Immunogenomics: more powerful the more it's used

Here we present the fifth and final interview in our podcast series focused on immunogenomics, a field that is using new genomics tools to unravel the complexity of the human immune system and related diseases.

We recorded interviews with experts on the subject from UAB, Harvard, Stanford and the National Institutes of Health at a recent immunogenomics symposium organized jointly by the HudsonAlpha Institute for Biotechnology and leading medical journal Nature Immunology. The symposium was sponsored in part by UAB and its Center for Clinical and Translational Science.

Our guest for this podcast is John O’Shea, M.D., scientific director of the National Institute of Arthritis and Musculoskeletal and Skin Diseases, and chief of the NIAMS Molecular Immunology and Inflammation Branch.

We talked about how immunogenomics will only achieve its potential when its tools become inexpensive and straight-forward enough that they can be folded into research efforts by non-genomics experts. O'Shea said early examples of that could be found in the symposium presentations, some of which provided insight into how the immune system drives disease while others predicted which patients should benefit most from new classes of drugs.

Show notes for the interview

1:01 Those who study the immune system have also closely studied genomics for years. What has changed in immunogenomics is the leaps made possible by new technologies. Immunologists now have the ability, given cheap, powerful tools, to conduct genomics studies as part of their research.

2:31 High-powered gene sequencing, bioinformatics and computing tools will only become truly powerful when immunologists, cardiologists and neurologists (non-genomics experts) start using them in their labs worldwide. Many presentations at the symposium represent examples of that starting to happen.

2:57 O'Shea's lab, which was a pure immunology lab five years ago, now includes several high-throughput sequencing machines, not to mention a dedicated computational biologist. Immunogenomics is changing the makeup of the average research lab.

3:34 Immunogenomics is important to O'Shea's research in particular because he works with immune cell signalling pathways that play a central role in autoimmune diseases like rheumatoid arthritis, where the immune system mistakenly targets and damages our own cells. It provides a whole new window on related mechanisms if you can understand which small variations in certain spots within our genetic code add risk for the disease.

4:03 Specifically, Dr. O'Shea is interested in immune signaling chemicals called cytokines that ramp up our immune response to infectious disease invaders, but that also trigger inappropriate immune reactions as part of autoimmune disease. Genomics tools helped the field determine that a certain cytokine signaling cascade called the JAK-STAT pathway was centrally involved in autoimmune disease. Now we know that small genetic changes, so-called polymorphisms, in STAT molecules confer risk for rheumotoid arthritis, lupus, Sjogren's syndrome, etc.

5:29 Interestingly, as the field tries to figure out what confers disease risk relative to the JAK-STAT pathway, a new class of drugs, the JAK inhibitors, are arriving on the scene. Some are under consideration for marketing approval at the U.S. Food and Drug Administration right now. With this arrival, new immunogenomics tools will help researchers understand which patients are more likely to respond to the new drugs, saving them time and misery.

6:08  O'Shea's presentation at the meeting was titled "Environmental Sensors and Master Regulators in the Emergence of Active Enhancer Landscapes." Put simply, all cells in a person have the same DNA, but all cells don't read the same sections of the instruction encoded in that DNA. To fulfill its specific functions, each cell reads certain parts of the same code, with mechanisms in place to open and close the right sections of the book. The mechanisms that control when genes are expressed are regulatory sequences, the subject of study in the science of epigenetics.

7:20 An increasingly popular theory is that the origin of many diseases, including autoimmune diseases, lies not with genes, but instead within the small pieces of epigenetic code, the enhancers and regulators, that control the process of when and where genes are turned on.

9:21 Genomics and epigenomics, the genetic cards we are dealt, have a great deal to do with our risk for disease, but our "environment" plays a big role as well. Environment in this context could mean sunlight, hormonal changes (estrogen versus testosterone), or how much inflammation a person has thanks to chronic disease. The excitement is around our new ability to measure the interplay between genetics and these other factors in disease risk using the new tools.

11:40 Over time, O'Shea and others have switched from using technologies that examine a single gene, to a few genes, and now, all human genes at once, the analysis of 3 billion coding units. As a result, many diseases are now known to be the result of changes in large networks of genes.

14;19 For more information on where immunogenomics meets epigenetics, O'Shea recommends the Nature website covering the ENCODE project, the NIH-funded effort to begin to map the regulatory portions of the human genetic code.

Key to immunogenomics value: embed research in healthcare system

Here we present the fourth interview in our podcast series focused on immunogenomics, a field is using new genomics tools to unravel the complexity of the human immune system and related diseases.

