A putative nitroreductase from the DosR regulon of Mycobacterium tuberculosis induces pro-inflammatory cytokine expression via TLR2 signaling pathway.
Tuberculosis caused by Mycobacterium tuberculosis is a global encumbrance and it is estimated that nearly one third population of the world acts as a reservoir for this pathogen without any symptoms. In this study, we attempted to characterise one of the genes of DosR regulon, Rv3131, a FMN binding nitroreductase domain containing protein, for its ability to alter cytokine profile, an essential feature of M. tuberculosis latency. Recombinant Rv3131 stimulated pro-inflammatory cytokines in THP-1 cells and human peripheral blood mononuclear cells in a time and dose dependent manner. In silico analyses using docking and simulations indicated that Rv3131 could strongly interact with TLR2 via a non-covalent bonding which was further confirmed using cell based colorimetric assay. In THP-1 cells treated with Rv3131 protein, a significant upsurge in the surface expression, overall induction and expression of mRNA of TLR2 was observed when analysed by flow cytometry, western blotting and real time PCR, respectively. Activation of TLR2 by Rv3131 resulted in the phosphorylation of NF- κβ. Results of this study indicate a strong immunogenic capability of Rv3131 elicited via the activation of TLR2 signalling pathway. Therefore, it can be surmised that cytokine secretion induced by Rv3131 might contribute to establishment of M. tuberculosis in the granulomas.
Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad, Hyderabad 500046 India.
Vidyullatha
V
Peddireddy
Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad, Hyderabad 500046 India.
Sankara Narayana
SN
Doddam
Department of Biotechnology and Bioinformatics, University of Hyderabad, Hyderabad India.
Insaf A
IA
Qureshi
Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad, Hyderabad 500046 India.
Priyadarshini
P
Yerra
Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad, Hyderabad 500046 India.
Niyaz
N
Ahmed
D001426:Bacterial Proteins / Q000235:genetics*; D016207:Cytokines / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D009601:Nitroreductases / Q000235:genetics*; D011494:Protein Kinases / Q000235:genetics*; D018085:Regulon; D015398:Signal Transduction; D051195:Toll-Like Receptor 2 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D016207:Cytokines; D004268:DNA-Binding Proteins; C542863:DosR protein, Mycobacterium tuberculosis; D018836:Inflammation Mediators; D016328:NF-kappa B; D051195:Toll-Like Receptor 2; D009601:Nitroreductases; D011494:Protein Kinases