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Mycobacterium abscessus activates the NLRP3 inflammasome via Dectin‐1–Syk and p62/SQSTM1
Author(s) -
Lee HyeMi,
Yuk JaeMin,
Kim KiHye,
Jang Jichan,
Kang Gun,
Park Jin Bong,
Son JiWoong,
Jo EunKyeong
Publication year - 2012
Publication title -
immunology and cell biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.999
H-Index - 104
eISSN - 1440-1711
pISSN - 0818-9641
DOI - 10.1038/icb.2011.72
Subject(s) - inflammasome , pyrin domain , aim2 , syk , innate immune system , cathelicidin , caspase 1 , signal transducing adaptor protein , tlr2 , toll like receptor , microbiology and biotechnology , biology , signal transduction , immune system , immunology , inflammation , tyrosine kinase
Numerous atypical mycobacteria, including Mycobacterium abscessus (Mabc), cause nontuberculous mycobacterial infections, which present a serious public health threat. Inflammasome activation is involved in host defense and the pathogenesis of autoimmune diseases. However, inflammasome activation has not been widely characterized in human macrophages infected with atypical mycobacteria. Here, we demonstrate that Mabc robustly activates the nucleotide binding and oligomerization domain‐like receptor family pyrin domain containing 3 (NLRP3) inflammasome via dectin‐1/Syk‐dependent signaling and the cytoplasmic scaffold protein p62/SQSTM1 (p62) in human macrophages. Both dectin‐1 and Toll‐like receptor 2 (TLR2) were required for Mabc‐induced mRNA expression of pro‐interleukin (IL)‐1β, cathelicidin human cationic antimicrobial protein‐18/LL‐37 and β‐defensin 4 (DEFB4). Dectin‐1‐dependent Syk signaling, but not that of MyD88, led to the activation of caspase‐1 and secretion of IL‐1β through the activation of an NLRP3/apoptosis‐associated speck‐like protein containing a caspase recruitment domain (ASC) inflammasome. Additionally, potassium efflux was required for Mabc‐induced NLRP3/ASC inflammasome activation. Furthermore, Mabc‐induced p62 expression was critically involved in NLRP3 inflammasome activation in human macrophages. Finally, NLRP3/ASC was critical for the inflammasome in antimicrobial responses to Mabc infection. Taken together, these data demonstrate the induction mechanism of the NLRP3/ASC inflammasome and its role in innate immunity to Mabc infection.