HIV can persist for years in myeloid cells of people on antiretroviral therapy

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

Scientific Frontline: "At a Glance" Summary: HIV Persistence in Myeloid Cells

• Main Discovery: HIV can persist for years in myeloid cells, specifically short-lived monocytes and longer-lived monocyte-derived macrophages, in individuals who have been virally suppressed on antiretroviral therapy.
• Methodology: Researchers isolated monocytes from the blood of virally suppressed participants and cultured them with antiretroviral drugs. After the monocytes differentiated into macrophages, an immune activating agent and fresh white blood cells were introduced to track viral reactivation and spread over a 12-day period using a novel quantitative method.
• Key Data: Detectable levels of HIV genetic material were found in the myeloid cells of 30 participants who had been on antiretroviral therapy for at least five years. Furthermore, cell cultures from 5 out of 10 participants demonstrated that the virus in these macrophages could reactivate, produce more virus, and infect new cells.
• Significance: The identification of myeloid cells as a long-lived and stable reservoir capable of viral rebound challenges the prevailing scientific consensus that monocytes are too short-lived to significantly impede HIV eradication efforts.
• Future Application: HIV cure strategies must be fundamentally broadened beyond their current scope to simultaneously target and eradicate viral reservoirs in both CD4 T cells and myeloid cells.
• Branch of Science: Virology and Microbiology
• Additional Detail: The study was led by researchers at the Johns Hopkins University School of Medicine, funded by the National Institutes of Health, and published in the journal Nature Microbiology.

With fewer salmon to eat, Southern Resident killer whales spend less time in the San Juan Islands

killer whales
Photo Credit: Michelle Klampe

As a key food supply declines, the endangered population of Southern Resident killer whales, known to frequent the Salish Sea off the coasts of Washington and British Columbia, is spending far less time in that region, a new study shows.

The Salish Sea around the San Juan Islands has traditionally been a hotspot for the whales. The Southern Residents would spend the summer months feeding on Chinook salmon, much of which belonged to the Fraser River stock that passes through the islands on its way to spawning grounds upriver.

But 17 years of whale sighting data shows that as the Fraser River Chinook salmon population dropped, the time spent by the Southern Residents around the San Juan Islands also declined ­– by more than 75%, said Joshua Stewart, an assistant professor with Oregon State University’s Marine Mammal Institute and the study’s lead author.

The findings were just published in the journal Marine Mammal Science. Co-authors of the paper are Jane Cogan, an independent researcher in Friday Harbor, Washington; John Durban, a professor with MMI who is also affiliated with the nonprofit SeaLife Response, Rehabilitation and Research (SR3); Holly Fearnback of SR3; David Ellifrit, Mark Malleson and Ken Balcomb of the nonprofit Center for Whale Research; and Melisa Pinnow of San Juan Orcas, a website dedicated to identification of individual orcas.

Components of Cytoskeleton Strengthen Effect of Sex Hormones

Super-high-resolution microscopic image of a cell that has been exposed to the sex hormone dihydrotestosterone. The androgen receptor (violet) and actin (green) are visible in the cell nucleus. Both molecules are stained with fluorescent dyes and thus made visible. The individual structures made visible (right) are only 200 nanometers (200 millionths of a millimeter) small.
Image Credit: Julian Knerr/University of Freiburg

Researchers from Freiburg and Kiel discover that actin acts in the cell nucleus and is partly responsible for the expression of male sexual characteristics

Steroid hormones, to which belong sex hormones like estrogen or testosterone, are important signaling molecules and are responsible among other things for controlling female and male phenotypic sex differentiation. They act by binding to receptor molecules that switch on and off the activity of hormone-dependent genes. Researchers at the University of Freiburg and Kiel University Hospital have discovered that components of the cytoskeleton are critically involved in this process. The findings are relevant for the diagnosis of medical conditions and the study of diseases and cancers in which steroid hormones play important roles. The study was published in the renowned journal Nature.

The new research findings show that filamentous actin, a component of the cytoskeleton, interacts with the androgen receptor directly in the cell nucleus and strengthens its effect. The androgen receptor mediates the signals of sex hormones for male sex development but also promotes the progression of prostate cancer.

Giant planet atmospheres vary widely, JWST confirms

 A ‘hot Jupiter’ called HD 149026b, is about 3 times hotter than the rocky surface of Venus, the hottest planet in our solar system.
Illustration Credit: NASA/JPL-Caltech

Gas giants orbiting our sun show a clear pattern; the more massive the planet, the lower the percentage of “heavy” elements (anything other than hydrogen and helium) in the planet’s atmosphere. But out in the Galaxy, the atmospheric compositions of giant planets do not fit the solar system trend, an international team of astronomers has found.

