AIDS vaccine candidate appears to completely clear virus from the body in monkeys

Sep. 11, 2013 — An HIV/AIDS vaccine candidate developed by researchers at Oregon Health & Science University appears to have the ability to completely clear an AIDS-causing virus from the body. The promising vaccine candidate is being developed at OHSU’s Vaccine and Gene Therapy Institute. It is being tested through the use of a non-human primate form of HIV, called simian immunodeficiency virus, or SIV, which causes AIDS in monkeys. Following further development, it is hoped an HIV-form of the vaccine candidate can soon be tested in humans.These research results were published online today by the journal Nature. The results will also appear in a future print version of the publication.”To date, HIV infection has only been cured in a very small number of highly-publicized but unusual clinical cases in which HIV-infected individuals were treated with anti-viral medicines very early after the onset of infection or received a stem cell transplant to combat cancer,” said Louis Picker, M.D., associate director of the OHSU Vaccine and Gene Therapy Institute. “This latest research suggests that certain immune responses elicited by a new vaccine may also have the ability to completely remove HIV from the body.”The Picker lab’s approach involves the use of cytomegalovirus, or CMV, a common virus already carried by a large percentage of the population. In short, the researchers discovered that pairing CMV with SIV had a unique effect. They found that a modified version of CMV engineered to express SIV proteins generates and indefinitely maintains so-called “effector memory” T-cells that are capable of searching out and destroying SIV-infected cells.T-cells are a key component of the body’s immune system, which fights off disease, but T-cells elicited by conventional vaccines of SIV itself are not able to eliminate the virus. The SIV-specific T-cells elicited by the modified CMV were different. …

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Adenoviruses may pose risk for monkey-to-human leap

July 25, 2013 — Adenoviruses commonly infect humans, causing colds, flu-like symptoms and sometimes even death, but now UC San Francisco researchers have discovered that a new species of adenovirus can spread from primate to primate, and potentially from monkey to human.UCSF researchers previously identified a new adenovirus in New World titi monkeys that killed most of the monkeys infected during an outbreak in a closed monkey colony in California in 2009. At the time, a research scientist who worked closely with the monkeys and a family member, both of whom were found to have antibodies to the virus, also became ill.In a new study, which appears July 24 in the online journal PLOS One, UCSF scientists exposed three marmoset monkeys to the same virus. All three developed a mild, “cold-like” respiratory illness and an antibody response to the infection, but were able to eliminate the virus within twelve days.The results conclusively demonstrate that the new virus is capable of infecting and causing disease across primate species, according to Charles Chiu, MD, PhD, director of the UCSF-Abbott Viral Diagnostics and Discovery Center, and the lead scientist of the new study.”This study raises more concerns about the potential of unknown viruses to spread from animals to humans,” said Chiu, who is an assistant professor of medicine at UCSF. “We still don’t understand the full extent of viruses that exist in the world and their potential to cause outbreaks in human populations.”Last year, Chiu and colleagues also identified another new adenovirus, named simian adenovirus C, which sickened four of nine captive baboons and killed two of them at a primate facility in 1997. Several staff members at the facility also complained of upper respiratory symptoms at the time of the outbreak. Re-examining the samples many years later, Chiu and his colleagues found antibodies targeted to simian adenovirus C in the human samples.Chiu concluded that staff members had been exposed to the new virus, and that the virus may have jumped from baboon to human, an idea also supported by follow-up experiments in which laboratory strains of simian adenovirus C efficiently infected both human and baboon cells.”Adenoviruses to date have not generally been linked to cross-species infections between monkeys and humans,” Chiu said.In light of these findings, however, he said the normal vigilance in tracking animal viruses that might also infect humans should extend beyond influenza and coronaviruses to include adenoviruses. Chiu is working on new computational techniques to more rapidly identify novel, disease-causing viruses.Viruses with RNA genes, including influenza viruses, make many errors in replicating their genetic material, and are thereby likely to generate new, mutated forms that alter their pathogenic nature, occasionally allowing them to infect new hosts.In contrast, viruses that use DNA as their genetic material, such as adenoviruses, are thought to have less chance of spreading between species because they replicate with fewer mutations that could serve as the basis for infection-enhancing changes.However, beyond mutation during replication, the mixing of genes though recombination of distinct virus species or strains also can give rise to new viruses that are more pathogenic or that infect across mammalian species. This applies to DNA viruses as well as RNA viruses, according to Chiu.In 2009, scientists demonstrated that a more virulent strain of human adenovirus arose from recombination with other distinct strains of milder human adenoviruses.”We believe that’s similar to what happened with the simian adenovirus C outbreak in Texas,” Chiu said. “This new virus likely formed when an existing adenovirus recombined with another, generating a new strain that was highly virulent to baboons.”

