Tuberculosis (TB) remains a significant global health challenge, with approximately 1.5 million deaths per year. The Bacillus Calmette-Guérin (BCG) vaccine against TB is used in infants but shows variable protection.
View Article and Find Full Text PDFMethionine sulfoxide reductase A (MsrA) is a ubiquitous antioxidant repair enzyme which specifically reduces the oxidized methionine (Met-O) in proteins to methionine (Met). Previous studies have shown that lack of or overexpression of MsrA in cells affects the function of proteins and can lead to altered cellular processes. Interestingly, some pathogenic bacteria secrete and/or carry MsrA on their surface, suggesting some key roles for this enzyme in the modulation of host cellular processes.
View Article and Find Full Text PDFWe have recently reported that in vitro and intracellular organic peroxide stress oxidizes OhrR of Mycobacterium smegmatis and that the oxidized OhrR consequently derepresses the expression of Ohr. Here we demonstrate that the OhrR-Ohr system is highly useful for the expression of recombinant mycobacterial proteins and also for the delivery of Mycobacterium tuberculosis (Mtb) antigens to the phagosomal compartments. Recombinant M.
View Article and Find Full Text PDFAmong the various strategies to improve vaccines against infectious diseases, targeting of antigens to dendritic cells (DCs), which are professional antigen presenting cells (APCs), has received increased attention in recent years. Here, we investigated whether a synthetic peptide region named RVG, originated from Rabies Virus Glycoprotein that binds to the α-7 subunit of the nicotinic acetylcholine receptors (AchR-α7) of APCs, could be used for the delivery of Mycobacterium tuberculosis (Mtb) peptide antigens to DCs and macrophages. Mouse bone marrow derived DCs (BMDCs) and human THP-1 macrophages stimulated with RVG fused peptide epitopes 85B and 85B (represent Ag85B and Ag85B, respectively) from antigen 85B (Ag85B) of Mtb showed enhanced antigen presentation as compared to unfused peptide epitopes and BCG.
View Article and Find Full Text PDFOrganic hydroperoxide reductase regulator (OhrR) in bacteria is a sensor for organic hydroperoxide stress and a transcriptional regulator for the enzyme organic hydroperoxide reductase (Ohr). In this study we investigated, using a GFP reporter system, whether Mycobacterium smegmatis OhrR has the ability to sense and respond to intracellular organic hydroperoxide stress. It was observed that M.
View Article and Find Full Text PDFTuberculosis continues to be a great cause of morbidity and mortality in different parts of the world. Unfortunately, the current BCG vaccine being administered is not fully protective against tuberculosis; therefore, there is a great need for alternate vaccines. With an aim to develop such vaccines, we have analyzed the utility of Bacillus subtilis spores for the expression of two major immunodominant antigens of Mycobacterium tuberculosis, Ag85B and CFP10.
View Article and Find Full Text PDFFront Cell Infect Microbiol
September 2017
MicroRNAs (miRNAs) are short non-coding RNAs that regulate the expression of protein coding genes of viruses and eukaryotes at the post-transcriptional level. The eukaryotic genes regulated by miRNAs include those whose products are critical for biological processes such as cell proliferation, metabolic pathways, immune response, and development. It is now increasingly recognized that modulation of miRNAs associated with biological processes is one of the strategies adopted by bacterial pathogens to survive inside host cells.
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