FEB 22, 2017 08:12 AM PST

A Newborn's First Breath Forges A Lifetime of Immunity

WRITTEN BY: Kara Marker

More than ten thousand liters of air enter the lungs on a given day, but it’s not just oxygen that fills the lungs; pathogens and pollutants also hitch a ride into the body via breathing. To combat these invaders, the immune system employs an intricately-designed mechanism that simultaneously keeps pathogens at bay and soothes the lung tissue to allow for healthy exchange of oxygen and carbon dioxide with each breath.

Fluorescent staining of IL-33 in a newborn mouse lung. Source: Seth Scanlon / MRC Laboratory of Molecular Biology, Cambridge

A new study in mice explored how a newborn immune system “learns” how to preserve the delicate balance between remaining dormant and actively mounting a response against any bacteria, virus, or other foreign agent that enters the lungs after birth.

During this study, scientists at the CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences identified a series of immune cells and molecules specifically designed to keep this balance, cells that newborn lungs employ upon first breath.

Upon birth, “spontaneous ventilation” occurs that immediately stimulates the release of a cytokine called interleukin-33 (IL-33). This chemical messenger then signals to type 2 innate lymphoid cells (ILC2s) which, according to IL-33 direction, travel into the lung tissue to release another cytokine, IL-13. This cytokine then induces macrophages in the lung tissue to become anti-inflammatory, allowing the peaceful exchange of gases necessary for respiration.

In addition to respiratory tissue, ILC2s are found in gastrointestinal and skin tissue where they seem to perform a completing opposite role; some studies have shown that they promote allergic inflammation. Whether ILC2s stimulate anti- or pro-inflammatory macrophages seems to depend on which interleukin signals to them. In the case of newborn lung maintenance, it is anti-inflammatory activity instructed by IL-33.

"Now we understand that right after birth, ILC2s are responsible for the differentiation of alveolar macrophages into specialized cells that keep the immune system in check and ensure that the lungs stay calm and healthy to ensure proper gas exchange,” explained first author Simona Saluzzo, PhD Student at CeMM.

Source: Cell Press

However, overactive anti-inflammatory macrophages can also have a negative impact on the lungs, preventing the immune system from adequately attacking pathogens. “The mechanism that maintains the lung function of gas exchange at the same time explains why bacterial pneumonia is the primary cause of death by an infectious disease in Western countries,” explained senior author Sylvia Knapp.

The delicate balance required in the lungs for both immune defense and adequate gas exchange has never been so clearly evident. Given the ubiquity of environmental pollutants and pathogens, it is vital that the immune system flawlessly maintains homeostasis in the lungs, either on its own or with clinical intervention.

Knapp’s study was recently published in the journal Cell Reports.

Sources: Current Immunology Reviews, Advances in Immunology, CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences

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
SEP 17, 2019
Immunology
SEP 17, 2019
A Possible Key to Severe Flu
By studying the impact that NPY and its receptor Y1R have on influenza in mice, the research group has now discovered that NPY produced in lung phagocytes can aggravate influenza....
SEP 17, 2019
Immunology
SEP 17, 2019
T Cell Stimulation for Zika Vaccine Design
Immune cells called CD4+ T cells could be important mediators of protection against the Zika virus...
SEP 17, 2019
Immunology
SEP 17, 2019
High Res Look Into the Brain of MS
Researchers have revealed a subtype of immune cell aiding in the autoimmune disorder Multiple Sclerosis...
SEP 17, 2019
Immunology
SEP 17, 2019
Silent Inflammation, the Silent Problem
People who have chronic inflammation in middle-age may develop problems with thinking and memory...
SEP 17, 2019
Cancer
SEP 17, 2019
Widely Prescribed Breast Cancer Medication Promotes Metastasis
The primary goals of metastatic breast cancer treatment are to ensure that the patient has the longest survival possible while experiencing the highes...
SEP 17, 2019
Immunology
SEP 17, 2019
Fecal Transplant improves ASD
Our understanding of the brain-gut connection is increasing by the day. Individuals with autism spectrum disorder (ASD) also experience gastrointestinal sy...
Loading Comments...