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

Focus on mitochondria in schizophrenia research

Despite advances in genomics in recent years, schizophrenia remains one of the most complex challenges of both genetics and neuroscience. The chromosomal abnormality 22q11 deletion syndrome, also known as DiGeorge syndrome, offers a way in, since it is one of the strongest genetic risk factors for schizophrenia. Out of dozens of genes within the 22q11 deletion, several encode proteins found in mitochondria. A team of Emory scientists, led by cell biologist Victor Faundez, recently analyzed 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