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Comment by Dr. Krishna Kumari Challa 2 hours ago

Scientists discover proteins that initiate cellular immunity in bone marrow

Researchers have shown how a critical pathway is fundamental to the immune system.

Establishing cellular immunity depends on the thymus, a lymph gland located in front of the heart. This gland produces and exports T cells, a workhorse white blood cell, out to the rest of the body, using the building blocks of stem cells from the bone marrow. But it has remained a riddle how T cell fate is initiated.

The new paper shows that two protein "transcription factors" called Tcf1 and Lef1 are critical modulators that direct bone marrow stem cells to the T cell path in the thymus.

By carefully removing these proteins via in vivo and ex vivo models, the team of scientists revealed a foundational event in the immune system, which represents essentially the very origin of a functional cellular immune competence.

This discovery illustrates a whole new understanding of T cell formation, and could lead to a wide range of novel approaches in treating immune deficiencies, autoimmune diseases, and optimizing immunotherapies in the ongoing fight against cancer.

"These findings reveal that Tcf1 and Lef1 act much earlier than previously recognized, extending beyond their roles in promoting T-cell lineage specification and commitment at later stages in the thymus," the authors write, adding that the "downstream" Notch signaling pathway is corrupted without these two assisting proteins.

 Xin Zhao et al, Single-cell multiomics identifies Tcf1 and Lef1 as key initiators of early thymic progenitor fate, Science Immunology (2025). DOI: 10.1126/sciimmunol.adq8970

Comment by Dr. Krishna Kumari Challa 3 hours ago

The study also revealed that participants who experienced breakthrough infections had lower levels of IgA(S) antibodies in their blood several weeks after vaccination. These antibodies protect the nose and throat and are our first line of defense against respiratory viruses.

Importantly, the researchers found a strong correlation between blood IgA(S) levels and nasal IgA(S) levels, suggesting that blood tests can reliably indicate the strength of immune protection in airways. As a result, measuring blood IgA(S) levels after vaccination may help identify individuals at higher risk for breakthrough infection, especially among vulnerable groups.
The researchers emphasize the importance of identifying the underlying biological mechanisms responsible for the rapid decline in antibody levels in order to develop more effective vaccination strategies.
Previous research points to factors such as age, genetic variation, vaccine-specific characteristics, and environmental influences, including sleep habits, stress levels, and medications being taken at the same time.
Identifying the rapid-decliner pattern is especially important—it helps explain why some people may need boosters sooner than others.

This could potentially contribute to better, more personalized vaccination strategies.

 Longitudinal antibody titers measured after COVID-19 mRNA vaccination can identify individuals at risk for subsequent infection, Science Translational Medicine (2025). DOI: 10.1126/scitranslmed.adv4214

Part 2

Comment by Dr. Krishna Kumari Challa 3 hours ago

COVID-19 vaccine responses show four patterns, with 'rapid-decliners' at higher infection risk

Two health care workers get COVID-19 vaccinations on the same day. Both show strong antibody responses initially, but six months later one stays healthy while the other contracts the virus. A new study published in Science Translational Medicine could help explain this difference.

Researchers tracked individuals' antibody levels after vaccinations and identified four distinct patterns of immune response after the first booster vaccination. Notably, people in the group that started with the highest antibody levels but experienced a faster decline were infected earlier. People with lower blood levels of IgA(S) antibodies, which protect the nose and throat, were also at higher risk. The findings suggest that monitoring how antibody levels change over time could assist in identifying individuals at greater risk of infection.

The research team measured antibody levels in 2,526 people over 18 months to see how vaccine responses changed between the first vaccination and later booster shots. They developed a mathematical classification system for COVID-19 vaccine responses using long-term tracking and AI-based computer analysis, becoming the first to systematically identify and characterize the "rapid-decliner" group.

The researchers found that immune responses fell into four clear patterns: Some people maintained high antibody levels over time (durable responders), others started with strong levels but lost them quickly (rapid-decliners), a third group produced few antibodies that also declined rapidly (vulnerable responders), and the rest fell in between (intermediate responders).

A breakthrough or subsequent infection refers to infections that occur after vaccination because the virus overcomes the immune protection that vaccines provide. The researchers found that people whose antibodies declined faster, either because they started low or dropped quickly (vulnerable responders and rapid-decliners), were slightly more likely to get breakthrough infections earlier.

After booster vaccinations, 29% of participants fell into the durable responder category, 28% were vulnerable responders, and 19% were rapid-decliners. The remaining participants showed intermediate patterns. The differences in breakthrough infection rates between groups were modest—5.2% for durable responders and 6% for vulnerable and rapid-decliners.

