AUG 16, 2017 05:33 PM PDT

Genes Have an Influence on our Response to Infection

WRITTEN BY: Carmen Leitch
1 19 619

When an infectious illness sickens multiple people, they often respond in different ways; there can be differences in symptoms that people exhibit, or a range of severities, or sometimes some infected people don’t get sick at all. New research has suggested that small variations in our genetics are to blame for the varied responses. The work, reported in Nature Communications, shows that infections cause changes in gene expression levels, but those changes are different in different people. Genes alter the response to the illness. The video below outlines the work.

"We wanted to understand how genetic differences between individuals affect this cellular response to infection," said one senior author, Dr. Johannes Schumacher of the University of Bonn.

"Our defense mechanisms against microbial pathogens rely on white blood cells that are specialized to detect infection. Upon encounter of microbes, these cells trigger cellular defense programs via activating and repressing the expression of hundreds of genes," explained Dr. Veit Hornung of the Ludwig-Maxmilians-Universität in Munich and another senior author of the study. The researchers used donated monocytes from 134 volunteers for this research.

The immune system not only fights infectious disease; through inflammation and autoimmunity, it can also play a role in many other diseases. Small differences in genes the investigators identified were affecting the immune system and its response to infection.

"These genes include many of the well-known genes of the human immune system, demonstrating that genetic variation has an important role in how the human immune system works," said lead author Dr. Sarah Kim-Hellmuth of the New York Genome Center, Columbia University. "While earlier studies have mapped some of these effects, this study is particularly comprehensive, with three stimuli and two time points analyzed."

A micrograph of monocytes, the cell type used for this work. / Credit: Wikimedia Commons

Some of the genetic variants identified in the study had links to celiac disease, others were associated with cholesterol level. The variants had different effects on gene regulation depending on a cell’s infectious state.

Because gene expression patterns were analyzed at the population level, researchers were able to show how innate immune responses differed widely among individuals that were exposed to myriad pathogens on multiple occasions. The study suggested that genetics underpins the many differences in immune response among the members of a population. It also showed that the immune system influences genetic association with disease. The work provides some insight into how genetic elements impact the response to environmental stimuli, as well as the dynamics of immune response.

"This supports a paradigm where genetic disease risk is sometimes driven not by genetic variants causing constant cellular dysregulation, but by causing a failure to respond properly to environmental conditions such as infection," said co-senior author Dr. Tuuli Lappalainen of the New York Genome Center and Columbia University.

”It's been known for a long time that most diseases have both genetic and environmental risk factors. But it's actually more complicated than that because genes and environment interact. As demonstrated in our study, a genetic risk factor may manifest only in certain environments," explained Dr. Lappalainen. "We are still in early stages of understanding the interplay of genetics and environment, but our results indicate that this is a key component of human biology and disease. The molecular approach that we took in our study can be a particularly powerful way for researchers to delve deeper into this question."


Sources: Science Daily via New York Genome Center, Nature Communications

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
JUN 11, 2018
JUN 11, 2018
Post-Trauma Treatment Relieves System-Wide Immune Reaction
The immune response after a traumatic physical injury is essentially the same as a body-wide bacterial infection: inflammatory, systemic, and lethal. From
JUL 06, 2018
Cell & Molecular Biology
JUL 06, 2018
Small Molecules Found to Dial Down Autoimmunity
Scientists have now identified two combinations of small molecules that tamp down a protein called STING.
JUL 20, 2018
Genetics & Genomics
JUL 20, 2018
Nanoparticle-based Gene Therapy Cures Disease in Fetal Mice
Although CRISPR has grabbed a lot of headlines in recent years, it is not the only gene-editing game in town.
AUG 04, 2018
Cell & Molecular Biology
AUG 04, 2018
Bioengineered Lung Successfully Grown and Transplanted
The complexity of human organs has made them difficult to engineer, but real progress is being made.
AUG 04, 2018
AUG 04, 2018
A Radical New Approach to Treating Neurodegeneration
The pathways that neural impulses travel can't be retrieved once they're lost... or can they?
AUG 13, 2018
AUG 13, 2018
Insight Into the Origins of Junk DNA - From Koalas
The human genome isn't only genes. There's also long, repetitive sequences with an unknown function and origin.
Loading Comments...