LOS ANGELES, United States: The Thymulin hormone reduced age-related inflammation and improved cancer immunotherapy responses in older mice, according to a peer-reviewed University of Southern California study.
The researchers identified thymulin as a thymus-derived peptide that declines with age. It suppressed inflammatory cytokines by inhibiting NF-κB, a signalling pathway that regulates immune responses, the Nature Communications study found.
The team used shared-circulation experiments, bone-marrow chimaeras, and breast-cancer mouse models to examine inflammation associated with ageing. Researchers also administered thymulin to aged mice and studied its effects on immune cells.
Thymulin delayed tumour growth and prolonged survival in the older animals. It also made their tumours more responsive to anti-PD-L1 immunotherapy, which had produced no significant benefit when used alone in the study.
Researchers separately examined blood cells from human donors. Inflammatory myeloid cells increased with donor age, while thymulin reduced several inflammatory cytokines when scientists treated cells from older donors in vitro.
Fumito Ito, MD, PhD, a professor of surgery and immunology at USC’s Keck School of Medicine, led the research. He said the findings revealed a pathway connecting ageing, inflammation and cancer immunity, according to the university’s research announcement.
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However, researchers have not tested thymulin as a treatment in people. The findings, therefore, do not establish that the hormone can slow human ageing or improve cancer survival in patients.
The team plans to investigate thymulin’s role in tumour development and chronic diseases linked to age-related inflammation.
