Comment

Comment by Dr. Krishna Kumari Challa 6 hours ago

For the new study, researchers set out to study if the viral proteins known to be targeted by T cells induced by VACV vaccination, would also be conserved in JYNNEOS and in mpox.

While antibodies are key for vaccine efficacy and preventing reinfections, T cells are essential for both preventing severe infections and "remembering" past infections.

By recognizing infected cells, T cells are able to limit how much viruses can spread inside the body modulate disease severity, and ultimately terminate the infection. T cell responses also tend to be long lasting, and resilient to viral mutations to escape immune recognition. What we have seen in the context of SARS-CoV-2 is that even if the virus mutates somewhat, T cells reactivity is still largely preserved.

The researchers demonstrated that the known targets of T cell responses seen in the VACV proven -efficacy vaccine, are also found in JYNNEOS and mpox, suggesting that the JYNNEOS vaccine can indeed trigger an effective T cell response against mpox infection. The initial test of their hypothesis was based on developing viral peptide "megapools," or reagents designed to detect T cell reactivity to mpox antigens. The experiments further showed that these megapools can be used to accurately detect specific T cells.

Vaccines such as JYNNEOS should be able to induce T cells that also recognize mpox and can provide protection from severe disease. 

 Alba Grifoni et al, Defining antigen targets to dissect vaccinia virus and monkeypox virus-specific T cell responses in humans, Cell Host & Microbe (2022). DOI: 10.1016/j.chom.2022.11.003

Part 2

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Comment by Dr. Krishna Kumari Challa 6 hours ago

Scientists confirm smallpox vaccine also teaches T cells to fight mpox

There's even more reason to think a vaccine developed against smallpox can help the body fight against mpox (monkeypox virus disease) as well, according to researchers. A new study, published in Cell Host & Microbe, is the first to provide evidence that the vaccinia vaccine MVA-BN (brand name JYNNEOS) should also train virus-fighting T cells to recognize mpox sequences.

This study gives us confidence that T cell response induced by the JYNNEOS vaccine should be able to also recognize mpox virus.

Although the JYNNEOS vaccine, based on a non-live attenuated orthopox virus called modified vaccine ankara (MVA), is approved to prevent mpox infection and severe disease, researchers don't yet have clinical efficacy data from human trials. Still, researchers know that mpox virus is similar enough to other orthopoxviruses that immunization against an orthopoxvirus called vaccinia (VACV) can also train the immune system to fight mpox.

Mpox (termed "monkeypox" until recently) is a member of the orthopox family of viruses. The deadliest, of course, was variola virus,causing the disease known as smallpox. Smallpox was eradicated worldwide in 1980 thanks to a massive and successful vaccination campaign to administer the Dryvax vaccine, based on VACV.

VACV and variola virus have a lot of immune system targets (called antigens), in common. This means training the body to recognize VACV also taught immune cells to recognize variola virus. But there was a downside—Dryvax (and a newer version called Acambis 2000) had harmful side effects, especially in immunocompromised people.

JYNNEOS was designed to have a better safety profile. While the vaccine performed well in pre-clinical tests, the eradication of smallpox meant scientists couldn't see how JYNNEOS performed in human patients in real-world infection scenarios, such as a smallpox outbreak or possible case of smallpox-based biological warfare.

Part 1

Comment by Dr. Krishna Kumari Challa 6 hours ago

Governments and people around the world, please listen: It is risky bet on forests and soils to reach net zero emissions

New research  highlights the risks of countries relying on nature-based solutions to achieve net zero.

National climate strategies set out how countries plan to reduce emissions, for example by phasing out fossil fuel use, to get to net zero in 2050. The study found that once the bulk of emissions have been reduced, countries plan to "cancel out" the leftover difficult-to-decarbonize emissions, such as those from agriculture, by using forests and soils to remove carbon from the atmosphere.

However, this may prove risky because forests and soils are also threatened by a range of impacts, such as fire, disease, changes in farming practices, and deforestation. These threats mean that forests and soils could lose their stored carbon back to the atmosphere.

There is also a risk of being overly optimistic about the amount of carbon that forests and soils can remove to reach net zero, especially if combined with delays to reducing emissions from coal, oil, and gas.

The findings, published in the journal Communications Earth & Environment, show that most of the strategies submitted to the United Nations Framework Convention on Climate Change (UNFCCC) do not quantify the amount of carbon "removals" needed in 2050.

With progress on reducing emissions stalling at COP27, the researchers call for the reporting requirements on long-term national climate plans to be urgently strengthened.

The deployment of carbon dioxide removal is essential to reach global and national net zero emissions targets, but little attention has been paid to its practical deployment by countries. 

Nature-based removals, such as using forests and soils, remain vital to address challenges in biodiversity and climate adaptation, but may be risky if used as the only way to remove carbon. Countries should also explore engineered carbon removal methods. To meet the challenge of net zero, we need both.

'Long-term National Climate Strategies Bet on Forests and Soils to Reach Net-Zero', Communications Earth & Environment (2022).