Part 1

Comment by Dr. Krishna Kumari Challa 3 hours ago

How an essential vitamin B-derived nutrient concentrates in mitochondria

There's a molecule that our body makes from vitamin B₅ that is critical for all of the metabolic processes essential for human life. And when something goes wrong in that molecule's production, it affects nearly every organ system in our body and causes a number of diseases.

Researchers have discovered that up to 95% of this molecule—called essential cofactor coenzyme A (CoA)—is located inside mitochondria, organelles that supply cellular energy and regulate cellular metabolism. But what has not been clear is how CoA gets there.

Reporting in Nature Metabolism, researchers have now uncovered that CoA is trafficked into mitochondria and have identified the mechanisms responsible.

This information, the researchers say, is important for future considerations about when and where to target treatments for diseases in which CoA is implicated.

The researchers were able to identify 33 different CoA conjugates in whole cells as well as 23 CoA conjugates in mitochondria.

The question then was whether the CoA conjugates in the mitochondria were made there or brought in from elsewhere.

In additional experiments, the researchers discovered that the enzyme required to make CoA largely exists outside of mitochondria. Further, when they made cells that lacked the molecular transporters that can move CoA around, mitochondria had far less CoA.

These findings strongly support the idea that CoA is being imported into mitochondria, and these transporters are required for that to happen.

This study advances the fundamental understanding of CoA and how it gets to where it needs to be in order to perform its essential functions. That, in turn, sheds light on how disruptions of this process might contribute to illness.

For instance, mutations in the genes that produce CoA transporters are associated with diseases such as encephalomyopathy, a disorder that can include neurodevelopmental delay, epilepsy, and decreased muscle tone. Mutations in the enzymes that produce CoA have been implicated in neurodegeneration.

In the context of brain disorders, such as neurodegeneration and psychiatric disorders, there's an emerging idea that dysregulated mitochondrial metabolism is a contributor.

Ran Liu et al, Cellular pan-chain acyl-CoA profiling reveals SLC25A42/SLC25A16 in mitochondrial CoA import and metabolism, Nature Metabolism (2025). DOI: 10.1038/s42255-025-01358-y

Comment by Dr. Krishna Kumari Challa 3 hours ago

Research has also recently revealed that lithornithids may have had a bony organ on the tip of their beaks which made them excel at foraging for insects.

But what about the second condition—a lack of predators?

Researchers suspect that paleognath ancestors likely started evolving towards flightlessness after dinosaurs went extinct around 65 million years ago.

With all the major predators gone, ground-feeding birds would have been free to become flightless, which would have saved them a lot of energy.

The small mammals that survived the event that wiped out the dinosaurs would have taken some time to evolve into predators.

This would have given flightless birds "time to adapt by becoming swift runners" like the emu, ostrich and rhea—or even "becoming themselves dangerous and intimidating, like the cassowary.

Quantitative analysis of stem-palaeognath flight capabilities sheds light on ratite dispersal and flight loss, Biology Letters (2025). DOI: 10.1098/rsbl.2025.0320. royalsocietypublishing.org/doi … .1098/rsbl.2025.0320

Part 2

Comment by Dr. Krishna Kumari Challa 3 hours ago

Ostrich and emu ancestor could fly, scientists discover

How did the ostrich cross the ocean?

We have long been puzzled by how the family of birds that includes African ostriches, Australian emus and cassowaries, New Zealand kiwis and South American rheas spread across the world—given that none of them can fly.

However, a study published this week may have found the answer to this mystery: the family's oldest-known ancestors were able to take wing.

The only currently living member of this bird family—which is called paleognaths—capable of flight is the tinamous in Central and South America. But even then, the shy birds can only fly over short distances when they need to escape danger or clear obstacles.

Researchers analyzed the specimen of a lithornithid, the oldest paleognath group for which fossils have been discovered. They lived during the Paleogene period 66–23 million years ago.

The fossil of the bird Lithornis promiscuus was first found in the US state of Wyoming, but had been sitting in the Smithsonian museum's collection.

Because bird bones tend to be delicate, they are often crushed during the process of fossilization, but this one was not. 

Crucially for this study, it retained its original shape. This allowed the researchers to scan the animal's breastbone, which is where the muscles that enable flight would have been attached.

They determined that Lithornis promiscuus was able to fly—either by continuously beating its wings or alternating between flapping and gliding.

But  why did these birds give up the power of flight?

Birds tend to evolve flightlessness when two important conditions are met: they have to be able to obtain all their food on the ground, and there cannot be any predators to threaten them.

Part 1

Comment by Dr. Krishna Kumari Challa 4 hours ago

Coral reefs set to stop growing as climate warms

Most coral reefs will soon stop growing and may begin to erode—and almost all will do so if global warming hits 2°C, according to a new study in the western Atlantic. 

