El sistema inmune bacteriano (CRISPR), una herramienta universal en la edición de genomas.

Desde hace muchos años se llevan estudiando técnicas de edición genómica que hagan posible llevar a cabo un estudio exhaustivo del genoma celular. Sin embargo, ha sido el descubrimiento del sistema CRISPR/Cas el que ha supuesto un gran avance en el mundo de la edición genómica. Originalmente, constituye el sistema inmunitario adaptativo de los organismos procariotas mediado por un grupo de repeticiones palindrómicas cortas agrupadas e interespacidas (CRISPR). Está técnica permite manipular el genoma celular de formas nunca vistas hasta el momento empleando nucleasas guiadas por RNA, como es el caso de la nucleasa Cas9; de una forma sencilla, rápida y específica pudiendo actuar sobre genes endógenos concretos de múltiples organismos diferentes que hasta el momento habían sido imposibles de manipular genéticamente. Aunque todavía quedan por definir todas sus características, el sistema CRISPR posee una amplia gama de aplicaciones, como pueden ser el diagnóstico y tratamiento de enfermedades genéticas e infecciosas, el control de plagas o en el rastreo y el control de la expresión génica empleando variantes de Cas9

Síntesis de análogos de nucleosidodifosfatohexosas con actividad antiviral potencial

Se describe la preparacion de una seria de analogos de uridinadifosfatoglucosa para su posterior evaluacion como agentes antivirales. En estos analogos el puente difosfato de cinco atomos se ha sustituido por otros puentes de tres o seis atomos que poseen, ademas, diferente estructura quimica. Para la obtencion de estos analogos de uridinadifosfatoglucosa fue necesaria la preparacion de una serie de intermedios sinteticos, derivados de glucosa y de uridina, que a su vez han exigido la creacion de nuevos metodos sinteticos y el mejoramiento de otros conocidos

Síntesis de análogos de nucleosidodifosfatohexosas con actividad antiviral potencial

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Químicas, Departamento de Química Orgánica I, leída el 11-07-1986.Se describe la preparacion de una seria de analogos de uridinadifosfatoglucosa para su posterior evaluacion como agentes antivirales. En estos analogos el puente difosfato de cinco atomos se ha sustituido por otros puentes de tres o seis atomos que poseen, ademas, diferente estructura quimica. Para la obtencion de estos analogos de uridinadifosfatoglucosa fue necesaria la preparacion de una serie de intermedios sinteticos, derivados de glucosa y de uridina, que a su vez han exigido la creacion de nuevos metodos sinteticos y el mejoramiento de otros conocidos.Depto. de Química OrgánicaFac. de Ciencias QuímicasTRUEProQuestpu

Dimerization inhibitors of HIV-1 reverse transcriptase, protease and integrase: A single mode of inhibition for the three HIV enzymes?

The genome of human immunodeficiency virus type 1 (HIV-1) encodes 15 distinct proteins, three of which provide essential enzymatic functions: a reverse transcriptase (RT), an integrase (IN), and a protease (PR). Since these enzymes are all homodimers, pseudohomodimers or multimers, disruption of protein-protein interactions in these retroviral enzymes may constitute an alternative way to achieve HIV-1 inhibition. A growing number. of dimerization inhibitors for these enzymes is being reported. This mini review summarizes some approaches that have been followed for the development of compounds that inhibit those three enzymes by interfering with the dimerization interfaces between the enzyme subunits. (c) 2006 Elsevier B.V. All rights reserved

TSAO compounds: The comprehensive story of a unique family of HIV-1 specific inhibitors of reverse transcriptase

Emergence of drug-resistant viral strains is one of the major milestones and the main cause for the failure of antiretroviral therapy. Combination of different anti-HIV agents has E become the standard clinical practice to keep the viral load at low or even undetectable levels and to prevent emergence of virus-drug resistance. Among the human immunodeficiency virus (HIV) reverse transcriptase (RT) inhibitors, the so called nonnucleoside RT inhibitors (NNRTIs) have gained a definitive place in the treatment of HIV infections in combination with nucleoside analogue RT inhibitors (NRTIs) and HIV protease inhibitors (PIs). The virus can be markedly suppressed for a relatively long period of time when exposed to multiple drug combination therapy (highly active antiretroviral therapy, HAART). TSAO derivatives are a peculiar group of highly functionalized nucleosides that belong to the so-called nonnucleoside RT inhibitors (NNRTIs). They exert their unique selectivity for HIV-1 through a specific interaction with the p51 subunit of HIV-1 RT. They are the first small molecules that seem to interfere with the dimerization process of the enzyme. This review covers the work carried out with this unique class of specific inhibitors of HIV-1 reverse transcriptase, including structure activity relationship studies (SAR), its mechanism of action, resistance studies, model of interaction with the enzyme, etc

