Repurposing a transplant drug for bone growth

The transplant immunosuppressant drug FK506, also known as tacrolimus or Prograf, can stimulate bone formation in both cell culture and animal Read more

Beyond the amyloid hypothesis: proteins that indicate cognitive stability

If you’re wondering where Alzheimer’s research might be headed after the latest large-scale failure of a clinical trial based on the “amyloid hypothesis,” check this Read more

Mother's milk is OK, even for the in-between babies

“Stop feeding him milk right away – just to be safe” was not what a new mother wanted to hear. The call came several days after Tamara Caspary gave birth to fraternal twins, a boy and a girl. She and husband David Katz were in the period of wonder and panic, both recovering and figuring out how to care for them. “A nurse called to ask how my son was doing,” says Caspary, a developmental Read more

HIV/AIDS

Low vitamin D in people with HIV: links to heart risk, immune function

In people with HIV, low vitamin D levels have been linked to thicker carotid arteries as well as a weaker comeback for the immune system after starting antiretroviral therapy.

These results, published online recently in the journal Antiviral Therapy, are the first to confirm an association between low vitamin D levels and a measure of higher cardiovascular risk in people with HIV. They also suggest that the benefits of vitamin D supplementation for people with HIV should be evaluated in a clinical trial.

Allison Ross, MD, is an infectious disease specialist in the Department of Pediatrics and the Emory-Children's Pediatric Research Center.

The advent of effective antiretroviral therapy against HIV has dramatically improved life expectancies for people with HIV over the last 15 years. The presence of HIV is known to perturb cardiovascular health, even in the absence of an active infection. Since vitamin D levels are known to have an impact on the immune system and cardiovascular disease risk, that drove infectious disease specialist Allison Ross and her colleagues to probe these connections in people living with HIV. The results were also described on the Web sites AidsMeds and NAM/AidsMap.

Ross studied a group of HIV-positive people enrolled in Case Western Reserve University’s HIV clinic in Cleveland. Colleagues from Emory and Case Western were co-authors.

They tested vitamin D levels, immune function and heart health in 149 HIV-positive people and a matched group of 34 HIV-negative people. Vitamin D levels were significantly lower in the HIV-positive group, even when controlling for known factors that affect vitamin D.

The researchers looked at how much the immune system was able to come back after starting retroviral therapy. This involves comparing someone’s lowest ever CD4 T cell count from the current CD4 count. They found that people with the poorest level of immune restoration were the most likely to have the lowest level of vitamin D. In addition, people with the lowest vitamin D levels were more than 10 times as likely to have thickening of the carotid arteries, as measured by ultrasound.

Inflammation can be a driving factor for heart disease, but in the study, low vitamin D was not linked to higher levels of inflammation markers. Additional research could determine whether those who are starting antiretroviral therapy would see better immune recovery if they took a vitamin D supplement.

Researchers at Emory have been investigating several aspects of low Vitamin D levels and their impact on health, including a connection with Parkinson’s disease. Endocrinologist Vin Tangpricha notes that Emory studies are looking at vitamin D in the context of tuberculosis, sepsis, sickle cell disease, cancer, cystic fibrosis and pain sensitivity.

Posted on by Quinn Eastman in Heart Leave a comment

One reason why SIV-infected sooty mangabeys can avoid AIDS

Sooty mangabeys are a variety of Old World monkey that can be infected by HIV’s cousin SIV, but do not get AIDS. Emory immunologist and Georgia Research Alliance Eminent Scholar Guido Silvestri, MD, has been a strong advocate for examining non-human primates such as the sooty mangabey, which manage to handle SIV infection without crippling their immune systems. Silvestri is division chief of microbiology and immunology at Yerkes National Primate Research Center.

Research shows sooty mangabeys have T cells that can do the same job as those targeted by SIV, even if they don't have the same molecules on their surfaces

A recent paper in the Journal of Clinical Investigation reveals that sooty mangabeys have T cells that perform the same functions as those targeted by SIV and HIV, but have different clothing.

Silvestri and James Else, the animal resources division chief at Yerkes, are co-authors on the paper, while Donald Sodora at Seattle Biomedical Research Institute is senior author.

One main target for SIV and HIV is the group of T cells with the molecule CD4 on their surfaces. These are the “helper” T cells that keep the immune system humming. Doctors treating people with HIV infections tend to keep an eye on their CD4 T cell counts.

In the paper, the scientists show that sooty mangabeys infected with SIV lose their CD4 T cells, without losing the ability to regulate their immune systems. What’s remarkable here is that sooty mangabeys appear to have “double negative” or DN T cells that can perform the same functions as those lost to SIV infection, even though they don’t have CD4.

CD4 isn’t just decoration for T cells. It’s a part of how they recognize bits of host or pathogen protein in the context of MHC class II (the molecule that “presents” the bits on the outside of target cells). Somehow, the T cells in sooty mangabeys have a way to get around this requirement and still regulate the immune system competently. How they do this is the topic of ongoing research.

The authors write:

It will be important to assess DN T cells in HIV-infected patients, particularly to determine whether these cells are preserved and functional in long-term nonprogressors. These efforts may lead to future immune therapies or vaccine modalities designed to modulate DN T cell function. Indeed, the main lesson we have learned to date from this cohort of SIV-infected CD4-low mangabeys may be that managing immune activation and bolstering the function of nontarget T cells through better vaccines and therapeutics has the potential to contribute to preserved immune function and a nonprogressive outcome in HIV infection even when CD4+ T cell levels become low.