Using NASA’s James Webb Space Telescope (JWST), the researchers discovered that the atmosphere of exoplanet HD149026b, a ‘hot Jupiter’ orbiting a star comparable to our sun, is super-abundant in the heavier elements carbon and oxygen – far above what scientists would expect for a planet of its mass. In addition, the diagnostic carbon-to-oxygen ratio of HD149026b, also known as “Smertrios,” is elevated relative to our solar system.

A ‘hot Jupiter’ called HD 149026b, is about 3 times hotter than the rocky surface of Venus, the hottest planet in our solar system.

These findings, published in “High atmospheric metal enrichment for a Saturn-mass planet,” in Nature on [March 27] are an important first step toward obtaining similar measurements for a large sample of exoplanets in order to search for statistical trends, the researchers said. They also provide insight into planet formation.

Beaver Fossil Named After Buc-ee’s

Matthew Brown (left) and Steve May with beaver skulls new and old in the vertebrate paleontology collections at the Jackson School of Geosciences. Brown, the director of the collections, holds a skull from a modern North American Beaver. May, a research associate, holds a skull from Anchitheriomys buceei, a new species of ancient beaver that he discovered in the collections and named.
Photo Credit: UT Jackson School of Geosciences.

A new species of ancient beaver that was rediscovered by researchers in The University of Texas Austin’s fossil collections has been named after Buc-ee’s, a Texas-based chain of popular travel centers known for its cartoon beaver mascot.

The beaver is called Anchitheriomys buceei, or “A. buceei” for short.

Steve May, a research associate at the UT Jackson School of Geosciences, said that the beaver’s Texas connection and a chance encounter with a Buc-ee’s billboard are what inspired the name.

May is the lead author of the paper that describes A. buceei, along with another, much smaller, species of fossil beaver. Published in the journal Palaeontologia Electronica, the paper provides an overview of beaver occurrences along the Texas Gulf Coast from 15 million to 22 million years ago based on bones and archival records in the UT collections.

While driving down a highway in 2020, May spotted a Buc-ee’s billboard that said “This is Beaver Country.” The phrase brought to mind the Texas beaver fossils he had been studying at UT’s Texas Vertebrate Paleontology Collections.

Understanding nitrogen metabolism could revolutionize TB treatment, finds study

Illustration Credit: Courtesy of University of Surrey

Development of new drugs to effectively target the bacterium that causes tuberculosis (TB) could be one step closer following an important discovery from the University of Surrey.

The Surrey study used a technology called fluxomics to reveal important information about how cells process nitrogen, which could help us better understand how harmful bacteria survive and cause disease. These findings have significant implications for studying the behavior and impact of pathogenic bacteria on human health.

In the most comprehensive study of its kind, the research team from Surrey conducted a study on the bacterium that causes tuberculosis, called Mycobacterium tuberculosis (Mtb). They wanted to understand how nitrogen is processed within Mtb cells, which is essential for the bacterium's survival. Surprisingly, previous studies had mostly examined the role of carbon in Mtb's survival, leaving the role of nitrogen poorly understood.

Earth’s first plants likely to have been branched, study finds

Selaginella
Photo Credit: Vicky Spencer

A new discovery by scientists at the University of Bristol changes ideas about the origin of branching in plants.

By studying the mechanisms responsible for branching, the team have determined what the first land plants are likely to have looked like millions of years ago. 

Despite fundamentally different patterns in growth, their research has identified a common mechanism for branching in vascular plants.

Dr Jill Harrison from Bristol’s School of Biological Sciences explained: “Diverse shapes abound in the dominant flowering plant group, and gardeners will be familiar with ‘pinching out’ plants’ shoot tips to stimulate side branch growth, leading to a bushier overall form.

“However, unlike flowering plants, other vascular plants branch by splitting the shoot apex into two during growth, a process known as ‘dichotomy’.

As an ancient vascular plant lineage that formed coal seams during the Carboniferous era, lycophytes preserve the ancestral pattern of dichotomous branching.

Surprise effect: Methane cools even as it heats

Annual mean near-surface air temperature response to methane, decomposed into (a) longwave and shortwave effects; (b) longwave effects only; and (c) shortwave effects only.
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Illustration Credit: Robert Allen / University of California, Riverside

Most climate models do not yet account for a new UC Riverside discovery: methane traps a great deal of heat in Earth’s atmosphere, but also creates cooling clouds that offset 30% of the heat. 

