An antimicrobial peptide of the cathelicidin family that provides innate immune defense by killing pathogens and modulating inflammation and wound healing.
Stie. Jamal J; Jesaitis. Andrew V AV; Lord. Connie I CI; Gripentrog. Jeannie M JM; Taylor. Ross M RM...
The study shows that the precursor protein hCAP-18, which releases the LL‑37 peptide, moves to the surface of neutrophils when they’re activated, sticking there through a likely protein‑protein link. This surface binding is stable against salt but breaks down with strong base, hinting it’s part of the cell’s membrane machinery. While interesting for understanding how LL‑37 works in the body, the findings don’t give direct guidance on how to take or dose the peptide for health benefits.
Karlsson. Christofer C; Andersson. Marie-Louise ML; Collin. Mattias M; Schmidtchen. Artur A; Bjö...
Researchers found that a protein called SufA, made by the common skin bacterium Finegoldia magna, can break down the human antimicrobial peptide LL‑37, which helps fight infections. This means that when this bacterium is present in large numbers, it might weaken one of our natural defenses.
Galván. Estela M EM; Lasaro. Melissa A S MA; Schifferli. Dieter M DM
The paper shows that the human antimicrobial peptide LL‑37 can kill the plague bacterium Yersinia pestis in the lungs and works even better when paired with another natural peptide, beta‑defensin 1, but the bacteria have a protein (Pla) that can break down LL‑37 unless another surface protein (F1) is present.
Koprivnjak. Tomaz T; Weidenmaier. Christopher C; Peschel. Andreas A; Weiss. Jerrold P JP
The study found that Staphylococcus aureus lacking wall teichoic acids becomes much more resistant to two immune proteins (gIIA phospholipase A2 and human beta‑defensin 3), but its sensitivity to the antimicrobial peptide LL‑37 stays the same as normal bacteria. This suggests LL‑37 can still kill these bacteria even when they develop other resistance tricks.
The study shows that the gene that makes the antimicrobial peptide LL‑37 is controlled by several DNA switches, including spots that turn the gene down and spots that turn it up, and that different versions of the gene appear in bone‑marrow cells but not in blood neutrophils.
Ji. S S; Kim. Y Y; Min. B-M BM; Han. S H SH; Choi. Y Y
The study shows that different mouth bacteria affect the cells lining the gums in distinct ways, changing the levels of natural antimicrobial proteins like LL‑37 and inflammatory signals. Friendly bacteria boost these defenses without causing inflammation, while some harmful bacteria can either trigger inflammation or suppress the immune response, especially when they’re alive.
A short pre‑treatment with a tiny amount of bacterial flagellin makes eye‑surface cells less reactive to later big hits, cutting down inflammation while still boosting natural antibiotics like LL‑37. This tolerance doesn’t change the amount of the flagellin sensor (TLR5) on the cells, but it does keep the cells ready to fight infection.
Calabretta. Michelle K MK; Kumar. Amit A; McDermott. Alison M AM; Cai. Chengzhi C
A study found that certain synthetic molecules called amino‑terminated PAMAM dendrimers can kill the harmful Gram‑negative bacteria Pseudomonas aeruginosa at very low doses, even better than the natural antimicrobial peptide LL‑37, while being safe for human eye cells. However, these dendrimers are much less effective against Gram‑positive Staphylococcus aureus compared to LL‑37.
Scientists figured out a way to make small antimicrobial pieces of the human peptide LL‑37 using bacteria and a two‑step purification, getting a few milligrams per liter of culture and measuring how well each piece stops bacterial growth.
The eye’s surface naturally contains small proteins called defensins and LL‑37 that help keep infections away and aid healing. These peptides do more than just kill germs – they also call in immune cells and may connect the eye’s immediate defenses to longer‑term immunity. The article reviews what’s known about these roles, especially for LL‑37, the only human cathelicidin found in tears.
Weber. Günther G; Chamorro. Clara Ibel CI; Granath. Fredrik F; Liljegren. Annelie A; Zreika. Sa...
