Life-saving predictions from the ICU

Similar to the “precogs” who predict crime in the movie Minority Report, but for sepsis, the deadly response to infection. Read more

Five hot projects at Emory in 2017

Five hot projects at Emory in 2017: CRISPR gene editing for HD, cancer immunotherapy mechanics, memory enhancement, Zika immunology, and antivirals from Read more

Shaking up thermostable proteins

Imagine a shaker table, where kids can assemble a structure out of LEGO bricks and then subject it to a simulated earthquake. Biochemists face a similar task when they are attempting to design thermostable proteins, with heat analogous to shaking. Read more

Arash Grakoui

Antiviral success makes some immune cells stickier

As they succeed in clearing a viral infection from the body, some virus-hunting T cells begin to stick better to their target cells, researchers from Emory Vaccine Center and Georgia Tech have discovered.

The increased affinity helps the T cells kill their target cells more efficiently, but it depends both on the immune cells’ anatomic location and the phase of the infection.

The results were published this week in the journal Immunity.

Arash Grakoui, PhD

Arash Grakoui, PhD

After the peak of the infection, cells within the red pulp of the spleen or in the blood displayed a higher affinity for their targets than those within the white pulp. However, the white pulp T cells were more likely to become long-lasting memory T cells, critical for vaccines.

“These results provide a better understanding of how memory precursor populations are established and may have important implications for the development of efficacious vaccines,” the scientists write.

In the mouse model the researchers were using, the differences in affinity were only detectable a few days after the non-lethal LCMV viral infection peaks. How the differences were detected illustrates the role of serendipity in science, says senior author Arash Grakoui, PhD.

Typically, the scientists would have taken samples only at the peak (day 7 of the infection) and weeks later, when memory T cells had developed, Grakoui says. In January 2014, the weather intervened during one of these experiments. Snow disrupted transportation in the Atlanta area and prevented postdoctoral fellow Young-Jin Seo, PhD from taking samples from the infected mice until day 11, which is when the differences in affinity were apparent.

Seo and Grakoui collaborated with graduate student Prithiviraj Jothikumar and Cheng Zhu, PhD at Georgia Tech, using a technique Zhu’s laboratory has developed to measure the interactions between T cells and their target cells. Co-author Mehul Suthar, PhD performed gene expression analysis.

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Posted on by Quinn Eastman in Immunology Leave a comment

Spotlight on liver fibrosis

For a May explainer, we’d like to spotlight liver fibrosis. Two recent papers from Emory research teams in the journal Hepatology focus on this process.

Liver fibrosis is an accumulation of scar tissue and proteins outside cells that occurs as a result of chronic damage to the liver. It involves inflammation and immune cells, as well as activation of a type of cell in the liver (hepatic stellate cells), which usually stores fat and vitamin A. Fibrosis and cirrhosis are not the same. Think of it this way: cirrhosis is the late stage of the disease, but fibrosis is how someone can get there.

The liver has a remarkable, even mythical, ability to regenerate, but there is a long list of ways that someone can injure this most vital organ. Quickly – take too much acetaminophen (the most common cause of acute liver failure in the United States). More slowly – develop a hepatitis C infection. Drink large quantities of alcohol. Or something with more subtle effects: consume a diet high in sugar, which can lead to fatty liver. The relationship between fatty liver and more serious liver disease is currently under investigation.

One of the Hepatology papers comes at liver fibrosis from a malaria angle. Patrice Mimche, Tracey Lamb and colleagues show the involvement of EphB2 tyrosine kinase, a signaling molecule not previously known to be involved in liver fibrosis.

Malaria parasites have a complex life cycle, growing in the liver and then in the blood. Lamb says an important part of her paper was the finding that in mouse malaria infection, EphB2 is activated during the blood stage on immune cells infiltrating into the liver. EphB2 (an active drug discovery target) may be acting as a tissue-specific adhesion molecule, she says.

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Posted on by Quinn Eastman in Immunology Leave a comment