• IMMUNE NETWORK
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• 제8권1호
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• pp.1-6
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• 2008

Apoptosis signal-regulating kinase 1 (ASK1), a mitogen- activated protein kinase kinase kinase, plays pivotal roles in stress responses. In addition, ASK1 has emerged as a key regulator of immune responses elicited by pathogen-associated molecular patterns (PAMPs) and endogenous danger signals. Recent studies have demonstrated that reactive oxygen species (ROS)-dependent activation of ASK1 is required for LPS-stimulated cytokine production as well as extracellular ATP-induced apoptosis in immune cells. The mechanism of ROS-dependent regulation of ASK1 activity by thioredoxin and TRAFs has been well characterized. In this review, we focus on the molecular details of the activation of ASK1 and its involvement in innate immunity.

• BMB Reports
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• 제46권7호
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• pp.376-381
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• 2013

It is unknown how soluble pattern-recognition receptors in blood, such as mannose-binding lectin (MBL) and ficolins, modulate mast cell-mediated inflammatory responses. We investigate how mouse MBL-A or ficolin-A regulate mouse bone marrow-derived mast cells (mBMMCs)-derived inflammatory response against bacterial lipopolysaccharide (LPS) stimulation. LPS-mediated pro-inflammatory cytokine productions on mBMMCs obtained from Toll-like receptor4 (TLR4)-deficient mice, TLR2-defficient mice, and their wildtype, were specifically attenuated by the addition of either mouse MBL-A or ficolin-A in a dose-dependent manner. However, the inhibitory effects by mouse MBL-A or ficolin-A were restored by the addition of mannose or N-acetylglucosamine, respectively. These results suggest that mouse MBL-A and ficolin-A bind to LPS via its carbohydrate-recognition domain and fibrinogen-like domain, respectively, whereby cytokine production by LPS-mediated TLR4 in mBMMCs appears to be down-regulated, indicating that mouse MBL and ficolin may have an inhibitory function toward mouse TLR4-mediated excessive inflammation on the mast cells.

• Journal of Veterinary Science
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• 제24권5호
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• pp.72.1-72.16
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• 2023

Background: Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) on the surface of Streptococcus dysgalactiae, coded with gapC, is a glycolytic enzyme that was reported to be a moonlighting protein and virulence factor. Objective: This study assessed GAPDH as a potential immunization candidate protein to prevent streptococcus infections. Methods: Mice were vaccinated subcutaneously with recombinant GAPDH and challenged with S. dysgalactiae in vivo. They were then evaluated using histological methods. rGAPDH of mouse bone marrow-derived dendritic cells (BMDCs) was evaluated using immunoblotting, reverse transcription quantitative polymerase chain reaction, and enzyme-linked immunosorbent assay methods. Results: Vaccination with rGAPDH improved the survival rates and decreased the bacterial burdens in the mammary glands compared to the control group. The mechanism by which rGAPDH vaccination protects against S. dysgalactiae was investigated. In vitro experiments showed that rGAPDH boosted the generation of interleukin-10 and tumor necrosis factor-α. Treatment of BMDCs with TAK-242, a toll-like receptor 4 inhibitor, or C29, a toll-like receptor 2 inhibitor, reduced cytokines substantially, suggesting that rGAPDH may be a potential ligand for both TLR2 and TLR4. Subsequent investigations showed that rGAPDH may activate the phosphorylation of MAPKs and nuclear factor-κB. Conclusions: GAPDH is a promising immunization candidate protein for targeting virulence and enhancing immune-mediated protection. Further investigations are warranted to understand the mechanisms underlying the activation of BMDCs by rGAPDH in a TLR2- and TLR4-dependent manner and the regulation of inflammatory cytokines contributing to mastitis pathogenesis.