The human peptide LL‑37, which is part of the body's natural antimicrobial system, was found to make breast cancer cells more aggressive and likely to spread. In lab experiments, adding LL‑37 boosted signals that drive tumor growth, helped cancer cells move faster, and caused more metastases in mice. A shorter version of the peptide could block some of these effects, but the overall picture is that LL‑37 can promote cancer spread.
Niyonsaba. François F; Ushio. Hiroko H; Nakano. Nobuhiro N; Ng. William W; Sayama. Koji K; Hash...
The study shows that certain skin‑produced antimicrobial peptides (beta‑defensins 2, 3, and 4) can kick‑start skin cells to move, multiply, and release inflammation signals, which helps wound healing. LL‑37 itself wasn’t tested, so the findings don’t give direct tips for using that peptide.
de Haar. Susanne F SF; Hiemstra. Pieter S PS; van Steenbergen. Martijn T J M MT; Everts. Vincent V;...
The study shows that a group of immune enzymes in white blood cells turn a precursor protein into the antimicrobial peptide LL‑37, which helps fight a gum‑disease bacterium. People with a rare genetic disorder lack these enzymes, produce less LL‑37, and can’t neutralize the bacteria’s toxin well, leading to worse gum disease.
Altman. H H; Steinberg. D D; Porat. Y Y; Mor. A A; Fridman. D D; Friedman. M M; Bachrach. G G
The study tested three antimicrobial peptides, including the human peptide LL‑37, against common mouth bacteria. LL‑37 didn’t stop most of the tested germs, especially the ones that cause cavities and gum disease. A frog‑derived peptide (K4‑S4(1‑15)a) worked best, even killing bacteria stuck to surfaces or in biofilms, though bacteria become a bit tougher when attached.
Yamasaki. Kenshi K; Schauber. Jürgen J; Coda. Alvin A; Lin. Henry H; Dorschner. Robert A RA; Sc...
The study shows that skin enzymes called kallikreins cut the precursor of the antimicrobial peptide LL‑37 into its active form and other smaller pieces, and that the balance of these enzymes controls how well the skin can fight microbes.
Cirioni. Oscar O; Giacometti. Andrea A; Ghiselli. Roberto R; Bergnach. Cristina C; Orlando. Fiorenza...
In rats with deadly gram‑negative bacterial infections, giving the natural peptide LL‑37 helped them survive better than just salt, and it lowered harmful toxins in the blood even more than some standard antibiotics.
The antimicrobial peptide LL-37 helps skin cells move to close wounds by turning on a growth‑factor receptor (EGFR) and downstream signals. This effect was seen in lab dishes at a concentration of about 1 µg/ml and can be blocked by drugs that stop EGFR or its signaling pathways.
Mookherjee. Neeloffer N; Brown. Kelly L KL; Bowdish. Dawn M E DM; Doria. Silvana S; Falsafi. Reza R;...
LL-37, a natural human peptide, can tone down inflammation in lab tests by blocking key signals that lead to cytokine release, especially after exposure to bacterial components like LPS. It works at low, body‑like levels and mainly interferes with the NF‑kB pathway, but the findings are from cell cultures, not human trials, so it’s not yet a ready‑to‑use supplement.
Nagaoka. Isao I; Tamura. Hiroshi H; Hirata. Michimasa M
The study shows that the natural peptide LL‑37, which our bodies make to fight infections, can also keep immune cells called neutrophils alive longer by stopping their programmed death, and it does this through two specific cell receptors.
Li. Xia X; Li. Yifeng Y; Peterkofsky. Alan A; Wang. Guangshun G
Scientists examined a frog peptide called aurein 1.2 and made new versions, including one (LLAA) that borrows parts of the human immune peptide LL‑37. LLAA was far more effective at killing bacteria because it has extra positive charges, while swapping the last aromatic amino acid reduced activity. The work shows that charge and the position of aromatic rings are key to how these tiny proteins disrupt cell membranes.