red list already. Investigating the deaths of these elephants is crucial to sustaining the future of this majestic species. 

Post-COVID condition is not linked to ongoing infection or active brain damage


Post COVID-19 condition does not appear to be linked to direct viral invasion of the brain or active brain damage. This has been shown by a study at the University of Gothenburg. Searching for abnormal biomarkers among the participants yielded no hits in either blood or cerebrospinal fluid samples.

The condition that can follow the acute phase of COVID-19 infection, termed “Post-COVID condition,” or “long-covid” can persist for several months subsequent to the initial infection. The condition includes various combinations of fatigue, apathy, and difficulties with memory and concentration.

The current study, published in The Journal of Infectious Diseases, included 25 people with confirmed post-COVID condition, six people without residual symptoms after COVID-19, and 17 control subjects who were completely free of COVID-19.

The strength of the study lies not in the number of participants, which is fairly limited, but in the fact that they all – including the control subjects – underwent not only blood tests but also the considerably more invasive procedure of lumbar punctures to collect cerebrospinal fluid.

At the time when the samples were taken, at least three months had passed since the first symptoms of COVID-19 in those who had had the disease. The samples were taken between February and November 2021, and were analyzed for a total of 37 different biomarkers.

Tuesday, October 24, 2023

Preventing Airborne Infection without Impeding Communication with Ions and Electric Field

Figure 1.
Novel device for preventing airborne infection The design (a) and schematic (b) of the mechanism of the device for capturing infectious droplets and aerosols without hindering communication. The negatively charged ions attach to the droplets and the electric field guides them to the collecting electrode.
Illustration Credit: Courtesy of Tokyo Institute of Technology

A novel device developed by Tokyo Tech researchers in a new study utilizes ions and an electric field to effectively capture infectious droplets and aerosols, while letting light and sound pass through to allow communication. The innovation is significant in the wake of the COVID-19 pandemic, since it shows promise in preventing airborne infection while facilitating communication.

Airborne infections, such as H1N1 influenza, SARS, and COVID-19, are spread by aerosols and airborne droplets. While droplet/aerosol transmission can be prevented using acrylic partitions or, as with the COVID-19 pandemic, by imposing lockdowns in severe cases, these countermeasures can significantly impede communication. This, in turn, can lead to unintended consequences.

For instance, lockdown measures during the COVID-19 pandemic led to severe economic losses as well as a rise in cases of mental illness like depression and suicide around the world. Therefore, as we prepare for a potential future pandemic, it is necessary to develop more sustainable countermeasures that do not disrupt economic activities and daily face-to-face interactions.

To this end, a research team including Kaito Kanda, a graduate student at Tokyo Institute of Technology (Tokyo Tech) at the time of research, Assistant Professor Tetsuya Yamada, from the Institute of Innovative Research at Tokyo Tech, and Professor Takeo Fujiwara from Tokyo Medical and Dental University (TMDU) and Chiba University researchers, has now developed a device that successfully captures droplets and aerosols while allowing the transmission of light and sound for effective communication.

Tuesday, October 17, 2023

Boosting weak immune system: scientists find an unusual weapon against virus

An overview of how the method proposed by the Sieweke group boosts weak immune system. (A) M-CSF cytokine works in the bone marrow to promote generation of monocytes and macrophages, without disturbing the formation of other immune cells; (B) Monocytes and macrophages activate natural killer cells to enable them to target virus-infected cells and kill them through cell–cell contact and the release of toxic agents.
Illustration Credit: © EMBO
(CC BY 4.0 DEED)

Infections with cytomegalovirus (CMV) are extremely common and often pose no major threat to the vast majority of people. They can, however, be deadly for people whose immune system is weakened, e.g., after bone marrow transplantation. Current treatments against CMV infections are very limited and can have severe side effects. Researchers led by Prof. Michael Sieweke at the Center for Regenerative Therapies Dresden (CRTD) at TUD Dresden University of Technology and the Center of Immunology of Marseille Luminy (CIML) propose a new way to protect against CMV. Instead of targeting the virus, their approach boosts the weak immune system and lets it fight the virus on its own. The results were published in the journal EMBO Molecular Medicine.

