May 16, 2022

Zika is spread mainly through the bite of an infected Aedes species mosquito. And while many people infected with the Zika virus will only have mild symptoms, contracting Zika during pregnancy can lead to severe brain defects.  

 The 2015-2016 Zika outbreak in Brazil and other countries in the Americas caused a surge in miscarriages and a constellation of congenital disabilities, prompting the World Health Organization to declare a public health emergency of international concern. 

 While there has never been a vaccine or medicine to prevent Zika, a recent collaboration between Trudeau Institute, Texas Biomedical Research Institute’s Southwest National Primate Research Center (SNPRC), and Walter Reed Army Institute of Research (WRAIR) demonstrated a vaccine candidate successfully prevented the virus from passing from mother to fetus during animal studies. 

 In-Jeong Kim, Ph.D., a viral immunologist at Trudeau Institute and the first paper author states, “Our proof-of-concept studies conducted at Trudeau and Texas Biomed show very promising results that the vaccine given before pregnancy will provide high levels of protection for mothers and babies.” 

 Testing pregnant women is highly restrictive due to ethical and safety reasons, which is why the Trudeau Institute and Texas Biomed team evaluated the vaccine in pregnant mice and marmosets. The results? More than 90% effectiveness in marmosets, making it a viable approach for countering the persistent threat of Zika in humans. 

March 31, 2022

Oxytocin, a brain chemical known for promoting social bonding and nurturing behavior, has been used in several studies to potentially treat disorders such as autism, but with inconsistent results. 

Yerkes National Primate Research Center Division Chief Larry Young and his research colleagues in Yerkes’ Division of Behavioral Neuroscience and Psychiatric Disorders as well as Emory’s Center for Translational Social Neuroscience found the dynamic response of neurons to oxytocin may vary depending on the past social experiences of the individual. 

The study was conducted in female prairie voles because they form lifelong bonds with their partners and focused on the nucleus accumbens because it plays an important role in the brain for pair bonding. Tissue from the nucleus accumbens was exposed to TGOT, a drug that mimics oxytocin signals. 

Robert Liu, PhD, professor of biology and director of Emory’s Neuroscience graduate program compared the electrical responses of neurons to oxytocin signals to an analog television, before and after the television is tuned to a station. “Before the animal forms a pair bond, oxytocin reduces the static noise: the neurons in the nucleus accumbens fire spontaneously less often,” said Liu. “But after an animal has been exposed to a partner, it increases the clarity of the signal from the station: the neurons gradually fire with greater strength – but only when electrically triggered.”

In an unexpected turn, researchers found that after bonding, oxytocin signals became coupled to endocannabinoids, molecules produced within the brain resembling the psychoactive substances found in cannabis. By blocking the endocannabinoids, the scientists could interfere with some aspects of the prairie voles pair interactions. 

Blocking endocannabinoid signals increased the likelihood the female vole would display a defensive upright posture, a sign of rejection, in the presence of their partner, but not toward a stranger. However, the pair-bonded animals still spent more time with their partner than a stranger. This reaction shows endocannabinoid signaling is modulating defensive interactions, rather than pair bonding. 

The study suggests the way oxytocin modulates brain circuits changes with prior experience, which may help explain inconsistent results from human studies involving oxytocin.

October 13, 2021

Adolescents may face many challenges throughout their teenage years, from depression and poor body image to loneliness and even substance abuse. To help address and limit these concerns, researchers are continually looking for connections between the human brain, environment and mental health.

The impact of COVID-19 on adolescent mental health is especially important to address following the social isolation intended to limit the spread of the virus. Yerkes National Primate Research Center neuroscientist Shannon Gourley’s research on the effect of isolation on adolescent mice will be a resource to researchers studying how the COVID-19 pandemic has affected children.

Gourley’s research provides insights into adolescent brain mechanisms. She and her research team discovered mice that have a history of social isolation have higher dendritic spine densities in regions of the brain relevant to decision-making, such as the prefrontal cortex. Social isolation interferes with the pruning of dendritic spines, the structures that underlie connections between neurons.

