Mouse version of 3q29 deletion: insights into schizophrenia/ASD pathways

Emory researchers see investigating 3q29 deletion as a way of unraveling schizophrenia’s biological and genetic Read more

B cells off the rails early in lupus

Emory scientists could discern that in people with SLE, signals driving expansion and activation are present at an earlier stage of B cell differentiation than previously Read more

Head to head narcolepsy/hypersomnia study

At the sleep research meeting in San Antonio this year, there were signs of an impending pharmaceutical arms race in the realm of narcolepsy. The big fish in a small pond, Jazz Pharmaceuticals, was preparing to market its recently FDA-approved medication: Sunosi/solriamfetol. Startup Harmony Biosciences was close behind with pitolisant, already approved in Europe. On the horizon are experimental drugs designed to more precisely target the neuropeptide deficiency in people with classic narcolepsy type 1 Read more

Immunology

Present at the creation: immunology from chickens to lampreys

You can get far in biology by asking: “Which came first, the chicken or the egg?” Max Cooper discovered the basis of modern immunology by asking basic questions.

Cooper was selected for the 2012 Dean’s Distinguished Faculty Lecture and Award, and on Thursday evening dazzled an Emory University School of Medicine audience with a tour of his scientific career. He joined the Emory faculty in 2008 as a Georgia Research Alliance Eminent Scholar.

Max Cooper, MD

Cooper’s research on the development of the immune system, much of it undertaken before the era of cloned genes, formed the underpinnings of medical advances ranging from bone marrow transplants to monoclonal antibodies. More recently, his research on lampreys’ divergent immune systems has broadened our picture of how adaptive immunity evolved.

Cooper grew up in Mississippi and was originally trained as a pediatrician, and became interested in inherited disorders that disabled the immune system, leaving children vulnerable to infection. He joined Robert Good’s laboratory at the University of Minnesota, where he began research on immune system development in chickens.

In the early 1960s, Cooper explained, scientists thought that all immune cells developed in one place: the thymus. Working with Good, he showed that there are two lineages of immune cells in chickens: some that develop in the thymus (T cells) and other cells responsible for antibody production, which develop in the bursa of Fabricius (B cells). [On Thursday, he evoked chuckles by noting that a critical discovery that drove his work was published in the journal Poultry Science after being rejected by Science.]

Cooper moved on to the University of Alabama, Birmingham, and there made several discoveries related to how B cells develop. A collaboration with scientists at University College, London led to the identification of the places where B cells develop in mammals: fetal liver and adult bone marrow.

Cooper’s research on lampreys began in Alabama and has continued after he came to Emory in 2008. Primitive lampreys are thought to be an early offshoot on the evolutionary tree, before sharks, the first place where an immune system resembling those of mammals and birds is seen. Lampreys’ immune cells produce “variable lymphocyte receptors” that act like our antibodies, but the molecules look very different in structure. These molecules were eventually crystallized and their structure probed, in collaboration with Ian Wilson in San Diego.

Lampreys have variable lymphocyte receptors, which resemble our antibodies in function but not in structure

Cooper said he set out to figure out “which came first, T cells or B cells?” but ended up discovering something even more profound. He found that lampreys also have two separate types of immune cells, and the finding suggests that the two-arm nature of the immune system may have preceded the appearance of the particular features that mark those cells in evolution.

 

 

 

Posted on by Quinn Eastman in Immunology 1 Comment

Fertility: a new frontier in treating those with HIV

HIV

Not long ago, physicians who treated those with HIV focused only on helping their patients stay well. Today some physicians are also beginning to focus on helping those patients conceive.

“Most of the patients who are now diagnosed with HIV are in their reproductive years, and as many as a third express a desire to have children,” says Emory reproductive endocrinologist Vitaly Kushnir, MD.

This emerging area of treatment has been made possible thanks to the growing effectiveness of a combination of drugs known as Highly Active Antiretroviral Therapy, or HAART, used for years to treat retroviruses, including HIV.

“Now that people with HIV are living longer, fertility and HIV is an emerging area of interest,” says Kushnir. “Several studies have indicated that HIV drugs if given early in the course of the disease can reduce the risk of transmission from an HIV-positive person to an HIV-negative person.”