• Journal of Microbiology and Biotechnology
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• 제29권5호
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• pp.704-712
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• 2019

Although nanometric dead Lactobacillus plantarum has emerged as a potentially important modulator of immune responses, its underlying mechanism of action has not been fully understood. This study aimed to identify the detailed biochemical mechanism of immune modulation by micronized and heat-treated L. plantarum LM1004 (MHT-LM1004, <$1{\mu}m$ in size). MHT-LM1004 was prepared from L. plantarum LM1004 via culture in a specifically designed membrane bioreactor and heat treatment. MHT-LM1004 was shown to effectively induce the secretion of $TNF-{\alpha}$ and IL-6 and the mRNA expression of inducible nitric oxide synthase (iNOS). MHT-LM1004 enhanced the expression of TLR-2, phosphorylation of MAPKs (ERK), and nuclear translocation of $NF-{\kappa}B$ in a dose-dependent manner. Oral administration of MHT-LM1004 ($4{\times}10^9$ or $4{\times}10^{11}cells/kg$ mouse body weight) increased the splenocyte proliferation and serum cytokine levels. These results suggested that MHT-LM1004 effectively enhances early innate immunity by activating macrophages via the TLR-2/MAPK/$NF-{\kappa}B$ signalling pathway and that this pathway is one of the major routes in immune modulation by the Lactobacillus species.

• 한국가금학회지
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• 제40권2호
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• pp.83-89
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• 2013

iNOS(inducible nitric oxide synthase)와 TLR-4(toll-like receptor 4) 유전자는 모든 생물의 면역반응에 필요한 필수유전자로 알려져 있다. iNOS는 닭에서 19번 염색체에 위치하고 있으며, NO를 면역기관에서 생산되어 면역반응을 일으키는 것으로 알려져 있으며, TLR-4는 TLRs(toll-like receptors)중 하나로 알려져 있고, 그람 음성균의 LPS을 인식하여 초기 면역반응에 참여하는 것으로 알려져 있다. 이들의 유전적 변이는 살모넬라균에 감염되었을 때 맹장의 장내 균총에 영향을 주는 것으로 알려져 있다. 본 연구는 iNOS의 intron 24 영역 내 C14513T와 TLR-4의 exon 3 영역 내 G4409T 변이 지역을 대상으로 3품종(한국 재래닭, 코니쉬, 로드아일랜드 레드)을 이용하여 유전자형을 확인하고, 경제 형질 간의 연관성 분석을 실시하였다. 분석 결과, iNOS의 변이 지역(C14513T)은 한국 재래닭과 로드아일랜드 레드종에서 270일령 몸무게와 유의적인 연관성이 확인되었으며, TLR-4의 변이 지역(G4409T)은 경제 형질과의 연관성이 확인되지 않았다. 본 연구 결과는 면역 및 경제 형질 관련 표지인자 발굴을 위한 유용한 기초 자료로 활용될 수 있으며, 추가적인 연구를 통해 분자 육종을 위한 유전표지인자 개발에 활용이 가능할 것으로 사료된다.

• Biomolecules & Therapeutics
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• 제24권6호
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• pp.638-649
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• 2016

In the previous study, the rhizome mixture of Anemarrhena asphodeloides and Coptis chinensis (DW2007), improved TNBS-, oxazolone-, or DSS-induced colitis in mice by regulating macrophage activation. Therefore, to understand the effect of DW2007 on the T cell differentiation involved in the adaptive immunity, we measured its effect on both Th17 and Treg cell differentiation in splenocytes, in the lamina propria of mice with DSS-induced colitis (DIC), and in the spleens of mice with collagen-induced arthritis (CIA). Results showed that DW2007 potently inhibited the differentiation of splenocytes into Th17 cells, but increased Treg cell differentiation in vitro. In the colon of wild type and $TLR4^{-/-}$ mice with DIC, DW2007 potently suppressed DSS-induced colon shortening and myeloperoxidase activity. DW2007 also suppressed collagen-induced paw thickening, clinical index, and myeloperoxidase activity in CIA mice. Overall, DW2007 potently suppressed Th17 cell differentiation in mice with CIA and DIC, but increased Treg cell differentiation. Moreover, DW2007 strongly inhibited the expression of TNF-${\alpha}$ and IL-$1{\beta}$, as well as the activation of NF-${\kappa}B$. Based on these findings, DW2007 may ameliorate inflammatory diseases by regulating the innate immunity via the inhibition of macrophage activation and the adaptive immunity via the correction of disturbed Th17/Treg cells.

