An antimicrobial peptide of the cathelicidin family that provides innate immune defense by killing pathogens and modulating inflammation and wound healing.
Shaykhiev. Renat R; Sierigk. Johannes J; Herr. Christian C; Krasteva. Gabriela G; Kummer. Wolfgang W...
The study shows that the natural peptide LL‑37 can help lung cells pull in bacterial LPS and trigger more inflammation, especially when the cell layer is damaged. This means LL‑37 acts like a messenger that makes cells more sensitive to bacterial signals, leading to higher levels of inflammatory chemicals IL‑6 and IL‑8.
Muratov. Vladislaw V; Lundahl. Joachim J; Mandic-Havelka. Aleksandra A; Elvin. Kerstin K; Ost. Ake A...
A small study tested a modified blood‑filter device (Cellsorba EX) that removes white blood cells in ulcerative colitis patients using a common anticoagulant. It was safe, lowered disease activity scores in half the participants, and showed that the antimicrobial peptide LL‑37 rose inside the filter system, but it didn’t change blood counts or inflammation markers.
Mount. Kristy L B KL; Townsend. Carisa A CA; Rinker. Sherri D SD; Gu. Xiaoping X; Fortney. Kate R KR...
The study shows that a protein called SapA helps the sexually transmitted bacterium Haemophilus ducreyi survive attacks by the human antimicrobial peptide LL‑37. When SapA is removed, the bacteria become more vulnerable to LL‑37 and cause fewer skin pustules in volunteers. This reveals that LL‑37’s ability to kill some bacteria can be blocked by bacterial defenses.
Steinstraesser. Lars L; Hirsch. Tobias T; Schulte. Matthias M; Kueckelhaus. Maximilian M; Jacobsen....
A lab-made peptide called IDR-1018 helps wounds heal faster in healthy animals and is less toxic to cells than the natural human peptide LL‑37. It works without killing bacteria and boosts fibroblast activity, but it doesn’t help heal diabetic wounds and doesn’t reduce infection levels.
Leonard. Brian C BC; Chu. Hiutung H; Johns. Jennifer L JL; Gallo. Richard L RL; Moore. Peter F PF; M...
Scientists discovered the only cat version of the antimicrobial peptide LL-37, called feCath. It’s made mostly in bone marrow and neutrophils, kills several bacteria just like human LL-37, but unlike LL-37 it doesn’t stick to DNA.
Spencer. H H; Karavolos. M H MH; Bulmer. D M DM; Aldridge. P P; Chhabra. S R SR; Winzer. K K; Willia...
The study shows that the body’s stress hormones (like adrenaline) can make the Salmonella bacteria more vulnerable to the natural antimicrobial peptide LL‑37 by turning down certain bacterial genes. It also finds that blocking alpha‑adrenergic receptors can reverse some of these hormone effects, while beta‑blockers do not. This suggests stress hormones influence how bacteria respond to our innate defenses, but the findings are mainly basic science without direct tips for everyday use.
Eissa. Azza A; Amodeo. Vanessa V; Smith. Christopher R CR; Diamandis. Eleftherios P EP
Researchers showed that the enzyme KLK8 is active in human skin and sweat, works best at a slightly alkaline pH but still works at skin‑like acidity, and its activity is boosted by calcium and magnesium while being blocked by zinc. KLK8 can turn on the antimicrobial peptide LL‑37 and is activated by other skin enzymes, suggesting it plays a role in skin barrier maintenance and inflammation.
Lee. Ha Young HY; Kim. Sang Doo SD; Shim. Jae Woong JW; Lee. Sun Young SY; Yun. Jeanho J; Bae. Yoe-S...
The study shows that the natural peptide LL‑37 can stop a specific inflammation signal (SAA) from making immune cells release the chemical IL‑8 and from moving toward inflammation sites. It does this by blocking key signaling pathways (ERK and p38 MAPK) through a receptor called FPRL1. This suggests LL‑37 has anti‑inflammatory properties, but the work was done in isolated cells, not in people.
