Project description:Analysis of undifferentiated keratinocytes or differentiated keratinocytes stimulated with or without human cathelicidin antimicrobial peptide (CAMP) LL37. Results provide insight into the biological effects of CAMP on human keratinocytes. NHEKs were divided into two groups; low calcium (0.05 mM) and high calcium condition (1.6 mM). Then keratinocytes were stimulated with human cathelicidin antimicrobial peptide LL37 at 0, 2.56, and 7.68 M-NM-<M for 12 h to 24 h.
Project description:We reported the transcriptional profiles of E.coli expressing antimicrobial peptide LL37 under stress response condition. 4 samples, two groups, one group is under aerobic condition, the other group is under anaerobic condition. One of samples is E.coli which expressed LL37 as induction in each group, another sample is E.coli with no LL37 expression in vivo as control in each group.
Project description:Analysis of undifferentiated keratinocytes or differentiated keratinocytes stimulated with or without human cathelicidin antimicrobial peptide (CAMP) LL37. Results provide insight into the biological effects of CAMP on human keratinocytes.
Project description:Ceragenins are a family of synthetic amphipathic molecules designed to mimic the properties of naturally-occurring cationic antimicrobial peptides (CAMPs). Although ceragenins have potent antimicrobial activity, whether their mode of action is similar to that of CAMPs has remained elusive. Here we report the results of a comparative study of the bacterial responses to two well-studied CAMPs, LL37 and colistin, and two ceragenins with related structures, CSA13 and CSA13.
Project description:The balance between tolerogenic and inflammatory responses determines immune homeostasis in the gut. Dysbiosis and a defective host defense against invading intestinal bacteria can shift this balance via bacterial-derived metabolites and trigger chronic inflammation. We show that the short chain fatty acid butyrate modulates monocyte to macrophage differentiation by promoting antimicrobial effector functions. The presence of butyrate modulates antimicrobial activity via a shift in macrophage metabolism and reduction in mTOR activity. This mechanism is furthermore dependent on the inhibitory function of butyrate on histone deacetylase 3 (HDAC3) driving transcription of a set of antimicrobial peptides including calprotectin. The increased antimicrobial activity against several bacterial species is not associated with increased production of conventional cytokines. Butyrate imprints antimicrobial activity of intestinal macrophages in vivo. Our data suggest that commensal bacteria derived butyrate stabilize gut homeostasis by promoting antimicrobial host defense pathways in monocytes that differentiate into intestinal macrophages.
Project description:Neutrophil extracellular traps (NETs) are a key antimicrobial feature of cellular innate immunity mediated by polymorphonuclear neutrophils (PMNs). NETs trap and kill microbes but have also been linked to inflammation in atherosclerosis, arthritis, or psoriasis by unknown mechanisms. We here report that NET-associated RNA (naRNA, which was RNA-sequenced from human primary neutrophil NETs here) stimulated further NET formation in naïve PMNs via a unique TLR8-NLRP3-caspase-1-gasdermin D-dependent inflammasome pathway. Keratinocytes also responded to naRNA with expression of psoriasis-related genes (e.g. IL17, IL36) via atypical NOD2-RIPK signaling. In vivo naRNA drove skin inflammation, which was drastically ameliorated by genetic ablation of RNA sensing. The naRNA-LL37 ‘composite DAMP’ was pre-stored in resting neutrophil granules, defining sterile NETs as intentionally inflammatory webs that amplify neutrophil activation. However, the activity of the naRNA-LL37 DAMP was transient and hence supposedly self-limiting under physiological conditions. Only upon dysregulated NET release like psoriasis, TLR-NLRP3-mediated naRNA sensing may represent both potential cause of disease and new intervention target.
Project description:Snake venoms contain a variety of toxins with a range of biological activity. Among these are the cysteine-rich secreted proteins (CRISPs). The proteins of this family have masses of 20–30 kDa and display homologous amino acid sequences containing 16 cysteine residues, forming eight disulfide bonds. Some of these proteins have been explored, characterized, and described in terms of their activity; however, little is known of their range of activities. A search for new antimicrobial molecules is ongoing, as the number of microbial strains resistant to available antibiotics is increasing. We identified antimicrobial activity in the secretion of the Duvernoy’s gland of the rear-fanged Philodryas patagoniensis. Fractions of this venom were subjected to Reverse Phase – High Performance Liquid Chromatography and analyzed to determine their antimicrobial activity with a liquid broth inhibition assay. One of the fractions presented activity against a Gram-negative bacterium and a filamentous fungus. This fraction was analyzed with LC-MS/MS, and a protein of 24,848.8 Da was identified. Database searches allowed us to identify it as a CRISP due to the presence of some unique fragments in the molecule. We called it patagonin-CRISP, as the same protein in the venom of P. patagoniensis had previously been characterized as having a different biological activity. Patagonin-CRISP presented activity at very low concentrations and showed no cytotoxic activity. This is the first time that antimicrobial activity has been identified for P. patagoniensis venom or for a CRISP family protein.
Project description:Plants have a long history of use for their medicinal properties. The complexity of botanical extracts presents unique challenges and necessitates the application of innovative approaches to correctly identify and quantify bioactive compounds. With this study, we employed untargeted metabolomics to explore the antimicrobial activity of the botanical Rumex crispus (yellow dock), a member of the Polygonaceae family that is used as an herbal remedy for bacterial infections. Ultra high-performance liquid chromatography coupled to high resolution mass-spectrometry (UPLC-MS) was used to identify and quantify the known antimicrobial compound emodin. In addition, we used biochemometric approaches to integrate data measuring antimicrobial activity from R. crispus root starting material and fractions against methicillin resistant Staphylococcus aureus (MRSA) with UPLC-MS data. Our results support the hypothesis that multiple constituents, including the anthraquinone emodin, contribute to the antimicrobial activity of R. crispus against MRSA.
