Project description:Tumor Progression Locus 2 (TPL-2) kinase mediates Toll-like Receptor (TLR) activation of ERK1/2 and p38 MAP kinases in myeloid cells to modulate expression of key cytokines in innate immunity. This study identified a novel MAP kinase-independent regulatory function for TPL-2 in phagosome maturation, an essential process for killing of phagocytosed microbes. TPL-2 catalytic activity was demonstrated to induce phagosome acidification and proteolysis in primary mouse and human macrophages following uptake of latex beads. Quantitative proteomics revealed that blocking TPL-2 catalytic activity significantly altered the protein composition of phagosomes, particularly reducing the abundance of V-ATPase proton pump subunits. Furthermore, TPL-2 stimulated the phosphorylation of DMXL1, a critical regulator of V-ATPases, to induce phagosome acidification. Consistent with these results, TPL-2 catalytic activity was required for phagosome maturation and the efficient killing of Staphylococcus aureus following phagocytic uptake by macrophages. These results indicate that TPL-2 controls the innate immune response of macrophages to bacteria via V-ATPase induction of phagosome maturation.
Project description:Engineered macrophage-based therapies offer promising potential for cancer treatment but are limited by slow, uncontrolled drug release and the risk of macrophage reprogramming into tumor-promoting phenotypes. Here, we developed a thermally induced macrophage autolysis release system, the macrophage-microbe encapsulation bomb (MME-Bomb), which combines engineered macrophages loaded with indocyanine green (ICG)-encapsulated nanoparticles and antitumor attenuated Salmonella typhimurium strain. This system utilizes photothermally triggered pyroptosis to induce controlled macrophage rupture within the tumor microenvironment, releasing intracellular bacteria to stimulate prolonged antitumor immunity. By integrating light-responsive biomodulation, our approach enables site-specific activation of engineered cells, enhancing the rapid delivery of therapeutic agents and maximizing the synergy between macrophage-based and bacterial therapies. In preclinical cancer models, MME-Bomb significantly reduces the tumor burden and improves survival outcomes, both alone and in combination with checkpoint inhibitors. This innovative strategy offers a versatile and precise framework for advancing cancer immunotherapies.
Project description:Opioids such as morphine have many beneficial properties as analgesics, however, opioids may induce multiple adverse gastrointestinal symptoms. We have recently demonstrated that morphine treatment results in significant disruption in gut barrier function leading to increased translocation of gut commensal bacteria. However, it is unclear how opioids modulate the gut homeostasis. By using a mouse model of morphine treatment, we studied effects of morphine treatment on gut microbiome. We characterized phylogenetic profiles of gut microbes, and found a significant shift in the gut microbiome and increase of pathogenic bacteria following morphine treatment when compared to placebo. In the present study, wild type mice (C57BL/6J) were implanted with placebo, morphine pellets subcutaneously. Fecal matter were taken for bacterial 16s rDNA sequencing analysis at day 3 post treatment. A scatter plot based on an unweighted UniFrac distance matrics obtained from the sequences at OTU level with 97% similarity showed a distinct clustering of the community composition between the morphine and placebo treated groups. By using the chao1 index to evaluate alpha diversity (that is diversity within a group) and using unweighted UniFrac distance to evaluate beta diversity (that is diversity between groups, comparing microbial community based on compositional structures), we found that morphine treatment results in a significant decrease in alpha diversity and shift in fecal microbiome at day 3 post treatment compared to placebo treatment. Taxonomical analysis showed that morphine treatment results in a significant increase of potential pathogenic bacteria. Our study shed light on effects of morphine on the gut microbiome, and its role in the gut homeostasis.
Project description:Tumor Progression Locus 2 (TPL-2) kinase mediates Toll-like Receptor (TLR) activation of ERK1/2 and p38-alpha MAP kinases in myeloid cells to modulate expression of key cytokines in innate immunity. This study identified a novel MAP kinase-independent regulatory function for TPL-2 in phagosome maturation, an essential process for killing of phagocytosed bacteria. TPL-2 catalytic activity was demonstrated to induce phagosome acidification and proteolysis in primary mouse and human macrophages following uptake of latex beads. Mass spectrometry analysis revealed that blocking TPL-2 catalytic activity significantly altered the protein composition of phagosomes, particularly reducing the abundance of V-ATPase proton pump subunits. Furthermore, TPL-2 was shown to stimulate the phosphorylation of DMXL1, a critical regulator of V-ATPases, to induce phagosome acidification. Consistent with these results, TPL-2 catalytic activity was required for phagosome acidification, activation of phagosome acid-sensitive cathepsins and the efficient killing of Staphylococcus aureus following phagocytic uptake by macrophages. These results indicate that TPL-2 controls the innate immune response of macrophages to bacteria via MAP kinase regulation of gene expression and V-ATPase induction of phagosome maturation.
Project description:Our microbiota affects numerous processes involved in development, health, and the response to chemotherapeutic drugs. Tamoxifen is a selective estrogen receptor (ER) modulator that is used to treat ER positive breast cancer, but that at high doses kills both ER positive and ER-negative breast cancer cells. We recapitulate this off-target effect in Caenorhabditis elegans, which does not have an ER ortholog. We find that different bacteria dramatically modulate tamoxifen toxicity in C. elegans, with a three-order of magnitude difference between animals fed Escherichia coli, Comamonas aquatica, and Bacillus subtilis. Remarkably, host fatty acid (FA) biosynthesis mitigates tamoxifen toxicity, and different bacteria provide the animal with different FAs, resulting in distinct FA profiles. Surprisingly these bacteria modulate tamoxifen toxicity by different death mechanisms, some of which are modulated by FA supplementation and others by antioxidants. Together, this work reveals a complex interplay between bacteria, FA metabolism and tamoxifen toxicity that may provide a blueprint for similar studies in more complex mammals.
Project description:The aim of this experiment was to determine if the development of resistance to antibiotics can be driven by the concentration and speciation of Cu. Experimental setup was designed to investigate two hypotheses for which two strains of Gram- bacteria have been selected: - Do TE enhance AR in resistant bacteria? Resistant strain: Bioluminescent Pseudomonas aeruginosa PAO1 (Xen41, Tetracycline resistant) - Do TE induce AR in sensitive bacteria? Sensitive strain: Pseudomonas aeruginosa PAO1 (Wild Type)
Project description:The aim of this experiment was to determine if the development of resistance to antibiotics can be driven by the concentration and speciation of Cu. Experimental setup was designed to investigate two hypotheses for which two strains of Gram- bacteria have been selected: - Do TE enhance AR in resistant bacteria? Resistant strain: Bioluminescent Pseudomonas aeruginosa PAO1 (Xen41, Tetracycline resistant) - Do TE induce AR in sensitive bacteria? Sensitive strain: Pseudomonas aeruginosa PAO1 (Wild Type)
Project description:We isolate the cultivable microbiome of a diatom and show that different bacteria have commensal, antagonistic, or synergistic effects on the diatom. One synergistic bacterium enhances growth of the diatom by production of auxin, a phytohormone. The diatom and its synergistic bacterium appear to use auxin and tryptophan as signaling molecules that drive nutrient exchange. Detection of auxin molecules and biosynthesis gene transcripts in the Pacific Ocean suggests that these interactions are widespread in marine ecosystems.