Tag Archives: dormant

COVID-19 and Flu Could Reactivate Dormant Lung Cancer Cells

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Lung tissue samples from mice, depicting cells (blue), cancerous cells (green), and proliferation markers (magenta)

Bryan Johnson

Respiratory viruses are capable of triggering the growth of dormant cancer cells that have metastasized to the lungs from other body areas. Infectious diseases, such as influenza, can instigate an inflammatory response that aids the immune system in combating pathogens, yet they may also adversely influence cancer progression.

Cancer fatalities frequently result from tumor cells migrating from their primary sites. These cells may remain dormant in new locations for extended periods—potentially years or decades—before forming detectable tumors.

While it is uncertain if these cells will eventually proliferate, previous studies have suggested that once cancer cells infiltrate the lungs, inflammation induced by respiratory virus infections might play a significant role. “Nevertheless, no comprehensive research has been conducted to establish a clear cause-and-effect relationship,” notes James DeGregori from the University of Colorado.

To address this research gap, DeGregori and his team employed genetically modified mice to develop tumors in their mammary glands. By two months of age, each mouse had developed a mammary tumor and fewer than ten dormant cancer cells in their lungs.

Subsequently, the researchers infected half of the mice with the H1N1 influenza strain, commonly referred to as swine flu, causing illness for approximately two weeks. During the nine days following the infection, the number of lung cancer cells surged by 100-fold, whereas uninfected mice exhibited minimal changes.

In complementary experiments, the team discovered that the SARS-CoV-2 virus, responsible for COVID-19, led to a tenfold increase in cancer cell numbers in the mice’s lungs, again with no significant alterations in uninfected counterparts.

The researchers hypothesized that this expansion occurred due to viral infections elevating the levels of inflammatory molecules known as IL-6.

To investigate this hypothesis, they conducted further experiments with genetically modified mice deficient in IL-6 and found significantly fewer lung cancer cells compared to typical mice with normal IL-6 levels.

Another experiment suggested that IL-6 seemed to rejuvenate dormant cancer cells that had already migrated to the lungs instead of promoting the dissemination of these cells from the breasts.

However, IL-6 levels wane when the infection subsides. At this juncture, the researchers observed that cancer cells in the mouse lungs had ceased to proliferate but had acquired alterations in gene expression typically associated with tumor metastasis, according to DeGregori.

These findings suggest a potential impact on individuals with undetected levels of cancer cells in the lungs who are believed to be in remission, as stated by Anne Zeuner at the National Institutes of Health in Rome, Italy.

To determine the relevance of these findings to humans, researchers analyzed health records from 36,800 women in the U.S. diagnosed with breast cancer before the COVID-19 pandemic, who were thought to be non-metastatic.

Women who tested positive during the initial three years of the outbreak were significantly more likely to receive a diagnosis of secondary lung cancer in that timeframe. However, some women may have avoided testing due to asymptomatic infections, while others might not have sought tests, thereby complicating the validation of this finding, notes DeGregori.

Further research is necessary to corroborate these findings and explore the interactions between various respiratory viruses and cancer types, according to Zeuner. “Individual factors are likely to significantly influence the relationship between respiratory infections and cancer recurrence,” she adds.

The research focused solely on swine flu and SARS-CoV-2, but DeGregori expresses hope that a spectrum of viruses will exhibit similar behaviors, as many are known to elevate IL-6 levels. He also underscores the importance of vaccination, stating, “As a cancer survivor, I would ensure I am protected against common respiratory viruses like influenza and COVID-19,” remarks DeGregori.

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Source: www.newscientist.com

Physicists suggest that the capture and annihilation of dark matter could reignite dormant neutron stars

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A team of particle physicists from the University of Melbourne, Australian National University, King’s College London, and Fermi National Accelerator Laboratory has discovered that the energy transferred when dark matter particles collide and annihilate inside a cold neutron star. They calculated that the star could be heated rapidly. Previously, this heating was thought to be irrelevant because this energy transfer takes a very long time, in some cases longer than the age of the universe itself.

An artist’s impression of a neutron star.

A number of recent studies have focused on trapping dark matter in neutron stars as sensitive probes of the interaction of dark matter with ordinary matter.

This could potentially be used to test dark matter interactions in a way that is highly complementary to experiments on Earth, especially since dark matter is accelerated to relativistic speeds during a fall into a neutron star. there is.

