An antimicrobial peptide of the cathelicidin family that provides innate immune defense by killing pathogens and modulating inflammation and wound healing.
Wei. Ran R; Dhawan. Puneet P; Baiocchi. Robert A RA; Kim. Ki-Yoon KY; Christakos. Sylvia S
The study shows that taking vitamin D can turn on the gene that makes the antimicrobial peptide LL‑37 in lung cells, and that this effect is stronger when certain other proteins (PU.1 and CEBPα) are present. It also finds that drugs or nutrients that change how DNA is packaged (like HDAC inhibitors) can further boost LL‑37, while another protein (PRMT5) can dampen it. In plain terms, vitamin D helps the lungs make a natural antibiotic, and tweaking the cell's epigenetic machinery might make this effect bigger.
Lüthje. P P; Walker. S S; Kamolvit. W W; Mohanty. S S; Pütsep. K K; Brauner. A A
The study shows that the cholesterol drug simvastatin can raise levels of the natural antimicrobial peptide LL‑37 in several types of human cells, but the effect varies by cell type and works through different pathways, including blocking histone deacetylases and boosting vitamin D activation.
Martin Jensen. M M; Jia. Wanjian W; Schults. Austin J AJ; Ye. Xiangyang X; Prestwich. Glenn D GD; Oo...
A mouse study shows that the antimicrobial peptide LL‑37 can trigger bladder inflammation and pain by raising IL‑33 levels, which then activate mast cells. Mice lacking mast cells had far less inflammation and pain, suggesting that the IL‑33‑mast cell pathway drives the symptoms of interstitial cystitis.
Li. Hui H; Zhang. Shutao S; Nie. Bin'en B; Du. Zhe Z; Long. Teng T; Yue. Bing B
A tiny piece of the natural antimicrobial peptide LL-37, called KR-12, was shown in lab tests to make human bone‑marrow stem cells turn into bone‑forming cells more efficiently. It does this by turning on the BMP/SMAD signaling pathway, which is a key driver of bone growth, without harming the cells or causing them to die.
The study used computer simulations to watch how the human antimicrobial peptide LL‑37 behaves when it meets two types of cell membranes: a negatively charged one that mimics bacteria (POPG) and a neutral one that mimics human cells (POPC). LL‑37 quickly sticks to the bacterial‑like membrane, stays helical, lies flat, and bends the membrane, while it interacts more slowly with the human‑like membrane, loses its shape, and barely penetrates it.
Findlay. Fern F; Pohl. Jan J; Svoboda. Pavel P; Shakamuri. Priyanka P; McLean. Kevin K; Inglis. Neil...
The study shows that tiny carbon particles, like those from soot or engineered nanomaterials, can stick to the natural antimicrobial peptide LL‑37 in our bodies, change its shape, and make it far less effective at killing bacteria and viruses. Even low levels of these particles cause a noticeable drop in LL‑37’s protective function, suggesting that exposure to carbon nanoparticles could weaken our innate immune defenses.
Durnaś. Bonita B; Piktel. Ewelina E; Wątek. Marzena M; Wollny. Tomasz T; Góźd...
Researchers tested natural peptide LL‑37 and synthetic mimics called ceragenins (CSA‑13 and CSA‑131) against harmful anaerobic bacteria. The lab results showed the ceragenins killed the bugs more effectively than LL‑37 or the antibiotic metronidazole, and CSA‑131 also stopped biofilm formation. They even attached these compounds to magnetic nanoparticles and kept the antibacterial effect.
Bucki. Robert R; Durnaś. Bonita B; Wątek. Marzena M; Piktel. Ewelina E; Cruz. Katrina K;...
The study shows that the sticky DNA and actin nets that form in pus can trap positively‑charged antibiotics and the natural antimicrobial peptide LL‑37, reducing their killing power. Breaking down these nets with enzymes like DNase 1, gelsolin, or even simple poly‑aspartic acid makes many antibiotics work better against bacteria.
Kim. Miri M; Kim. Jongsic J; Jeong. Seo-Won SW; Jo. Hyunmu H; Woo. Yu Ri YR; Park. Hyun Jeong HJ
A study in mice showed that a skin gel containing brimonidine (a drug already approved for rosacea) not only improves the visible redness but also cuts down the number of mast cells, a type of immune cell that drives inflammation in rosacea. This suggests the gel works by calming the immune response, not just by tightening blood vessels.
