“These results suggest that vaccines inducing durable protective immunity against SARS-CoV-2 do so by stimulating robust germinal center responses — a question that can be effectively answered using the rhesus model,” said Smita Iyer, assistant professor of pathology, microbiology and immunology at the UC Davis School of Veterinary Medicine and Center for Immunology and Infectious Diseases.

The immune response to coronavirus plays a protective role in recovery from disease, and most patients make a full recovery, Iyer said. But an uncontrolled immune response or “cytokine storm” is also implicated in causing severe complications in some people.

Animal studies are critical to conclusively identify markers of vaccine-mediated protection, by telling us which immune cells triggered by the vaccine are protective. Understanding immune determinants of protection against infection and disease is crucial to enhance vaccine efficacy, Iyer said.

Signs of an effective immune response

Iyer and colleagues infected eight rhesus macaques at the CNPRC with SARS-CoV-2 virus isolated from the first human patient treated at UC Davis. At the time (early March) the case was the first known example of “community transmission” in the U.S. that could not be traced to someone arriving from another country.

The researchers followed immune responses in the animals over about two weeks. The animals showed either mild disease that was quickly resolved or no symptoms, with a brief and transient immune response, Iyer said.

The animals showed all the signs of producing an effective immune response to a viral infection. They made a type of helper cell called Th1 cells in the blood, lungs and lymph nodes, and produced both IgM-type antibodies and the higher-affinity IgG antibodies associated with long-term immune protection.

Importantly, structures called germinal centers developed in the lymph nodes near the lungs. These contained cells called T follicular helper, or Tfh, cells. Germinal centers and Tfh cells are associated with generating plasma cells, which remain in the body for many years to produce antibodies against pathogens the immune system has seen before. These plasma cells allow the immune system to “remember” and react to infections that occurred years or decades previously.

“These results suggest that vaccines that induce Th1-Tfh responses will support immunity,” Iyer said.

Additional authors on the study are: at UC Davis: Yashavanth Shaan Lakshmanappa, Sonny Elizaldi, Jamin Roh, Brian Schmidt, Timothy Carroll, Anil Verma Jesse Deere, Joseph Dutra, Rebecca Lee Sammak, Katherine Olstad, J. Rachel Reader, Zhong-Min Ma, Nancy Nguyen, Jennifer Watanabe, Jodie Usachaenko, Ramya Immareddy, JoAnn Yee, Dennis Hartigan-O’Connor, Stephen McSorley, John Morrison, Nam Tran, Koen Van Rompay and Christopher Miller; Kourtney Weaver, Justin Smith and Pamela Kozlowski, Louisiana State University Health Sciences Center, New Orleans; Mars Stone, Graham Simmons and Michael Busch, UCSF and Vitalant Research Institute, San Francisco; and Daniela Weiskopf and Alessandro Sette, UC San Diego.

The work was partly supported by grants from the National Institutes of Health.

In a study published today in the journal Nature Communications, Australian researchers teamed up with researchers from the French National Centre for Space Studies (CNES) and the French metrology lab Systèmes de Référence Temps-Espace (SYRTE) at Paris Observatory.

The team set the world record for the most stable laser transmission by combining the Aussies’ ‘phase stabilisation’ technology with advanced self-guiding optical terminals.

Together, these technologies allowed laser signals to be sent from one point to another without interference from the atmosphere.

Lead author Benjamin Dix-Matthews, a PhD student at ICRAR and UWA, said the technique effectively eliminates atmospheric turbulence.

“We can correct for atmospheric turbulence in 3D, that is, left-right, up-down and, critically, along the line of flight,” he said.

“It’s as if the moving atmosphere has been removed and doesn’t exist.

“It allows us to send highly-stable laser signals through the atmosphere while retaining the quality of the original signal.”

The result is the world’s most precise method for comparing the flow of time between two separate locations using a laser system transmitted through the atmosphere.

ICRAR-UWA senior researcher Dr Sascha Schediwy said the research has exciting applications.

“If you have one of these optical terminals on the ground and another on a satellite in space, then you can start to explore fundamental physics,” he said.

“Everything from testing Einstein’s theory of general relativity more precisely than ever before, to discovering if fundamental physical constants change over time.”

The technology’s precise measurements also have practical uses in earth science and geophysics.

“For instance, this technology could improve satellite-based studies of how the water table changes over time, or to look for ore deposits underground,” Dr Schediwy said.