While we typically think more of something is better, this is not the case for dendritic spines. Instead, such elevated levels related to social adversity experienced during sensitive adolescent periods lead to long-term consequences, despite a typical social environment later in life.

Gourley says, “our findings suggest adolescence is a critical period during which social experience optimizes one’s ability to seek and attain goals later in life.”

Interrupting social experiences may translate into poor choices about homework, food and even hygiene, and that makes Gourley’s research critical now and in the future to help her team and other researchers counter additional, long-term impacts of COVID-19.

 

Note: The NPRCs will update this blog with our latest COVID-19 news.

Since beginning COVID-19 research in early 2020, NPRC researchers have made encouraging progress in efforts to better understand, diagnose, prevent and treat this novel disease. We’re committed to conducting and enabling research to end this global pandemic and to providing information so the public has ready access to our scientific results.

Our most recent COVID-19 news includes: 

Below is even more information about our extensive and collaborative COVID-19 research:

Diagnostics:

Prevention:

Treatments:

Additional NPRC COVID-19 News:

Bookmark this page so you can easily return here for the latest NPRC COVID-19 research information. We’ve also compiled a list of resources here and provided links to previous NPRC COVID-19 news and national media stories here.

July 13, 2021

HIV (human immunodeficiency virus) attacks the body’s immune system, and if left untreated, HIV can lead to AIDS (acquired immunodeficiency syndrome). HIV/AIDS currently impacts 38 million people worldwide. While there is no cure yet, proper medical care can control the disease and allow for a relatively long and healthy life. In particular, antiviral therapy (ART) is the current leading treatment for HIV/AIDS and can reduce the virus to undetectable levels. 

Yerkes National Primate Research Center researchers, in collaboration with Institut Pasteur, recently determined that when added to ART, a combination immunotherapy of Interleukin-21 (IL-21) and interferon alpha (IFNɑ) is effective in generating highly functional natural killer (NK) cells that can help control and reduce simian immunodeficiency virus (SIV), the primate equivalent to HIV, content in tissue.

“Our results indicate the ART plus combo-treated rhesus monkeys showed enhanced antiviral NK cell responses,” says Justin Harper, lab manager of Dr. Mirko  Paiardini’s research lab at Yerkes. “These robust NK cell responses helped clear cells harboring virus in lymph nodes, which is normally shielded from robust immune responses and serves as a critical tissue that supports viral persistence.”

These new findings open the door to additional treatment strategies to help support remission without using ART, a costly treatment option that requires strict, long-term adherence. Ultimately, the researchers are working to reduce the burden of HIV to individuals and the world. To learn more about NPRC research into HIV/AIDs, please visit here

June 8, 2021

Tuberculosis (TB) is a serious infectious disease that typically affects the lungs. Spread of TB typically occurs in the air via coughs or sneezes. Treatment often poses a challenge to immunologists, as it represents a chronic infection characterized by persistence of the pathogen despite development of antigen-specific immune responses.

Researchers at Emory University and the Yerkes National Primate Research Center have completed the first study to report on temporal dynamics of Mycobacterium tuberculosis (Mtb)-specific T cell responses in latent Mtb infection. With it, they discovered the T cell response emerged as early as three weeks post infection and continued throughout the six-month study. 

“Because TB is the leading infectious disease killer, claiming 1.5 million lives every year, we want to know why some people who are infected with Mtb progress to TB disease while others remain asymptomatic and do not,” says Jyothi Rengarajan, PhD, lead author and associate professor of medicine, Division of Infectious Diseases, Emory University School of Medicine and a researcher at the Emory Vaccine Center and Yerkes National Primate Research Center. 

Because TB is difficult to assess in humans, researchers worked with primates because they develop and respond to the disease much like humans do

Rengarajan states, “Monkeys develop and respond to latent TB infection similar to the way humans do, which makes them an excellent translational model for studying the immunological basis for asymptomatic TB and then applying the results to humans and animals.”

Findings proved the rapid response of T cells, and knowing where to activate them (lungs versus blood) will help researchers create better treatments and even a vaccine to prevent TB infections.

NPRC researchers are working to find new potential treatments and cures for this infectious disease. Take a look at some of our other recent studies to learn about the progress we’ve made toward a TB-free world.