Optimization of a class of tryptophan dendrimers that inhibit HIV replication leads to a selective, specific, and low-nanomolar inhibitor of clinical isolates of enterovirus A71

Tryptophan dendrimers that inhibit HIV replication by binding to the HIV envelope glycoproteins gp120 and gp41 have unexpectedly also proven to be potent, specific, and selective inhibitors of the replication of the unrelated enterovirus A71. Dendrimer 12, a consensus compound that was synthesized on the basis of the structure-activity relationship analysis of this series, is 3-fold more potent against the BrCr lab strain and, surprisingly, inhibits a large panel of clinical isolates in the low-nanomolar/high-picomolar range.This work has been supported by the Spanish MINECO (Project SAF2012-39760-C02-01, cofinanced by the FEDER program; Plan Nacional de Cooperación Público-Privada; and Subprograma INNPACTO IPT-2012-0213-060000, cofinanced by the FEDER program) and the Comunidad de Madrid (BIPEDD2-CM-S2010/BMD-2457). This work was also funded by EU FP7 (FP7/2007-2013) Project EUVIRNA under Grant408 Agreement 264286 by EU FP7 SILVER (Contract HEALTH-F3-2010- 260644), a grant from the Belgian Interuniversity Attraction Poles (IAP) Phase VII–P7/45 (BELVIR), and the EU FP7 Industry-Academia Partnerships and Pathways Project AIROPICO. The Spanish MEC/MINECO is also acknowledged for a grant to E.R.-B. L.S. was funded by China Scholarship Council (CSC) Grant 201403250056. We also acknowledge Charlotte Vanderheydt for help with the processing of the antiviral data.Peer Reviewe

Tryptophan dendrimers that inhibit HIV replication, prevent virus entry and bind to the HIV envelope glycoproteins gp120 and gp41

Dendrimers containing from 9 to 18 tryptophan residues at the peryphery have been efficiently synthesized and tested against HIV replication. These compounds inhibit an early step of the replicative cycle of HIV, presumably virus entry into its target cell. Our data suggest that HIV inhibition can be achieved by the preferred interaction of the compounds herein described with glycoproteins gp120 and gp41 of the HIV envelope preventing interaction between HIV and the (co)receptors present on the host cells. The results obtained so far indicate that 9 tryptophan residues on the periphery are sufficient for efficient gp120/gp41 binding and anti-HIV activity.This work has been supported by the Spanish MINECO (project SAF2012-39760-C02, co-financed by the FEDER programme); Plan Nacional de Cooperacion Público-Privada, subprograma INNPACTO (project IPT-2012-0213-060000, co-financed by the FEDER programme), the Comunidad de Madrid (BIPEDD2-CM-S2010/BMDE2457) and by “The Centers of Excellence” of the K.U.Leuven (EF-05/ 15 and PF-10/18). The Spanish MICINN/MINECO are also acknowledged for a grant to E. Rivero-BucetaPeer Reviewe

Peptidoglycan editing in non-proliferating intracellular Salmonella as source of interference with immune signaling

This work was funded by grants PID2020-112971GB-I00/10.13039/501100011033 (F.G-dP.) and PID2019-104070RB-C21 (S.V.) of the Spanish Ministry of Science and Innovation, VR2018-02823 of the Swedish Research Council (F.C.), KAW2012.0184 of the Knut and Alice Wallenberg Foundation (F.C.), and SMK2062 of the Kempe Foundation (F.C.

