Fundación Instituto Leloir

About: Fundación Instituto Leloir is a facility organization based out in Buenos Aires, Argentina. It is known for research contribution in the topics: Dentate gyrus & Neurogenesis. The organization has 702 authors who have published 1052 publications receiving 39299 citations.

I-COMS: Interprotein-COrrelated Mutations Server

Abstract: Interprotein contact prediction using multiple sequence alignments (MSAs) is a useful approach to help detect protein–protein interfaces. Different computational methods have been developed in recent years as an approximation to solve this problem. However, as there are discrepancies in the results provided by them, there is still no consensus on which is the best performing methodology. To address this problem, I-COMS (interprotein COrrelated Mutations Server) is presented. I-COMS allows to estimate covariation between residues of different proteins by four different covariation methods. It provides a graphical and interactive output that helps compare results obtained using different methods. I-COMS automatically builds the required MSA for the calculation and produces a rich visualization of either intraprotein and/or interprotein covariating positions in a circos representation. Furthermore, comparison between any two methods is available as well as the overlap between any or all four methodologies. In addition, as a complementary source of information, a matrix visualization of the corresponding scores is made available and the density plot distribution of the inter, intra and inter+intra scores are calculated. Finally, all the results can be downloaded (including MSAs, scores and graphics) for comparison and visualization and/or for further analysis.

Maintaining Epigenetic Inheritance During DNA Replication in Plants.

Abstract: Biotic and abiotic stresses alter the pattern of gene expression in plants. Depending on the frequency and duration of stress events, the effects on the transcriptional state of genes are “remembered” temporally or transmitted to daughter cells and, in some instances, even to offspring (transgenerational epigenetic inheritance). This “memory” effect, which can be found even in the absence of the original stress, has an epigenetic basis, through molecular mechanisms that take place at the chromatin and DNA level but do not imply changes in the DNA sequence. Many epigenetic mechanisms have been described and involve covalent modifications on the DNA and histones, such as DNA methylation, histone acetylation and methylation, and RNAi dependent silencing mechanisms. Some of these chromatin modifications need to be stable through cell division in order to be truly epigenetic. During DNA replication, histones are recycled during the formation of the new nucleosomes and this process is tightly regulated. Perturbations to the DNA replication process and/or the recycling of histones lead to epigenetic changes. In this mini-review, we discuss recent evidence aimed at linking DNA replication process to epigenetic inheritance in plants.

Protection of Mice against Shiga Toxin 2 (Stx2)-Associated Damage by Maternal Immunization with a Brucella Lumazine Synthase-Stx2 B Subunit Chimera

Abstract: Hemolytic-uremic syndrome (HUS) is defined as the triad of anemia, thrombocytopenia, and acute kidney injury. Enterohemorrhagic Shiga toxin (Stx)-producing Escherichia coli (EHEC), which causes a prodromal hemorrhagic enteritis, remains the most common etiology of the typical or epidemic form of HUS. Because no licensed vaccine or effective therapy is presently available for human use, we recently developed a novel immunogen based on the B subunit of Shiga toxin 2 (Stx2B) and the enzyme lumazine synthase from Brucella spp. (BLS) (BLS-Stx2B). The aim of this study was to analyze maternal immunization with BLS-Stx2B as a possible approach for transferring anti-Stx2 protection to the offspring. BALB/c female mice were immunized with BLS-Stx2B before mating. Both dams and pups presented comparable titers of anti-Stx2B antibodies in sera and fecal extracts. Moreover, pups were totally protected against a lethal dose of systemic Stx2 injection up to 2 to 3 months postpartum. In addition, pups were resistant to an oral challenge with an Stx2-producing EHEC strain at weaning and did not develop any symptomatology associated with Stx2 toxicity. Fostering experiments demonstrated that anti-Stx2B neutralizing IgG antibodies were transmitted through breast-feeding. Pups that survived the EHEC infection due to maternally transferred immunity prolonged an active and specific immune response that protected them against a subsequent challenge with intravenous Stx2. Our study shows that maternal immunization with BLS-Stx2B was very effective at promoting the transfer of specific antibodies, and suggests that preexposure of adult females to this immunogen could protect their offspring during the early phase of life.