TLR4 and NLRP3 inflammasome activation in monocytes by N-propionyl cysteaminylphenol-maleimide-dextran (NPCMD).

Abstract

BACKGROUND:

N-propionyl cysteaminylphenol-maleimide-dextran (NPCMD) is a toxic tyrosinase substrate developed to treat melanoma.

OBJECTIVE:

We investigated the effect of NPCMD on innate immune responses in monocytes.

METHODS:

CD14⁺ monocytes and a monocytic cell line, THP-1, were stimulated with NPCMD in vitro. Cytokines in the culture supernatants were determined by ELISA and flow cytometry.

RESULTS:

NPCMD stimulated CD14⁺ monocytes and THP-1 cells to secrete TNFα, IL-6 and IL-8, but not IL-10 or IL-12. TNFα secretion from THP-1 cells stimulated with NPCMD was inhibited by addition of an anti-TLR4 mAb in culture. Moreover, NPCMD stimulated production of pro-IL-1β in CD14⁺ monocytes and monocytic cell line THP-1 cells and activated the NLRP3-inflammasome, resulting in production of mature IL-1β. Use of ASC and NLRP3-deficient THP-1 cell lines established involvement of the NLRP3 inflammasome in an IL-1β secretion in treatment with NPCMD. Inhibition of IL-1β secretion by an endocytosis inhibitor, cytochalasin B, and a lysosomal enzyme cathepsin B inhibitor, CA-074 Me, suggested the involvement of lysosomal rupture and leakage of cathepsin B into the cytosol in NLRP3 activation by NPCMD.

CONCLUSION:

The immunopotentiating effect of NPCMD mediated by TLR4 and NLRP3 inflammasome activation could be useful for eliciting effective adaptive immune responses against melanoma and other tumors.

• Authors: Yu Mizote, Kazumasa Wakamatsu, Shosuke Ito, Akiko Uenaka, Yoshihiro Ohue, Koji Kurose, Midori Isobe, Akira Ito, Yasuaki Tamura, Hiroyuki Honda, Toshiharu Yamashita, Satoshi Nohara, Mikio Oka, Kowichi Jimbow, Eiichi Nakayama
• Journal: Journal of dermatological science (J Dermatol Sci) Vol. 73 Issue 3 Pg. 209-15 (Mar 2014) ISSN: 1873-569X [Electronic] Netherlands
• PMID: 24315204 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2013 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

Chemical References

• Carrier Proteins
• Dextrans
• Inflammasomes
• Interleukin-1beta
• Maleimides
• N-propionyl-4-S-cysteaminylphenol
• NLR Family, Pyrin Domain-Containing 3 Protein
• NLRP3 protein, human
• Phenols
• TLR4 protein, human
• Toll-Like Receptor 4
• maleimide
• Cystamine

Topics

• Carrier Proteins (physiology)
• Cell Line, Tumor
• Cystamine (analogs & derivatives, pharmacology)
• Dextrans (pharmacology)
• Humans
• Inflammasomes (physiology)
• Interleukin-1beta (metabolism)
• Maleimides (pharmacology)
• Monocytes (drug effects, physiology)
• NLR Family, Pyrin Domain-Containing 3 Protein
• Phenols (pharmacology)
• Toll-Like Receptor 4 (physiology)