Mookherjee. Neeloffer N; Lippert. Dustin N D DN; Hamill. Pamela P; Falsafi. Reza R; Nijnik. Anastasi...
Researchers found that the immune‑boosting peptide LL‑37 sticks to a protein called GAPDH inside immune cells, and this connection is needed for the cell’s signaling pathways that control inflammation. Knocking down GAPDH stops LL‑37 from triggering these signals, showing GAPDH acts like a receptor for the peptide.
The researchers stuck several natural antimicrobial proteins onto a common surgical mesh and tested whether they could stop Staph bacteria from growing. Only lysostaphin killed the bugs; LL-37 (the cathelicidin peptide) did not reduce bacterial numbers at all.
LL-37 is the only cathelicidin peptide humans make. It’s kept inactive inside neutrophils and becomes active after release, where it kills microbes and also helps attract immune cells, neutralize toxins, promote new blood vessels, and heal wounds, acting as a bridge between the body’s first‑line and later immune defenses.
Kanthawong. Sakawarat S; Bolscher. Jan G M JG; Veerman. Enno C I EC; van Marle. Jan J; Nazmi. Kamran...
Scientists tested pieces of the human peptide LL-37 to see how well they kill a bacteria called Burkholderia thailandensis. They found that a short piece called IG-19 still works, and a slightly longer piece called LL-31 kills the bacteria even better by breaking its cell membrane.
The study found that people with chronic gum disease have higher levels of the natural antimicrobial peptide LL‑37 in the fluid around their teeth, and these higher levels match how bad the disease is. Another immune molecule, IL‑18, didn’t change. This suggests LL‑37 is part of the body’s response to gum inflammation, but the research doesn’t give a new treatment or easy way to use this info right now.
Mookherjee. Neeloffer N; Hamill. Pamela P; Gardy. Jennifer J; Blimkie. Darren D; Falsafi. Reza R; Ch...
The study shows that the natural peptide LL‑37 can activate many types of immune cells and turn on hundreds of genes, especially those linked to inflammation and cell signaling. It maps out which pathways and transcription factors are involved, but it doesn’t give dosage or safety guidance for people who might want to use LL‑37 themselves.
Otte. Jan-Michel JM; Zdebik. Anna-Elisabeth AE; Brand. Stephan S; Chromik. Ansgar M AM; Strauss. Sar...
The study shows that the natural peptide LL‑37 helps gut lining cells move, grow protective mucus, and avoid cell death, which together strengthen the intestinal barrier. This was seen in lab-grown human gut cells, and the effects involve specific cell receptors and signaling pathways.
In mouse experiments, mixing the natural peptide LL‑37 with a DNA‑based immune stimulant (CpG‑ODN) helped the immune system fight ovarian cancer better, mainly by activating natural killer cells, but this was only shown in animals and not ready for human use.
Chamorro. Clara I CI; Weber. Günther G; Grönberg. Alvar A; Pivarcsi. Andor A; Ståhle....
The study found that the natural skin peptide LL‑37 can protect skin cells from dying when they’re stressed, by turning on a protective pathway involving COX‑2 and a protein called IAP‑2. This effect was seen in lab-grown human skin cells, not in people, and it was blocked when COX‑2 was inhibited.
Zhang. Zhifang Z; Cherryholmes. Gregory G; Shively. John E JE
The study shows that the peptide LL‑37, which the body makes to fight microbes, can push dying white blood cells (neutrophils) from a normal, tidy death into a messy, inflammatory death called secondary necrosis. This releases signaling molecules and cell contents that could boost inflammation, and the effect isn’t stopped by many common immune signals but is partly reduced by blood serum.
Pistolic. Jelena J; Cosseau. Celine C; Li. Yuexin Y; Yu. Jie Jessie JJ; Filewod. Niall C J NC; Gella...
The study shows that the natural peptide LL‑37, when applied to human airway cells, ramps up inflammation signals like IL‑6 by turning on the NF‑kappaB pathway. This means LL‑37 can boost immune activity in the lungs but also may cause unwanted inflammation if used too much or in the wrong way.