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Monkey nation: Mainland Africa’s most important nation for primates

July 17, 2013 — A five-year study by the Wildlife Conservation Society gives new hope to some of the world’s most endangered primates by establishing a roadmap to protect all 27 species in Tanzania — the most primate-diverse country in mainland Africa.The study combines Tanzania’s first-ever inventory of all primate species and their habitats with IUCN Red List criteria and other factors such as threats and rarity, ranking all 27 species from most vulnerable to least vulnerable. The authors then identify a network of “Priority Primate Areas” for conservation.The paper appears in the July 17 issue of the journal Oryx. Authors are Tim Davenport of the Wildlife Conservation Society, Katarzyna Nowak of the Udzungwa Elephant Project, and Andrew Perkin of the Tanzania Forest Conservation Group.A third of Tanzania’s primate species are found nowhere else on earth. The study found that the most vulnerable was the kipunji, first discovered by WCS in 2003 on Mt Rungwe and described by WCS as an entirely new genus in 2006. Another extremely vulnerable species is the Zanzibar red colobus, a species whose population is currently being counted by WCS. More common species include the baboons, black and white colobus monkeys and vervets.The study assigned a score to pinpoint the most important areas for protection. The analysis revealed more than 60 important primate areas including national parks, game reserves, forest reserves, conservation areas, and currently unprotected landscapes. However, the adequate protection of just nine sites, including six national parks (Kilimanjaro, Kitulo, Mahale, Saadani, Udzungwa and Jozani-Chwaka Bay), one nature reserve (Kilombero) and two forest reserves (Minziro and Mgambo), totaling 8,679 square kilometers (3,350 square miles), would protect all 27 of Tanzania’s primate species.The authors say that the Priority Primate Areas could be applied in other nations rich in wildlife but facing burgeoning pressures from population growth. This could be similar to “Important Bird Areas” a global effort to identify and conserve places that are vital to birds and other biodiversity. In fact, Tanzania’s Priority Primate Areas were also often rich in bird life underscoring their value to conservation in general.”We believe Priority Primate Areas can be a valuable conservation tool worldwide, similar to the successful Important Bird Area concept,” said the study’s lead author, Tim Davenport of WCS. …

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Personality test finds some mouse lemurs shy, others bold

June 18, 2013 — Anyone who has ever owned a pet will tell you that it has a unique personality.Yet only in the last 10 years has the study of animal personality started to gain ground with behavioral ecologists, said Jennifer Verdolin of the National Evolutionary Synthesis Center, in Durham, NC.She and a colleague have now found distinct personalities in the grey mouse lemur (Microcebus murinus), the tiny, saucer-eyed primate native to the African island of Madagascar.In a study published in the journal Primates, Verdolin gave fourteen gray mouse lemurs living at the Duke Lemur Center a personality test.Verdolin filmed the lemurs’ reactions to a variety of familiar and unfamiliar objects — such as a tissue box, an egg carton, an orange ball, and a stuffed toy frog — which she placed one at a time into the animals’ enclosures. She then measured how long it took each animal to work up the nerve to approach and investigate each object. Mouse lemurs that were quick to approach objects were considered “bold,” whereas those that behaved more cautiously were considered “shy.”She also noted how agitated the lemurs got when handled by their human caretakers during routine weigh-ins and cleanings.Verdolin found that those that hung back were also harder for their human caretakers to handle, meaning the lemurs’ distinct personality traits held up across a range of situations.The report that mouse lemurs have distinct personalities doesn’t come as a shock to staff at the Duke Lemur Center. “[The mouse lemur named] Pesto is very chatty. Asparagus gets beat up by the girls. Wasabi is mean as sin, and her favorite flavor is human fingers,” said Duke Lemur Center researcher Sarah Zehr, who was not an author of the study. Other scientists have also found evidence of personality differences among grey mouse lemurs living in the wild.But for animals living in captivity, Verdolin hopes that personality studies like hers will help researchers determine which individuals are best candidates for breeding programs or for reintroduction back into the wild, as has been done with the North American swift fox, the giant panda, and the golden lion tamarin.The next step, Verdolin says, is to determine the extent to which lemur personalities are influenced by the presence of other individuals, or whether behavioral training for some personality types could improve their chances of surviving in the wild.

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Potential disease-transmission sources in animals ID’d by calculating risk using social network mathematics

June 11, 2013 — Spanish and US scientists have successfully identified animal species that can transmit more diseases to humans by using mathematical tools similar to those applied to the study of social networks like Facebook or Twitter. Their research — recently published in the journal PNAS — describes how parasite-primate interactions transmit diseases like malaria, yellow fever or AIDS to humans. Their findings could make an important contribution to predicting the animal species most likely to cause future pandemics.Professor José María Gómez of the University of Granada Department of Ecology is the principal author of this research, in collaboration with Charles L. Nunn (University of Cambridge, Massachusetts, US) and Miguel Verdú (Spanish National Research Council Desertification Research Center, Valencia, Spain). They propose a criterion to identify disease-transmission agents based on complex network metrics similar to those used to study social networks.As Prof Gómez explains, “most emerging diseases in humans are zoonotic, that is, they are transmitted to humans by animals. To identify animal species that are potential high-risk sources of emerging diseases it’s essential we set up mechanisms that control and observe these diseases.”Study of 150 primate speciesTo conduct their study, the researchers constructed a network in which each node represented one of the approximately 150 non-human primate species about which we have enough data on their parasite fauna. “Each primate species is connected to the other primates as a function of the number of parasites they share. Once the network was constructed, we studied each primate species’ position — whether central or peripheral. A primate’s centrality is measured by its connection intensity with many other primates that are, in turn, closely connected,” says the University of Granada researcher.The article published in PNAS reports the researchers’ discovery that the most central primates could be more capable of transmitting parasites to other species and, therefore, to humans, than the rest. “This is comparable to the idea that, in social networks, web pages that are central and have links to many other pages, spread their contents all through the Web,” José María Gómez affirms.The researchers have confirmed their hypothesis by relating the centrality value of each primate with the number of emerging pathogens shared with humans. …

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