Comment by Dr. Krishna Kumari Challa 7 hours ago

New branch on tree of life includes 'lions of the microbial world'

There's a new branch on the tree of life and it's made up of predators that nibble their prey to death.

These microbial predators fall into two groups, one of which researchers have dubbed "nibblerids" because they, well, nibble chunks off their prey using tooth-like structures. The other group, nebulids, eat their prey whole. And both constitute a new ancient branch on the tree of life called Provora, according to a paper published today in Nature.

Like lions, cheetahs, and more familiar predators, these microbes are numerically rare but important to the ecosystem. Using water samples from marine habitats around the world, including the coral reefs of Curaçao, sediment from the Black and Red seas, and water from the northeast Pacific and Arctic oceans, the researchers discovered new microbes.

Culturing these microbial predators was no mean feat, since they require a mini-ecosystem with their food and their food's food just to survive in the lab.

Denis Tikhonenkov, Microbial predators form a new supergroup of eukaryotes, Nature (2022). DOI: 10.1038/s41586-022-05511-5. www.nature.com/articles/s41586-022-05511-5

Comment by Dr. Krishna Kumari Challa 7 hours ago

Discovery of world's oldest DNA breaks record by one million years

Two-million-year-old DNA has been identified for the first time—opening a 'game-changing' new chapter in the history of evolution.

Microscopic fragments of environmental DNA were found in Ice Age sediment in northern Greenland. Using cutting-edge technology, researchers discovered the fragments are one million years older than the previous record for DNA sampled from a Siberian mammoth bone.

The ancient DNA has been used to map a two-million-year-old ecosystem which weathered extreme climate change. Researchers hope the results could help to predict the long-term environmental toll of today's global warming.

Extensive work by 40 researchers from several countries  unlocked the secrets of the fragments of DNA. The process was painstaking—first they needed to establish whether there was DNA hidden in the clay and quartz, and if there was, could they successfully detach the DNA from the sediment to examine it? The answer, eventually, was yes. The researchers compared every single DNA fragment with extensive libraries of DNA collected from present-day animals, plants and microorganisms. A picture began to emerge of the DNA from trees, bushes, birds, animals and microorganisms.

Some of the DNA fragments were easy to classify as predecessors to present-day species, others could only be linked at genus level, and some originated from species impossible to place in the DNA libraries of animals, plants and microorganisms still living in the 21st century.

The two-million-year-old samples also help academics build a picture of a previously unknown stage in the evolution of the DNA of a range of species still in existence today.

Eske Willerslev, A 2-million-year-old ecosystem in Greenland uncovered by environmental DNA, Nature (2022). DOI: 10.1038/s41586-022-05453-y. www.nature.com/articles/s41586-022-05453-y

Comment by Dr. Krishna Kumari Challa yesterday

This is what we wanted: EU agrees ban on imports driving deforestation

The European Union reached an agreement yesterday to ban the import of products including coffee, cocoa and soy in cases where they are deemed to contribute to deforestation.

The draft law, which aims to ensure "deforestation-free supply chains" for the 27-nation EU, was hailed by environmental groups as "groundbreaking".

It requires companies importing into the EU to guarantee products are not produced on land that suffered deforestation after December 31, 2020, and that they comply with all laws of the source country.

The scope encompasses palm oil, cattle, soy, coffee, cocoa, timber and rubber as well as derived products such as beef, furniture and chocolate.

Illegal production has spurred massive deforestation in countries such as Brazil, Indonesia, Malaysia, Nigeria, the Democratic Republic of Congo, Ethiopia, Mexico and Guatemala.

The United Nations' Food and Agriculture Organization estimates that an aggregate area of land bigger than the European Union, or some 420 million hectares (more than one billion acres), has been deforested around the world over the past three decades.

The law opened the way for technology such as satellite monitoring and DNA analysis to verify the provenance of targeted imports. The legislation would be reviewed one year after coming into force, to see whether it should be extended to other wooded land. Another review at the two-year mark would have the commission considering whether to expand it to cover other ecosystems and commodities, as well as financial institutions.

WWF, called the agreement "groundbreaking" and "historic".

source: AFP

Comment by Dr. Krishna Kumari Challa on Tuesday

Insulin sensitivity is preserved in mice made obese by feeding a high starch diet

Abstract: Obesity is generally associated with insulin resistance in liver and muscle and increased risk of developing type 2 diabetes, however there is a population of obese people that remain insulin sensitive. Similarly, recent work suggests that mice fed high carbohydrate diets can become obese without apparent glucose intolerance. To investigate this phenomenon further, we fed mice either a high fat (Hi-F) or high starch (Hi-ST) diet and measured adiposity, glucose tolerance, insulin sensitivity, and tissue lipids compared to control mice fed a standard laboratory chow. Both Hi-ST and Hi-F mice accumulated a similar amount of fat and tissue triglyceride compared to chow-fed mice. However, while Hi-F diet mice developed glucose intolerance as well as liver and muscle insulin resistance (assessed via euglycaemic/hyperinsulinaemic clamp), obese Hi-ST mice maintained glucose tolerance and insulin action similar to lean, chow-fed controls. This preservation of insulin action despite obesity in Hi-ST mice was associated with differences in de novo lipogenesis and levels of C22:0 ceramide in liver and C18:0 ceramide in muscle. This indicates that dietary manipulation can influence insulin action independently of the level of adiposity and that the presence of specific ceramide species correlates with these differences.

https://elifesciences.org/articles/79250?utm_source=content_alert&a...

