October 20, 2021

Dengue spreads to humans through the bite of an infected mosquito generally living in tropical climates. Symptoms (lasting 2-7 days) commonly seen with dengue include fever, nausea, rash, aches, and pains.

While most people who contract the virus see minimal long-term effects, the Wisconsin National Primate Research Center is studying whether the severity of maternal and fetal Zika virus infection increases in pregnant women who previously had dengue fever.

This first-ever study relating dengue to Zika arose from a concern that a previous dengue infection may become the catalyst leading to more potentially dangerous immune system responses when contracting Zika, especially in pregnant women and their fetuses.

Rhesus macaques were used for the study because their placental development closely mimics humans. Using them as the control, researchers uncovered prior exposure has no measurable impact on Zika replication in maternal plasma. All animal pregnancies resulted in healthy births and infants (in contrast to a small percentage of human infants born to women infected with the disease).

Researchers believe further study to understand the risks of antibody-dependent enhancement to pregnant women worldwide is needed as vaccines against dengue and Zika are developed.

Want to know more about the ongoing fight to eliminate Zika? Here are some additional ways NPRC scientists across the country are making progress against this disease.

Sources: https://www.cdc.gov/dengue/index.html

September 1, 2021

Fear struck many when HIV (human immunodeficiency virus) and AIDS (acquired immunodeficiency syndrome) began in the mid-to the late 1970s. No one knew the causes of this mysterious new virus, and there were no treatments, preventions, or cures available. Over the past few decades, scientific advances have enabled patients to receive life-extending treatments and medications. 

The majority of HIV researchers agree that the virus evolved from the closely related simian immunodeficiency virus (SIV), transferring from non-human primates to humans.

CytoDyn Inc., a late-stage biotechnology company developing a drug called leronlimab, released an exciting study in partnership with Oregon National Primate Research Center showing that the drug prevents non-human primates from being infected with simian human immunodeficiency virus (SHIV), a monkey-human chimeric form of HIV. 

“Our study findings indicate leronlimab could be a new weapon against the HIV epidemic,” said Jonah Sacha, Ph.D., an Oregon Health & Science University professor at OHSU’s Oregon National Primate Center and Vaccine & Gene Therapy Institute.

Five clinical trials demonstrate how leronlimab can significantly reduce or control HIV viral load in humans—and ultimately prevent human infection from the virus that causes AIDS. If approved for clinical use, leronlimab will join other AIDS PrEP drugs (“Pre-Exposure Prophylaxis”), medicines taken by individuals who are at risk for exposure to HIV to prevent infection. The drug also benefits other diseases (NASH, cancer, and COVID-19) without the side effects previously experienced from other treatments such as kidney and bone problems.

While the research and trials are still ongoing, early results are promising. To learn more about NPRC research into HIV, please click here.

 

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 20, 2021

Lyme disease, also known as Lyme borreliosis, is an infectious disease caused by Borrelia burgdorferi bacterium, which is spread by ticks. The most common sign of infection is a red rash that appears at the site of the tick bite. Other signals of Lyme include flu-like symptoms, joint pain and weakness in the limbs.

After a 69-year-old woman was diagnosed and repeatedly treated for Lyme disease for 15 years before her death, researchers at the Tulane National Primate Research Center who had previously discovered the persistence of B. burgorferi  despite antibiotic therapy found that the same bacterium was still intact upon autopsy. 

In addition to the typical symptoms of Lyme, she experienced continual neurological decline, including a severe movement disorder and personality changes. The woman eventually passed away after being diagnosed with Lewy body dementia— a disease that presents itself with similar declined motor functions of Parkinson’s Disease with the added element of significant memory issues.  

The Tulane research team found that her central nervous system (CNS) still harbored intact spirochetes despite aggressive antibiotic therapy for Lyme disease at different times throughout her illness. The findings may lead to a correlation between Lyme disease and Lewy body dementia.

“These findings underscore how persistent these spirochetes can be in spite of multiple rounds of antibiotics targeting them,” said Monica Embers, associate professor of microbiology and immunology at Tulane. “We will be interested in investigating the role that B. burgdorferi may play in severe neurological disease, as this is an area of research that has not yet been fully explored.”

To learn more about research being done by Tulane NPRC, please visit 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.

May 18, 2021

Tuberculosis (TB) is a serious disease that mostly affects the lungs, but can also cause damage to the kidneys, spine or brain. TB spreads from person to person through small droplets transferred via coughing and sneezing. Symptoms of TB include severe coughing for over three weeks, chest pain and coughing up blood or mucus.

Even after years of research, tuberculosis still remains one of the world’s deadliest diseases— especially in low-income countries. While TB related deaths have decreased by 30% globally, 1.4 million people died from it in 2019. Fortunately, researchers at the Southwest National Primate Research Center (SNPRC) at Texas Biomedical Research Institute are getting closer to pinpointing a new way to treat and control TB.

“Single-cell RNAseq is a novel approach that has developed in the past three or four years. It’s an approach that allows us to look at the immune response more granularly, in higher resolution. We were able to identify an immune response to Mtb infection in single lung cells as the infection progressed to disease, in some cases, or was controlled in others,” stated Deepak Kaushal, Ph.D., director of SNPRC.

The study highlights that plasmacytoid dendritic cells, which sense infections in the body, overproduce Type I interferons—a response correlated with disease instead of control. This discovery gives scientists the information needed to alter vaccines.

Dr. Kaushal explains, “When we have a more precise understanding of how an infection develops, that knowledge can lead us to identify new drugs or therapies to treat disease and improve vaccines.”

Overall, the research being done by SNPRC may lead to finding a way to control and prevent TB. Learn more about our TB-related studies by visiting this link.   

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.

December 7, 2020

Tuberculosis (TB) and HIV are two of the world’s deadliest infectious diseases, and they’re far worse when they occur together. Now, Southwest National Primate Research Center (SNPRC) researchers at Texas Biomedical Research Institute have pinpointed an important mechanism that could lead to a new mode of treatment for this co-infection.

It’s been long-assumed the reason people with HIV are more likely to develop TB is a depletion of specific immune cells. However, SNPRC scientists showed other effects of viral co-infection play a crucial role in this process.

Using data from nearly 40 rhesus macaques, the research team found lung-specific chronic immune activation is responsible for the progression of TB. Chronic immune activation is a dysfunction of immune pathways that create molecules (cytokines and chemokines) that fight off pathogens such as bacteria, viruses and fungi.

Professor and SNPRC Director Deepak Kaushal, PhD, used an analogy to explain what this dysfunction caused by an HIV infection does in the body.

“It’s like all the taps and faucets in your house are turned on full blast all the time,” he said. “You are going to lose a lot of water. With this dysfunction, all cytokines and chemokines are constantly being produced to the highest levels. This dysregulates the body’s ability to fight off other infections.”

Even with antiretroviral therapy (ART) for people with HIV, chronic immune activation still persists. Kaushal said this study shows, “we need to develop approaches to target chronic immune activation,” perhaps with a drug that would be an additional therapy to ART.

Kaushal said he is hopeful new treatment strategies could reach the clinic within a decade, and the effects could be huge. Up to a fourth of the world’s population is infected with TB, and this co-infection is considered a global syndemic, meaning the diseases are pandemics infecting people all around the world, and they promote each other.

Understanding TB is a priority for NPRC scientists, and this study is a continuation of the groundbreaking research being done across the organization. Just last year, researchers explored the possibility of treating the disease using a cancer drug.

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