LL-37 serves dual roles — protecting against infections but also triggering autoimmune inflammation in psoriasis and lupus by acting as an autoantigen that activates interferon-producing immune cells.
Autoantigen in psoriasis and lupusLL-37 complexed to self-DNA triggers plasmacytoid dendritic cell interferon production driving autoimmune inflammation
What the researchers found
LL-37 complexed to self-DNA acts as an autoantigen in psoriasis and lupus, activating interferon production by plasmacytoid dendritic cells, while also having dual antiviral and pro-inflammatory roles.
Why it matters
LL-37 is central to both antimicrobial defense and autoimmune disease. Understanding its dual roles is essential for developing therapies that preserve its protective functions while blocking its pathogenic activities.
The numbers in context
LL-37 produced by neutrophils, monocytes, macrophages, epithelial cells; acts as autoantigen when complexed with self-DNA
How the study worked
Narrative review of LL-37 immunomodulatory roles in autoimmune diseases (psoriasis, lupus) and viral infections.
Who was studied
Not applicable (narrative review)
What this study cannot tell us
Review without new experimental data; LL-37 roles in different viral infections vary widely; therapeutic targeting strategies are largely conceptual.
How to read the evidence
Well-established mechanisms reviewed from published literature, but therapeutic targeting strategies remain largely theoretical.
When this study was published
Published in 2020; LL-37 gained additional attention during COVID-19 research for its potential antiviral and immunomodulatory roles.
The bigger picture
LL-37 exemplifies the fine line between immune defense and autoimmunity — the same peptide that protects against infections can drive chronic inflammatory disease when regulation fails.
Questions still open
- Can LL-37-DNA complex formation be blocked specifically to treat psoriasis without compromising antimicrobial defense?
- Which viral infections benefit most from LL-37 antiviral activity versus being worsened by its inflammatory effects?
- Could LL-37 inhibitors prevent autoimmune flares triggered by skin injury?
Common questions
Can your own antimicrobial peptides cause disease?
Does LL-37 help fight viruses?
Read the original research
Immunomodulatory Role of the Antimicrobial LL-37 Peptide in Autoimmune Diseases and Viral Infections.
Vaccines, 8(3)
Citation
Pahar, Bapi; Madonna, Stefania; Das, Arpita; Albanesi, Cristina; Girolomoni, Giampiero. (2020). Immunomodulatory Role of the Antimicrobial LL-37 Peptide in Autoimmune Diseases and Viral Infections.. Vaccines, 8(3). https://doi.org/10.3390/vaccines8030517