April 27, 2021

Did you know the rhesus macaque is the most widely studied nonhuman primate in biomedical research? The U.S. research colonies of rhesus macaques were founded primarily with animals imported from India decades ago and with the addition of Chinese-origin rhesus macaques over time. A deep understanding of their evolution and genetics is key to recognizing the origins of human traits and identifying disease genes of value to improving human health.

Rhesus macaques at the seven National Primate Research Centers (NPRCs) are key in the discovery and development of new and robust models of human disease and in evaluating the effect of genetic variation on experimental treatments prior to human clinical trials.  

In a recent publication in Science that detailed researchers’ use of advanced sequencing technology and analysis of more than 850 macaques across the seven NPRCs, researchers present a complete reference genome for the rhesus macaque. “In particular, we can now finally tackle some of the more complex regions of the genome and begin to understand how new genes evolve including the processes that have shaped them,” says University of Washington genome sciences professor and senior author in the paper, Evan Eichler, PhD.

In addition, the study identified animals that naturally carry potentially damaging genetic mutations, allowing researchers to better understand genetic variation and susceptibility to diseases of relevance to humans. So far, the findings reveal thousands of naturally occurring genetic variants (mutations), including those in genes linked to Autism Spectrum Disorder and other neurodevelopmental disorders in humans, such as SHANK3.

Jeffrey Rogers, PhD, associate professor at the Human Genome Sequencing Center and Department of Molecular and Human Genetics at Baylor College of Medicine and co-author of the paper explains, “Rhesus macaques are important for studies of conditions ranging from infectious disease (including COVID-19) to neuroscience, cancer and reproductive biology. A high-quality reference genome can aid researchers who are looking to understand the causes of various illnesses or aiming to develop treatments.”

The study is a great example of a broad collaboration across the NPRCs and other research centers in the U.S. that will continue to make a difference in human health. By identifying rhesus macaques that carry naturally occurring mutations, NPRC and other researchers are now able to examine biobehavioral traits associated with mutations. The researchers can also follow the monkeys’ offspring, and, in some cases, actually create new breeding groups to generate animals with specific genetic mutations and phenotypes. 

“This new information will lay the foundation for us to create naturally occurring models of human genetic diseases,” says Paul Johnson, MD, director of the Yerkes (now Emory) NPRC. “The development of these new models could have a profound impact on our ability to translate research in animal models into treatments and cures in people,” he continues.

To learn more about NPRC advances in genetics and genomics, explore additional research here

March 3, 2021

Scientific discovery is an ongoing process that takes time, observation, data collection and analysis, patience and more. At the NPRCs, our recent COVID-19 research is an example of the ongoing basic science process — how current research builds on previous discoveries and how discoveries help improve human health. This article from the National Institutes of Health (NIH) explains why basic science, such as the NPRCs conduct, is important and how taking time, as long as it takes, is a necessary part of scientific discovery.

Discoveries in Basic Science: A Perfectly Imperfect Process

Have you ever wondered why science takes so long? Maybe you haven’t thought about it much. But waiting around to hear more about COVID-19 may have you frustrated with the process.

Science can be slow and unpredictable. Each research advance builds on past discoveries, often in unexpected ways. It can take many years to build up enough basic knowledge to apply what scientists learn to improve human health.

“You really can’t understand how a disease occurs if you don’t understand how the basic biological processes work in the first place,” says Dr. Jon Lorsch, director of NIH’s National Institute of General Medical Sciences. “And of course, if you don’t understand how the underlying processes work, you don’t have any hope of actually fixing them and curing those diseases.”

Basic research asks fundamental questions about how life works. Scientists study cells, genes, proteins, and other building blocks of life. What they find can lead to better ways to predict, prevent, diagnose, and treat disease.

How Basic Research Works

When scientists are interested in a topic, they first read previous studies to find out what’s known. This lets them figure out what questions still need to be asked.

Using what they learn, scientists design new experiments to answer important unresolved questions. They collect and analyze data, and evaluate what the findings might mean.