Greenhouse gases like methane create a kind of blanket in the atmosphere, trapping heat from Earth’s surface, called longwave energy, and preventing it from radiating out into space. This makes the planet hotter. 

“A blanket doesn’t create heat, unless it’s electric. You feel warm because the blanket inhibits your body’s ability to send its heat into the air. This is the same concept,” explained Robert Allen, UCR assistant professor of Earth sciences.

In addition to absorbing longwave energy, it turns out methane also absorbs incoming energy from the sun, known as shortwave energy. “This should warm the planet,” said Allen, who led the research project. “But counterintuitively, the shortwave absorption encourages changes in clouds that have a slight cooling effect.”

Fish Will Help Scientists to Measure Levels of Radiation

Researchers' finding will supplement the radiation monitoring of rivers and lakes in the Southern Urals.
 Photo Credit: Rodion Narudinov

The method showed its effectiveness in radionuclide-contaminated waters of the South Urals

Otoliths are hearing and equilibrium maintenance organs of fish that do not contain living cells. They can be used as individual dosimeters for radiobiology and radioecology studies. This was discovered by a team of scientists from the Ural Federal University along with their colleagues from the Chelyabinsk State University and the Ural Scientific-Practical Center of Radiation Medicine.

When exposed to ionizing radiation, otolith hydroxyapatite crystals accumulate stable radicals. These radicals are proportional to the absorbed dose. Dosimetry using electron paramagnetic resonance (EPR) detects carbonate ions. As a result, the total radiation accumulated by the fish can be quantified.

The findings of the researchers will supplement the radiation monitoring of rivers and lakes in the Southern Urals, in particular, to detect the impact of radiation from strontium-90 radionuclides in the influence zone of the "Mayak" production association. Scientists concluded that EPR dosimetry in fish otoliths is a promising tool for external or comparable internal exposure.

Researchers develop electrolyte enabling high efficiency of safe, sustainable zinc batteries

Photo Credit: Courtesy of Oregon State University

Scientists led by an Oregon State University researcher have developed a new electrolyte that raises the efficiency of the zinc metal anode in zinc batteries to nearly 100%, a breakthrough on the way to an alternative to lithium-ion batteries for large-scale energy storage.

The research is part of an ongoing global quest for new battery chemistries able to store renewable solar and wind energy on the electric grid for use when the sun isn’t shining and the wind isn’t blowing.

Xiulei “David” Ji of the OSU College of Science and a collaboration that included HP Inc. and GROTTHUSS INC., an Oregon State spinout company, reported their findings in Nature Sustainability.

“The breakthrough represents a significant advancement toward making zinc metal batteries more accessible to consumers,” Ji said. “These batteries are essential for the installation of additional solar and wind farms. In addition, they offer a secure and efficient solution for home energy storage, as well as energy storage modules for communities that are vulnerable to natural disasters.”

A battery stores electricity in the form of chemical energy and through reactions converts it to electrical energy. There are many different types of batteries, but most of them work the same basic way and contain the same basic components.

Revolutionary discovery for blood clotting

Treatment with soluble GPV prevents the formation of a vascular-closing thrombus in an experimental mouse model for thrombosis formation (right). On the left is a vascular-closing thrombus of an untreated mouse.
Image Credit: Sarah Beck / University Hospital Würzburg

The platelet glycoprotein V is an important switching point for hemostasis and thrombus formation. This new finding could have great clinical potential.

If our blood vessels are injured by cuts or abrasions or bruises, it is vital that the bleeding is stopped and the wound closed. In technical terms, this process is called hemostasis. This consists of two processes: the hemostasis, in which platelets (platelets) attach to the wound edges, form a plug and temporarily seal the injury. And the blood clotting or coagulation cascade, in which long fibers are formed from fibrin, which together with the platelets seal the wound firmly.

However, if fibrin is formed in excess, for example in chronic wounds, vascular occlusions, so-called thrombosis, can occur. Strict regulation of fibrin formation is therefore important. However, how coagulation is limited has not yet been fully understood.

In an international project coordinated by Würzburg University Medicine, researchers have now deciphered a central regulatory mechanism for fibrin formation and derived new therapeutic approaches from it. The results are released in the renowned journal Nature Cardiovascular Research.

A readily available dietary supplement may reverse organ damage caused by HIV and antiretroviral therapy

Photo Credit: Courtesy of MitoQ

MitoQ, a mitochondrial antioxidant that is available to the public as a diet supplement, was found in a mouse study to reverse the detrimental effects that HIV and antiretroviral therapy (ART) have on mitochondria in the brain, heart, aorta, lungs, kidney and liver.

