scholarly journals Novel Protein Antigen (JHP940) from the Genomic Plasticity Region of Helicobacter pylori Induces Tumor Necrosis Factor Alpha and Interleukin-8 Secretion by Human Macrophages

2007 ◽  
Vol 190 (3) ◽  
pp. 1146-1151 ◽  
Author(s):  
Mohammed Rizwan ◽  
Ayesha Alvi ◽  
Niyaz Ahmed

ABSTRACT The plasticity region of the Helicobacter pylori genome comprises strain-specific gene loci. We performed genotyping and functional biology analysis of one such locus (jhp940) that was previously found to be functionally unknown but present in gastric cancer-associated strains from many different countries. We found its geographic prevalence to be independent of cagA presence and disease status. Cloning, expression, and purification of JHP940 revealed a novel, ∼36-kDa protein in a biologically active form which elicited strong and significant levels of tumor necrosis factor alpha and interleukin-8 in human macrophages. Also, JHP940 was able to induce enhanced translocation of the transcription factor NF-κB complex in cultured macrophages. The induction of the proinflammatory cytokines by JHP940, therefore, points to its putative role in chronic gastric inflammation and, possibly, the various other outcomes of H. pylori infection, including gastric cancer.

2001 ◽  
Vol 69 (8) ◽  
pp. 4823-4830 ◽  
Author(s):  
Véronique Jubier-Maurin ◽  
Rose-Anne Boigegrain ◽  
Axel Cloeckaert ◽  
Antoine Gross ◽  
Maria-Teresa Alvarez-Martinez ◽  
...  

ABSTRACT Brucella spp. can establish themselves and cause disease in humans and animals. The mechanisms by whichBrucella spp. evade the antibacterial defenses of their host, however, remain largely unknown. We have previously reported that live brucellae failed to induce tumor necrosis factor alpha (TNF-α) production upon human macrophage infection. This inhibition is associated with a nonidentified protein that is released into culture medium. Outer membrane proteins (OMPs) of gram-negative bacteria have been shown to modulate macrophage functions, including cytokine production. Thus, we have analyzed the effects of two major OMPs (Omp25 and Omp31) of Brucella suis 1330 (wild-type [WT] B. suis) on TNF-α production. For this purpose, omp25and omp31 null mutants of B. suis(Δomp25 B. suis and Δomp31 B. suis, respectively) were constructed and analyzed for the ability to activate human macrophages to secrete TNF-α. We showed that, in contrast to WTB. suis or Δomp31 B. suis, Δomp25 B. suis induced TNF-α production when phagocytosed by human macrophages. The complementation of Δomp25 B. suis with WT omp25 (Δomp25-omp25 B. suis mutant) significantly reversed this effect: Δomp25-omp25 B. suis-infected macrophages secreted significantly less TNF-α than did macrophages infected with the Δomp25 B. suismutant. Furthermore, pretreatment of WT B. suis with an anti-Omp25 monoclonal antibody directed against an epitope exposed at the surface of the bacteria resulted in substancial TNF-α production during macrophage infection. These observations demonstrated that Omp25 of B. suis is involved in the negative regulation of TNF-α production upon infection of human macrophages.


Tumor Biology ◽  
2015 ◽  
Vol 37 (1) ◽  
pp. 405-412 ◽  
Author(s):  
Kayhan Erturk ◽  
Didem Tastekin ◽  
Murat Serilmez ◽  
Elif Bilgin ◽  
Hamza Ugur Bozbey ◽  
...  

2021 ◽  
Vol 22 (3) ◽  
pp. 1235
Author(s):  
Andressa Vilas Boas Nogueira ◽  
Marjan Nokhbehsaim ◽  
Anna Damanaki ◽  
Sigrun Eick ◽  
Christian Kirschneck ◽  
...  

There is little known about the effect of the periodontopathogen Filifactor alocis on macrophages as key cells of the innate immune defense in the periodontium. Therefore, the aim of the present study was to investigate the effect of F. alocis and additionally of the pro-inflammatory cytokine tumor necrosis factor-alpha (TNFα) on visfatin and other pro-inflammatory and proteolytic molecules associated with periodontitis in human macrophages. The presence of macrophage markers CD14, CD86, CD68, and CD163 was examined in gingival biopsies from healthy individuals and periodontitis patients. Human macrophages were incubated with F. alocis and TNFα for up to 2 d. The effects of both stimulants on macrophages were determined by real-time PCR, ELISA, immunocytochemistry, and immunofluorescence. F. alocis was able to significantly stimulate the synthesis of visfatin by human macrophages using TLR2 and MAPK pathways. In addition to visfatin, F. alocis was also able to increase the synthesis of cyclooxygenase 2, TNFα, and matrix metalloproteinase 1. Like F. alocis, TNFα was also able to stimulate the production of these proinflammatory and proteolytic molecules. Our results highlight the pathogenetic role of F. alocis in periodontal diseases and also underline the involvement of visfatin in the aetiopathogenesis of periodontitis.


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