Salmonella Enteritidis antitoxin DinJ inhibits NLRP3-dependent canonical inflammasome activation in macrophages

The inflammasome is a pivotal component of the innate immune system, acting as a multiprotein complex that plays an essential role in detecting and responding to microbial infections. Salmonella Enteritidis have evolved multiple mechanisms to regulate inflammasome activation and evade host immune system clearance. Through screening S. Enteritidis C50336ΔfliC transposon mutant library, we found that the insertion mutant of dinJ increased inflammasome activation. In this study, we demonstrated the genetic connection between the antitoxin DinJ and the toxin YafQ in S. Enteritidis, confirming their co-transcription. The deletion mutant ΔfliCΔdinJ increased cell death and IL-1β secretion in J774A.1 cells. Western blotting analysis further showed elevated cleaved Caspase-1 product (p10 subunits) and IL-1β secretion in cells infected with ΔfliCΔdinJ compared to cells infected with ΔfliC. DinJ was found to inhibit canonical inflammasome activation using primary bone marrow-derived macrophages (BMDMs) from Casp-/- C57BL/6 mice. Furthermore, DinJ specifically inhibited NLRP3 inflammasome activation, as demonstrated in BMDMs from Nlrp3-/- and Nlrc4-/- mice. Fluorescence resonance energy transfer (FRET) experiments confirmed the translocation of DinJ into host cells during infection. Finally, we revealed that DinJ could inhibit the secretion of IL-1β and IL-18 in vivo, contributing to S. Enteritidis evading host immune clearance. In summary, our findings provide insights into the role of DinJ in modulating the inflammasome response during S. Enteritidis infection, highlighting its impact on inhibiting inflammasome activation and immune evasion.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:92

Enthalten in:

Infection and immunity - 92(2024), 4 vom: 09. Apr., Seite e0050523

Sprache:

Englisch

Beteiligte Personen:

Gu, Dan [VerfasserIn]
Li, Ang [VerfasserIn]
Zang, Xirui [VerfasserIn]
Huang, Tingting [VerfasserIn]
Guo, Yaxin [VerfasserIn]
Jiao, Xinan [VerfasserIn]
Pan, Zhiming [VerfasserIn]

Links:

Volltext

Themen:

Antitoxins
Caspase 1
DinJ
EC 3.4.22.36
Immune evasion
Inflammasomes
Interleukin-1beta
Journal Article
NLR Family, Pyrin Domain-Containing 3 Protein
NLRP3 inflammasome
Salmonella Enteritidis

Anmerkungen:

Date Completed 10.04.2024

Date Revised 11.04.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1128/iai.00505-23

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM369673026