Project description:Treatment of pneumococcal infections is limited by antibiotic resistance and exacerbation of disease by bacterial lysis releasing pneumolysin toxin and other inflammatory factors. We identified a novel peptide in the Klebsiella pneumoniae secretome, which enters Streptococcus pneumoniae via its AmiA-AliA/AliB permease. Subsequent downregulation of genes for amino acid biosynthesis and peptide uptake was associated with reduction of pneumococcal growth in defined medium and human cerebrospinal fluid, irregular cell shape, decreased chain length and decreased genetic transformation. The bacteriostatic effect was specific to S. pneumoniae and Streptococcus pseudopneumoniae with no effect on Streptococcus mitis, Haemophilus influenzae, Staphylococcus aureus or K. pneumoniae. Peptide sequence and length were crucial to growth suppression. The peptide reduced pneumococcal adherence to primary human airway epithelial cell cultures and colonization of rat nasopharynx, without toxicity. We also analysed the effect of peptide on the proteome of S. pneumoniae. We found alteration of the proteome by the peptide with some proteins turned on or off in line with the transcriptomic changes. We therefore identified a peptide with potential as a therapeutic for pneumococcal diseases suppressing growth of multiple clinical isolates, including antibiotic resistant strains, while avoiding bacterial lysis and dysbiosis.
Project description:Influenza A virus (IAV) predisposes individuals to secondary infections with the bacterium Streptococcus pneumoniae (the pneumococcus). Infections may manifest as pneumonia, sepsis, meningitis or otitis media (OM). It remains controversial as to whether secondary pneumococcal disease is due to the induction of an aberrant immune response or IAV induced immunosuppression. Moreover, as the majority of studies have been performed in the context of pneumococcal pneumonia, it remains unclear how far these findings can be extrapolated to other pneumococcal disease phenotypes. Here, we demonstrate that the viral hemagglutinin (HA) mediates bacterial OM by inducing a pro-inflammatory response in the middle ear cavity in a replication-dependent manner. Importantly, our findings show that it is the inflammatory response that mediates pneumococcal replication; not viral suppression of the immune system or epithelial damage. This study provide the first evidence that HA induced inflammation drives pneumococcal replication in the middle ear cavity, which has important consequences to the treatment of pneumococcal OM.
Project description:Patients with inflammatory bowel disease (IBD) will be assessed for immunologic response to pneumococcal vaccination. Patients with IBD meet criteria as outlined by the Centers for Disease Control (CDC) for pneumococcal vaccination, yet the investigators have found that pneumococcal vaccination in this population is under-utilized. It is unknown whether or not IBD or IBD-related medications impact the immune response to this recommended vaccine.
Three groups of 25 patients each will be recruited. The first group will consist of outpatients with IBD who are receiving infliximab (Remicade TM) while on concommitant immunosuppressive therapy (with either 6MP, azathioprine, or methotrexate). This group is intended to represent a common ‘heavily immunosuppressed’ patient group with IBD.
The second group will consist of patients with IBD seen in our outpatient clinic who are not on any immune-suppressive medications. These patients meet CDC criteria for vaccination by virtue of having a chronic medical illness. The third group will consist of healthy age-matched (to the first group) controls.
After obtaining informed consent, patients will be screened with baseline lab tests including testing for antibodies against pneumococcus. At the baseline visit, patients will also undergo a brief medical history, physical examination, and assessment of their IBD disease activity.
Included patients will then undergo a one-time intramuscular vaccination with 23-valent polysaccharide pneumococcal vaccine (Pneumovax TM). One month later, subjects will return for a blood draw to assess for response to pneumococcal vaccination.
Project description:Streptococcus pneumoniae is an opportunistic human pathogen that typically colonizes the nasopharyngeal passage and causes lethal disease in other host niches such as the lung or the meninges. How pneumococcal genes are expressed and regulated at the different stages of its life cycle, as commensal or as pathogen, has not been entirely described. To chart the transcriptional responses of S. pneumoniae, we quantified the transcriptome under 22 different infection-relevant conditions. The transcriptomic compendium exposed a high level of dynamic expression and, strikingly, all annotated pneumococcal genomic features were expressed in at least one of the studied conditions. By computing the correlation of gene expression of every two genes across all studied conditions, we created a co-expression matrix that provides valuable information on both operon structure and regulatory processes. The co-expression data is highly consistent with well-characterized operons and regulons, such as the PyrR, ComE and ComX regulons, and had allowed us to identify a new member of the competence regulon. Finally, we created an interactive data center (www.veeninglab.com/pneumoexpress) that enables users to access the expression data as well as the co-expression matrix in an intuitive and efficient manner, providing a valuable resource to the pneumococcal research community.
Project description:Thanks to surface digestion protocol above pneumococcal pediatric strains and in silico selection, we selected 94 pneumococcal proteins according to their surface-exposed domains and/or interactions with surface environment. Then, that proteins were cloned as recombinant form in Escherichia coli and face off to pediatric sera from control and pneumococcal patients.
Project description:The goal of this study was to evaluate the impact of mechanical ventilation on immune and mitochondrial dysfunctions, in the setting of pneumococcal pneumonia in rabbits. Then, in a randomized trial, we assessed the effect of human umbilical cord-derived mesenchymal stem cells (MSCs), either alone, or in association with an atibiotic treatment (Ceftaroline) in the setting of pneumococcal pneumonia submitted to adverse mechanical ventilation. Pulmonary gene expression was analysed in an attempt to elucidate the effects of MSCs.
Project description:METTL3 play nonnegligible function in PCa progression.RSM3,RSM3, a peptide inhibitor targeting METTL3. Here, we seek to explore the effect of RSM3 on transcriptome profile in PC3 cells
Project description:Rationale: Streptococcus pneumoniae is the most common bacterial cause of community acquired pneumonia. Some clinical trials have demonstrated a beneficial effect of corticosteroid therapy in community acquired pneumonia, but the mechanisms of this benefit remain unclear. Objectives: To investigate the biologic effects of corticosteroids in pneumococcal pneumonia in mice and in patients Methods: We studied lower respiratory tract transcriptomes from an observational cohort of mechanically ventilated patients and from a pneumonia model in mice. We also carried out comprehensive physiologic, biochemical, and histological analyses in mice to identify mechanisms of lung injury in S. pneumoniae with and without adjunctive steroid therapy. Measurement and Main Results: Transcriptomic analysis identified pleiotropic effects of steroid therapy on the lower respiratory tract in critically ill patients with pneumococcal pneumonia, findings that were reproducible in mice. In mice with pneumonia, dexamethasone in combination with ceftriaxone reduced (1) pulmonary edema formation, (2) alveolar protein permeability, (3) proinflammatory cytokine release, (4) histopathology lung injury score, and (5) hypoxemia, but did not increase bacterial burden. Conclusions: In combination with appropriate antibiotics in mice, treatment of pneumococcal pneumonia with steroid therapy reduces hypoxemia, pulmonary edema, lung permeability, and histologic criteria of lung injury, and also altered inflammatory responses at the protein and gene expression level. The concordance of transcriptional data in the mouse model and in patients with pneumococcal pneumonia supports the translational relevance of this work.