Differential regulation of biosynthesis of cell surface and secreted TNF-α in LPS-stimulated murine macrophages

1997 ◽  
Vol 62 (2) ◽  
pp. 249-257 ◽  
Author(s):  
Geeta Chaudhri
2021 ◽  
Vol 19 ◽  
pp. 205873922110008
Author(s):  
Se Hyang Hong ◽  
Jin Mo Ku ◽  
Ye Seul Lim ◽  
Hyo In Kim ◽  
Yong Cheol Shin ◽  
...  

The objective of this study was to investigate the effects of Cervus nippon var. mantchuricus water extract treated with digestive enzymes (CE) on the promotion of M1 macrophage polarization in murine macrophages. Macrophages polarize either to one phenotype after stimulation with LPS or IFN-γ or to an alternatively activated phenotype that is induced by IL-4 or IL-13. Cell viability of RAW264.7 cells was determined by WST-1 assay. NO production was measured by Griess assay. IL-6, IL-12, TNF-α, and iNOS mRNA levels were measured by RT-PCR. IL-6, IL-12, and IL-10 cytokine levels were determined by ELISA. TLR4/MAPK/NF-κB signaling in RAW264.7 cells was evaluated by western blotting. The level of NF-κB was determined by immunoblotting. CE induced the differentiation of M1 macrophages. CE promoted M1 macrophages to elevate NO production and cytokine levels. CE-stimulated M1 macrophages had enhanced IL-6, IL-12, and TNF-α. CE promoted M1 macrophages to activate TLR4/MAPK/NF-κB phosphorylation. M2 markers were downregulated, while M1 markers were upregulated in murine macrophages by CE. Consequently, CE has immunomodulatory activity and can be used to promote M1 macrophage polarization through the TLR4/MAPK/NF-κB signaling pathways.


1996 ◽  
Vol 170 (1) ◽  
pp. 34-40 ◽  
Author(s):  
Hong Jiang ◽  
John A. Rummage ◽  
Charles A. Stewart ◽  
Mary J. Herriott ◽  
Irina Kolosova ◽  
...  

2008 ◽  
Vol 8 (13-14) ◽  
pp. 1767-1772 ◽  
Author(s):  
Yuefan Zhang ◽  
Shaozhan Wang ◽  
Yuanyuan Li ◽  
Zhenyu Xiao ◽  
Zhenlin Hu ◽  
...  
Keyword(s):  

2000 ◽  
Vol 68 (10) ◽  
pp. 5525-5529 ◽  
Author(s):  
Patrick F. McDermott ◽  
Federica Ciacci-Woolwine ◽  
James A. Snipes ◽  
Steven B. Mizel

ABSTRACT Flagella from diverse gram-negative bacteria induce tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β) synthesis by human monocytes (F. Ciacci-Woolwine, P. F. McDermott, and S. B. Mizel, Infect. Immun. 67:5176–5185, 1999). In this study, we establish that purified flagellin (FliC or FljB), the major filament protein from Salmonella enterica serovar Enteritidis,S. enterica serovar Typhimurium, and Pseudomonas aeruginosa, is an extremely potent inducer of TNF-α production by human monocytes and THP-1 myelomonocytic cells. Fifty percent of maximal TNF-α production (EC50) was obtained with 1.5 × 10−11 M flagellin (0.75 ng/ml). Mutagenesis studies revealed that the central hypervariable region of flagellin is essential for the TNF-α-inducing activity of the protein. Although less active than the wild-type protein, a Salmonellaflagellin mutant composed of only the central hypervariable region retained substantial TNF-α-inducing activity at nanomolar concentrations. In contrast, the conserved amino- and carboxy-terminal regions are inactive. Mutational analysis of the hypervariable region revealed that it contains two equally active TNF-α-inducing domains. The ability of THP-1 cells to respond to purified flagellins is dramatically reduced by mild trypsin treatment of the cells. Taken together, our results demonstrate that the cytokine-inducing activity of flagellins from gram-negative bacteria results from the interaction of these proteins with high-affinity cell surface polypeptide receptors on monocytes.


2008 ◽  
Vol 314 (6) ◽  
pp. 1327-1336 ◽  
Author(s):  
FengQin Liu ◽  
Yan Liu ◽  
Vincent C.H. Lui ◽  
Jonathan R. Lamb ◽  
Paul K.H. Tam ◽  
...  
Keyword(s):  

2001 ◽  
Vol 12 (1) ◽  
pp. 37-46
Author(s):  
RALPH KETTRITZ ◽  
ADRIAN SCHREIBER ◽  
FRIEDRICH C. LUFT ◽  
HERMANN HALLER