The type of experiment depends on the question and the field of science. A lot of what we know about basic biology so far has come from studying organisms other than people.

“If one wants to delve into the intricate details of how cells work or how the molecules inside the cells work together to make processes happen, it can be very difficult to study them in humans,” Lorsch explains. “But you can study them in a less complicated life form.”

These are called research organisms. The basic biology of these organisms can be similar to ours, and much is already known about their genetic makeup. They can include yeast, fruit flies, worms, zebrafish, and mice.

Computers can also help answer basic science questions. “You can use computers to look for patterns and to try to understand how the different data you’ve collected can fit together,” Lorsch says.

But computer models have limits. They often rely on what’s already known about a process or disease. So it’s important that the models include the most up-to-date information. Scientists usually have more confidence in predictions when different computer models come up with similar answers.

This is true for other types of studies, too. One study usually only uncovers a piece of a much larger puzzle. It takes a lot of data from many different scientists to start piecing the puzzle together.

Building Together

Science is a collective effort. Researchers often work together and communicate with each other regularly. They chat with other scientists about their work, both in their lab and beyond. They present their findings at national and international conferences. Networking with their peers lets them get feedback from other experts while doing their research.

Once they’ve collected enough evidence to support their idea, researchers go through a more formal peer-review process. They write a paper summarizing their study and try to get it published in a scientific journal. After they submit their study to a journal, editors review it and decide whether to send it to other scientists for peer review.

“Peer review keeps us all informed of each other’s work, makes sure we’re staying on the cutting-edge with our techniques, and maintains a level of integrity and honesty in science,” says Dr. Windy Boyd, a senior science editor who oversees the peer-review process at NIH’s scientific journal of environmental health research and news.

Different experts evaluate the quality of the research. They look at the methods and how the results were gathered.

“Peer reviewers can all be looking at slightly different parts of the work,” Boyd explains. “One reviewer might be an expert in one specific method, where another reviewer might be more of an expert in the type of study design, and someone else might be more focused on the disease itself.”

Peer reviewers may see problems with the experiments or think different experiments are needed. They might offer new ways to interpret the data. They can also reject the paper because of poor quality, a lack of new information, or other reasons. But if the research passes this peer review process, the study is published.

Just because a study is published doesn’t mean its interpretation of the data is “right.” Other studies may support a different hypothesis.

Scientists work to develop different explanations, or models, for the various findings. They usually favor the model that can explain the most data that’s available.

“At some point, the weight of the evidence from different research groups points strongly to an answer being the most likely,” Lorsch explains. “You should be able to use that model to make predictions that are testable, which further strengthens the likelihood that that answer is the correct one.”

An Ever-Changing Process

Science is always a work in progress. It takes many studies to figure out the “most accurate” model—which doesn’t mean the “right” model.

It’s a self-correcting process. Sometimes experiments can give different results when they’re repeated. Other times, when the results are combined with later studies, the current model no longer can explain all the data and needs to be updated.

“Science is constantly evolving; new tools are being discovered,” Boyd says. “So our understanding can also change over time as we use these different tools.”

Science looks at a question from many different angles with many different techniques. Stories you may see or read about a new study may not explain how it fits into the bigger picture.

“It can seem like, at times, studies contradict each other,” Boyd explains. “But the studies could have different designs and often ask different questions.”

The details of how studies are different aren’t always explained in stories in the media. Only over time does enough evidence accumulate to point toward an explanation of all the different findings on a topic.

“The storybook version of science is that the scientist is doing something, and there’s this eureka moment where everything is revealed,” Lorsch says. “But that’s really not how it happens. Everything is done one increment at a time.”

 

December 18, 2020

Researchers at Yerkes National Primate Research Center (YNPRC) have discovered a way to use cancer immunotherapy treatments to reliably shrink the size of the viral “reservoir” in simian immunodeficiency virus (SIV)-infected nonhuman primates treated with antiviral drugs.

In humans, antiviral drugs can suppress human immunodeficiency virus (HIV) to the point of being undetectable in blood, but the virus embeds itself in the DNA of specific immune cells (T cells). Each reservoir consists of T cells that continue to harbor the virus even during antiviral drug treatment.