Some viruses can be dormant throughout a person’s life and cause no harm but become dangerous when the immune system is weakened. One such virus is human cytomegalovirus (CMV). Harmless to the general public but life-threatening to patients with a suppressed immune system.

Friday, October 13, 2023

Targeting a coronavirus ion channel could yield new Covid-19 drugs

MIT chemists found that the SARS-CoV-2 E protein, which acts as an ion channel, has a broad opening at the bottom when in the closed state and a narrower opening in the open state.
Image Credits: Courtesy of the researchers, MIT News, and iStock
(CC BY-NC-ND 3.0 DEED)

The genome of the SARS-CoV-2 virus encodes 29 proteins, one of which is an ion channel called E. This channel, which transports protons and calcium ions, induces infected cells to launch an inflammatory response that damages tissues and contributes to the symptoms of Covid-19.

MIT chemists have now discovered the structure of the “open” state of this channel, which allows ions to flow through. This structure, combined with the “closed” state structure that was reported by the same lab in 2020, could help scientists figure out what triggers the channel to open and close. These structures could also guide researchers in developing antiviral drugs that block the channel and help prevent inflammation.

“The E channel is an antiviral drug target. If you can stop the channel from sending calcium into the cytoplasm, then you have a way to reduce the cytotoxic effects of the virus,” says Mei Hong, an MIT professor of chemistry and the senior author of the study.

MIT postdoc Joao Medeiros-Silva is the lead author of the study, which appears today in Science Advances. MIT postdocs Aurelio Dregni and Pu Duan and graduate student Noah Somberg are also authors of the paper.

Wednesday, October 11, 2023

Antigen testing can reduce, but not eliminate, the risk of COVID-19 clusters according to mathematical model

Illustration Credit: Kojima Kyoko

A research group has created a new model to calculate the probability of the occurrence of localized clusters caused by novel coronavirus infections. Led by Shingo Iwami at Nagoya University with collaborators in the United Kingdom and South Korea model, they revealed that screening of infected persons by antigen testing is effective in significantly reducing the probability of cluster occurrence. However, their findings also suggest that it is not sufficient to prevent clusters caused by highly infectious mutant strains, such as Omicron.  

With the availability of COVID-19 vaccines and population immunity, countries around the world are seeking to resume social activities while also trying to prevent the spread of infection. However, outbreaks of new strains of the coronavirus, associated with increased infectiousness and evasion of existing immunity, continue to be a threat. In several countries, new infections are increasing as the northern hemisphere enters the autumn and winter months.

Tuesday, October 10, 2023

Red Algae Could Be Used to Create a Drug for Coronavirus

Chemical research on Laurencia red algae began in 1965.
Photo Credit: 🇸🇮 Janko Ferlič

Laurencia red algae can be used as a basis for new drugs against the SARS-CoV-2 virus, biochemists have found. A team of scientists from the Ural Federal University, the Institute of Organic Synthesis of the Ural Branch of the Russian Academy of Sciences, together with colleagues from Australia and Germany, carried out molecular docking of 300 bioactive components (ligands) of red algae and found seven compounds with the required activity. The scientists published a description of the experiments and results in the journal Microbiology Research

"Laurencia belongs to the family Rhodomelaceae, which is considered one of the largest families of marine red algae, with an estimated 125 genera and 700 species worldwide. Laurencia has recently been the subject of active research. Since 2015, a total of 1,047 secondary metabolites with various useful properties have been isolated from Laurencia species alone," explains Grigory Zyryanov, Chief Researcher of the UrFU Laboratory of Advanced Materials, Green Methods and Biotechnology.

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.

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