The study, published in the journal Nature, projects that more than 70% of the region's reefs will stop growing by 2040—and over 99% will do so by 2100 if warming reaches 2°C or more above pre-industrial levels. The paper is titled "Reduced Atlantic reef growth past 2°C warming amplifies sea-level impacts."

Climate change—along with other issues such as coral disease and deteriorating water quality—reduces overall reef growth by killing corals and impacting colony growth rates, the study concludes.

 Chris Perry, Reduced Atlantic reef growth past 2°C warming amplifies sea-level impacts, Nature (2025). DOI: 10.1038/s41586-025-09439-4. www.nature.com/articles/s41586-025-09439-4

Comment by Dr. Krishna Kumari Challa 4 hours ago

Some small asteroids can abruptly explode

Some asteroids are more dangerous than others, according to a report published in Nature Astronomy by an international team of researchers.

The team had presented their findings of an investigation into the impact of small asteroid 2023 CX1 over France in February 2023. This new paper revealed that small asteroids can explode on atmospheric entry.

The researchers confirmed the existence of a new population of asteroids linked to L-type chondrites, capable of fragmenting abruptly in the atmosphere and releasing almost all their energy at once. 

Such asteroids must be accounted for in planetary defense strategies, as they pose an increased risk to populated areas, they say.

Auriane Egal et al, Catastrophic disruption of asteroid 2023 CX1 and implications for planetary defence, Nature Astronomy (2025). DOI: 10.1038/s41550-025-02659-8.

Comment by Dr. Krishna Kumari Challa 4 hours ago

Estimated 16,500 climate change deaths during Europe summer: Study

Scientists estimated this week that rising temperatures from human-caused climate change were responsible for roughly 16,500 deaths in European cities this summer, using modeling to project the toll before official data is released.

The rapidly produced study is the latest effort by climate and health researchers to quickly link the death toll during heat waves to global warming—without waiting months or years to be published in a peer-reviewed journal.

The estimated deaths were not actually recorded in the European cities, but instead were a projection based on methods such as modeling used in previously peer-reviewed studies.

Death tolls during heat waves are thought to be vastly underestimated because the causes of death recorded in hospitals are normally heart, breathing or other health problems that particularly affect the elderly when the mercury soars.

researchers used climate modeling to estimate that global warming made temperatures an average of 2.2 degrees Celsius hotter in 854 European cities between June and August.

Using historical data indicating how such soaring temperatures drive up mortality rates, the team estimated there were around 24,400 excess deaths in those cities during that time.

They then compared this number to how many people would have died in a world that was not 1.3C warmer due to climate change caused by humans burning fossil fuels.

Nearly 70%—16,500—of the estimated excess deaths were due to global warming, according to the rapid attribution study.

This means climate change could have tripled the number of heat deaths this summer, said the study from scientists at Imperial College London and epidemiologists at the London School of Hygiene & Tropical Medicine.

The estimates did reflect previous peer-reviewed research, such as a Nature Medicine study which determined there were more than 47,000 heat-related deaths during the European summer of 2023.

Numerous prominent climate and health researchers also backed the study.

What makes this finding even more alarming is that the methods used in these attribution studies are scientifically robust, yet conservative.

The actual death toll could be even higher, warn the researchers. And what about if the figures for the entire world taken into account! Extremely alarming.

Source: Nature Medicine

Comment by Dr. Krishna Kumari Challa 4 hours ago

Study provides first evidence that plastic nanoparticles can accumulate in the edible parts of vegetables

Plastic pollution represents a global environmental challenge, and once in the environment, plastic can fragment into smaller and smaller pieces.

A new study shows for the first time that some of the tiniest particles found in the environment can be absorbed into the edible sections of crops during the growing process.

The research used radishes to demonstrate, for the first time, that nanoplastics—some measuring as little as one millionth of a centimeter in diameter—can enter the roots, before spreading and accumulating into the edible parts of the plant.

The researchers say the findings reveal another potential pathway for humans and animals to unintentionally consume nanoplastics and other particles and fibers that are increasingly present in the environment.

It also underscores the need for further research to investigate what is an emerging food safety issue, and the precise impacts it could have on environmental and human health.

This study provides clear evidence that particles in the environment can accumulate not only in seafood but also in vegetables. This work forms part of our growing understanding on accumulation, and the potentially harmful effects of micro- and nanoparticles on human health.

Nathaniel J. Clark et al, Determining the accumulation potential of nanoplastics in crops: An investigation of 14C-labelled polystyrene nanoplastic into radishes, Environmental Research (2025). DOI: 10.1016/j.envres.2025.122687

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