Psoriasis Autoantigens: How LL-37 and Other Peptides Trigger Autoimmune Skin Inflammation | Research

The takeaway

Four psoriasis autoantigens have been identified — including cathelicidin LL-37 — with autoreactive T cells and autoantibodies found in patients, establishing psoriasis as an autoimmune disease.

4 autoantigens
Discovered since 2014, including cathelicidin LL-37, establishing psoriasis as an autoimmune disease

What the researchers found

LL-37 and ADAMTSL5 autoantibodies are strongly associated with psoriatic arthritis, establishing psoriasis as an autoimmune disease with specific peptide autoantigens.

Why it matters

Identifying specific autoantigens opens the door to antigen-targeted therapies that could treat psoriasis without broadly suppressing the immune system.

The numbers in context

4 autoantigens since 2014; autoreactive T cells; anti-LL-37 and anti-ADAMTSL5 antibodies linked to PsA

How the study worked

Review of published studies on psoriasis autoantigen discovery, autoreactive T cell characterization, and autoantibody association with disease subtypes.

Who was studied

Review of studies in moderate-severe plaque psoriasis patients

What this study cannot tell us

Review article. The relative contribution of each autoantigen to disease initiation and maintenance is still being established.

How to read the evidence

Review of autoantigen discovery studies with strong immunological evidence. Autoantibody-disease associations are well-documented.

When this study was published

Published in 2020. Autoimmune aspects of psoriasis continue to be a major research focus.

The bigger picture

Establishing psoriasis as a true autoimmune disease with defined autoantigens could lead to tolerance-inducing therapies — essentially teaching the immune system to stop attacking these specific peptides.

Questions still open

Could antigen-specific immunotherapy desensitize patients to LL-37?
Do autoantibody levels predict progression from psoriasis to psoriatic arthritis?
Are there additional undiscovered psoriasis autoantigens?

Common questions

Is psoriasis an autoimmune disease?

Yes — this review confirms that psoriasis has defined autoantigens (LL-37, ADAMTSL5, PLA2G4D, keratin 17) against which the immune system mounts specific T cell and antibody responses. This establishes it as a true autoimmune condition, not just an inflammatory disease.

What is LL-37 and why does the body attack it?

LL-37 is cathelicidin, an antimicrobial peptide normally produced by skin cells to fight infection. In psoriasis, the immune system mistakenly recognizes LL-37 as foreign and attacks cells expressing it, driving the chronic skin inflammation seen in psoriatic plaques.

Read the original research

Current knowledge on autoantigens and autoantibodies in psoriasis.

Scandinavian journal of immunology, 92(4), e12945

View on PubMed ↗Publisher’s paper ↗

Citation

Ten Bergen, Lisa Lynn; Petrovic, Aleksandra; Aarebrot, Anders Krogh; Appel, Silke. (2020). Current knowledge on autoantigens and autoantibodies in psoriasis.. Scandinavian journal of immunology, 92(4), e12945. https://doi.org/10.1111/sji.12945