An antimicrobial peptide of the cathelicidin family that provides innate immune defense by killing pathogens and modulating inflammation and wound healing.
Chessa. Céline C; Bodet. Charles C; Jousselin. Clément C; Larivière. Andy A; Damour....
The study shows that the natural skin peptide LL‑37 can directly knock down West Nile virus particles and lower the amount of virus that skin cells release, while another peptide, hBD‑3, doesn’t stop the virus. Both peptides also boost immune signaling when the cells are already activated, but they do nothing on their own.
Kim. Ju J; Yang. Ye Lin YL; Jeong. Yongsu Y; Jang. Yong-Suk YS
Scientists tested the human peptide LL‑37 as a helper (adjuvant) in a nose‑spray vaccine against MERS‑CoV in mice. Adding LL‑37 to the viral protein boosted both local (IgA) and systemic (IgG) antibodies, improved lung T‑cell responses, and helped mice survive infection better than the protein alone. While promising for vaccine design, it isn’t a ready‑to‑use supplement or protocol for individuals.
In a rat model of menopause‑related osteoporosis, the antimicrobial peptide LL‑37 helped keep bones stronger by turning on a growth‑promoting pathway (Wnt/beta‑catenin) and slowing down bone‑breaking cells. The benefit disappeared when that pathway was blocked, showing LL‑37 works through this mechanism.
The study found that the amount of the antimicrobial peptide LL‑37 in blood, when adjusted for how many white blood cells a person has, is lower in people with more severe COVID‑19. Plain LL‑37 levels or vitamin D levels alone didn’t predict how sick someone would get. Measuring the LL‑37‑to‑leukocyte ratio early in a hospital stay might help flag patients at higher risk of worsening disease.
Yusuf. Muhammad M; Destiarani. Wanda W; Firdaus. Ade Rizqi Ridwan ARR; Rohmatulloh. Fauzian Giansyah...
The study used detailed computer simulations to see how the antimicrobial peptide LL‑37 sticks to and penetrates bacterial‑like membranes versus human‑like membranes. It found that the peptide first contacts the membrane with two leucine residues, then uses positively charged parts (lysine and arginine) to pull into the bacterial membrane, especially using the segment from amino acids 18‑29. This part doesn’t interact much with human‑type membranes, suggesting it’s the key region for antibacterial action.
Activating the aryl hydrocarbon receptor (AhR) with the topical drug benvitimod reduced skin redness and inflammation caused by the peptide LL‑37 in mice and human skin cells, mainly by lowering the activity of TLR2 and several inflammation‑related chemokines.
Masadeh. Majed M; Ayyad. Afnan A; Haddad. Razan R; Alsaggar. Mohammad M; Alzoubi. Karem K; Alrabadi....
Researchers created a new antimicrobial peptide called MAA-41 by mixing parts of two natural peptides (LL-37 and BMAP-28) and tweaking its amino acids. It kills a wide range of bacteria, including drug‑resistant strains, at low micromolar levels and can also break down bacterial biofilms. It’s less harmful to red blood cells but still toxic to some kidney cells, and it works even better when paired with regular antibiotics.
Miyoshi. Shin-Ichi SI; Kumagai. Mika M; Tanida. Ryousuke R; Soda. Kohei K; Yoshimoto. Yuri Y; Mizuno...
The study shows that a natural human peptide called LL‑37, at low doses, can lower the production of a key protein (flagellin) that helps the dangerous bacteria Vibrio vulnificus move and cause disease. By cutting down this protein, the bacteria become less motile and potentially less harmful.
The study shows that a molecule called S1P can make bladder cells produce more of the peptide LL‑37, and that extra LL‑37 makes bladder cancer cells grow faster. Blocking S1P receptors stops this effect, indicating the pathway drives tumor growth rather than offering health benefits.
A study found that the human peptide LL‑37 can make a model of the mitochondrial membrane leaky even at very low (nanomolar) levels, especially when the membrane is rich in a lipid called phosphoethanolamine. The peptide groups together and inserts deeper into the membrane, which could trigger cell death. This suggests LL‑37 might affect mitochondria more easily than previously thought.