We recorded interviews with nationally recognized experts in this area from UAB, Harvard, Stanford and the National Institutes of Health at a recent immunogenomics symposium organized jointly by the HudsonAlpha Institute for Biotechnology and leading medical journal Nature Immunology. The symposium was sponsored in part by UAB and its Center for Clinical and Translational Science.

Our guest for this podcast is meeting presenter Robert Plenge, M.D., Ph.D., assistant professor of Medicine at Harvard Medical School – and Director of Genetics and Genomics within the Division of Rheumatology, Immunology and Allergy at Brigham and Women’s Hospital.

We discussed how immunogenomics has provided a flood of new clues about the genetic quirks contributing to many diseases, but the field must now, with the quirks as a guide, delve back into cells to learn the details of how such changes cause disease. To do so, they must collect human cells from patients known to have a given disease, and related efforts will accelerated the trend toward "embedded" genomics research.



Show notes for the interview:

1:01 Genomics is the study of DNA, RNA and the proteins that code for and how they contribute to health and disease. Immunology is the study of how several cell types fight infection, and why they attack our own tissues in some case to cause inflammation as part of inflammatory and autoimmune diseases. Immunogenomics then is the study of how these components work together, the genetic programming of the immune cell sets.

1:54 Plenge's work focuses on determining the genetic basis of predisposition for autoimmune diseases, and for rheumatoid arthritis in particular. Past genomic studies have determined some of the genes that contribute risk for rheumatoid arthritis, but immunogenomic studies are going further to determine the effect that genetic variations are having in cells, and at what that says about disease mechanisms.

3:19 The last few years have seen the rise of genome-wide association (GWAS) studies, where researchers use genomic technologies to examine every coding unit in the entire genomes of two sets of people (one with a disease, one without) to reveal every small genetic difference. They use tool called microarrays to look at large numbers of genetic sequences all at once, and to find small variations called single nucleotide polymorphisms (SNPs) associated with any given disease.

3:35 But GWAS studies only show that certain families have certain genetic variations that make them more susceptible to certain disease. They do not tell how or why the variations cause disease.  The next step then for Plenge and others will be to roll up their sleeves, go into the lab with this GWAS information and study the cells of people with disease-causing genetic variations to reveal disease mechanisms that can be countered with precision designed therapies.

4:29 Plenge's presentation talks about the importance of biomarkers, the physical measures that show a disease is underway or that a drug is countering it.. These are the tests that give meaning to clinical trial results. Researchers hope that new biomarkers will help them predict who will respond to a given treatment for rheumatoid arthritis based on their immunogenomic profile.

5:12 Plenge is working with the Pharmacogenomic Research Network (PGRN), organized by the National Heart Lung and Blood Institute, part of the Institutes of Health, to see if genomic patient profiles can be used to predict which patients are likely to respond, for instance, to an important category of treatments for rheumatoid arthritis called anti-TNF biologic drugs.

5: 47 It may be that most clinical trials will soon come to benefit from the addition of immunogenomic tools that predict any given patient's response to treatment, or their likelihood to experience a given complication of side effect.

6:22  It's easy to think of the immune system as involved in fighting infection, or even in autoimmune diseases like rheumatoid arthritis where the system mistakenly recognizes its own tissue as foreign and attacks it. Mounting evidence argues, however, show that "mistakes" by the immune system bring about inflammation at the root of cardiovascular disease, neurodegeneritive conditions, cancer, pulmonary disease, etc. A profound understanding of the interplay between genomics and immunology will offer tremendous opportunities to develop new therapies, says Plenge.

7:25 Immunogenomics may help to lessen the massive time and cost necessary today to conduct the average clinical trial. Plenge hopes that emerging techniques and advances will create efficiencies in medical research.  Treatments that address inflammation in rheumatoid arthritis may also prove to have utility in reducing inflammation contributing to say diseased arteries. The potential for this becomes greater the more profound the field's understanding of genomic/immune system interplay.

9:27 Many of the past studies in immunology and genomics were done in mice meant to serve as models of human disease.  But mice are different than humans. There are now many more opportunities to do what Plenge calls "embedded immunogenomics," where registries collect cells and data from human patients for study as part of routine clinical care.  The research is embedded in the healthcare system. If patients consent for a quick blood draw, researchers gain access to details of subsets of cells and genes linked to diseases, and can follow changes over time.

11:13  One emerging trend may be the uncoupling of such genetic registries from a doctor's office visit. People participating in the new registries may just stop by a lab (e.g. Quest Diagnostics) for testing whenever they don't feel well.

