scholarly journals MLN4924 suppresses lipopolysaccharide‑induced proinflammatory cytokine production in neutrophils in a dose‑dependent manner

Author(s):  
Jiayang Jin ◽  
Zhaofei Jing ◽  
Zhenjie Ye ◽  
Lu Guo ◽  
Lei Hua ◽  
...  
2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Xin Ma ◽  
Teng Wang ◽  
Zhen-Long Zhao ◽  
Yu Jiang ◽  
Shu Ye

We previously reported that propofol upregulated the expression of ATP-binding cassette transporter subfamily A member 1 (ABCA1) via peroxisome proliferator-activated receptor gamma/liver X receptor in macrophage-derived foam cells. Here, we provide evidence that in addition to inducing ABCA1 expression, propofol represses proinflammatory cytokine production by increasing ABCA1 expression in a LOC286367-dependent manner. Western blot analysis showed that ABCA1 expression was elevated in macrophages by propofol treatment and this effect was markedly reduced by LOC286367 overexpression. Moreover, propofol treatment downregulated the production of the proinflammatory cytokines interleukin-6, tumor necrosis factor, and interferon gamma in lipopolysaccharide-stimulated macrophages by enhancing ABCA1 expression. Notably, propofol achieved this effect in a LOC286367-dependent manner. To the best of our knowledge, this is the first report of the mechanism in which propofol represses proinflammatory cytokine production mediated by ABCA1.


Author(s):  
Wei Zhang ◽  
Zhixing Li ◽  
Haitao Yang ◽  
Guanglu Wang ◽  
Gang Liu ◽  
...  

Aeromonas sobria, a common conditional pathogenic bacteria, is widely distributed in the environment and causes gastroenteritis in humans or septicemia in fish. Of all Aeromonas species, A. sobria is the most frequently isolated from human infections especially in immunocompromised subjects. Innate immunity is the first protection system of organism to resist non-specific pathogens invasion; however, the immune response process of hosts against A. sobria infection re\mains unexplored. The present study established an A. sobria infection model using primary mouse peritoneal macrophages (PMφs). The adherence and cytotoxicity of A. sobria on PMφs were determined by May-Grünwald Giemsa staining and LDH release measurement. Pro-inflammatory cytokine expression levels were measured using qPCR, western blotting, and ELISA methods. We also investigated the levels of ASC oligomerization and determined the roles of active caspase-1 in IL-1β secretion through inhibition assays and explored the activated pattern recognition receptors through immunofluorescence. We further elucidated the roles of activated inflammasome in regulating the host’s inflammatory response through inhibition combined with ELISA assays. Our results showed that A. sobria induced lytic cell death and LDH release, whereas it had no adhesive properties on PMφs. A. sobria triggered various proinflammatory cytokine transcription level upregulation, and IL-1β occupied the highest levels. The pro-IL-1β protein expression levels increased in a dose-dependent manner with MOI ranging from 1 to 100. This process was regulated by ASC-dependent inflammasome, which cleavage pro-IL-1β into active IL-1β p17 with activated caspase-1 p20. Meanwhile, the expression levels of NLRP3 receptor significantly increased, location analysis revealed puncta-like surrounding nuclear, and inhibition of NLRP3 inflammasome downregulated caspase-1 activation and IL-1β secretion. Blocking of NLRP3 inflammasome activation through K+ efflux and cathepsin B or caspase approaches downregulated A. sobria–induced proinflammatory cytokine production. Overall, these data indicated that A. sobria induced proinflammatory cytokine production in PMφs through activating NLRP3 inflammasome signaling pathways.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A903-A903
Author(s):  
Justin Kenkel ◽  
Po Ho ◽  
Sameera Kongara ◽  
Karla Henning ◽  
Cindy Kreder ◽  
...  

BackgroundTumor-associated macrophages (TAMs) are an abundant immune cell population in most cancers that support tumor progression through their immunosuppressive effects. We discovered that TAMs express the pattern recognition receptor Dectin-2 (Clec4n/CLEC6A), an activating C-type lectin receptor (CLR) that binds to high-mannose glycans on fungi and other microbes and induces protective immune responses against infectious disease. Dectin-2 is selectively expressed by myeloid cells, and upon ligation mediates enhanced phagocytosis, antigen processing and presentation, and proinflammatory cytokine production. Given these properties, we evaluated the therapeutic potential of targeting Dectin-2 using naturally derived ligands. We also generated human Dectin-2-targeted agonistic antibodies capable of robustly activating immunosuppressive ”M2” or TAM-like macrophages.MethodsDectin-2 expression was assessed by flow cytometry, immunohistochemistry, and using public databases. Mouse and human monocytes were differentiated into macrophages using recombinant cytokines or tumor-conditioned media, and stimulation was measured following overnight incubation with Dectin-2 ligands or antibodies. Mouse tumor cell lines were implanted into syngeneic hosts and mice were treated with mannan derived from S. cerevisiae via IT or IV administration.ResultsDectin-2 gene expression is minimal in normal human tissues but elevated across many tumor types, including breast, colon, lung, and kidney cancers. Dectin-2 is strongly expressed by macrophages differentiated in vitro and on primary TAMs. The fungal Dectin-2 ligand mannan stimulated proinflammatory cytokine production (e.g. TNFalpha) and costimulatory molecule expression (e.g. CD86) by macrophages in a Dectin-2-dependent manner. Treatment of tumor-bearing mice with mannan mediated tumor regression in multiple syngeneic tumor models, with high rates of tumor clearance in the MB49 bladder cancer model. These effects were Dectin-2 dependent, as efficacy was not observed when a Dectin-2-blocking antibody was co-administered or in knockout mice lacking Dectin-2 signaling components. Furthermore, depletion of either macrophages or T cells impaired efficacy, suggesting that Dectin-2-stimulated TAMs augment anti-tumor T cell responses. Based on these data, we developed novel Dectin-2 targeted agonist antibodies capable of activating human ”M2” or TAM-like macrophages in vitro to produce an array of proinflammatory cytokines and chemokines akin to tumor-destructive ”M1” macrophages.ConclusionsThe data presented demonstrate the therapeutic potential of targeting Dectin-2 using natural ligands or agonistic antibodies as a novel pan-cancer approach for myeloid cell-directed tumor immunotherapy.Ethics ApprovalAll animal studies were performed in accordance with Institutional Animal Care and Use Committee (IACUC)-approved protocols.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1353.2-1353
Author(s):  
A. Yadon ◽  
D. Ruelas ◽  
G. Min-Oo ◽  
J. Taylor ◽  
M. R. Warr

