LL-37, also known as CAP-18 (tensin-activated antimicrobial protein 18), is an antimicrobial peptide expressed in nearly all tissues and organs. It is produced by many cell types, including macrophages, airway epithelial cells, skin and ocular epithelial cells, and natural killer (NK) cells.
Description
What is LL-37?
LL-37, also known as CAP-18 (tensin-activated antimicrobial protein 18), is an antimicrobial peptide expressed in nearly all tissues and organs. It is produced by many cell types, including macrophages, airway epithelial cells, skin and ocular epithelial cells, and natural killer (NK) cells.
Since its discovery in 1995, LL-37 has been studied in a number of ways. These studies have shown that LL-37 has anticancer effects in colon and gastric cancer. This natural peptide may also modulate the development of inflammatory and autoimmune diseases.
LL-47 has been reported to exert a protective effect in a mouse model of collagen-induced arthritis. It has also been found to kill gram-negative bacteria through direct antimicrobial activity as well as regulation. In addition, it has been shown to promote wound closure in lung disease.
LL-37 has also been shown to downregulate signaling of specific Toll-like receptors (TLRs), thereby reducing the production of pro-inflammatory cytokines. It also exhibits anti-inflammatory effects, primarily by blocking signaling in Gram-negative bacteria.
The following are the functions that LL-37 has been shown to have:
Regulates TLR Function
Toll-like receptors (TLRs) are important mediators of intestinal inflammatory pathways. LL-37 has been shown to downregulate signaling through TLR4 by binding to its ligand LPS. This results in reduced levels of pro-inflammatory cytokines when LL-37 and LPTS are present simultaneously.Regulates inflammation
LL-37 has both pro-inflammatory and anti-inflammatory functions. This difference may be explained by the disease context and the microenvironment in which it is present.Regulates cell death
LL-37 may promote or inhibit cell death, depending on the cell type involved and the environment in which it is mimicked. For example, higher doses of this peptide induce necrotic cell death in neutrophils. However, in other cells, it exhibits anti-apoptotic effects.
Exerts antimicrobial activity
LL-37 has been shown to have antimicrobial activity against bacteria, viruses, fungi, and parasites. Low concentrations of this peptide can prevent the formation of biofilms, while high concentrations can disrupt existing biofilms. Infections associated with biofilms may result in death.
Induces angiogenesis
Angiogenesis, the formation of new blood vessels, is necessary for normal growth and development. It is also essential for wound healing.
LL-37 research
The following is a summary of the current research on LL-37. The information provided in this section is for educational purposes only. It does not constitute medical advice. LL-37 peptides sold by PureRawz are for laboratory, educational, and scientific research purposes only.LL-37 and Cancer
Several studies have shown that LL-37 plays an important role in human cancer.LL-37 and Rheumatoid Arthritis
Rheumatoid arthritis is an autoimmune disease that affects the joints of the hands, wrists, and knees.Preclinical studies have shown that LL-37 induces apoptosis of keratinocytes in a psoriasis model. Keratinocytes are the main cell type in the outermost layer of the skin, accounting for approximately 90% of the cells in the skin's outermost layer. Psoriasis is characterized by keratinocyte hyperplasia, which LL-37 prevents.
LL-37 and Bacteria
In preclinical studies, LL-37 has demonstrated moderate antibacterial activity against a variety of gram-negative and gram-positive bacteria that cause skin infections.LL-37 has been reported to kill bacteria through direct antibacterial activity as well as modulation of the immune system (immunomodulation). Direct effects include disruption of the bacterial membrane, which compromises cell integrity and ultimately leads to cell death.
LL-37 and the Intestine
Cell culture studies have shown that LL-37 has multiple effects, including increasing migration of cells required for maintenance of the intestinal epithelial barrier and reducing cell death in intestinal inflammation.LL-37 and COPD
Chronic obstructive pulmonary disease (COPD) refers to a group of diseases that cause airflow obstruction and breathing-related problems. Approximately 16 million Americans suffer from this lung disease.LL-37 and toxic dust syndrome
Organic dust syndrome is common among agricultural workers. It is characterized by fever and flu-like symptoms that develop 4 to 12 hours after exposure.FAQ
Is LL-37 an antimicrobial peptide?