This review proposed the term "immunotransmitter" for immune-system molecules like thymosin alpha 1 and beta 4 that communicate directly with the brain and nervous system.
New concept: immunotransmittersProposed term for immune molecules like thymosin α1 and β4 that signal directly to neurons and the brain
What the researchers found
The paper argued that certain molecules made by immune cells can send signals directly to the brain. The authors named these 'immunotransmitters,' a new term for molecules that carry information from the immune system to the central nervous system (CNS).
Examples include thymosin alpha 1 and thymosin beta 4 (peptides from the thymus gland), as well as ACTH (a stress hormone), TSH (thyroid hormone), and beta-endorphin (a natural painkiller) produced by lymphocytes (white blood cells).
The review presented evidence that thymosin peptides can alter the hypothalamic-pituitary-adrenal (HPA) axis, which is the brain's master hormone control system. They also appeared to affect the gonadal (reproductive hormone) axis.
Why it matters
This paper helped establish the concept of neuroimmunology, the idea that the immune system and nervous system are deeply interconnected. It moved beyond the old view that these systems operate independently. The 'immunotransmitter' concept influenced decades of research.
How the study worked
This is a narrative review. The authors collected evidence from multiple studies showing immune-to-brain communication. No new experiments were conducted.
What this study cannot tell us
This is a review paper, not original research. The concept of immunotransmitters was speculative at the time and based on limited experimental evidence. Many of the proposed mechanisms had not yet been confirmed.
How to read the evidence
Narrative review from 1985 synthesizing early evidence. Conceptually influential but based on limited experimental data available at the time.
When this study was published
Published in 1985 — a pioneering conceptual paper. The neuroimmune communication it proposed has since been extensively confirmed by modern research.
The bigger picture
This paper was a landmark in neuroimmunology — the field studying how the immune and nervous systems communicate. The concept that immune molecules act as brain signals helped explain phenomena like why infections cause fatigue and mood changes, and laid groundwork for understanding how peptides like thymosin alpha 1 have effects beyond the immune system.
Questions still open
- Which immunotransmitters have the strongest effects on brain function?
- Can thymosin peptides be used therapeutically to modulate the stress response?
- How do immunotransmitter levels change with aging?
Common questions
What is an immunotransmitter?
How do thymosin peptides affect the brain?
Read the original research
Evidence that thymosins and other biologic response modifiers can function as neuroactive immunotransmitters.
Journal of immunology (Baltimore, Md. : 1950), 135(2 Suppl), 806s-811s
Citation
Hall, N R; McGillis, J P; Spangelo, B L; Goldstein, A L. (1985). Evidence that thymosins and other biologic response modifiers can function as neuroactive immunotransmitters.. Journal of immunology (Baltimore, Md. : 1950), 135(2 Suppl), 806s-811s.