There are further potential benefits for optical communications, an emerging field that uses light to carry information.

Optical communications can securely transmit data between satellites and Earth with much higher data rates than current radio communications.

“Our technology could help us increase the data rate from satellites to ground by orders of magnitude,” Dr Schediwy said.

“The next generation of big data-gathering satellites would be able to get critical information to the ground faster.”

The phase stabilisation technology behind the record-breaking link was originally developed to synchronise incoming signals for the Square Kilometre Array telescope.

The multi-billion-dollar telescope is set to be built in Western Australia and South Africa from 2021.

Cooling atoms is equivalent to slowing them down, which makes them a lot easier to study. At room temperature, atoms whiz through the air at nearly the speed of sound, some 343 meters per second. The rapid, randomly moving atoms have only fleeting interactions with other particles, and their motion can make it difficult to measure transitions between atomic energy levels. When atoms slow to a crawl — about 0.1 meters per second — researchers can measure the particles’ energy transitions and other quantum properties accurately enough to use as reference standards in a myriad of navigation and other devices.

For more than two decades, scientists have cooled atoms by bombarding them with laser light, a feat for which NIST physicist Bill Phillips shared the 1997 Nobel Prize in physics. Although laser light would ordinarily energize atoms, causing them to move faster, if the frequency and other properties of the light are chosen carefully, the opposite happens. Upon striking the atoms, the laser photons reduce the atoms’ momentum until they are moving slowly enough to be trapped by a magnetic field.

But to prepare the laser light so that it has the properties to cool atoms typically requires an optical assembly as big as a dining-room table. That’s a problem because it limits the use of these ultracold atoms outside the laboratory, where they could become a key element of highly accurate navigation sensors, magnetometers and quantum simulations.

Now NIST researcher William McGehee and his colleagues have devised a compact optical platform, only about 15 centimeters (5.9 inches) long, that cools and traps gaseous atoms in a 1-centimeter-wide region. Although other miniature cooling systems have been built, this is the first one that relies solely on flat, or planar, optics, which are easy to mass produce.

“This is important as it demonstrates a pathway for making real devices and not just small versions of laboratory experiments,” said McGehee. The new optical system, while still about 10 times too big to fit on a microchip, is a key step toward employing ultracold atoms in a host of compact, chip-based navigation and quantum devices outside a laboratory setting. Researchers from the Joint Quantum Institute, a collaboration between NIST and the University of Maryland in College Park, along with scientists from the University of Maryland’s Institute for Research in Electronics and Applied Physics, also contributed to the study.

The apparatus, described online in the New Journal of Physics, consists of three optical elements. First, light is launched from an optical integrated circuit using a device called an extreme mode converter. The converter enlarges the narrow laser beam, initially about 500 nanometers (nm) in diameter (about five thousandths the thickness of a human hair), to 280 times that width. The enlarged beam then strikes a carefully engineered, ultrathin film known as a “metasurface” that’s studded with tiny pillars, about 600 nm in length and 100 nm wide.

The nanopillars act to further widen the laser beam by another factor of 100. The dramatic widening is necessary for the beam to efficiently interact with and cool a large collection of atoms. Moreover, by accomplishing that feat within a small region of space, the metasurface miniaturizes the cooling process.

The metasurface reshapes the light in two other important ways, simultaneously altering the intensity and polarization (direction of vibration) of the light waves. Ordinarily, the intensity follows a bell-shaped curve, in which the light is brightest at the center of the beam, with a gradual falloff on either side. The NIST researchers designed the nanopillars so that the tiny structures modify the intensity, creating a beam that has a uniform brightness across its entire width. The uniform brightness allows more efficient use of the available light. Polarization of the light is also critical for laser cooling.

The expanding, reshaped beam then strikes a diffraction grating that splits the single beam into three pairs of equal and oppositely directed beams. Combined with an applied magnetic field, the four beams, pushing on the atoms in opposing directions, serve to trap the cooled atoms.

Each component of the optical system — the converter, the metasurface and the grating — had been developed at NIST but was in operation at separate laboratories on the two NIST campuses, in Gaithersburg, Maryland and Boulder, Colorado. McGehee and his team brought the disparate components together to build the new system.

“That’s the fun part of this story,” he said. “I knew all the NIST scientists who had independently worked on these different components, and I realized the elements could be put together to create a miniaturized laser cooling system.”

