Thymus Hormone May Reduce Inflammation and Boost Cancer Therapy

Researchers have identified a pathway linking the ageing thymus with chronic inflammation, cancer progression and reduced responses to immunotherapy.

Could a hormone produced by the thymus help reduce the chronic inflammation that develops as people grow older?
Researchers from the Keck School of Medicine of USC have identified thymulin, a hormone produced by the thymus, as a potential regulator of age-related inflammation, often called inflammaging.

The researchers found that thymulin levels decline with age while inflammatory activity increases. In older mice, raising thymulin levels reduced inflammation, strengthened immune responses against tumours, improved survival and made cancer immunotherapy more effective. The peer-reviewed findings were published in Nature Communications.

What Is Inflammaging?

Inflammaging is persistent, low-grade inflammation that becomes more common with age. Unlike short-term inflammation, which helps the body respond to infection or injury, this chronic inflammatory state can continue without an immediate threat..(1^✔ ✔Trusted Source
Inflammaging: Mechanisms, Markers, and Intervention Strategies

Go to source

)

Age-related inflammation has been linked to several major health conditions, including cancer, heart disease, metabolic disorders and neurodegenerative diseases. Scientists are still working to understand exactly what causes it and how its harmful effects might be reduced.

The new study identified increased numbers of inflammatory myeloid cells in older mice and humans. These immune cells produced higher levels of inflammatory cytokines, including IL-1α, IL-1β, IL-6 and TNF-α.

Thymulin May Help Keep Inflammation Under Control

The thymus is a small organ located behind the breastbone. It is best known for producing and training T cells, which help the immune system fight infections and recognise abnormal cells, including cancer cells.

Using human blood samples and mouse models, the researchers found that thymulin helps regulate cytokines, signalling proteins that control inflammation. As thymulin levels fall with age, inflammatory cytokine activity rises.

“The thymus is best known for producing T-cells, but our findings show it also helps keep age-related inflammation in check.” — Fumito Ito, Keck School of Medicine of USC

The team also used heterochronic parabiosis, an experimental method in which an older mouse and a younger mouse are surgically joined so they share blood circulation. Inflammation declined in the older animals, suggesting that a factor present in younger blood could counter age-related immune changes. Further analysis pointed to thymulin as an important part of that pathway.(2^✔ ✔Trusted Source
Thymulin restrains age-associated myeloid inflammation and enhances cancer immunotherapy

Go to source)

Thymulin Improved Cancer Outcomes in Older Mice

Chronic inflammation can weaken the immune system’s ability to attack tumours and may reduce the effectiveness of immune checkpoint inhibitors. In older mice with cancer, thymulin strengthened antitumour immune activity and improved overall survival.

The treatment was also associated with better responses to anti-PD-1/PD-L1 therapy, a form of cancer immunotherapy that helps immune cells recognise and attack cancer.

In the animal models, increasing thymulin levels was associated with:

• Lower age-related inflammatory activity
• Stronger immune responses against tumours
• Improved survival in older mice with cancer
• Greater responsiveness to anti-PD-1/PD-L1 immunotherapy

Clinical Trials Must Confirm Thymulin’s Potential

The findings do not show that thymulin is ready to treat inflammation, cancer or other age-related diseases in people. Most of the treatment evidence came from animal models, and clinical studies will be required to establish its safety, effective dose and potential benefits in humans.

The researchers plan to examine whether thymulin affects how tumours develop and spread. They also intend to study its possible role in other conditions associated with inflammaging, including diabetes, chronic kidney disease and Alzheimer’s disease.

The study further highlights the importance of using older animals in research on diseases of ageing.(2^✔ ✔Trusted Source
Thymulin restrains age-associated myeloid inflammation and enhances cancer immunotherapy

Go to source)

Experiments conducted only in young animals may overlook immune and inflammatory changes that can influence disease progression and treatment response later in life.

References:

1. Inflammaging: Mechanisms, Markers, and Intervention Strategies- (https://www.nia.nih.gov/research/dab/workshops/inflammaging-mechanisms-markers-and-intervention-strategies)
2. Thymulin restrains age-associated myeloid inflammation and enhances cancer immunotherapy- (https://www.nature.com/articles/s41467-026-75383-0)

Source-Medindia