Exosomes as potential biomarkers of radiation exposure

Exosomes = potential biomarkers of radiation in the Read more

Before the cardiologist goes nuclear w/ stress #AHA17

Measuring troponin in CAD patients before embarking on stress testing may provide Read more

Virus hunting season open

Previously unknown viruses, identified by Winship + UCSF scientists, come from a patient with a melanoma that had metastasized to the Read more

Crohn’s disease

Starvation signals control intestinal inflammation in mice

Intestinal inflammation in mice can be dampened by giving them a diet restricted in amino acids, the building blocks of proteins, researchers have found. The results were published online by Nature on Wednesday, March 16.

The findings highlight an ancient connection between nutrient availability and control of inflammation. They also suggest that a low protein diet — or drugs that mimic its effects on immune cells — could be tools for the treatment of inflammatory bowel diseases, such as Crohn’s disease or ulcerative colitis.

The research team, led by Emory Vaccine Center immunologist Bali Pulendran, discovered that mice lacking the amino acid sensor GCN2 are more sensitive to the chemical irritant DSS (dextran sodium sulfate), often used to model colitis in animals. This line of research grew out of the discovery by Pulendran and colleagues that GCN2 is pivotal for induction of immunity to the yellow fever vaccine.

“It is well known that the immune system can detect and respond to pathogens, but these results highlight its capacity to sense and adapt to environmental changes, such as nutritional starvation, which cause cellular stress,” he says.

Read more

Posted on by Quinn Eastman in Immunology Leave a comment

Providing the potent part of probiotics

A Emory News item on a helpful part of the microbiome focuses on how the same type of bacteria – lactobacilli – activates the same ancient signaling pathway in intestinal cells in both insects and mammals. It continues a line of research from Rheinallt Jones and Andrew Neish on how beneficial bacteria stimulate wound healing by activating ROS (reactive oxygen species).

Asma Nusrat, MD

A idea behind this research is: if we know what parts of the bacteria stimulate healing, perhaps doctors can deliver that material, or something very close, to patients directly to treat intestinal diseases such as Crohn’s or ulcerative colitis.

This idea has advanced experimentally, as demonstrated by two papers from Jones and Neish’s frequent collaborator, Asma Nusrat, who recently moved from Emory to the University of Michigan. This team had shown that a protein produced by human intestinal cells called annexin A1 activates ROS, acting through the same N-formyl peptide receptors that bacteria do.

Nusrat told me Friday her team began investigating annexins a decade ago at Emory, and it was fortuitous that Neish was working on beneficial bacteria right down the hall, since it is now apparent that annexin A1 and the bacteria are activating the same molecular signals. (Did you know there is an entire conference devoted to annexins? I didn’t until a few days ago.)

In a second Journal of Clinical Investigation paper published this February, Nusrat and her colleagues show that intestinal cells release vesicles containing annexin A1 following injury. The wound closure-promoting effects of these vesicles can be mimicked with nanoparticles containing annexin A1. The nanoparticles incorporate a form of collagen, which targets them to injured intestinal tissue. Read more

Posted on by Quinn Eastman in Immunology, Uncategorized Leave a comment

Freezing stem cells disrupts their function

What applies to meat, vegetables and fish may also apply to cells for use in cell therapy: frozen often isn’t quite as good.

Ian Copland and colleagues from Emory’s Personalized Immunotherapy Center have a paper this week in Stem Cells Reports discussing how freezing and thawing stem cells messes them up. Specifically, it disrupts their actin cytoskeletons and impairs their ability to find their niches in the body. Culturing the cells for 48 hours after thawing does seem to correct the problem, though.

The findings have some straightforward implications for researchers planning to test cell therapies in clinical applications. The authors conclude:

Until such time as a cryopreservation and thawing procedure can yield a viable and fully functional MSC product immediately after thawing, our data support the idea of using live MSCs rather than post-thaw cryo MSCs for clinical evaluation of MSCs as an immunosuppressive agent.

Notably, the Emory Personalized Immunotherapy Center has built a process designed around offering never-frozen autologous (that is, the patient’s own) mesenchymal stem cells, as therapies for autoimmune disorders such as Crohn’s disease.

Posted on by Quinn Eastman in Immunology Leave a comment

Emory University Hospital Set to Be Launch Site for EPIC

Can it really be possible to transform a person’s own cells into a weapon against various forms of disease? And what if those very cells could be retrained to attack cancer cells or to prevent autoimmune diseases?

Answers to these questions and many more are about to soon be realized, as Emory University Hospital will serve as the launch site for the very appropriately-named EPIC (Emory Personalized Immunotherapy Center).