But researchers and physicians know very little yet about how treatments for HIV, the virus itself, and the comorbidities associated with HIV affect fertility. So, Kushnir and his colleague, Emory pathologist William Lewis, MD, decided it was time to explore existing data on how HIV and its treatment affect fertility, especially in women. Their review paper on the subject appears in the August 2011 issue of Fertility and Sterility.

Because there are safety concerns and legal restrictions on fertility treatments in couples in which one partner is HIV positive and the other is not, treatment options often are limited.

“This is becoming more and more of an issue,” says Kushnir. “It’s probably time for us to have a more open discussion about the access these patients have to fertility treatment. I think the current system probably discourages these patients from pursuing treatments that are a lot safer than trying to get pregnant on their own.”

Posted on by Robin Tricoles in Immunology Leave a comment

Excitement building over potential for universal flu vaccine

Francis Collins, director of the National Institutes of Health, made a splash last week predicting the arrival of a universal flu vaccine in the next five years.

Francis Collins told USA Today he is "guardedly optimistic" about the possibility of long-term vaccination that could replace seasonal flu shots.

His prediction came at the same time as a report in Science identifying an antibody that can protect against several strains of the flu virus. Taking a look at the Science paper, how the scientists found the “super antibody” seems remarkably similar to how Emory’s Jens Wrammert, Rafi Ahmed and colleagues found a similar broadly protective antibody. Their results were published in the Journal of Experimental Medicine in January.

In both cases, the researchers started with someone who had been infected with the 2009 H1N1 swine origin flu virus, sifted through the antibodies that person produced and found some that reacted against several varieties of the flu virus. There must be something special about that 2009 pandemic strain!

Posted on by Quinn Eastman in Immunology Leave a comment

Dispelling confusion about probiotic bacteria

While humans have been consuming fermented foods such as yogurt and kimchi for centuries, a visitor to a modern grocery store can see the recent commercial enthusiasm for adding probiotic bacteria to foods. A recent article in Slate explores the confusion over potential health benefits for these added bacteria.

The bacteria that live inside us seem to play an important role regulating metabolism, the immune system and the nervous system, but scientists have a lot to learn about how those interactions take place.

Researchers at Emory have been clarifying exactly how probiotic bacteria promote intestinal health. Andrew Neish and his colleagues have found that the bacteria give intestinal cells a little bit of oxidative stress, which is useful for promoting the healing of the intestinal lining.

Beneficial bacteria induce reactive oxygen species production by intestinal cells, which promotes wound healing.

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

HIV vaccine design: always a moving target

HIV presents a challenge to vaccine design because it is always changing. If doctors vaccinate people against one variety of virus, will the antibodies they produce stop the virus that they later encounter?

A recently published report on an experimental HIV vaccine’s limited effectiveness in human volunteers illustrates this ongoing puzzle in the HIV vaccine field.

Paul Spearman, now chief research officer for Children’s Healthcare of Atlanta and vice chair for research for Emory’s Department of Pediatrics, began overseeing the study when he was at Vanderbilt. The report is in the April 15 issue of the Journal of Infectious Diseases.

Paul Spearman, MD

The vaccine was designed to elicit both antibody and T cell responses against HIV and in particular, to generate broadly neutralizing antibodies. Unfortunately, it didn’t work. Volunteers who received the vaccine made antibodies that could neutralize the virus in the vaccine, but not related viruses thought to be like what participants in a larger study might encounter.

“High levels of neutralizing antibodies can be raised against HIV, while at the same time, breadth of neutralization has never yet been achieved in a vaccine,” Spearman says. “The essential problem is that the antibodies raised have a narrow specificity, while the virus is extremely variable. In contrast, about 20% of HIV-infected individuals will demonstrate neutralization breadth.”

Last year, scientists demonstrated a method for identifying these broadly neutralizing antibodies in HIV-infected individuals. However, having a vaccine hit that target reliably is still elusive.

Spearman reports that he is in charge of a new trial that will be boosting the same individuals that participated in the previous trial with HIV protein from a clade C virus, starting later this year. Clade C is the predominant HIV subtype in southern Africa, while clade B, used in the published trial, is the predominant subtype in North America and Western Europe.

Posted on by Quinn Eastman in Immunology 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

Another avenue of HIV trickery reveals opportunity

Emory and University of Rochester researchers have discovered an extra way by which HIV adapts to survive in a hiding spot in the human immune system. The results are published in the Journal of Biological Chemistry.

