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Looped host defense peptide CLP-19 binds to microtubules and inhibits surface expression of TLR4 on mouse macrophages.
- Source :
-
Journal of immunology (Baltimore, Md. : 1950) [J Immunol] 2013 Jun 15; Vol. 190 (12), pp. 6083-92. Date of Electronic Publication: 2013 May 10. - Publication Year :
- 2013
-
Abstract
- The looped host defense peptide CLP-19 is derived from a highly functional core region of the Limulus anti-LPS factor and exerts robust anti-LPS activity by directly interacting with LPS in the extracellular space. We previously showed that prophylactic administration of CLP-19 even 20 h prior to LPS challenge might significantly increase the survival rate in a lethal endotoxin shock mouse model. Such an effect may be associated with immune regulation of CLP-19. To investigate the underlying mechanisms, peptide affinity chromatography, immunofluorescence, and Western blotting procedures were used to identify α- and β-tubulin as direct and specific binding partners of CLP-19 in the mouse macrophage cell line RAW 264.7. Bioinformatic analysis using the AutoDock Vina molecular docking and PyMOL molecular graphics system predicted that CLP-19 would bind to the functional residues of both α- and β-tubulin and would be located within the groove of microtubules. Tubulin polymerization assay revealed that CLP-19 might induce polymerization of microtubules and prevent depolymerization. The immunoregulatory effect of CLP-19 involving microtubules was investigated by flow cytometry, immunofluorescence, and Western blotting, which showed that CLP-19 prophylactic treatment of RAW 264.7 cells significantly inhibited LPS-induced surface expression of TLR4. Taken together, these results suggest that CLP-19 binding to microtubules disrupts the dynamic equilibrium of microtubules, reducing the efficacy of microtubule-dependent vesicular transport that would otherwise translocate TLR4 from the endoplasmic reticulum to the cell surface.
- Subjects :
- Animals
Antimicrobial Cationic Peptides chemistry
Antimicrobial Cationic Peptides immunology
Arthropod Proteins chemistry
Arthropod Proteins immunology
Blotting, Western
Cell Line
Cell Membrane immunology
Cell Membrane metabolism
Chromatography, Affinity
Flow Cytometry
Fluorescent Antibody Technique
Macrophages immunology
Membrane Proteins immunology
Membrane Proteins metabolism
Mice
Microtubules immunology
Peptides, Cyclic chemistry
Peptides, Cyclic immunology
Peptides, Cyclic metabolism
Toll-Like Receptor 4 immunology
Tubulin immunology
Tubulin metabolism
Antimicrobial Cationic Peptides metabolism
Arthropod Proteins metabolism
Macrophages metabolism
Microtubules metabolism
Protein Transport physiology
Toll-Like Receptor 4 metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1550-6606
- Volume :
- 190
- Issue :
- 12
- Database :
- MEDLINE
- Journal :
- Journal of immunology (Baltimore, Md. : 1950)
- Publication Type :
- Academic Journal
- Accession number :
- 23667111
- Full Text :
- https://doi.org/10.4049/jimmunol.1203167