In some cases, neutron star technology may be able to probe interactions that are difficult or impossible to observe with direct dark matter detection experiments. These include dark matter, which is too light to leave a detectable signal in nuclear recoil experiments, and interactions where non-relativistic scattering cross sections are momentum suppressed.

It was recently pointed out that an isolated old neutron star near the Sun could be heated by the capture of dark matter, increasing its temperature by 2000 K.

Once older than 10 million years, an isolated neutron star is expected to cool to temperatures below this unless reheated by standard matter accretion or internal heating mechanisms.

As a result, observations of local neutron stars may place severe constraints on dark matter interactions. Importantly, neutron stars with temperatures in this range produce near-infrared radiation that could be detected by future telescopes.

“Our new calculations show for the first time that most of the energy is stored in just a few days,” said Professor Nicole Bell from the University of Melbourne, lead author of the study.

“The search for dark matter is one of science’s greatest detective stories.”

“Dark matter makes up 85% of the matter in the universe, but we can’t see it.”

“It doesn’t interact with light. It doesn’t absorb, reflect, or emit light.”

“This means that even if we know it exists, we can’t directly observe it with our telescopes.”

“Rather, its attraction to an object that we can see tells us that it must be there.”

“Predicting dark matter theoretically and observing it experimentally are two different things.”

“Earth-based experiments are limited by the technical challenges of building a large enough detector.”

“But neutron stars act as huge natural dark matter detectors, collecting dark matter over astronomically long timescales, so they are a good place to focus our efforts.”

“Neutron stars form when supermassive stars run out of fuel and collapse,” Professor Bell said.

“They have a similar mass to our sun and are squeezed into a sphere just 20km wide. If they got any denser, they would become black holes.”

“Dark matter is the main type of matter in the universe, but it is very difficult to detect because it interacts very weakly with normal matter.”

“In fact, dark matter is so weak that it can pass straight through the Earth and even the Sun.”

“But neutron stars are different. Because neutron stars are so dense, dark matter particles are much more likely to interact with the star.”

“If dark matter particles collide with neutrons inside a star, they lose energy and become trapped.”

“Over time, this will lead to an accumulation of dark matter within the star.”

“We expect this to cause old, cold neutron stars to heat up to a point where they can be observed in the future, or even cause the star to collapse into a black hole,” said the University of Melbourne doctor. candidate Michael Vilgat, co-author of the study.

“If the energy transfer happens quickly enough, the neutron star will heat up.”

“For this to happen, the dark matter would have to collide within the star many times, transferring more and more of the dark matter’s energy until all the energy is stored in the star.”

“Until now it was unknown how long this process takes, because as dark matter particles become less and less energetic, they become less and less likely to interact again.”

“As a result, it was thought that it would take a very long time to transfer all the energy, in some cases longer than the age of the universe.”

Instead, the researchers calculated that 99% of the energy is transferred in just a few days.

“This is good news, because it means dark matter can potentially heat neutron stars to detectable levels,” Birgat said.

“As a result, observations of cold neutron stars will provide important information about the interactions between dark matter and ordinary matter and shed light on the nature of this elusive matter.”

“If we are to understand the ubiquity of dark matter, it is important to use every technology at our disposal to understand what the hidden matter in our universe actually is.” .”

of study Published in Journal of Cosmology and Astroparticle Physics.

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Nicole F. Bell other. 2024. Thermalization and extinction of dark matter in neutron stars. JCAP 04,006; doi: 10.1088/1475-7516/2024/04/006

Source: www.sci.news

COVID-19 can lie dormant in the lungs for as long as 18 months

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SARS-CoV-2 Virus Persistence Study

The SARS-CoV-2 Virus Persistence Study

The SARS-CoV-2 virus can remain in the lungs for up to 18 months after infection, a study has found, challenging the notion that it is undetectable after initial recovery. This persistence is associated with a failure of the innate immune system. This study confirms the existence of “viral reservoirs” similar to those found in HIV and highlights the role of NK cells in controlling these reservoirs. This discovery is extremely important for understanding long-term COVID-19 infections and the mechanisms of viral persistence.