A team led by Baek Kim from the University of Rochester and Raymond Schinazi from Emory found that when HIV faces a shortage of the building blocks it usually uses to replicate, the virus adapts by using different building blocks. The discovery may offer scientists a new way to try to stop the virus.

One of HIV’s favorite hiding spots is an immune cell called a macrophage, whose job is to chew up and destroy foreign invaders and cellular debris. One can think of macrophages as worker bees: they don’t reproduce because they’re focused on getting stuff done.

Raymond Schinazi, PhD, DSc, is director of the Laboratory of Biochemical Pharmacology at Emory's Center for AIDS Research

Normally, HIV uses “dNTPs” (building blocks of DNA), but dNTPs are found at very low levels in macrophages because they’ve stopped dividing and making new DNA. Current drugs generally target dNTPs, and aim at the infection in a different type of cells: T cells.

Macrophages do have high levels of RNA building blocks (“rNTPs”). The team found that HIV uses primarily rNTPs instead of dNTPs to replicate inside macrophages. When the team blocked the ability of the virus to interact with rNTPs, its ability to replicate in macrophages was cut by more than 90 percent.

“The first cells that HIV infects in the genital tract are non-dividing target cell types such as macrophages,” Kim says. “Current drugs were developed to be effective only when the infection has already moved beyond these cells. Perhaps we can use this information to help create a microbicide to stop the virus or limit its activity much earlier.”

Compounds that interfere with the use of rNTPs already exist and have been tested as anti-cancer drugs.

“We are now developing new anti-HIV drugs jointly based on this novel approach that are essentially non-toxic and can be used to treat and prevent HIV infections,” Schinazi says.

Baek Kim, PhD

The first authors of the paper are graduate students Edward Kennedy from Rochester and Christina Gavegnano from Emory. Other authors include graduate students Laura Nguyen, Rebecca Slate and Amanda Lucas from Rochester, and postdoc Emilie Fromentin from Emory.

The research was funded by the National Institute of Allergy and Infectious Disease and the Department of Veterans Affairs.

University of Rochester press release

Posted on by Quinn Eastman in Immunology 1 Comment

H1N1 2009 virus may point way to universal flu vaccine

Emory MedicalHorizon

Scientists at Emory and the University of Chicago have discovered that the 2009 H1N1 flu virus provides excellent antibody protection. This may be a milestone discovery in the search for a universal flu vaccine.

Researchers took blood samples from patients infected with the 2009 H1N1 strain and developed antibodies in cell culture. Some of the antibodies were broadly protective and could provide protection from the H1N1 viruses that circulated over the past 10 years in addition to the 1918 pandemic flu virus and even avian influenza or bird flu (H5N1).

The antibodies protected mice from a lethal viral dose, even 60 hours post-infection.

The research is published online in the Journal of Experimental Medicine.

Some of the antibodies stuck to the “stalk” region, or hemagglutinin (H in H1N1) protein part of the virus. Because this part of the virus doesn’t change as much as other regions, scientists have proposed to make it the basis for a vaccine that could provide broader protection. The antibodies could guide researchers in designing a vaccine that gives people long-lasting protection against a wide spectrum of flu viruses.

The paper’s first author, Emory School of Medicine’s Jens Wrammert, PhD, says “Our data shows that infection with the 2009 pandemic influenza strain could induce broadly protective antibodies that are very rarely seen after seasonal flu infections or flu shots. These findings show that these types of antibodies can be induced in humans, if the immune system has the right stimulation, and suggest that a pan-influenza vaccine might be feasible.”

Rafi Ahmed, PhD, director of the Emory Vaccine Center, and a Georgia Research Alliance Eminent Scholar, is co-senior author of the publication, along with Patrick Wilson at University of Chicago.

Multimedia

Video

  • See YouTube for video commentary by Dr. Ahmed
  • For access to raw video for media purposes, contact Kathi Baker, kobaker@emory.edu, 404-727-9371 Office, 404-686-5500 Pager (ID 14455), 404-227-1871 Mobile.

Audio

Posted on by Jennifer Johnson in Immunology 2 Comments

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.

Read more

Posted on by Quinn Eastman in Immunology Leave a comment