• IMMUNE NETWORK
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• 제13권5호
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• pp.205-212
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• 2013

Dectin-1, which specifically recognizes ${\beta}$-glucan of fungal cell walls, is a non-Toll-like receptor (TLR) pattern recognition receptor and a representative of C-type lectin receptors (CLRs). The importance of Dectin-1 in innate immune cells, such as dendritic cells and macrophages, has previously been well studied. However, the function of Dectin-1 in B cells is very poorly understood. To determine the role of Dectin-1 in B cell activation, we first investigated whether mouse B cells express Dectin-1 and then assessed the effect of Dectin-1 stimulation on B cell proliferation and antibody production. Mouse B cells express mRNAs encoding CLRs, including Dectin-1, and surface Dectin-1 was expressed in B cells of C57BL/6 rather than BALB/c strain. Dectin-1 agonists, heat-killed Candida albicans (HKCA) and heat-killed Saccharomyces cerevisiae (HKSC), alone induced B cell proliferation but not antibody production. Interestingly, HKSC, HKCA, and depleted zymosan (a selective Dectin-1 agonist) selectively enhanced LPS-driven IgG1 production. Taken together, these results suggest that, during fungal infection, ${\beta}$-glucan-stimulated Dectin-1 may cooperate with TLR4 to specifically enhance IgG1 production by mouse B cells.

• IMMUNE NETWORK
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• 제21권6호
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• pp.42.1-42.20
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• 2021

Eosinophils play critical roles in the maintenance of homeostasis in innate and adaptive immunity. Although primarily known for their roles in parasitic infections and the development of Th2 cell responses, eosinophils also play complex roles in other immune responses ranging from anti-inflammation to defense against viral and bacterial infections. However, the contributions of pattern recognition receptors in general, and NOD-like receptors (NLRs) in particular, to eosinophil involvement in these immune responses remain relatively underappreciated. Our in vivo studies demonstrated that NLRC4 deficient mice had a decreased number of eosinophils and impaired Th2 responses after induction of an allergic airway disease model. Our in vitro data, utilizing human eosinophilic EoL-1 cells, suggested that TLR2 induction markedly induced pro-inflammatory responses and inflammasome forming NLRC4 and NLRP3. Moreover, activation by their specific ligands resulted in caspase-1 cleavage and mature IL-1β secretion. Interestingly, Th2 responses such as secretion of IL-5 and IL-13 decreased after transfection of EoL-1 cells with short interfering RNAs targeting human NLRC4. Specific induction of NLRC4 with PAM3CSK4 and flagellin upregulated the expression of IL-5 receptor and expression of Fc epsilon receptors (FcεR1α, FcεR2). Strikingly, activation of the NLRC4 inflammasome also promoted expression of the costimulatory receptor CD80 as well as expression of immunoregulatory receptors PD-L1 and Siglec-8. Concomitant with NLRC4 upregulation, we found an increase in expression and activation of matrix metalloproteinase (MMP)-9, but not MMP-2. Collectively, our results present new potential roles of NLRC4 in mediating a variety of eosinopilic functions.

• 생명과학회지
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• 제27권4호
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• pp.482-499
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• 2017

Allergy 질환은 지난 십여년 동안 개발도상국을 포함해서 전 세계적으로 증가하고 있다. Allergy 염증 반응은 수지상 세포와 같은 항원제시 세포에 의한 allergy 항원섭취를 시작으로 하여 Th2 면역 반응에 의해서 일어난다. 장내 미생물은 신체의 대사나 생리적 기능을 조절하고, 생애 초기의 면역 체계 성숙과 일생 동안 면역 체계 항상성 및 상피세포 총체성에 기여한다. Bifidobacteria는 Th1/Th2 balance에 strain-specific 한 면역 자극 특성을 가지며, TSLP와 IgE 발현을 억제 시키고 Flg과 FoxP3 발현을 촉진 시켜 allergy를 완화시킨다. 또한 Unmethylated CpG motif ODN은 B 세포와 수지상 세포의 TLR9에 의해 인식 되어 선천성과 적응성 면역 반응을 유도하고, Clostridium butyricum에 의해서 생산된 butyrate는 수지상 세포의 anti-inflammatory 유전자의 발현을 유도하기 위해 GPR109a signaling pathway를 활성화시키고, GPR43 활성화를 통하여 tTreg 세포 proliferation을 직접 자극하거나 HADC 활성을 억제시켜 Foxp3 gene intronic enhancer의 histone H3 acetylation을 통해 naive $CD4^+$ T 세포를 pTreg 세포로 분화시킨다.