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Yerkes Research Advancements

AIDS

  • Created an AIDS vaccine now in clinical trials via the HIV Vaccine Trials Network (HVTN).
  • Isolated and characterized T-cells that respond to HIV.
  • Identified the first animal model for AIDS-related dementia.
  • Discovered the strength of the immune response very early in the course of HIV infection predicts whether HIV eventually will invade the brain.
  • Safely and significantly reduced the plasma viral load and also prolonged survival of rhesus macaques severely infected with SIV by blocking programmed death-1 (PD-1), an immune receptor molecule known to inhibit the immune response to chronic viral infections. 
  • Confirmed CD8+ lymphocytes have an important effect in reducing the level of virus replication in rhesus macaques infected with SIV, a virus closely related to HIV.
  • Identified a way some sooty mangabeys' immune cells resist SIV infection, which is helping researchers identify strategies to help HIV-infected individuals cope better with infection. 
  • Explained why vaccines designed to protect against HIV can backfire and lead to increased rates of infection, known as the backfire effect, and recommended vaccine researchers may need to steer away from vaccines that activate too many viral target cells in mucosal tissues.
  • Developed a non-invasive method to image simian immunodeficiency virus (SIV) replication in real-time, in vivo, which has broad application to the study of immunodeficiency virus pathogenesis and drug and vaccine development, as well as to the potential use with human patients to identify viral reservoirs potentially leading to a cure of HIV/AIDS. 
  • Found an immunity stimulator, IL-21, is effective at reducing residual inflammation and improving the reconstitution of cells critical for intestinal immunity.
  • Showed combining ART with an immune-enhancing treatment may destabilize viral reservoirs in macaques infected with simian immunodeficiency virus (SIV), a strategy potentially applicable to humans to diminish HIV reservoirs and reduce the amount of HIV in a person’s body to the point where the immune system could control the infection without antiretroviral drugs.
  • Achieved sustained remission in SIV infection in rhesus macaques by supplementing antiretroviral drugs with an antibody during and after drug treatment. This finding could make it so someone would not need to continuously take anti-retroviral drugs, and it could help researchers craft more effective vaccines.
  • Identified a group of antiviral T cells that can gain access into germinal centers and, therefore, may be important for designing better therapeutic vaccines as well as suppressing HIV long-term.

Cognitive Function/Decline

  • Identified deleterious effects of estrogen on cognitive function.
  • Determined spatial memory declines at a greater rate in nonhuman primate males than females, suggesting a species' sex may influence age-related cognitive decline.
  • Discovered the first conclusive evidence of Alzheimer’s-like neurofibrillary brain tangles in an aged nonhuman primate.
  • Discovered a compound used to diagnose Alzheimer’s disease in humans may also be useful in determining why humans develop the disease and other primates do not.
  • Developed a test in nonhuman primates that uses infrared eye tracking to detect mild cognitive impairment (MCI) in humans. Researchers hope the advanced technology will be helpful in predicting the onset of Alzheimer’s disease.

Drug Addiction

  • Developed a new class of compounds, phenyltropanes, which are being tested as candidate medications for treatment of cocaine addiction.
  • Identified a new gene called CART (cocaine and amphetamine regulated transcript), whose expression increases with the administration of cocaine.
  • Found CART peptides are partially responsible for many of the behavioral changes caused by cocaine and also regulates feeding. Researchers at Yerkes now are studying new ways to treat obesity.
  • Determined neurochemical changes in the brain associated with cocaine use also can be triggered by environmental stimuli in the absence of cocaine.
  • Determined cocaine's effects in the brain depend upon the context in which the drug is acquired.

Evolution and Behavior

  • Discovered capuchin monkeys cooperate to obtain food and share the rewards of their efforts. This behavior has implications for understanding the evolutionary basis of reciprocity, a fundamental feature of human society.
  • Showed chimpanzees respond to crowding with powerful coping mechanisms rather than becoming aggressive.
  • Learned chimpanzees recognize faces as well as people do.
  • Observed similarities between chimpanzee culture and human culture through chimpanzees' ability to adopt social norms, pass down behaviors and traditions to other individuals and to formulate arbitrary sequences of behaviors specific to individual social groups.
  • Demonstrated chimpanzees respond empathetically to animated chimpanzees, showing a level of identification with the animations. Understanding why and how chimpanzees connect with animations may help researchers understand why and how humans empathize with others.
  • Discovered chimpanzees prefer to follow the example of older, high-status individuals when it comes to solving a problem or adopting a new behavior.
  • Identified chimpanzees' contagious yawning is a sign of social connection between the animals. This finding is helping researchers understand empathy in chimpanzees and humans, and may help show how social biases strengthen or weaken empathy. 
  • Demonstrated chimpanzees have a significant bias for prosocial behavior, which challenged previous findings that humans are an altruistic anomaly.
  • Showed chimpanzees choose cooperation over competition, thus challenging the perceptions humans are unique in our ability to cooperate and chimpanzees are overly competitive. This suggests the roots of human cooperation are shared with other primates.

