LL-37: Double-Edged Sword in Autoimmune Disease and Viral Infections
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.
Quick Facts
What This Study 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.
Key Numbers
LL-37 produced by neutrophils, monocytes, macrophages, epithelial cells; acts as autoantigen when complexed with self-DNA
How They Did This
Narrative review of LL-37 immunomodulatory roles in autoimmune diseases (psoriasis, lupus) and viral infections.
Why This Research 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 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.
What This Study Doesn't Tell Us
Review without new experimental data; LL-37 roles in different viral infections vary widely; therapeutic targeting strategies are largely conceptual.
Questions This Raises
- ?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?
Trust & Context
- Key Stat:
- Autoantigen in psoriasis and lupus LL-37 complexed to self-DNA triggers plasmacytoid dendritic cell interferon production driving autoimmune inflammation
- Evidence Grade:
- Well-established mechanisms reviewed from published literature, but therapeutic targeting strategies remain largely theoretical.
- Study Age:
- Published in 2020; LL-37 gained additional attention during COVID-19 research for its potential antiviral and immunomodulatory roles.
- Original Title:
- Immunomodulatory Role of the Antimicrobial LL-37 Peptide in Autoimmune Diseases and Viral Infections.
- Published In:
- Vaccines, 8(3) (2020)
- Authors:
- Pahar, Bapi, Madonna, Stefania, Das, Arpita(2), Albanesi, Cristina, Girolomoni, Giampiero
- Database ID:
- RPEP-05047
Evidence Hierarchy
Summarizes existing research on a topic.
What do these levels mean? →Frequently Asked Questions
Can your own antimicrobial peptides cause disease?
Yes — LL-37 normally fights infections, but when it binds to self-DNA fragments it can trigger autoimmune inflammation in psoriasis and lupus by activating interferon-producing immune cells.
Does LL-37 help fight viruses?
LL-37 has antiviral activity against several viruses, but it can also worsen inflammation in viral infections — making its role context-dependent and sometimes counterproductive.
Read More on RethinkPeptides
Cite This Study
https://rethinkpeptides.com/research/RPEP-05047APA
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
MLA
Pahar, Bapi, et al. "Immunomodulatory Role of the Antimicrobial LL-37 Peptide in Autoimmune Diseases and Viral Infections.." Vaccines, 2020. https://doi.org/10.3390/vaccines8030517
RethinkPeptides
RethinkPeptides Research Database. "Immunomodulatory Role of the Antimicrobial LL-37 Peptide in ..." RPEP-05047. Retrieved from https://rethinkpeptides.com/research/pahar-2020-immunomodulatory-role-of-the
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.