Comment by Dr. Krishna Kumari Challa on Tuesday

Using a green algae capsule to deliver chemotherapeutic drugs to a ...

A team of researchers at the University of California, San Diego, has developed a green algae capsule for delivering chemotherapy drugs to the gastrointestinal (GI) tract. In their study, published in the journal Science Robotics, the group delivered drugs via the capsule, which passed through the stomach without being digested.

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Signs of brain ageing after severe COVID

Severe COVID-19 has been linked to changes in the brain similar to those seen in old age. Scientists studied brain samples from 21 people who had severe SARS-CoV-2 infections when they died. Inflammation and stress genes in the frontal cortex — a brain region essential for cognition — were more active in infected people than in uninfected people, and genes linked to forming connections between brain cells were less active. Proteomics researcher Daniel Martins-de-Souza says the work is preliminary but could ultimately help people who have lingering cognitive difficulties after COVID-19.

Comment by Dr. Krishna Kumari Challa on Tuesday

Researchers harness bacteria-eating viruses to create powerful food decontamination spray

Researchers  have created a powerful new weapon against bacterial contamination and infection.

They have developed a way to coax bacteriophages—harmless viruses that eat bacteria—into linking together and forming microscopic beads. Those beads can safely be applied to food and other materials to rid them of harmful pathogens such as E. coli 0157. Each bead is about 20 microns, (one 50th of a millimeter) in diameter and is loaded with millions of phages.

The researchers' sprayable new super-disinfectant is food-safe and highly effective, as they describe in an article  published recently in the journal Nature Communications.

Self-assembling nanofibrous bacteriophage microgels as sprayable antimicrobials targeting multidrug-resistant bacteria, Nature Communications (2022). DOI: 10.1038/s41467-022-34803-7

Comment by Dr. Krishna Kumari Challa on Tuesday

Study hints at the potentially crucial role of shear stress in the activation of pain sensing neurons

Feelings of pain and discomfort are crucial to the survival and evolution of animals, as they help to detect injuries or existential threats and pinpoint their location in the body. Pain signals are produced by nociceptors, sensory neurons that respond to damage to the body and send "threat" signals to the spinal cord.

Nociceptors (i.e., neurons sensing pain) are essentially bare nerve endings that can be found in all parts of the body, including the skin, muscles, bones and viscera. While many neuroscience studies have investigated their structure and function, the mechanisms underpinning their activation remain poorly understood.

Researchers have recently set out to better understand these mechanisms by conducting experiments on fruit fly larvae. Their findings, published in Neuron, suggest that these neurons specifically respond to shear stress (i.e., stress caused by two forces of similar strength acting on opposite sides of a body and moving in opposite directions), but do not respond to stretch.

The key goal of the recent work was to identify the specific forces that lead to the activation of these pain sensing neurons and elucidate the underlying transduction mechanisms. To do this, the researchers first conducted behavioral experiments, where they poked a fruit fly larva using a calibrated fishing line. "In the absence of stimulation, larvae tend to move forward with frequent changing of direction. However, when they poked a larva, it stopped moving and displayed a 360-degree body rotation. This rolling was interpreted as nocifensive behaviour (i.e., animal behavior aimed at withdrawing from danger). The strength of response was measured as a percentage of animals that rolled in response to poking. Using computer modeling, the team found that poking a fruit fly larva could elicit two different kinds of forces, stretch and shear stress to stimulate nociceptors. In the following calcium imaging experiments to explore which forces are responsible for nociceptor activation, the researchers stretched the larvae's nociceptors or apply a shear force to them. They found that the larvae's nociceptors were activated by shear stress, but not by stretch. They were also able to identify the specific type of ion channel that is found in nociceptors and is activated by shear stress, called transient receptor potential A1 (TrpA1). Interestingly, shear stress appeared to be able to activate TrpA1 in a small patch of cell membrane devoid of cellular environment, providing evidence of TrpA1 as a molecular sensor of shear stress. They further show the effect of shear stress was through modulation of membrane's fluidity.

This study has two notable findings:First, the researchers showed that shear stress could be a physiologically relevant force that is critical for activation of nociceptors. Second, it provided evidence that TrpA1 is a shear stress sensor and this property is conserved for TrpA1 derived from Drosophila, mice and humans.

Jiaxin Gong et al, Shear stress activates nociceptors to drive Drosophila mechanical nociception, Neuron (2022). DOI: 10.1016/j.neuron.2022.08.015

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