Project description:The upsurge of multidrug-resistant infections has rendered tuberculosis the principal cause of death among infectious diseases. A clonal outbreak multidrug-resistant triggering strain of Mycobacterium tuberculosis was identified in Kanchanaburi Province, designated “MKR superspreader”, which was found to subsequently spread to other regions, as revealed by prior epidemiological reports in Thailand. Herein, we showed that the MKR displayed a higher growth rate upon infection into host macrophages in comparison with the H37Rv reference strain. To further elucidate the MKR’s biology, we utilised RNA-Seq and differential gene expression analyses to identify host factors involved in the intracellular viability of the MKR. A set of host genes function in the cellular response to lipid pathway was found to be uniquely up-regulated in host macrophages infected with the MKR, but not those infected with H37Rv. Within this set of genes, the IL-36 cytokines which regulate host cell cholesterol metabolism and resistance against mycobacteria attracted our interest, as our previous study revealed that the MKR elevated genes associated with cholesterol breakdown during its growth inside host macrophages. Indeed, when comparing macrophages infected with the MKR to H37Rv-infected cells, our RNA-Seq data showed that the expression ratio of IL-36RN, the negative regulator of the IL-36 pathway, to that of IL-36G was greater in macrophages infected with the MKR. Furthermore, the intracellular survival of MKR was diminished with decreased IL-36RN expression. Overall, our results indicate that IL-36RN is critical for MKR intracellular survival and could serve as a new target against this emerging multidrug-resistant M. tuberculosis strain.
2022-10-28 | GSE194017 | GEO
Project description:Phages against multidrug-resistant bacteria
Project description:Bacterial infectious diseases have posed a serious challenge to public health, often resulting in treatment failure and infection recurrence due to the emergence of drug-resistant bacteria. Owing to inaccessible binding sites, pathogens can evade attack from host immune cells and traditional antibiotics, leading to local immunosuppressive status. Our study reports a novel bacteriophage-based immune scavenger labeling nanoplatform (Mn2+@Man-phage) to combat immune-evasive bacteria and reverse immunosuppressive status. Our nanosystem utilizes the inherent bacterium-targeting ability of bacteriophages to aggregate at infection sites and mediates mannose-dependent recognition, phagocytosis, and killing of bacteria by macrophages, while the released Mn2+ amplifies the antibacterial immune efficacy. Consequently, macrophages polarize towards M1 and secrete various pro-inflammatory factors, effectively clearing bacteria. Moreover, reprogramming macrophages directly activate T cells at infection sites, eliciting potent adaptive antibacterial immune responses and ultimately achieving bacterial eradication. Overall, we demonstrate a universal strategy for pathogen targeting and immunomodulation of macrophages against bacterial infection.
Project description:Bacterial infectious diseases have posed a serious challenge to public health, often resulting in treatment failure and infection recurrence due to the emergence of drug-resistant bacteria. Owing to inaccessible binding sites, pathogens can evade attack from host immune cells and traditional antibiotics, leading to local immunosuppressive status. Our study reports a novel bacteriophage-based immune scavenger labeling nanoplatform (Mn2+@Man-phage) to combat immune-evasive bacteria and reverse immunosuppressive status. Our nanosystem utilizes the inherent bacterium-targeting ability of bacteriophages to aggregate at infection sites and mediates mannose-dependent recognition, phagocytosis, and killing of bacteria by macrophages, while the released Mn2+ amplifies the antibacterial immune efficacy. Consequently, macrophages polarize towards M1 and secrete various pro-inflammatory factors, effectively clearing bacteria. Moreover, reprogramming macrophages directly activate T cells at infection sites, eliciting potent adaptive antibacterial immune responses and ultimately achieving bacterial eradication. Overall, we demonstrate a universal strategy for pathogen targeting and immunomodulation of macrophages against bacterial infection.
Project description:Phage therapy is a promising adjunct therapeutic approach against bacterial multidrug-resistant infections, including Pseudomonas aeruginosa-derived infections. Nevertheless, the current knowledge about the phage-bacteria interaction within a human environment is limited. In this work, we performed a transcriptome analysis of phage-infected P. aeruginosa adhered to a human epithelium (Nuli-1 ATCC® CRL-4011™). To this end, we performed RNA-sequencing from a complex mixture comprising phage–bacteria–human cells at early, middle, and late infection and compared it to uninfected adhered bacteria. Overall, we demonstrated that phage genome transcription is unaltered by bacterial growth and phage employs a core strategy of predation through upregulation of prophage-associated genes, a shutdown of bacterial surface receptors, and motility inhibition. In addition, specific responses were captured under lung-simulating conditions, with the expression of genes related to spermidine syntheses, sulfate acquisition, spermidine syntheses, biofilm formation (both alginate and polysaccharide syntheses), lipopolysaccharide (LPS) modification, pyochelin expression, and downregulation of virulence regulators. These responses should be carefully studied in detail to better discern phage-induced changes from bacterial responses against phage. Our results establish the relevance of using complex settings that mimics in vivo conditions to study phage-bacteria interplay, being obvious the phage versatility on bacterial cell invasion.
Project description:Objectives: Colistin remains a last-line treatment for multidrug-resistant Acinetobacter baumannii and combined use of colistin and carbapenems has shown synergistic effects against multidrug-resistant strains. In order to understand the bacterial responses to these antibiotics we analysed the transcriptome of A. baumannii following exposure to each.
Project description:Bacteria-based metabolic therapy has been acknowledged as a promising strategy for tumor treatment. However, the insufficient efficiency of wild-type bacteria severely restricts their therapeutic efficacy. Here, we successfully develop a ʟ-cystine (CySS)-addicted bacterial biocatalyst for metabolic therapy through a dual-selection directed evolution strategy. Our evolved strain (namely SFEc+) exhibits a 36-fold increase in CySS uptake and a 23-fold improvement in total activity of cysteine desulfhydrases compared to the wild-type strain. By conjugating with DMXAA-loaded liposomes, the engineered biocatalyst not only prevents the influx of nutrients into the tumor microenvironment by blocking neovasculature but also achieves efficient and durable CySS catabolism locally. The absence of CySS disrupts redox homeostasis in tumor cells and strikingly increases intracellular ROS level, resulting in effective tumor elimination. In multiple murine tumor models, intravenous administration of the engineered living biocatalyst displays favorable therapeutic outcomes. Our work not only highlights the promise of directed evolution strategy in enhancing the stability and efficiency of bacteria-based living biocatalyst, but also provides the new opportunities in antitumor metabolic therapy.
Project description:Tuberculosis (TB) remains one of the world’s major infectious diseases affecting nations with limited public health resources. Multidrug resistance development has seriously compromised therapeutic treatment choices. The pathology of latent TB shows evidence of a reservoir of Mycobacterium tuberculosis (Mtb) in the lungs of affected individuals. If the pathogen is contained by the immune system, no overt disease symptoms occur. The environmental and internal triggers leading to disease reactivation are not well understood. Proteomic investigations of blood plasma and sputum derived from subjects with active TB versus latent TB versus healthy individuals may yield new biomarkers and, when surveying larger longitudinally monitored cohorts, may discriminate infection outcomes in an endemic setting.