Although the optical system will have to be 10 times smaller to laser-cool atoms on a chip, the experiment “is proof of principle that it can be done,” McGehee added.

“Ultimately, making the light preparation smaller and less complicated will enable laser-cooling based technologies to exist outside of laboratories,” he said.

According to the study’s lead author, SFU Earth Sciences PhD student, Yu-Yen Pan, the trace fossil was found in a rocky area near coastal Taiwan. Trace fossils are part of a research field known as ichnology. “I was fascinated by this monster burrow at first glance,” she says. “Compared to other trace fossils which are usually only a few tens of centimetres long, this one was huge; two-metres long and two-to-three centimetres in diameter. The distinctive, feather-like structures around the upper burrow were also unique and no previously studied trace fossil has shown similar features.”

Pan and SFU Earth Sciences professor Shahin Dashtgard are part of an international team that named the homes of these ancient giant worms Pennichnus formosae. Pan initiated the work while completing her M.Sc. degree under the supervision of Professor Ludvig Löwemark, from the Department of Geosciences at National Taiwan University, Taiwan.

After investigating 319 specimens preserved in early Miocene strata (22 million — 20 million years ago) in northeast Taiwan, the morphological model of this trace fossil was constructed.

“Shahin encouraged us to reach out to marine biologists, marine photographers and aquarium keepers to compare the burrows to biological analogs, which enabled us to reach the conclusion that this trace fossil was produced by giant, ambush-predatory worms,” says Pan.

The modern-day Bobbit worm, which is also large and predatory, is sometimes called the ‘sand striker,’ sensing prey with its antennae, then grabbing them with its powerful jaws, and retreating into its burrow. When it burrows, its body occupies the whole burrow which explains the two-metre-long burrow observed in Pennichnus.

Further analysis revealed a high concentration of iron around the upper burrow, leading researchers to believe the worm secreted mucus to reinforce and rebuild its burrow wall after each feeding.

Modern Bobbit worm burrow openings are similar to that of Pennichnus, suggesting that the sediment collapsed into the burrow upon retreating or pulling still live prey below the seafloor.

Marine predatory worms have existed since the early Palaeozoic (> 400 million years ago), but their soft tissue bodies decay leaving little trace of their existence behind. Pennichnus formosae is believed to be the first known trace fossil produced by a sub-surface ambush predator, allowing researchers a rare opportunity to learn more about this ancient sand striker’s behaviour.

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Materials provided by Simon Fraser University. Note: Content may be edited for style and length.

Lupus, an autoimmune disease that can cause inflammation of the joints, skin, kidneys, blood cells, brain, heart and lungs, is caused when the immune system attacks its own tissue.

Previous research has established that in up to 80 percent of lupus patients, sunlight exposure can trigger both local skin inflammation and systemic flares, including kidney disease. But little has been understood about the underlying mechanisms that drive this process.

To define how UV light triggers kidney inflammation, the research team investigated the role of neutrophils — a type of white blood cell abundantly found in the body that acts as a first responder to any kind of inflammation and has been linked to skin and kidney tissue injury in lupus patients.

In the study, the researchers looked for markers of inflammation and injury in the skin, the blood, and the kidney at different time points following UV light exposure in mice. They were able to demonstrate that neutrophils not only infiltrated the UV light-exposed skin, but also dispersed throughout the circulatory system and migrated to the kidney.

“Interestingly, one subset of these neutrophils, the ones that we think are more damaging, first went to the skin that was exposed to the UV light and then turned around and went to the kidney,” says Sladjana Skopelja-Gardner, PhD, an assistant professor of medicine at Geisel who worked with Keith Elkon, MD, at UW on the study. “That’s a bit unusual — we normally think of neutrophils as short-lived cells that sort of zoom to where the inflammation is and then die off there.”

The investigators found that a single exposure of skin to UV light stimulates inflammatory and injury processes in the kidney, including transient proteinuria, even in normal, healthy mice.

“To be clear, normal, healthy mice don’t get the clinical type of kidney disease that you see in lupus patients,” explains Skopelja-Gardner. “They get what we call subclinical injury, meaning there is an inflammatory and injury process happening in the kidney that is not visible by pathology or looking at the tissue itself. The mice recover and are fine afterwards.