In mice, constantly exposing the skin to the peptide LL‑37 creates a rosacea‑like condition that gets inflamed and starts to scar. Giving the drug thalidomide reduced the redness, inflammation, and early scar tissue, and lowered related molecular signals. This shows thalidomide can counteract LL‑37‑driven skin problems in an animal model, but the drug’s serious side‑effects limit its use for self‑experimentation.
This study used computer models to see how common genetic changes (SNPs) might affect the human antimicrobial peptide LL‑37. Most changes looked harmless, but a few could lower the peptide’s charge or alter its shape, potentially weakening its ability to fight microbes and possibly influencing inflammation. The work is mostly theoretical and doesn’t give direct dosing advice, but it hints that personal genetics could matter for LL‑37‑based health strategies.
Ledger. Elizabeth V K EVK; Mesnage. Stéphane S; Edwards. Andrew M AM
Human blood serum makes Staph bacteria much less sensitive to antibiotics like daptomycin. The natural peptide LL‑37 in serum triggers a bacterial alarm system that builds extra cell wall and changes membrane fats, both of which protect the bugs. If you block these two changes, the bacteria become as vulnerable as they are in lab broth.
Menon. Nitasha D ND; Penziner. Samuel S; Montaño. Elizabeth T ET; Zurich. Raymond R; Pride. Dav...
The study found that when Pseudomonas aeruginosa becomes resistant to certain viruses (phages) and turns brown because of a gene change, it also loses a lot of DNA. This makes the bacteria weaker and more easily killed by the natural antimicrobial peptide LL‑37 and the antibiotic colistin, and it’s less able to cause disease in animals.
Lyu. Meinan M; Ayala. Julio C JC; Chirakos. Isabella I; Su. Chih-Chia CC; Shafer. William M WM; Yu....
Researchers discovered a new cyclic peptide called CASP that can stick inside a bacterial pump (MtrD) used by some Gram‑negative bugs to throw out antibiotics. While CASP didn’t help antibiotics work against the gonorrhea bug, it did make other rod‑shaped Gram‑negative bacteria more vulnerable to certain drugs, suggesting it could be used as a helper molecule in future antibiotic treatments.
Chen. Zongchao Z; Niu. Pengfei P; Ren. Xiaomei X; Han. Wenlong W; Shen. Ruyu R; Zhu. Min M; Yu. Yang...
Researchers found that a protein called SspA, secreted by a duck‑infecting bacteria, helps the bug cause disease and can break down the human antimicrobial peptide LL‑37 along with other proteins like gelatin and fibrinogen.
du Teil Espina. Marines M; Fu. Yanyan Y; van der Horst. Demi D; Hirschfeld. Claudia C; López-&#...
The study shows that a gum‑disease bacterium, Porphyromonas gingivalis, releases tiny vesicles that stick to your immune cells (neutrophils) and make them release antimicrobial peptides like LL‑37, but the bacteria’s enzymes then chew up LL‑37, letting the bugs survive and keep inflammation going. This helps explain why gum disease can link to other health problems.
de Buhr. Nicole N; Baumann. Tristan T; Werlein. Christopher C; Fingerhut. Leonie L; Imker. Rabea R;...
A study of a stroke patient who got a rare clotting problem after a COVID vaccine found that a protein called LL-37 was unusually high in the clot and blood, which may protect harmful DNA webs (NETs) from being broken down, making clots worse.
Researchers attached a short targeting piece (VTK) to the natural antimicrobial peptide LL‑37, creating VTK‑LL37. In lab tests and mouse sepsis models, this combo killed the harmful E. coli strain better than LL‑37 alone, stopped biofilm formation, lowered inflammation markers, and helped mice survive longer. The work is still early‑stage and not a ready‑to‑use treatment, but it shows that directing antimicrobial peptides to specific bugs can boost their effectiveness.
Klaiss-Luna. Maria C MC; Manrique-Moreno. Marcela M
The study used infrared spectroscopy to look at how complex, cell‑like membranes behave and how the antimicrobial peptide LL‑37 changes shape when it meets a Staph aureus‑like membrane, but not when it meets a red‑blood‑cell membrane.