Journal Article

Cathelicidin LL-37 Affects Surface and Intracellular Toll-Like Receptor Expression in Tissue Mast Cells

Różalska, Sylwia, Wiktorska, Magdalena, Żelechowska, Paulina, Pietrzak, Jacek, Brzezińska-Błaszczyk, Ewa, Agier, Justyna

2018

Overview

Undoubtedly, mast cells take part in host defense against microorganisms as they are numerous at the portal of infection, they release many proinflammatory and antimicrobial mediators, and they express pattern recognition receptors, such as TLRs. These receptors play a key role in recognition and binding molecules associated with microorganisms and molecules associated with damage. Cathelicidins exhibit direct antimicrobial activities against a broad spectrum of microbes by perturbing their cell membranes. Accumulating evidence suggests a role for these molecules in supporting cell activation. We examined the impact of human cathelicidin LL-37 on tissue mast cell TLR expression and distribution. Depending on context, we show that LL-37 stimulation resulted in minor to major effects on TLR2, TLR3, TLR4, TLR5, TLR7, and TLR9 expression. Confocal microscopy analysis showed that, upon stimulation, TLRs may translocate from the cell interior to the surface and conversely. FPR2 and EGFR inhibitors reduced the increase in expression of selected receptors. We also established that LL-37 acts as a powerful inducer of CCL3 and ROS generation. These results showed that in response to LL-37, mast cells enhance the capability to detect invading pathogens by modulation of TLR expression in what may be involved FPR2 or EGFR molecules.

• Publisher: Hindawi Publishing Corporation,Hindawi,John Wiley & Sons, Inc,Wiley
• Subject: Animals / Antimicrobial Cationic Peptides - metabolism / Apoptosis / Bacteria / Cathelicidins / CCL3 protein / Cell activation / Cell membranes / Cells, Cultured / Chemokine CCL3 - metabolism / Chemokines / Confocal microscopy / Cytokines / Epidermal growth factor / Epidermal growth factor receptors / ErbB Receptors - metabolism / Gene expression / Histamine / Humans / Immunity, Innate / Immunology / Infections - immunology / Inflammation / Intracellular Space - metabolism / Mast cells / Mast Cells - physiology / Microorganisms / Microscopy, Confocal / Neutrophils / Pattern recognition receptors / Peptides / Physiology / Protein Transport / Proteins / Reactive Oxygen Species - metabolism / Receptors, Formyl Peptide - metabolism / Receptors, Lipoxin - metabolism / Rodents / TLR2 protein / TLR3 protein / TLR4 protein / TLR5 protein / TLR7 protein / TLR9 protein / Toll-like receptors / Toll-Like Receptors - metabolism