The researchers used a molecular method to measure the ratio of human and murine mitochondrial (mtDNA) to nuclear DNA (ntDNA) ratio, a measure of mitochondrial dysfunction. Reduction in this ratio reflects mitochondrial dysfunction. Compared to uninfected mice, HIV infected mice treated with ART had mitochondrial dysfunction in the human immune cells in the brain, heart, liver, lungs, and gut. ART itself also affected mitochondrial function in mouse heart cells. When treated with MitoQ for 90 days, HIV infected mice had reduced mitochondrial dysfunction in organs compared to HIV infected mice on ART.

Mitochondria are the key cell structures that are important for the smooth function of organs such as the brain, heart, liver and kidney. HIV causes a chronic state of inflammation and immune dysfunction that contribute to damage to organs. The reasons for this are unclear, but it is known that mitochondrial dysfunction contributes to organ damage and is present in chronic HIV. There are no therapies for HIV associated diseases that affect organs such as the brain, heart and liver.

Climate change threatens global fisheries

Euchaeta marina (Calanoid Copepod).
Photo Credit: Julian Uribe-Palomino IMOS-CSIRO.

A major study has found that the diet quality of fish across large parts of the world’s oceans could decline by up to 10 per cent as climate change impacts an integral part of marine food chains.

QUT School of Mathematical Sciences researcher Dr Ryan Heneghan led the study published in Nature Climate Change that included researchers from the University of Queensland, University of Tasmania, University of NSW and CSIRO.

They modeled the impact of climate change on zooplankton, an abundant and extremely diverse group of microscopic animals accounting for about 40 per cent of the world’s marine biomass.

Zooplankton is the primary link between phytoplankton—which converts sunlight and nutrients into energy like plants do on land—and fish.  Zooplankton includes groups such as Antarctic krill—a major food source for whales—and even jellyfish.

New wood-based technology removes 80 percent of dye pollutants in wastewater

Researchers at Chalmers have developed a new biobased material, a form of powder based on cellulose nanocrystals to purify water from pollutants, including textile dyes. When the polluted water passes through the filter with cellulose powder, the pollutants are absorbed, and the sunlight entering the treatment system causes them to break down quickly and efficiently. Laboratory tests have shown that at least 80 percent of the dye pollutants are removed with the new method and material, and the researchers see good opportunities to further increase the degree of purification.
Illustration Credit: David Ljungberg | Chalmers University of Technology

Clean water is a prerequisite for our health and living environment, but far from a given for everyone. According to the WHO, there are currently over two billion people living with limited or no access to clean water.

This global challenge is at the center of a research group at Chalmers University of Technology, which has developed a method to easily remove pollutants from water. The group, led by Gunnar Westman, Associate Professor of Organic Chemistry, focuses on new uses for cellulose and wood-based products and is part of the Wallenberg Wood Science Center.

The researchers have built up solid knowledge about cellulose nanocrystals* – and this is where the key to water purification lies. These tiny nanoparticles have an outstanding adsorption capacity, which the researchers have now found a way to utilize.

“We have taken a unique holistic approach to these cellulose nanocrystals, examining their properties and potential applications. We have now created a biobased material, a form of cellulose powder with excellent purification properties that we can adapt and modify depending on the types of pollutants to be removed,” says Gunnar Westman.

Can Artificial Intelligence Predict Spatiotemporal Distribution of Dengue Fever Outbreaks with Remote Sensing Data?

Image Credit: Sophia University
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Researchers train machine learning model with climatic and epidemiology remote sensing data to predict the spatiotemporal distribution of disease outbreaks

Cases of dengue fever and other zoonotic diseases will keep increasing owing to climate change, and prevention via early warning is one of our best options against them. Recently, researchers combined a machine learning model with remote sensing climatic data and information on past dengue fever cases in Chinese Taiwan, with the aim of predicting likely outbreak locations. Their findings highlight the hurdles to this approach and could facilitate more accurate predictive models.

Outbreaks of zoonotic diseases, which are those transmitted from animals to humans, are globally on the rise owing to climate change. In particular, the spread of diseases transmitted by mosquitoes is very sensitive to climate change, and Chinese Taiwan has seen a worrisome increase in the number of cases of dengue fever in recent years.

Like for most known diseases, the popular saying “an ounce of prevention is worth a pound of cure” also rings true for dengue fever. Since there is still no safe and effective vaccine for all on a global scale, dengue fever prevention efforts rely on limiting places where mosquitoes can lay their eggs and giving people an early warning when an outbreak is likely to happen. However, thus far, there are no mathematical models that can accurately predict the location of dengue fever outbreaks ahead of time.