Project description:The biofilm proteome profile of endodontic and systemic pathogen E. faecalis has been analysed in this study to identify markers associated with its biofilm formation. Strong and weak biofilm forming E. faecalis clinical isolates were compared with two standard ATCC strains of E. faecalis in order to elucidate the biological pathways associated with the biofilm formation capability of E. faecalis.
Project description:Hepatic fibrosis is a dynamic process characterized by the net accumulation of extracellular matrix resulting from chronic liver injury such as nonalcoholic steatohepatitis. During the pathogenesis of hepatic fibrosis, activation of hepatic stellate cells (HSCs) causes transdifferentiation of quiescent cells into proliferative and fibrogenic myofibroblasts. In the present study, we developed a novel RORα-selective ligand, ODH-08, based on the modification of JC1-40, a previously reported N-methylthiourea analog. Administration of ODH-08 to Western diet (WD)-fed mice improved the signs of hepatic fibrosis: decreased hepatic collagen deposition and suppression of the expression of fibrogenic markers. ODH-08 inhibits the TGF1-induced fibrogenic activation of HSCs through suppression of the TGFβ1–SMAD signaling pathway, which represents a novel mechanism for the antifibrogenic effect of RORα. Thus, ODH-08 appears to be a promising antifibrotic agent to treat hepatic fibrosis. We performed a microarray analysis in the liver tissue of ODH-08-treated WD-fed mice to anlyse differentially expressed genes under ODH-08 administration. The control group was vehicle-treated WD-fed mice.
Project description:Indian rhesus macaques are arguably the most reliable animal models in AIDS research. In this species the MHC class I allele Mamu-B*08, among others, is associated with elite control of SIV replication. A similar scenario is observed in humans where the expression of HLA-B*27 or HLA-B*57 has been linked to slow or no progression to AIDS after HIV infection. Despite having large differences in their primary structure, it has been reported that HLA-B*27 and Mamu-B*08 display peptides with sequence similarity. To fine-map the Mamu-B*08 binding motif and assess its similarities with that of HLA-B*27 we affinity purified the peptidomes bound to these MHC class I molecules and analyzed them by LC-MS/MS identifying several thousands of endogenous ligands. Sequence analysis of both sets of peptides revealed a degree of similarity in their binding motifs, especially at peptide position 2 (P2) where arginine was present in the vast majority of ligands of both allotypes. In addition, several differences emerged from this analysis: (i) ligands displayed by Mamu-B*08 tended to be shorter and to have lower molecular weight, (ii) Mamu-B*08 showed a higher preference for glutamine at P2 as a suboptimal binding motif and (iii) the second major anchor position, found at P-omega, was much more restrictive in Mamu-B*08. In this regard, HLA-B*27 bound efficiently peptides with aliphatic, aromatic (including tyrosine) and basic C-terminal residues while Mamu-B*08 preferred peptides with leucine and phenylalanine in this position. These results deepen our understanding of the molecular basis of the presentation of peptides by Mamu-B*08 and can contribute to the detection of novel SIV epitopes restricted by this allotype.
Project description:Small non coding RNA molecules (sncRNAs) are key mediators of virulence and stress inducible gene expressions in some pathogens. In this work we identify sncRNAs in the Gram positive opportunistic pathogen Enterococcus faecalis. Enterococcus faecalis. We characterized 11 sncRNAs by tiling microarray analysis, 5’ and 3’ RACE-PCR, and Northern blot analysis. Six sncRNAs were specifically expressed at exponential phase, two sncRNAs were observed at stationary phase, and three were detected during both phases. This is the first experimental genome-wide identification of sncRNAs in E. faecalis and provides impetus to the understanding of gene regulation in this important human pathogen.