Anti-HIV-1 activity of a tripodal receptor that recognizes mannose oligomers

The glycoprotein gp120 of the HIV-1 viral envelope has a high content in mannose residues, particularly ¿-1,2-mannose oligomers. Compounds that interact with these high-mannose type glycans may disturb the interaction between gp120 and its (co)receptors and are considered potential anti-HIV agents. Previously, we demonstrated that a tripodal receptor (1), with a central scaffold of 1,3,5-triethylbenzene substituted with three 2,3,4-trihydroxybenzoyl groups, selectively recognizes ¿-1,2-mannose polysaccharides. Here we present additional studies to determine the anti-HIV-1 activity and the mechanism of antiviral activity of this compound. Our studies indicate that 1 shows anti-HIV-1 activity in the low micromolar range and has pronounced gp120 binding and HIV-1 integrase inhibitory capacity. However, gp120 binding rather than integrase inhibition seems to be the primary mechanism of antiviral activity of 1.The Spanish MICINN/MINECO (Project: SAF 201239760-C02-01, co-financed by the FEDER programme); Plan Nacional de Cooperación Público-Privada. Subprograma INNPACTO (IPT-2012-0213-060000, co-financed by the FEDER programme) and the Comunidad de Madrid (BIPEDD2-CM-S2010/BMD-2457) are acknowledged for fi nancial support. The Spanish ICINN/MINECCO is also acknowledged for a grant to E. Rivero-Buceta. We thank Leentje Persoons, Frieda De Meyer, Leen Ingels, Stijn Delmotte, Katrien Geerts, and Inge Vliegen for excellent technical assistance. Financial support of KU Leuven (GOA 10/14; PF 10/18) and the FWO (G-0528.12N) was provided for the antiviral experiments. The integrase studies were supported by the Center for Cancer Research, the Intramural Program of the National Cancer Institute,NIH (Z01-BC 007333).Peer Reviewe

Peptidoglycan editing in non-proliferating intracellular Salmonella as source of interference with immune signaling

Salmonella enterica causes intracellular infections that can be limited to the intestine or spread to deeper tissues. In most cases, intracellular bacteria show moderate growth. How these bacteria face host defenses that recognize peptidoglycan, is poorly understood. Here, we report a high-resolution structural analysis of the minute amounts of peptidoglycan puri- fied from S. enterica serovar Typhimurium (S. Typhimurium) infecting fibroblasts, a cell type in which this pathogen undergoes moderate growth and persists for days intracellularly. The peptidoglycan of these non-proliferating bacteria contains atypical crosslinked muropep- tides with stem peptides trimmed at the L-alanine-D-glutamic acid-(γ) or D-glutamic acid-(γ)- meso-diaminopimelic acid motifs, both sensed by intracellular immune receptors. This pepti- doglycan has a reduced glycan chain average length and ~30% increase in the L,D-cross- link, a type of bridge shared by all the atypical crosslinked muropeptides identified. The L,D- transpeptidases LdtD (YcbB) and LdtE (YnhG) are responsible for the formation of these L, D-bridges in the peptidoglycan of intracellular bacteria. We also identified in a fraction of muropeptides an unprecedented modification in the peptidoglycan of intracellular S. Typhi- murium consisting of the amino alcohol alaninol replacing the terminal (fourth) D-alanine. Alaninol was still detectable in the peptidoglycan of a double mutant lacking LdtD and LdtE, thereby ruling out the contribution of these enzymes to this chemical modification. Remark- ably, all multiple mutants tested lacking candidate enzymes that either trim stem peptides or form the L,D-bridges retain the capacity to modify the terminal D-alanine to alaninol and all attenuate NF-κB nuclear translocation. These data inferred a potential role of alaninol-con- taining muropeptides in attenuating pro-inflammatory signaling, which was confirmed with a synthetic tetrapeptide bearing such amino alcohol. We suggest that the modification of D- alanine to alaninol in the peptidoglycan of non-proliferating intracellular S. Typhimurium is an editing process exploited by this pathogen to evade immune recognition inside host cells.This work was funded by grants PID2020-112971GB-I00/10.13039/501100011033 (F.G-dP.) and PID2019-104070RB-C21 (S.V.) of the Spanish Ministry of Science and Innovation, VR2018-02823 of the Swedish Research Council (F.C.), KAW2012.0184 of the Knut and Alice Wallenberg Foundation (F.C.), and SMK2062 of the Kempe Foundation (F.C.). S.C. was recipient of an EMBO Short-Term Fellowship number 6426 for a stay in the lab of F.C. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscriptPeer reviewe