12:20 Plenge recommends that researchers interested in learning more about this area look into a database under development called Immunobase, which is working to catalog inherited genetic variations contributing to a wide variety of diseases. The work underway at Sage Bionetworks and  i2b2 (informatics for integrating biology and the bedside), an NIH-funded biocomputing initiative, represent other interesting initiatives. Patients interested in participating in research might look up 23andMe, and those with rheumatoid arthritis, the Arthritis Internet Registry.

Tune in next Friday to hear our talk with John O’Shea, M.D., chief of the Molecular Immunology and Inflammation Branch with the National Institute of Arthritis and Musculoskeletal and Skin Diseases, part of the National Institutes of Health.

New series on the human immunogenome

Most of the time The Mix covers general research topics, but for the next several Fridays we will feature a podcast series focused on the emerging field of immunogenomics. Guests will include nationally recognized experts in this area from UAB, HudsonAlpha, Harvard, Stanford and the National Institutes of Health.

We recorded the interviews live at a recent immunogenomics symposium organized jointly by the HudsonAlpha Institute for Biotechnology and leading medical journal Nature Immunology. The symposium was sponsored in part by UAB and its Center for Clinical and Translational Science.

Immunogenomics as a field is using new genomics tools to unravel the complexity of the human immune system and related diseases, which are now known to include heart disease, neurological disease and cancer because of their interplay with inflammation. The work promises to improve diagnostic tools and offer new treatment approaches.

Among the most important of genomics tools are microarrays, which enable researchers to measure the expression levels of many genes at once, and bioinformatic programs, which identify patterns in the massive data sets generated during genomic analysis of individuals and populations.

Our first guest in the series is S. Louis Bridges, Jr., M.D., Ph.D., director of the Division of Clinical Immunology and Rheumatology within the UAB School of Medicine and deputy director of the UAB Comprehensive Arthritis, Musculoskeletal, and Autoimmunity Center. Tune in next Friday, when we will talk with Stephen Quake, D.Phil., professor in the Department of Bioengineering at Stanford.




Show notes for the interview:

1:09 Immunogenomics can be defined as the use of the tools of genomics to study human immune cells, and to define the mechanism by which immune-related diseases damage the body. 

2:02 Rheumatoid arthritis is the most common autoimmune disease, in which immune cells called antibodies come to target the body's own tissues.

2:47 In many ways, RA represents a cogent example of the intersection between immunology and genomics in that about 30 percent of the risk for the disease is based on your genes. In addition, small changes in more than 35 different genes contribute to that risk.

3:39 Bridges and colleagues founded the CLEAR registry, which stands for Consortium for the Longitudinal Evaluation of African Americans with Early Rheumatoid Arthritis. The registry compares the incidence and severity of RA in African-Americans against other ethnic and racial groups over time to better understand how immune-system mechanisms cause damage. Past studies have found that RA is more severe in African-Americans than in whites.

4:42 Researchers are working to understand the genetic basis of RA severity in African-Americans in part by examining single genes (RANK ligand, peptidase) known to be associated with disease severity or early onset. Bridges and colleagues have also been conducting genome-wide association studies, which look at every piece of code making up every gene (nucleotide) in a group of people to identify the differences seen only in people with a certain condition. In many cases, such studies reveal that networks of genes contribute to a disease, as opposed to a problem with the code of any single gene.

5:40 All races share 80 to 90 percent of the genetic background leading to RA, so perhaps 2 to 5 percent of genes vary by race, says Bridges.

6:02 In some whites, a gene called PTP-N22, for instance, has randomly undergone a small change in its code called an SNP (single nucleotide polymorphism). People who happen to have that change in PTP-N22 are 1.9 times as likely to develop RA.

7:09 A change in a single piece of code out of 3 billion base pairs making up the human genome, if it's in the wrong spot, can contribute to either the incidence or severity of RA. Such changes may predict which patients will go on to see their joints destroyed.

7:56  Immunogenomics work will have its first impact in the clinic in the form of a new wave of identified biomarkers that predict which patients will do well on which treatments. Further down the road, Bridges sees the field identifying more specific subsets of cells most responsible for RA-related damage, which could in turn lead to the development of more targeted treatments.

9:44 Bridges recommends that members of the general public interested in learning more on RA and related research visit the Mayo Clinic's RA pages. Researchers may want to look up the work of Robert Plenge, M.D., Ph.D., assistant professor of medicine at Harvard Medical School, whose interview is coming up as part of this podcast series in a few weeks.

About the podcaster:

Greg Williams @gregscience @themixuab is research editor within Media Relations at the University of Alabama at Birmingham.