“However,” she adds, “this subclinical injury may lead to pathologic consequences in the vulnerable setting of pre-existing inflammation in lupus patients, and lead to kidney disease flare after exposure to sunlight.”

Importantly, the inflammatory and injury markers they detected in the mouse kidneys following UV light exposure were very similar to the renal injury markers that are associated with more severe kidney damage in lupus patients. In addition, the exposure to UV light also triggered an immune response that is often expressed in most lupus patients — the type 1 interferon response — in both the skin and kidney.

“Overall, I think what our research demonstrates is that skin exposure to UV light can be the source of inflammatory pathways that are relevant to lupus, and that neutrophils play an important role as a pathogenic mediator in this process, contributing to kidney damage,” says Skopelja-Gardner.

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Materials provided by The Geisel School of Medicine at Dartmouth. Original written by Timothy Dean. Note: Content may be edited for style and length.

The prototype starfish, which has features in common with both sea lilies and modern-day starfish, is a missing link for scientists trying to piece together its early evolutionary history.

The exceptionally preserved fossil, named Cantabrigiaster fezouataensis, was discovered in Morroco’s Anti-Atlas mountain range. Its intricate design — with feathery arms akin to a lacework — has been frozen in time for roughly 480 million years.

The new species is unusual because it doesn’t have many of the key features of its contemporary relatives, lacking roughly 60% of a modern starfish’s body plan.

The fossil’s features are instead a hybrid between those of a starfish and a sea lily or crinoid — not a plant but a wavy-armed filter feeder which fixes itself to the seabed via a cylindrical ‘stem’.

The discovery, reported in Biology Letters, captures the early evolutionary steps of the animal at a time in Earth’s history when life suddenly expanded, a period known as the Ordovician Biodiversification Event.

The find also means scientists can now use the new find as a template to work out how it evolved from this more basic form to the complexity of their contemporaries.

“Finding this missing link to their ancestors is incredibly exciting. If you went back in time and put your head under the sea in the Ordovician then you wouldn’t recognize any of the marine organisms — except the starfish, they are one of the first modern animals,” said lead author Dr Aaron Hunter, a visiting postdoctoral researcher in the Department of Earth Sciences.

Modern starfish and brittle stars are part of a family of spiny-skinned animals called the echinoderms which, although they don’t have a backbone, are one of the closest group of animals to vertebrates. Crinoids, and otherworldly creatures like the sea urchins and sea cucumbers are all echinoderms.

The origin of starfish has eluded scientists for decades. But the new species is so well preserved that its body can finally be mapped in detail and its evolution understood. “The level of detail in the fossil is amazing — its structure is so complex that it took us a while to unravel its significance,” said Hunter.

It was Hunter’s work on both living and fossil echinoderms that helped him spot its hybrid features. “I was looking at a modern crinoid in one of the collections at the Western Australian Museum and I realised the arms looked really familiar, they reminded me of this unusual fossil that I had found years earlier in Morocco but had found difficult to work with,” he said.

Fezouata in Morocco is something of a holy grail for palaeontologists — the new fossil is just one of the many remarkably well preserved soft-bodied animals uncovered from the site.

Hunter and co-author Dr Javier Ortega-Hernández, who was previously based at Cambridge’s Department of Zoology and is now based at Harvard University, named the species Cantabrigiaster in honour of the long history of echinoderm research at their respective institutions.

Hunter and Ortega-Hernández examined their new species alongside a catalogue of hundreds starfish-like animals. They indexed all of their body structures and features, building a road map of the echinoderm skeleton which they could use to assess how Cantabrigiaster was related to other family members.

Modern echinoderms come in many shapes and sizes, so it can be difficult to work out how they are related to one another. The new analysis, which uses extra-axial theory — a biology model usually only applied to living species — meant that Hunter and Ortega-Hernández could identify similarities and differences between the body plan of modern echinoderms and then figure out how each family member was linked to their Cambrian ancestors.

They found that only the key or axial part of the body, the food groove — which funnels food along each of the starfish’s arms — was present in Cantabrigiaster. Everything outside this, the extra-axial body parts, were added later.

The authors plan to expand their work in search of early echinoderms. “One thing we hope to answer in the future is why starfish developed their five arms,” said Hunter. “It seems to be a stable shape for them to adopt — but we don’t yet know why. We still need to keep searching for the fossil that gives us that particular connection, but by going right back to the early ancestors like Cantabrigiaster we are getting closer to that answer.”