Posted on by Quinn Eastman in Immunology Leave a comment

Reassuring news on viral immunity + HIV vaccine

A recent paper in Journal of Immunology suggests that a platform for an HIV vaccine developed by Yerkes National Primate Research Center scientists won’t run into the same problems as another HIV vaccine. Postdoc Sunil Kannanganat is the first author of the JI paper, with Emory Vaccine Center researcher Rama Amara as senior author.

Harriet Robinson, MD and Rama Rao Amara, PhD

Many HIV vaccines have been built by putting genes from HIV into the backbone of another virus. Some have used a modified cold virus (adenovirus 5). The vaccine developed at Yerkes uses modified vaccinia Ankara (MVA), a relative of smallpox and chicken pox.

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Posted on by Quinn Eastman in Immunology Leave a comment

Scientists still searching for HIV’s lethal ways

Guido Silvestri, MD

It’s a knotty, complex question, and one that’s nearly 30 years old: how does HIV cause AIDS? That is, how does the virus slowly destroy the immune system?

Emory immunologist and Georgia Research Alliance Eminent Scholar Guido Silvestri, MD, and his colleagues are using a method called comparative AIDS research to try and answer that question. In other words, the scientists compare humans infected with HIV who develop AIDS and nonhuman primates from Africa who are infected with SIV, or simian immunodeficiency virus.

Silvestri is chief of the Division of Microbiology and Immunology at Yerkes National Primate Research Center.

Although SIV is very similar to HIV in terms of genetic and molecular structure, once infected with this virus, the Old World Monkey, the sooty mangabey, does not get sick.

“It’s a major mystery in AIDS research because these animals have virus replication that remains active in their body as long as they’re alive,” says Silvestri. “So, it’s not just the infection and the virus replicating that kills people. There’s something more that happens.”

Silvestri describes this research in Emory University’s Sound Science.

Posted on by Robin Tricoles in Immunology Leave a comment

Federal research funding sparks economic growth

A recent report from The Science Coalition gives numerous examples of how federally funded research at universities has led to innovation, new companies, and the creation of jobs. The Sparking Economic Growth report lists the university research origins of 100 companies, including Google, Genentech, Cisco Systems and iRobot. Four Emory startup companies were highlighted among the success stories: GeoVax, Inc., Pharmasset, Inc., Syntermed, Inc., and Triangle Pharmaceuticals, which was later acquired by Gilead Sciences in California.

Emory President James Wagner wrote a followup editorial in the Atlanta Business Chronicle about the importance of scientific research in Georgia’s universities to the health of our economy.

“Atlanta can be proud that Emory University is a shining example in this report, with four highlighted successful companies that were launched because federally funded research resulted in innovative and life-saving discoveries. These four success stories only scratch the surface as examples of the more than 150 companies and the resulting 5,500 jobs created in Georgia from discoveries at its research universities.

“Since the 1990s, Emory has turned external research funding, the majority from the federal government, into more than $775 million in licensing revenues from drugs, diagnostics, devices and consumer products. This is money infused into the state’s economy that helps create jobs and educational opportunities, saves lives, and leads to more research discoveries for the benefit of all. Emory has launched 47 start-up companies and licensed 27 drugs, medical devices and diagnostics already in the marketplace and 12 more currently in human trials.”

GeoVax, Inc., is developing and testing a promising AIDS vaccine based on research at the Emory Vaccine Center and Yerkes National Primate Research Center. Gilead Sciences (from Triangle Pharmaceuticals) and Pharmasset, Inc. are creating AIDS drugs that are taken by over 90 percent of HIV-infected patients in the United States and many more around the world. Syntermed, Inc. distributes imaging software developed at Emory that helps in the diagnosis of more than four million heart disease patients every year.

Posted on by Holly Korschun in Uncategorized Leave a comment

Action Cycling 200 Mile Ride Benefits AIDS Vaccine Research

Riders gather at the Hope Clinic of the Emory Vaccine Center for the final leg of their ride.

More than 130 bicyclists rode 200 miles in two days to raise $188,660 for AIDS vaccine research at the Emory Vaccine Center. The AIDS Vaccine 200 on May 22-23, sponsored by Action Cycling Atlanta, was the eighth annual ride. The series now has raised more than $680,000 for AIDS vaccine research.

This year’s riders traveled from Emory to Eatonton, Georgia, and back to Emory along with a volunteer crew.

Because of generous sponsorships, Action Cycling donates 100 percent of funds raised by participants to AIDS vaccine research. These unrestricted funds fill gaps that cannot be met by grant dollars alone.

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Posted on by Holly Korschun in Uncategorized Leave a comment

A storied look at HIV/AIDS in Africa

At a recent Emory global health seminar series, Kate Winskell showed how fiction penned by young Africans can help inform the response to HIV and AIDS. Since 1997, more than 145,000 young Africans have participated in scriptwriting contests as part of Scenarios from Africa HIV communication process.

The resulting archive of stories is a unique source of cross-cultural and longitudinal data on social representations of HIV and AIDS. The archive now spans 47 countries and a critical 12-year period in the history of the epidemic. Winskell’s presentation analyzed the stories that were part of the 2005 Scenarios contest. Six African countries were represented.

The seed for Scenarios was planted more than a decade ago–before the rise of the Internet—when Winskell, a public health educator, and her husband, Daniel Enger, were searching for innovative ways to reduce the spread of HIV/AIDS. The old ways of trying to stop the spread of the disease, focusing only on medical aspects of the epidemic or relying on educational materials that were not culturally adapted, were clearly limited.

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Posted on by Robin Tricoles in Uncategorized Leave a comment