A new study of an exotic, infectious virus that has caused three recent outbreaks in the United States reveals clues to how the virus might damage lungs during infection. The findings also suggest possible new ways to treat lung diseases in humans.
Monkeypox causes infectious pustules as seen in this four-year old Liberian infected with the virus. Photo courtesy of CDC Public Health Image Library.
Not only does the infection from monkeypox virus increase production of proteins involved in inflammation, but it decreases production of proteins that keep lung tissue intact and lubricated. The findings appear in an upcoming issue of Molecular & Cellular Proteomics.
"Going into this study, we thought monkeypox caused disease primarily by inducing inflammation in the lung, and that leads to pneumonia," said lead author Joseph Brown, a systems biologist at the Department of Energy's Pacific Northwest National Laboratory. "We were surprised to see how badly the virus wrecked the structural integrity of the lungs."
The study was funded by the National Institute of Allergy and Infectious Diseases and the National Center for Research Resources, both part of the National Institutes of Health; the Department of Defense; and Battelle.
Collaborating with virologist Scott Wong, Ryan Estep and others at the Oregon Health & Science University's Vaccine and Gene Therapy Institute in Beaverton, Ore., Brown and the PNNL team examined how the virus affected the collection of proteins found in lung fluid from macaque monkeys at OHSU. The monkeys were part of an ongoing study of monkeypox infection at OHSU's Oregon National Primate Research Center in Beaverton.
Monkeypox and smallpox are closely related viruses that cause contagious pustules in humans, though monkeypox is less dangerous. However, monkeypox is as bad for monkeys as smallpox is for people, making it a good model for human smallpox disease. The study helps researchers better understand both monkeypox and smallpox infection.
"If researchers confirm similar events in people, doctors might be able to give surfactants — lubricating chemicals that aid in gas exchange — to help the lung function. And the findings could lead to new areas of pulmonary studies in general — bronchitis or emphysema, lung transplants, the flu," said PNNL co-author Josh Adkins.
The new pox on the street
Monkeypox infections in humans have been on the rise since smallpox was eradicated in the late 1970s. Up to 10 percent of those infected with monkeypox die of the disease. Monkeypox can be caught from infected rodents, pets and monkeys. Although mainly found in Africa, the first documented infection in the United States occurred in 2003, likely from imported pet prairie dogs.
Researchers attribute the rise of monkeypox infections to the end of smallpox vaccinations, which provided protection against monkeypox due to the similar nature of the two pox viruses. The smallpox vaccine is based upon yet another pox virus called vaccinia, which usually doesn't cause symptoms in people.
A better understanding of how monkeypox causes disease could help doctors manage outbreaks, which will likely continue to occur. Findings about monkeypox infection will also provide insight into smallpox, which is considered a potential bioterrorism agent.
Few studies exist that look at how monkeypox infection damages the lungs. Because symptoms in macaques and humans are so similar, researchers at the OHSU's Primate Center infected macaques with the monkeypox virus and followed the course of infection in the lungs of individual animals. To do this, the OHSU team washed the lungs of infected monkeys with a saline solution and sent the washes to PNNL for protein analysis. The complement of proteins produced by lung tissue before and during infection would indicate how the lungs are responding to the virus.
Immunity and structure
Using cultured cells, the team first verified that infected cells did indeed release proteins that could be detected without damaging the cells. Then the team took samples of a lung wash from four macaques as healthy controls. Next, they infected two of the four with monkeypox virus and the other two with the nearly symptomless vaccinia virus. They took additional washes every few days for up to seven weeks.
After prepping the saline sample at the primate facility in Oregon, the OHSU team sent non-infectious samples to EMSL, DOE's Environmental Molecular Sciences Laboratory on the PNNL campus, where the PNNL researchers measured and identified as many of the proteins in the samples as they could using proteomics instruments. They compared the infected samples to healthy samples to see whether the level of proteins rose or fell.
Early in infection, monkeypox and vaccinia viruses both stimulated an immune response, they found, ratcheting up production of proteins associated with inflammation. However, the monkeypox-infected lungs also showed a distinct decrease in some proteins — proteins involved in metabolism, structural proteins that serve as I-beams and cross-beams of lung tissue, and finally surfactant proteins, which provide lubrication and help with oxygen exchange.
A couple weeks into infection, the vaccinia infection wound down and the inflammatory protein production returned to normal levels. Inflammatory proteins also decreased over time in the monkeypox infected lung fluid samples, but the structural proteins continued to stay low.
"Our results suggest that inflammation contributes to disease but it may not be the main component. Interfering with the structural proteins may play a major role," said Brown.
Culture and virus
The researchers found similar trends with the cultured cells. This suggested that some aspects of monkeypox infection can be studied in test tubes. However, the animal studies provided novel insights into important physiological details.
In addition, the team directly detected viral proteins in the lung fluid samples. Usually, scientists need to use antibodies to detect viral proteins because there are so few of them swimming in a sea of host proteins. In this case, monkeypox produced 200 proteins to the macaque's estimated maximum of 46,000.
Ultimately, this type of research could have wider implications than viral infection. "This study serves as a great reference for pulmonary diseases," said Adkins. "It opens up the doors for other lung fluid studies."
Reference: Joseph N. Brown, Ryan D. Estep, Daniel Lopez-Ferrer, Heather M. Brewer, Theresa R. Clauss, Nathan P. Manes, Megan O'Connor, Helen Li, Joshua N. Adkins, Scott W. Wong, and Richard D. Smith, Characterization of macaque pulmonary fluid proteome during monkeypox infection: dynamics of host response, Mol Cell Proteomics (http://www.mcponline.org/content/early/2010/08/24/mcp.M110.001875).
Oregon Health & Science University is dedicated to improving the health and quality of life for all Oregonians through excellence, innovation and leadership in health care, education and research.
Oregon National Primate Research Center: As one of the eight National Primate Research Centers in the United States, our mandate as a Center is to provide Nonhuman Primate resources for the very best scientific programs, both within the Oregon Health & Science University community and beyond.
EMSL, the Environmental Molecular Sciences Laboratory, is a national scientific user facility sponsored by the Department of Energy's Office of Science, Biological and Environmental Research program that is located at Pacific Northwest National Laboratory. EMSL offers an open, collaborative environment for scientific discovery to researchers around the world. EMSL's technical experts and suite of custom and advanced instruments are unmatched. Its integrated computational and experimental capabilities enable researchers to realize fundamental scientific insights and create new technologies. Follow EMSL on Facebook.
Pacific Northwest National Laboratory is a Department of Energy Office of Science national laboratory where interdisciplinary teams advance science and technology and deliver solutions to America's most intractable problems in energy, the environment and national security. PNNL employs 4,900 staff, has an annual budget of nearly $1.1 billion, and has been managed by Ohio-based Battelle since the lab's inception in 1965. Follow PNNL on Facebook, LinkedIn and Twitter.
A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Materials Sciences