Imaging Capabilities

  • Using MRI and PET imaging, Yerkes is working to research and develop discovery isotopes to aid in diagnosing, treating and monitoring diseases with the goal of identifying earlier and more accurately the pharmacological effects of the compounds tested. These findings will be used to determine the potential use of these compounds in diagnosis, treatment and monitoring in humans.

Infectious Diseases (non HIV/AIDS)

  • Identified blood-based biomarkers in patients with active tuberculosis (ATB) that could lead to new blood-based diagnostics and tools for monitoring treatment response and cure.
  • Determined patterns of gene expression, known as molecular signatures, are important for predicting flu vaccine immunity in young and elderly.
  • Highlighted the need for more sensitive diagnostic tests based on showing that while a strain of bacteria is susceptible to an antibiotic it has the ability to ignore treatment with it.
  • Showed intestinal inflammation in mice can be dampened by subjecting them briefly to a diet restricted in amino acids, the building blocks of proteins, which highlights an ancient connection between cellular mechanisms to sense nutrient availability and control of inflammation. Researchers also suggested a low protein diet -- or drugs that mimic its effects on immune cells -- could be tools for the treatment of inflammatory bowel diseases, such as Crohn’s disease or ulcerative colitis. 

Neurobiology

  • Transformed an antisocial mouse into a more social animal by genetically manipulating the distribution of a specific receptor in the brain.
  • Discovered a specific neuropeptide in the brain is essential for social recognition in mice.
  • Identified unique neural mechanisms involved in mother-infant interactions using non-invasive techniques. These studies provide information on the neural basis of diseases such as autism and schizophrenia.
  • Determined the role of steroid hormones, neuropeptides, environmental variables and neuroendocrine mechanisms in primate behavior and reproduction.
  • Found a single gene, the vasopressin receptor, is responsible for making promiscuous male meadow voles monogomous.
  • Discovered the length of seemingly non-functional DNA, also referred to as junk DNA, may shape social behavior
  • Determined tamoxifen induces anxiety-like behavior in female monkeys, which may have implications for humans taking this cancer medication.
  • Showed inducing the release of brain oxytocin may be a viable therapeutic option for enhancing social function in psychiatric disorders, including autism spectrum disorders and schizophrenia.
  • Determined repeated exposure to anesthesia early in life causes alterations in emotional behavior that may persist long-term.
  • Discovered a social laboratory rodent, the prairie vole, shows an empathy-based consoling response when other voles are distressed, thus ending the long-standing belief detecting the distress of others and acting to relieve that stress is uniquely human, and highlighting the important implications for understanding and treating psychiatric disorders, including autism spectrum disorder (ASD) and schizophrenia, in which detecting and responding to the emotions of others can be disrupted.
  • Showed the chronic stress of life at lower socioeconomic levels can alter the immune system, even in the absence of other risk factors, and that upward mobility boosts immunity.

Parkinson's Disease

  • Identified cellular locales where dopamine and glutamate interact within the basal ganglia, the network of neurons that control movement.
  • Discovered specific glutamate receptors as targets for the development of new treatments and therapies.
  • Provided highly sought insights into the cause of Parkinson's disease (PD) by systematically recording for the first time neural activity in the human striatum, a deep brain structure that plays a major role in cognitive and motor function. This has promising implications for developing better treatments and preventions for PD.

Stem Cells

  • Discovered dental pulp stem cells can stimulate growth and generation of several types of neural cells. Findings from this study suggest dental pulp stem cells show promise for use in cell therapy and regenerative medicine, particularly therapies associated with the central nervous system.

Transgenic Research

  • Developed the first transgenic nonhuman primate model of Huntington’s disease (HD), one of the most devastating human neurodegenerative diseases. Development is expected to lead to greater understanding of the underlying biology of HD and to the development of potential therapies.
  • Showed transgenic Huntington’s disease monkeys display a full spectrum of symptoms resembling the human disease, thus strengthening the case transgenic Huntington’s disease monkeys could be used to evaluate emerging treatments before launching human clinical trials.

Transplantation Medicine

  • Successfully used antibodies to foster long-term acceptance of transplanted organs in mice without immunosuppressive medicine.
  • Developed new techniques for precise quantification and typing of T-cell subpopulations as means for measuring the success or failure of a transplanted organ.
  • Helped developed an FDA-approved transplant drug, belatacept, that preserves kidney function, prevents graft rejection and avoids toxicity common in immunosuppressive medications.