AUG 02, 2016 7:27 PM PDT

Immune System Error Creates Vulnerability to Sepsis

WRITTEN BY: Kara Marker
The immune system is usually equipped to handle most bacterial infections, but certain cases of severe infection can leave a person extremely vulnerable when certain blood cells fail to be continuously produced. In a new study from Indiana University, researchers looked at the errors that occur in a molecular signaling system to see what goes wrong.
Credit: rjjaramillo.wordpress.com
“Sepsis” describes the immune response to a severe bacterial infection, hospitalizations for which have more than doubled between 2000 and 2008. With an alarming mortality rate between 40 and 60 percent, scientists are largely invested in figuring out what pushes the immune system into an error-prone emergency mode where the activity of both immune cells and blood-producing, bone marrow-originating hematopoietic stem cells are inhibited. 

“More research is needed to better understand this process and develop better, and much needed, therapeutic strategies for sepsis,” said Nadia Carlesso, MD, PhD from the Indiana University School of Medicine. 

In a unique study that focused on the early stages of acute infection rather that late stages of sepsis, researchers looked at the molecular signaling system in mice models of sepsis thought to be responsible for suppression of key cells. If scientists can determine if the acute infection stage is where the system starts to err, intervention at this stage could potentially prevent a severe septic response from occurring in the body. 

First, the researchers discovered the details of the relationship between immune cells, hematopoietic stem cells, and the molecular signaling system during sepsis. For whatever reason, errors in signaling led to hematopoietic stem cells failing to produce mature neutrophils, immune cells vital for the clearance of bacteria from the body. 

Based on this finding, the researchers then studied the role of another player in the immune system called toll-like receptor 4 (TLR4). TLRs are charged with the sentinel duty of detecting invading bacteria and sending signals to warn the immune system. As part of a healthy immune response, TLR4 activates two signaling pathways that lead to the production of neutrophils during an infection. During massive bacterial infections, two different molecules downstream of TLR4 prevent proper signaling, leaving TLR4 and the associated molecules responsible for inhibiting neutrophil production as well as damage to hematopoietic stem cells in the bone marrow. 

What scientists learned from this study and what we can take away is this: the immune system is far from perfect. Even so, identifying and understanding when and how it falls short allows researchers to step in and improve the natural process with tools in modern medicine.

This study was published in the journal Stem Cell Reports.
 


Sources: Indiana University
 
About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
OCT 29, 2019
Microbiology
OCT 29, 2019
Antibody Discovered That May be the Key to a Universal Flu Vaccine
Instead of designing a new flu vaccine every year, researchers have made a breakthrough that may lead to a single vaccine that protects against all strains....
NOV 03, 2019
Genetics & Genomics
NOV 03, 2019
Can CRISPR Replace Antibiotics?
Antibiotic-resistant infections claim around 700,000 lives per year, with estimates saying that this number could swell to 10 million by 2050 (Jacobs: 2019...
NOV 22, 2019
Immunology
NOV 22, 2019
Rogue Inflammation Activates Depression During Pregnancy
Unresolved inflammation in a pregnant woman’s body can lead to serious depression during and after pregnancy. A new study investigates the physiologi...
JAN 04, 2020
Immunology
JAN 04, 2020
Why Do Skincare Products Sometimes Cause Rashes?
Chemicals commonly found in skincare products are intended to avoid interactions with the part of the immune system responsible for triggering allergic inf...
JAN 14, 2020
Technology
JAN 14, 2020
Can Virtual Reality Influence an Increase in Vaccinations?
Can a virtual reality (VR) help increase flu vaccination rates? Apparently, yes! A recent study using VR stimulation is aiming to show how the flu spreads ...
FEB 14, 2020
Immunology
FEB 14, 2020
Rewired natural killer cells show promising results in leukemia patients
Natural killer (NK) cells are a subset of white blood cells that are key players in the innate immune system, orchestrating host-rejection responses agains...
Loading Comments...