According to the researchers, chronic viral infection and cancer produce similar states of “exhaustion.” T cells that could fight virus or cancer are present but unable to respond. In long-term HIV or SIV infection, T cells harboring the virus display molecules on the cell surface that make them targets for checkpoint inhibitors (cancer immunotherapy drugs designed to counteract the exhausted state).

In this study, researchers combined two cancer immunotherapy treatments to block the surface molecules CTLA-4 and PD-1 in nonhuman primates. In subjects that received both CTLA-4- and PD-1-blocking agents, researchers noted a stronger activation of T cells compared to only a PD-1 blockade.

“We observed that combining CTLA-4 and PD-1 blockade was effective in reactivating the (SIV) virus from latency and making it visible to the immune system,” said Mirko Paiardini, PhD, an associate professor of pathology and laboratory medicine at Emory University School of Medicine and a researcher at YNPRC.

In previous studies, shrinkage of the viral reservoir has been limited and inconsistent when researchers use single checkpoint inhibitors or other immune-stimulating agents. During this study, however, combination-treated animals showed a consistently measurable and significant reduction in the size of the viral reservoir.

Despite these findings, the combination treatment does not prevent or delay viral rebound once antiviral drugs are stopped. Paiardini suggested the approach may have greater potential if combined with other strategies, for example a therapeutic vaccine, or it could be deployed in a target-rich environment, for example during ART interruption when the immune system is engaged in intercepting and fighting the rebounding virus. Other HIV researchers have started to test those tactics, he indicated.

It is also noteworthy the equivalent combination of CTLA-4 and PD-1 blockade in humans has been tested in the context of cancer treatment, and while the two drug types can be more effective together, patients sometimes experience adverse side effects like severe inflammation, kidney damage or liver damage. Fortunately, the combination-treated animals in this study did not experience comparable events.

Finding a complete HIV cure is still critically important because problematic issues, like social stigma and the long-term toxicity and cost of antiretroviral drugs, remain. 

To learn more about how NPRC scientists are working toward effective treatments—and ultimately a cure—visit this link.

December 15, 2020

Research with animals is crucial to improving human and animal health. Animals in research provide unique insights not available with other scientific models, and they help scientists determine safety and effectiveness of preventions, treatments and cures. During the COVID-19 pandemic, animals in research have been especially important in accelerating the development COVID-19 vaccines as well as better diagnostics and additional treatment options.

At the NPRCs, we’re helping fill a critical role in halting COVID-19 by leading NIH-funded studies at our centers. We’re also participating in the public-private partnership ACTIV (Accelerating COVID-19 Therapeutic Interventions and Vaccines) to develop treatments and vaccines by sharing our knowledge, resources and animals, including conducting preclinical studies with NPRC monkeys for some of the leading industry vaccine candidates.

Scientific collaboration is especially important during a pandemic when time is of the essence and, in this case, animal resources are limited. At the onset of the pandemic, monkey importation was halted, putting increasing demands on the NPRC animal colonies, which were already limited in quantity and availability. The NPRCs account for only 1 in every 5 nonhuman primates (NHPs) used in U.S.-based research, so the limited supply at a time of high demand impacts NPRC COVID-related studies as well as pre-pandemic studies under way at the NPRCs and those in planning stages.

The NPRCs remain dedicated to our other areas of study, including research into HIV/AIDS and other infectious diseases, the neurosciences, cardiovascular and respiratory health, genetics and transplant medicine. 

We are also committed to meeting the future needs of animals for NIH-funded research. We are already growing our on-site breeding colonies when time, space and funding permit, strategically assigning animals to research protocols, harmonizing across centers for efficient use of animals and increasing rigor and reproducibility to facilitate collaboration and consistency across research labs. These strategic steps now further position the NPRCs for the translation of our research advancements from cell and animal models to humans, and are indicative of our commitment to help people across generations and the world live longer, healthier lives. 

To learn more about the NPRCs’ ongoing efforts to combat COVID-19, visit this page.

Editor’s Note, 2/22/21: The New York Times covered the research monkey shortage in today’s issue. Read the story here.

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