LL-37

Definition

LL-37 is a human antimicrobial peptide that plays a crucial role in the innate immune response, particularly in the skin. It is part of the cathelicidin family, which is produced by various cells, including keratinocytes, and helps protect against bacterial infections by disrupting microbial membranes and promoting wound healing.

5 Must Know Facts For Your Next Test

1. LL-37 is synthesized by keratinocytes in response to infection or injury, enhancing the skin's defense mechanisms.
2. This peptide exhibits a broad spectrum of antimicrobial activity against bacteria, fungi, and viruses by disrupting their membranes.
3. LL-37 also has immunomodulatory properties, influencing the activity of various immune cells such as neutrophils and macrophages.
4. In addition to its antimicrobial functions, LL-37 promotes wound healing by stimulating cell migration and proliferation.
5. Alterations in LL-37 levels have been associated with several skin disorders, including psoriasis and atopic dermatitis, indicating its importance in skin health.

Review Questions

• How does LL-37 contribute to the skin's innate immune defense?
  • LL-37 contributes to the skin's innate immune defense by exerting antimicrobial activity against various pathogens. It disrupts microbial membranes, effectively killing bacteria and fungi that may invade through skin breaches. Additionally, it helps recruit and activate immune cells like neutrophils, enhancing the overall immune response at the site of infection or injury.
• Discuss the role of LL-37 in wound healing and how it may affect skin health.
  • LL-37 plays a significant role in wound healing by promoting cellular processes such as migration and proliferation of skin cells. This peptide not only acts as an antimicrobial agent but also enhances tissue repair by stimulating keratinocyte function and attracting immune cells to the injury site. An imbalance in LL-37 levels can lead to impaired wound healing and contribute to chronic skin conditions like psoriasis and atopic dermatitis.
• Evaluate the implications of altered LL-37 levels in skin disorders and potential therapeutic approaches.
  • Altered levels of LL-37 have been linked to various skin disorders, suggesting that this peptide is crucial for maintaining skin health. In conditions such as psoriasis and atopic dermatitis, reduced LL-37 may compromise the skin's ability to fight infections and heal properly. Understanding these relationships could lead to new therapeutic approaches that either replenish LL-37 levels or mimic its action to restore skin barrier function and improve treatment outcomes for affected individuals.

Related terms

Cathelicidins:

A family of antimicrobial peptides that are part of the innate immune system, known for their ability to kill bacteria and modulate immune responses.

Keratinocytes: The predominant cell type in the epidermis, responsible for forming a protective barrier and producing various proteins, including LL-37.

Innate Immunity:

The first line of defense against pathogens that is present at birth and includes physical barriers, immune cells, and antimicrobial peptides like LL-37.