The complete sequence of the P. vivax genome, reported in the Oct.9, 2008 journal Nature, could help scientists unlock its secrets.
P. vivax is responsible for at least 25 percent of the roughly 500 million cases of malaria worldwide and is the major cause of malaria outside Africa, mainly afflicting Asia and the Americas.
While P. vivax infection is usually non-lethal and doctors once considered it "benign," an increasing number of reports show the parasite can kill, says Mary Galinski, PhD, co-author of the Nature article and a researcher at Yerkes National Primate Research Center and Emory Vaccine Center of the Emory University School of Medicine.
Galinski, a professor of infectious diseases at Emory University School of Medicine, and her colleague at Yerkes, co-author and research associate Esmeralda Meyer, MD, played a critical role in assembling P. vivax's genetic information because the parasite cannot be cultured in the laboratory and can only be grown in living monkeys.
The full sequence and its analysis were a collaboration involving scientists from a dozen institutions and coordinated by the Institute of Genomic Research, part of the J. Craig Venter Institute in Rockville, Md. The first author is microbiologist Jane Carlton, PhD, now associate professor of parasitology at New York University School of Medicine.
Galinski says the complete genetic sequence of P. vivax has revealed unique genes that appear to be important for invading the host's cells and in evading the host's immune system. Unlike other malaria parasites such as P. falciparum, P. vivax can only invade reticulocytes, immature red blood cells.
Both P. vivax and P. falciparum are carried by mosquitoes and can cause fever, chills, headache, nausea and vomiting. P. falciparum's genomic sequence was published in 2002.
Compared with P. falciparum, P. vivax's ability to come back from dormancy in the liver, its faster development in the mosquito and the outdoor biting behavior of mosquitoes it prefers may make P. vivax more resilient to common control methods such as insecticide-treated nets, Galinski says.
She says knowing P. vivax's full set of genes could help scientists better understand the distinctive "hypnozoite" phase of its life cycle, when the parasite lays dormant in liver cells for months or years after initial infection.
"That's one of the areas we hope to crack, but it will only be possible by combining the new genetic information with experiments in living animals," she says.
The complete sequence of the P. vivax genome could help scientists look for new drugs and design vaccines. In the Nature paper, the authors analyzed P. vivax enzymes by computer to examine how easily resistance could develop against the antimalarial compounds artemisinin and atovaquone.
Despite the threat posed by P. vivax, Galinski notes that only two candidate vaccines and one drug against P. vivax are now in clinical trials, compared with 23 vaccine candidates and 13 drugs for P. falciparum.
She and Alberto Moreno, MD, professor of infectious diseases at Emory and an researchers at Yerkes and Emory Vaccine Center, recently published studies of a P. vivax vaccine candidate. They showed that the vaccine effectively stimulated monkeys' immune systems to produce antibodies, which in laboratory tests could block proteins the parasites use to invade blood cells.
Galinski is also a co-author on a companion paper in the same issue of Nature describing the genome of the malaria parasite Plasmodium knowlesi, whose natural host is the Kra monkey but can also infect humans. Because a laboratory culture system for P. vivax is lacking, this related parasite will be important for future malaria research, she says.
Sarah Goodwin | EurekAlert!
Full of hot air and proud of it
18.04.2018 | University of Pittsburgh
Keeping the excitement under control
18.04.2018 | Max-Delbrück-Centrum für Molekulare Medizin in der Helmholtz-Gemeinschaft
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
In an article that appears in the journal “Review of Modern Physics”, researchers at the Laboratory for Attosecond Physics (LAP) assess the current state of the field of ultrafast physics and consider its implications for future technologies.
Physicists can now control light in both time and space with hitherto unimagined precision. This is particularly true for the ability to generate ultrashort...
The Atlantic overturning – one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards – is weaker today than any time before in more than 1000 years. Sea surface temperature data analysis provides new evidence that this major ocean circulation has slowed down by roughly 15 percent since the middle of the 20th century, according to a study published in the highly renowned journal Nature by an international team of scientists. Human-made climate change is a prime suspect for these worrying observations.
“We detected a specific pattern of ocean cooling south of Greenland and unusual warming off the US coast – which is highly characteristic for a slowdown of the...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
18.04.2018 | Materials Sciences
18.04.2018 | Materials Sciences
18.04.2018 | Materials Sciences