Background:Rheumatoid arthritis (RA) is characterized by chronic, uncontrolled joint inflammation and tissue destruction. Macrophages are thought to be key mediators in both the initiation and perpetuation of this pathology.1,2The RA synovium contains a complex inflammatory milieu that can stimulate macrophage-dependent production of proinflammatory cytokines through multiple signaling pathways.1,2Existing evidence indicates that toll-like receptors (TLRs) and interleukin-1 receptors (IL-1R) along with their agonists, damage-associated molecular patterns (DAMPs) and IL-1β, are highly expressed in RA joints and are important mediators of synovial macrophage activation and proinflammatory cytokine production.1-9IRAK4 (interleukin-1 receptor-associated kinase 4) is a serine/threonine kinase that facilitates TLR and IL-1R signaling in many cell types, including macrophages.10IRAK4 inhibition represents an opportunity to reduce proinflammatory cytokine production in the joints of patients with RA.Objectives:To investigate the effect of a highly selective IRAK4 inhibitor on proinflammatory cytokine production from human macrophages stimulated with synovial fluid from patients with RA.Methods:Primary human monocytes from 2 independent donors were differentiated for 6 days with granulocyte-macrophage colony-stimulating factor (GM-CSF) to generate human monocyte-derived macrophages (hMDMs). hMDMs were then pretreated with an IRAK4 inhibitor for 1 hour and subsequently stimulated for 24 hours with RA synovial fluid from 5 patients. Culture supernatants were then assessed for secretion of proinflammatory cytokines by MesoScale Discovery.Results:RA synovial fluid stimulation of hMDMs resulted in the production of several proinflammatory cytokines, including IL-6, IL-8, and TNFα. Pretreatment of hMDMs with an IRAK4 inhibitor resulted in the dose-dependent inhibition of IL-6, IL-8, and TNFα production, with an average EC50± SD of 27 ± 31, 26 ± 41, and 28 ± 22 nM, respectively. Maximal percent suppression ± SD of IL-6, IL-8, and TNFα were 76 ± 8.8, 73 ± 15, and 77 ± 13, respectively. To evaluate the specific IRAK4-dependent signaling pathways mediating this response, hMDMs were pretreated with inhibitors of TLR4 (TAK242) and IL-1R (IL-1RA) prior to stimulation with RA synovial fluid. Both TAK242 and IL-1RA inhibited proinflammatory cytokine production. For TAK242, maximal percent suppression ± SD of IL-6, IL-8, and TNFα were 39 ± 25, 48 ± 24, and 50 ± 21, respectively. For IL-1RA maximal percent suppression ± SD of IL-6, IL-8, and TNFα were 18 ± 18, 20 ± 23, and 16 ± 18, respectively. The broad range of inhibition across each stimulation highlights the complexity and variability in the signaling pathways mediating proinflammatory cytokine production from hMDMs stimulated with RA synovial fluid, but demonstrates that RA synovial fluid can stimulate proinflammatory cytokine production in hMDMs, at least partly, through IRAK4-dependent pathways.Conclusion:This work demonstrates that IRAK4 inhibition can suppress proinflammatory cytokine production from macrophages stimulated with synovial fluid from patients with RA and supports a potential pathophysiological role for IRAK4 in perpetuating chronic inflammation in RA.References:[1]Smolen JS, et al.Nat Rev Dis Primers.2018;4:18001.[2]Udalova IA, et al.Nat Rev Rheumatol.2016;12(8):472-485.[3]Joosten LAB, et al.Nat Rev Rheumatol.2016;12(6):344-357.[4]Huang QQ, Pope RM.Curr Rheumatol Rep.2009;11(5):357-364.[5]Roh JS, Sohn DH.Immune Netw.2018;18(4):e27.[6]Sacre SM, et al.Am J Pathol.2007;170(2):518-525.[7]Ultaigh SNA, et al.Arthritis Res Ther.2011;13(1):R33.[8]Bottini N, Firestein GS.Nat Rev Rheumatol.2013;9(1):24-33.[9]Firestein GS, McInnes IB.Immunity.2017;46(2):183-196.[10]Janssens S, Beyaert R.Mol Cell.2003;11(2):293-302.Disclosure of Interests:Adam Yadon Employee of: Gilead, Debbie Ruelas Employee of: Gilead, Gundula Min-Oo Employee of: Gilead, James Taylor Employee of: Gilead, Matthew R. Warr Employee of: Gilead


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