The study shows that both forms of vitamin D (the inactive 25‑hydroxy and the active 1,25‑dihydroxy) can boost the body's own production of the antimicrobial peptide LL‑37 in gum cells, and this boost gets even bigger when the cells encounter bacterial components. Blocking the vitamin D pathway stops this effect, and vitamin D also lowers some inflammation signals. In plain terms, having enough vitamin D may help your gums make more natural antibiotics and keep inflammation down.
Switching the positions of lysine and arginine in LL-37‑derived antimicrobial peptides doesn’t change how much of the peptide is needed to stop bacterial growth, but it does change how quickly they kill bacteria and how safe they are for human cells. The original LL-37 sequence works faster, kills more efficiently, and is less toxic than the swapped versions, and the swapped peptides show unique patterns that could help identify different bacteria.
Pircher. Joachim J; Czermak. Thomas T; Ehrlich. Andreas A; Eberle. Clemens C; Gaitzsch. Erik E; Marg...
The study shows that the antimicrobial peptide LL-37 (and its mouse version CRAMP) can trigger platelets to form clots and drive inflammation, especially after blood vessel injury. High levels of LL-37 were found in heart attack clots, and mice lacking CRAMP had fewer clots and less lung damage. The peptide works by binding to a platelet receptor (GPVI) and activating signaling pathways that make platelets sticky.
The study shows that the gum‑damaging bacteria Porphyromonas gingivalis can lower the body’s natural antimicrobial peptide LL‑37 in gum cells by boosting a molecule called IL‑33. Vitamin D‑like compounds can raise LL‑37, but the bacteria’s effect can block this boost. Keeping the mouth free of this bacteria may help maintain higher LL‑37 levels, which are linked to better immune defense.
de Breij. Anna A; Riool. Martijn M; Cordfunke. Robert A RA; Malanovic. Nermina N; de Boer. Leonie L;...
Scientists made a new peptide called SAAP-148, based on the human peptide LL-37, that can kill tough drug‑resistant bacteria and break down biofilms. In lab tests and on mouse and human skin samples, a short 4‑hour treatment with a cream containing SAAP-148 wiped out infections from MRSA and MDR Acinetobacter, and it didn’t cause the bacteria to become resistant.
Adam. Lucille L; López-González. Moisés M; Björk. Albin A; Pålsson. Sandra...
In a mouse study, the strain that cleared a harmless TB‑like infection fastest showed a big jump in the natural antimicrobial peptide LL‑37 (called CRAMP in mice) right after exposure, without needing a flood of immune cells. The other mouse strain relied on lots of inflammatory cells and cytokines instead. This suggests that boosting LL‑37 could help the body fight certain infections early, without causing excess inflammation.
van den Berge. M M; Jonker. M R MR; Miller-Larsson. A A; Postma. D S DS; Heijink. I H IH
A study comparing two inhaled steroids—budesonide (BUD) and fluticasone propionate (FP)—found that BUD lets airway cells keep higher levels of some natural antimicrobial proteins (like lactoferrin and S100A8) than FP, while neither drug changes the amount of the peptide LL‑37. This may explain why COPD patients on FP have a higher pneumonia risk.
The study shows that four skin‑care ingredients—dextran sulfate, 4‑t‑butylcyclohexanol (BCH), pongamia oil, and hesperidin methyl chalcone (HMC)—can calm the inflammation and blood‑vessel changes that cause rosacea redness in lab tests. They each hit different parts of the rosacea pathway, and together they work even better, suggesting they could be useful in topical products for people with sensitive, red skin.
Choi. Heejun H; Yang. Zhilin Z; Weisshaar. James C JC
The human antimicrobial peptide LL-37 kills E. coli faster when oxygen is present. It first slips into the space between the outer and inner membranes, creates oxidative molecules there, and then, after the inner membrane is breached, causes a burst of hydrogen peroxide inside the cell. This oxidative killing needs a working electron‑transport chain and a strong proton‑motive force, so it’s much weaker when the bacteria grow without oxygen.
Luo. Yu Y; McLean. Denise T F DT; Linden. Gerard J GJ; McAuley. Danny F DF; McMullan. Ronan R; Lundy...
Researchers tested the natural antimicrobial peptide LL-37 and two shorter versions called KE-18 and KR-12 against common infection‑causing microbes. The short peptides were better at killing the microbes in lab tests, and KE-18 could also stop biofilm formation even at low doses, without harming human red blood cells. This suggests KE-18 might become a useful anti‑infection ingredient, but it’s still far from a consumer product.
The study explains that a specific receptor on certain immune cells (MRGPRX2) is turned on by the natural peptide LL‑37 and other similar molecules. When this receptor is activated, it can help fight infections but can also trigger inflammation and allergic‑type reactions, especially in conditions like severe asthma, rosacea, and chronic hives.