Abstract. Antineutrophil cytoplasmic antibodies (ANCA) may be important in the pathophysiology of necrotizing vasculitis. ANCA activate human neutrophils primed with tumor necrosis factor-α (TNF-α) in vitro. TNF-α priming results in translocation of ANCA antigens to the cell surface, where they are recognized by the antibodies. The signaling mechanisms involved in TNF-α priming and subsequent ANCA-induced activation were investigated. TNF-α-primed neutrophils were stimulated with monoclonal antibodies (MAb) to human myeloperoxidase (MPO) and proteinase 3 (PR3), and with preparations of human ANCA (three patients with PR3-ANCA and two patients with MPO-ANCA). Respiratory burst was measured with superoxide dismutase-inhibitable ferricytochrome C reduction and using dihydro-rhodamine-1,2,3. Phosphorylation of p38 mitogen-activated protein kinase (p38-MAPK) and the extracellular signal-regulated kinase (ERK) were assessed by immunoblotting. ANCA-antigen translocation was studied by flow cytometry. The tyrosine phosphorylation inhibitor genistein, but not calphostin or staurosporin, resulted in a significant dose-dependent superoxide generation inhibition (11.6 ± 1.7 nmol to 2.1 ± 0.5 for PR3-ANCA, and 16.0 ± 2.8 to 3.3 ± 1.3 for MPO-ANCA). The p38-MAPK inhibitor (SB202190) and the ERK inhibitor (PD98059) diminished PR3-ANCA-mediated superoxide production dose dependently (11.6 ± 1.7 nmol O2- to 1.9 ± 0.6 with 50 μM SB202190 and 4.0 ± 0.6 with 50 μM PD098059, respectively). For MPO-ANCA, the results were similar (16.0 ± 2.8 nmol to 0.9 ± 1.0 nmol with SB202190 and 6.4 ± 2.4 nmol with PD98059, respectively). Western blot showed phosphorylation of both p38-MAPK and ERK during TNF-α priming. The p38-MAPK inhibitor and the ERK inhibitor showed the strongest effect on respiratory burst when added before TNF-α priming, further supporting an important role for both signaling pathways in the priming process. Flow cytometry showed that p38-MAPK inhibition decreased the translocation of PR3 (by 93 ± 2%) and of MPO (by 64 ± 2%). In contrast, no such effect was seen when ERK was inhibited. Thus, p38-MAPK and ERK are important for the TNF-α-mediated priming of neutrophils enabling subsequent ANCA-induced respiratory burst. However, both pathways show differential effects, whereby p38-MAPK controls the translocation of ANCA antigens to the cell surface.


2018 ◽  
Vol 200 (14) ◽  
Author(s):  
Satya Deo Pandey ◽  
Shilpa Pal ◽  
Ganesh Kumar N ◽  
Ankita Bansal ◽  
Sathi Mallick ◽  
...  

ABSTRACTDuring the peptidoglycan (PG) maturation of mycobacteria, the glycan strands are interlinked by both 3-3 (between twomeso-diaminopimelic acids [meso-DAPs]) and 4-3 cross-links (betweend-Ala andmeso-DAP), though there is a predominance (60 to 80%) of 3-3 cross-links. Thedd-carboxypeptidases (dd-CPases) act on pentapeptides to generate tetrapeptides that are used byld-transpeptidases as substrates to form 3-3 cross-links. Therefore,dd-CPases play a crucial role in mycobacterial PG cross-link formation. However, the physiology ofdd-CPases in mycobacteria is relatively unexplored. In this study, we deleted twodd-CPase genes,msmeg_2433andmsmeg_2432, both individually and in combination, fromMycobacterium smegmatismc2155. Though the singledd-CPase gene deletions had no significant impact on the mycobacterial physiology, many interesting functional alterations were observed in the double-deletion mutant,viz., a predominance in PG cross-link formation was shifted from 3-3 cross-links to 4-3, cell surface glycopeptidolipid (GPL) expression was reduced, and susceptibility to β-lactams and antitubercular agents was enhanced. Moreover, the survival rate of the double mutant within murine macrophages was higher than that of the parent. Interestingly, the complementation with any one of thedd-CPase genes could restore the wild-type phenotype. In a nutshell, we infer that the altered ratio of 4-3 to 3-3 PG cross-links might have influenced the expression of surface GPLs, colony morphology, biofilm formation, drug susceptibility, and subsistence of the cells within macrophages.IMPORTANCEThe glycan strands in mycobacterial peptidoglycan (PG) are interlinked by both 3-3 and 4-3 cross-links. Thedd-CPases generate tetrapeptides by acting on the pentapeptides, andld-transpeptidases use tetrapeptides as substrates to form 3-3 cross-links. In this study, we showed that simultaneous deletions of twodd-CPases alter the nature of PG cross-linking from 3-3 cross-links to 4-3 cross-links. The deletions subsequently decrease the expression of glycopeptidolipids (significant surface lipid present in many nontuberculous mycobacteria, includingMycobacterium smegmatis) and affect other physiological parameters, like cell morphology, growth rate, biofilm formation, antibiotic susceptibility, and survival within murine macrophages. Thus, unraveling the physiology ofdd-CPases might help us design antimycobacterial therapeutics in the future.


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