Groundbreaking research reveals:

SARS-CoV-2 Due to malfunctioning of the innate immune system, it can remain in the lungs for months, undetected, leading to long-term COVID-19 infections. 1 to 2 weeks after being infected with the new coronavirus (SARS-CoV-2) virus It is generally undetectable in the upper respiratory tract. But does that mean it’s not present in the body? To find out, a team at the Institut Pasteur, which specializes in HIV, teamed up with France’s public research institute, the Commission for Alternative Energies and Atomic Energy (CEA), to study lung cells in animal models. It was conducted. This finding not only shows that SARS-CoV-2 can be detected in the lungs of certain individuals for up to 18 months after infection, but also that its persistence is associated with a failure of innate immunity, the first line of defense against the pathogen. It also shows that this is the case. ).This study was published in the journal innate immunology.

Discovery of virus carriers in the new coronavirus infection (COVID-19)

After causing an infection, some viruses remain in the body in a discreet and undetectable form. They remain in what is known as the “viral reservoir.” This is the case with HIV, which is latent in certain immune cells and can reactivate at any time. The same may be the case with the SARS-CoV-2 virus. COVID-19 (new coronavirus infection). At least, this is the hypothesis proposed in 2021 by a team of scientists at the Pasteur Institute, and now confirmed in a preclinical model in non-human primates.

“We observed that inflammation persisted for a long time in primates infected with SARS-CoV-2. We therefore thought that the presence of the virus in the body could be the cause,” said Pass. explains Michaela Müller Tortwin, head of the HIV, Inflammation and Persistence Unit at the Toole Institute. This study showed that the SARS-CoV-2 virus is transmitted from one macrophage to another through bridge-like cell processes, allowing it to spread. The cell nucleus is highlighted in pink and the viral protein NSP3 is highlighted in green. Credit: © Marie Lazzerini, Nicolas Huot, Institut Pasteur research result To study the persistence of the SARS-CoV-2 virus, scientists at the Institut Pasteur collaborated with CEA’s IDMIT (Infectious Disease Models for Innovative Therapies) Center to study the persistence of the SARS-CoV-2 virus from animal models infected with the virus. The collected biological samples were analyzed. Early results from the study show that the virus was detected in some people’s lungs 6 to 18 months after infection, even though it was not detected in their upper respiratory tract or blood. Another finding was that the amount of residual virus in the lungs was lower with the Omicron strain than with the original SARS-CoV-2 strain. “We were really surprised that we found the virus in specific immune cells (alveolar macrophages) after such a long period of time, when routine PCR testing was negative,” said the study’s lead author. Yes, says Nicolas Huot, a researcher in HIV, inflammation and inflammation at the Institut Pasteur. Persistence unit.

“Furthermore, we were able to culture these viruses and use the tools we developed to study HIV to observe that the viruses were still able to replicate.” To understand the role of innate immunity in controlling these viral reservoirs, scientists next turned to NK (natural killer) cells. “The innate immune cellular response, the body’s first line of defense, has so far been little studied in the context of SARS-CoV-2 infection,” says Michaela Müller-Turtwin. “However, it has long been known that NK cells play an important role in controlling viral infections.” The study found that in some animals, macrophages infected with SARS-CoV-2 were destroyed by NK cells. In other animals, NK cells have been shown to adapt to infection and destroy resistant cells (known as adaptive NK cells). For macrophages. Therefore, this study sheds light on a possible mechanism explaining the existence of ‘viral reservoirs’. People who had little or no virus over time had adaptive NK cell production, whereas people with higher levels of virus not only had no adaptive NK cells, but only cell activation. NK cell activity also decreases. Therefore, innate immunity appears to play a role in controlling persistent SARS-CoV-2 virus.

Future research directions

“We will undertake a study of a cohort infected with SARS-CoV-2 early in the pandemic to investigate whether the identified viral reservoirs and mechanisms are associated with long-lasting COVID-19 cases. “However, the results here already represent an important step in understanding the nature of the virus reservoir and the mechanisms regulating virus survival,” says Michaela Müller-Turtwin.

Reference:

“SARS-CoV-2 virus persistence in lung alveolar macrophages is controlled by IFN-γ and NK cells”, Nicolas Huot, Cyril Planchais, Pierre Rosenbaum, Vanessa Contreras, Beatrice Jacquelin, Caroline Petitdemange, By Marie Lazzerini, Emma Beaumont, Aurelio Horta-Rezendis, Felix A. Rey, R. Keith Reeves, Roger Le Grand, Hugo Mouquet, Michaela Müller-Tourtuin, November 2, 2023. innate immunology.

This research was primarily funded by families of major donors as part of the Coronavirus Research Program Call for Projects.


Source: scitechdaily.com