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The cationic peptide LL-37 binds Mac-1 (CD11b/CD18) with a low dissociation rate and promotes phagocytosis.
- Source :
-
Biochimica et biophysica acta [Biochim Biophys Acta] 2016 May; Vol. 1864 (5), pp. 471-8. Date of Electronic Publication: 2016 Feb 11. - Publication Year :
- 2016
-
Abstract
- As a broad-spectrum anti-microbial peptide, LL-37 plays an important role in the innate immune system. A series of previous reports implicates LL-37 as an activator of various cell surface receptor-mediated functions, including chemotaxis in integrin CD11b/CD18 (Mac-1)-expressing cells. However, evidence is scarce concerning the direct binding of LL-37 to these receptors and investigations on the associated binding kinetics is lacking. Mac-1, a member of the β2 integrin family, is mainly expressed in myeloid leukocytes. Its critical functions include phagocytosis of complement-opsonized pathogens. Here, we report on interactions of LL-37 and its fragment FK-13 with the ligand-binding domain of Mac-1, the α-chain I domain. LL-37 bound the I-domain with an affinity comparable to the complement fragment C3d, one of the strongest known ligands for Mac-1. In cell adhesion assays both LL-37 and FK-13 supported binding by Mac-1 expressing cells, however, with LL-37-coupled surfaces supporting stronger cell adhesion than FK-13. Likewise, in phagocytosis assays with primary human monocytes both LL-37 and FK-13 enhanced uptake of particles coupled with these ligands but with a tendency towards a stronger uptake by LL-37.<br /> (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Subjects :
- Amino Acid Sequence
Antimicrobial Cationic Peptides chemistry
Antimicrobial Cationic Peptides genetics
CD18 Antigens chemistry
CD18 Antigens genetics
Cell Adhesion genetics
Humans
Immunity, Innate genetics
Kinetics
Leukocytes metabolism
Macrophage-1 Antigen chemistry
Macrophage-1 Antigen genetics
Neutrophils metabolism
Phagocytosis genetics
Protein Binding
Cathelicidins
Antimicrobial Cationic Peptides metabolism
CD18 Antigens metabolism
Macrophage-1 Antigen metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0006-3002
- Volume :
- 1864
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Biochimica et biophysica acta
- Publication Type :
- Academic Journal
- Accession number :
- 26876535
- Full Text :
- https://doi.org/10.1016/j.bbapap.2016.02.013