(Press-News.org) In the ongoing Ebola outbreak in West Africa, whose death toll is approaching 10,000, little information has been available about how the human immune response unfolds after infection.
Researchers from Emory and the Centers for Disease Control and Prevention have now obtained a first look at the immune responses in four Ebola virus disease survivors who received care at Emory University Hospital in 2014, by closely examining their T cells and B cells during the acute phase of the disease. The findings reveal surprisingly high levels of immune activation, and have implications for the current effort to develop vaccines against Ebola.
All four patients' immune systems showed strong signs of T and B cell activation, according to a paper to be published in PNAS. Some previous research on Ebola virus disease had suggested that immune responses could be impaired.
"Our findings counter the idea that Ebola virus infection is immunosuppressive, at least in the patients that we were able to study," says lead author Anita McElroy, MD, assistant professor of pediatrics (infectious disease) at Emory University School of Medicine and a guest researcher at CDC's Viral Special Pathogens Branch. "They also demonstrate the value that supportive care may have in enabling the immune system to fight back against Ebola virus infection."
The paper emerged from a collaboration between immunologists at Emory Vaccine Center led by Rafi Ahmed, PhD, Aneesh Mehta, MD and Emory's Serious Communicable Diseases Unit team, and investigators from CDC's Viral Special Pathogens Branch, led by Christina Spiropoulou, PhD. Researchers from La Jolla Institute for Allergy and Immunology contributed to the paper.
"Until now, detailed studies like this in acute Ebola virus disease were logistically challenging," Ahmed says. "Our work only became possible through a close collaboration with the CDC and use of its biosafety level 4 facilities."
Each patient's level of immune activation reflected the relative intensity of their illnesses. Out of the four patients, the first two became very sick, the third was even sicker and required renal replacement therapy and respiratory support, and the fourth had a milder illness in comparison.
While hospitalized, the first three of the patients displayed lymphopenia, or low levels of immune cells in their blood. However, an extraordinarily high proportion of their B and T cells were activated, researchers found.
The immune activation continued even after the virus became undetectable in the blood and patients had left the hospital, suggesting that Ebola antigens persist in the body for several weeks.
Scientists tracked patients' B cells, important for generating antibodies against the Ebola virus, and cytotoxic CD8+ T cells, which directly kill infected cells.
The patients' CD8+ T cells targeted several proteins, and a major target was an internal Ebola virus protein called NP. However, vaccines now entering clinical trials in Africa contain only the external glycoprotein called GP. This suggests that NP could be added to existing vaccines to generate stronger T cell responses.
"CD8+ T cell responses have been associated with vaccine protection against Ebola infection in some animal models," McElroy says. "But the relative importance of T cell responses, compared to antibody responses, in driving survival and vaccine efficacy in humans is not known. We anticipate it will be an active area of research in the future."
INFORMATION:
March 9, 2015
PITTSBURGH--To fully understand how nanomaterials behave, one must also understand the atomic-scale deformation mechanisms that determine their structure and, therefore, their strength and function.
Researchers at the University of Pittsburgh, Drexel University, and Georgia Tech have engineered a new way to observe and study these mechanisms and, in doing so, have revealed an interesting phenomenon in a well-known material, tungsten. The group is the first to observe atomic-level deformation twinning in body-centered cubic (BCC) tungsten nanocrystals. ...
COLUMBUS, Ohio - Children whose parents think they're God's gift to the world do tend to outshine their peers - in narcissism.
In a study that aimed to find the origins of narcissism, researchers surveyed parents and their children four times over one-and-a-half years to see if they could identify which factors led children to have inflated views of themselves.
Results showed that parents who "overvalued" their children when the study began ended up with children who scored higher on tests of narcissism later on.
Overvalued children were described by their parents ...
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It has long been known that TS, which emerges in childhood and is characterized by troublesome motor and vocal tics, is often accompanied by other disorders, especially attention-deficit hyperactivity disorder (ADHD) and obsessive-compulsive ...
If advanced biofuels are to replace gasoline, diesel and jet fuel on a gallon-for-gallon basis at competitive pricing, we're going to need a new generation of fuel crops - plants designed specifically to serve as feedstocks for fuels. Researchers with the U.S. Department of Energy (DOE)'s Joint BioEnergy Institute (JBEI) have demonstrated the power of a new ally in this effort - proteomics!
In a study led by Benjamin Schwessinger, a grass geneticist with JBEI's Feedstocks Division, researchers used advanced proteomic techniques to identify 1,750 unique proteins in shoots ...
DURHAM, N.C. -- The discovery of the "exercise hormone" irisin three years ago and more than 170 related papers about it since have been called into question by recent research showing they were based on flawed testing kits.
Previous studies suggested that the hormone irisin -- named for the Greek messenger goddess Iris -- travels from muscle to fat tissue after exercise to tell fat cells to start burning energy instead of storing it. The finding ignited hope and press coverage that irisin could hold the key to fighting diabetes and obesity, perhaps one day taking the ...
In a study that helps to deconstruct how olfaction is encoded in the brain, neuroscientists at University of California, San Diego School of Medicine have identified a type of neuron that appears to help tune, amplify and dampen neuronal responses to chemosensory inputs from the nasal cavity.
The study, published March 9 in Nature Neuroscience, has applications to understanding the root cause of epileptic seizures, which are frequently centered in the olfactory cortex, the part of the brain that processes the sense of smell.
"Our sense of smell is complex and involves ...
A new class of drugs identified and validated by Mayo Clinic researchers along with collaborators at Scripps Research Institute and others, clearly reduces health problems in mice by limiting the effect of senescent cells -- cells that contribute to frailty and diseases associated with age. The researchers say this is a first step toward developing similar treatments for aging patients. Their findings appear today in the journal Aging Cell.
"If translatable to humans -- which makes sense as we were using human cells in many of the tests - this type of therapy could keep ...
Irvine, Calif., March 9, 2015 -- Long the stuff of science fiction, the disembodied "brain in a jar" is providing science fact for UC Irvine researchers, who by studying the whole brains of fruit flies are discovering the inner mechanisms of jet lag.
To do this, Todd C. Holmes, professor of physiology & biophysics in the UCI School of Medicine, and colleagues used imaging technology to make movies of fruit fly brains kept alive for six days in a petri dish. The scientists captured the activity of individual circadian clocks at single-cell resolution with an extremely ...
More than two years after Washington legalized marijuana, parents and teens may be hazy on the specifics of the law, if the findings of a new study are any indication.
University of Washington research, published recently in Substance Use & Misuse, found that only 57 percent of Washington parents surveyed knew the legal age for recreational marijuana use and just 63 percent knew that homegrown marijuana is illegal under the law.
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The new information helps predict how the global tropics may react to future climate change. These findings are detailed in a paper titled "Photosynthetic seasonality of global tropical forests constrained by hydroclimate," which was published in Nature Geoscience this month.
"A better understanding ...