The new Center, which is the creation of Dr. Jacques Galipeau, MD, professor of hematology and medical oncology & pediatrics of Emory University, will soon be operational after final touches have been put on construction of the lab. This cell processing facility will foster development of novel personalized cellular therapies for Emory patients facing catastrophic ailments and unmet medical needs.

According to Galipeau, the premise of EPIC and its overlying mission will focus on cellular and biological therapies that use a patient’s own cells as a weapon to seek and destroy cells that actually make a person sick. In partnership with the Winship Cancer Institute of Emory University, Children’s Healthcare of Atlanta, Aflac Cancer & Blood Disorders Center and the Emory School of Medicine, EPIC seeks to improve the health of children and adults afflicted with cancer and immune disease.

“First and foremost, we seek to bring a level of care and discovery that is first in Georgia, first in human and first in child. Blood and marrow derived cells have been used for more than a quarter century to treat life threatening hematological conditions and are now established therapies worldwide. More recently, the use of specific adult somatic cells from marrow, blood and other tissues are being studied in cellular medicine of a wide array of ailments including heart, lung, neurological and immune diseases,” says Galipeau. “The use of blood borne immune cells can also be exploited for treatment of cancer, autoimmune disease, organ transplantation and chronic viral illnesses such as HIV.”

Galipeau said that once operational, EPIC will begin by working with Crohn’s disease in pediatric and adult patients, an inflammatory bowel disease. Symptoms of Crohn’s disease include severe abdominal pain, diarrhea, fever, weight loss, and the inability for a child to properly grow. Resulting bouts of inflammation may also affect the entire digestive tract, including the mouth, esophagus and stomach.  In some cases, a radical surgery involving the removal of part of the lower intestinal tract is required.

“There is no current answer for what specifically causes Crohn’s disease, nor is there a cure. But we hope that through our research and efforts, we will be able to first target the inflammatory mechanisms in these patients through immunotherapy, and in turn reduce the amount of flare-ups and limit  the damage that occurs from this disease,” says Galipeau.

Galipeau says the EPIC program could represent a powerful cornerstone to the launch and the development of an entirely new, Emory-based initiative which bundles the strengths of the School of Medicine, Emory University Hospital, Children’s Healthcare of Atlanta, and many Woodruff Health Sciences Center centers of excellence,” says Galipeau.

“My ultimate goal is to elevate the biomedical scientific and scholarly enterprise to a higher level – making a difference in the lives of people. The EPIC program and multi-levels of support could be a fundamental underpinning to our success.”

Posted on by Lance Skelly in Immunology Leave a comment

Inflammatory bowel disease gene regions identified

In the largest, most comprehensive genetic analysis of childhood-onset inflammatory bowel disease (IBD), Emory and Children’s Healthcare of Atlanta gastroenterologist Subra Kugathasan, MD, and colleagues identified five new gene regions, including one involved in a biological pathway that helps drive the painful inflammation of the digestive tract that characterizes the disease.

Subra Kugathasan, MD

Subra Kugathasan, MD

IBD is a painful, chronic inflammation of the gastrointestinal tract, affecting about 2 million children and adults in the United States. Of that number, about half suffer from Crohn’s disease, which can affect any part of the GI tract, and half have ulcerative colitis, which is limited to the large intestine.

Most gene analyses of IBD have focused on adult-onset disease, but this study concentrated on childhood-onset IBD, which tends to be more severe than adult-onset disease.

Kugathasan and a team of international researchers performed a genome-wide association study on DNA from over 3,400 children and adolescents with IBD, plus nearly 12,000 genetically matched control subjects, all recruited through international collaborations in North America and Europe.

In a genome-wide association study, automated genotyping tools scan the entire human genome seeking gene variants that contribute to disease risk.

The study team identified five new gene regions that raise the risk of early-onset IBD, on chromosomes 16, 22, 10, 2 and 19. The most significant finding was at chromosome locus 16p11, which contains the IL27 gene that carries the code for a cytokine, or signaling protein, also called IL27.

Kugathasan says one strength of the current study, in addition to its large sample size, is the collaboration of many leading pediatric IBD research programs, which included Emory, The Children’s Hospital of Philadelphia, the Hospital for Sick Children of the University of Toronto; the University of Edinburgh, UK; Cedars Sinai Medical Center, Los Angeles; and the IRCCS-CSS Hospital, S. Giovanni Rotondo, Italy.

The study, “Common variants at five new loci associated with early-onset inflammatory bowel disease,” was published in the November 2009 online issue of Nature Genetics.

Learn more about Kugathasan’s work at Emory.

Posted on by adobbs in Uncategorized 1 Comment