DEC 05, 2017 11:39 AM PST

Scientists Finally Figure Out How Immune Cells Release IL-1

WRITTEN BY: Kara Marker

A signaling molecule called IL-1 was identified for the first time in 1984, and only now are scientists fully understanding how cells release it. From Boston Children’s Hospital, researchers describe the protein responsible for releasing IL-1 from immune cells.

Living macrophages releasing IL-1. The bright green spots are large protein complexes that stimulate gasdermin D to form pores allowing IL-1 to pass through. Credit: Charles Evavold, Boston Children's Hospital

Until now, scientists theorized that perhaps IL-1 wasn’t actively released by cells at all, that instead it was just “passively released from dead cells.” But IL-1 is indeed actively released by cells, thanks to a protein called gasdermin D. Why did it take so long to learn this about IL-1? "Most proteins have a secretion signal that causes them to leave the cell," explained senior author Jonathan Kagan, PhD. "IL-1 doesn't have that signal.”

Gasdermin D facilitates the release of IL-1 by poking holes in the cell membrane during an infection. Past studies showed gasdermin D triggering the release of other cytokines through a similar process called pyroptosis where the cell dies during the cytokine’s release. But sometimes, in the case of IL-1 release, the cell doesn’t have to die.

In 2016, some of the present study’s authors found that when dendritic cells release IL-1, they shift into a hyperactivated state, and their ability to recruit memory T cells enhances. Dendritic cells are antigen-presenting cells, which means they take pieces of foreign particles, potentially pathogens, and present them to T cells, which decide whether or not to launch an attack. In the new study, researchers experimented with hyperactivated macrophages, phagocytic cells that engulf and digest pathogens.

The new experiments showed that macrophages could also release IL-1 without dying. “Gasdermin forms enough pores to let IL-1 pass through, but not enough to kill the cell," Kagan explained.

In light of the results connecting immune cells, gastrodermin D, and the release of IL-1, boosting IL-1 release from live immune cells could be a new approach to increasing memory T cell levels. These are cells that “remember” past pathogens and are at the ready to target them again should the pathogen return.

This approach wouldn’t come without its risks, though. Researchers would have to be careful because too many inflammatory cells, a result of higher IL-1 release, can lead to autoimmune diseases; IL-1 is often a drug target for Alzheimer’s disease and inflammatory disorders.

The present study was published in the journal Immunity.

Sources: Immunology and Cell Biology, Boston Children’s Hospital

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
MAY 04, 2018
Clinical & Molecular DX
MAY 04, 2018
New Blood Test Detects Peanut Allergy with 98% Specificity
A new blood test trumps traditional diagnostic methods for determining peanut allergy, the most common allergy for children. From the Medical Research Coun...
JUL 17, 2018
Videos
JUL 17, 2018
Encouraging Progress on HIV Vaccine
In the quest to find a vaccine against HIV which causes AIDS, most attempts have failed. The HIV epidemic began about 35 years ago and in that time only fi...
JUL 19, 2018
Videos
JUL 19, 2018
Hazmat Spill at Johns Hopkins
Biohazards are a common problem in any kind of scientific research, and if a spill of dangerous materials occurs, it can be deadly. Luckily, a recent spill...
JUL 31, 2018
Immunology
JUL 31, 2018
The Immune Systems Molecular Alphabet
Lab-designed nucleic acid nanoparticles elicit varied and specific immune response from immune cells based on shape, size, and formulation of each particle....
AUG 17, 2018
Health & Medicine
AUG 17, 2018
Is Influenza Different in Obese Patients?
There are many health risks for obese patients. Cardiovascular disease, diabetes and even some forms of cancer. The immune system can be disrupted when a p...
AUG 31, 2018
Immunology
AUG 31, 2018
B Cells Control Connective Tissue Disorder Scleroderma
Effector and Regulatory B cells play reciprocal role in pathogenesis of scleroderma....
Loading Comments...