Publications by authors named "Nelson Acosta-Rivero"

The early expectations about growth factors' (GFs') discovery as an undisputed therapeutic solution for chronic wounds progressively eclipsed when they failed to accelerate acute wound closure and restore the healing trajectory of stagnant ulcers. Critical knowledge about chronic wound biology and GF pharmacology was a conundrum at that time. Diabetes undermines keratinocytes' and fibroblasts' physiology, impairing skin healing abilities.

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Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) remodels the endoplasmic reticulum (ER) to form replication organelles, leading to ER stress and unfolded protein response (UPR). However, the role of specific UPR pathways in infection remains unclear. Here, we found that SARS-CoV-2 infection causes marginal activation of signaling sensor IRE1α leading to its phosphorylation, clustering in the form of dense ER-membrane rearrangements with embedded membrane openings, and XBP1 splicing.

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There is an urgent need to understand severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-host interactions involved in virus spread and pathogenesis, which might contribute to the identification of new therapeutic targets. In this study, we investigated the presence of SARS-CoV-2 in postmortem lung, kidney, and liver samples of patients who died with coronavirus disease (COVID-19) and its relationship with host factors involved in virus spread and pathogenesis, using microscopy-based methods. The cases analyzed showed advanced stages of diffuse acute alveolar damage and fibrosis.

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We herein report, by using confocal immunofluorescence, the colocalization of the SARS-CoV-2 nucleocapsid within neurons, astrocytes, oligodendrocytes and microglia in three deceased COVID-19 cases, of between 78 and 85 years of age at death. The viral nucleocapsid was detected together with its ACE2 cell entry receptor, as well as the NLRP3 inflammasome in cerebral cortical tissues. It is noteworthy that NLRP3 was colocalized with CD68 + macrophages in the brain and lung of the deceased, suggesting the critical role of this type of inflammasome in SARS-CoV-2 lesions of the nervous system/lungs and supporting its potential role as a therapeutic target.

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Hepatitis C virus (HCV) infection has been related to self-reactivity, extrahepatic manifestations and autoimmune diseases. The main goals of this work were to study the prevalence of autoantibodies and their relationship with viral titers and biochemical markers of hepatic damage in patients infected with HCV. Autoantibodies (ANA, AMA, SMA, APC, LKM, DNAds, ANCA, ATG and RF) were determined in 73 individuals with chronic HCV infection and 44 healthy volunteers.

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Chronic infection with HCV is a leading cause of cirrhosis, hepatocellular carcinoma and liver failure. One of the least understood steps in the HCV life cycle is the morphogenesis of new viral particles. HCV infection alters the lipid metabolism and generates a variety of microenvironments in the cell cytoplasm that protect viral proteins and RNA promoting viral replication and assembly.

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HCV (hepatitis C virus) infection is among the leading causes of chronic liver disease, but currently there is no vaccine available. Data have accumulated about the importance of targeting different HCV antigens in vaccine candidate preparations. Here, a surface response study to select the optimal ratio of recombinant HCV structural antigens in a vaccine preparation, capable of generating in vivo functional cellular immune response in mice, was performed.

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In the present work, immunogenicity of recombinant in vitro assembled hepatitis C virus core particles, HCcAg.120-VLPs, either alone or in combination with different adjuvants was evaluated in BALB/c mice. HCcAg.

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HCV (hepatitis C virus) is a worldwide health problem nowadays. No preventive vaccine is available against this pathogen, and therapeutic treatments currently in use have important drawbacks, including limited efficacy. In the present work a recombinant fowlpox virus, FPCoE1, expressing a truncated HCV core-E1 polyprotein, was generated.

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Article Synopsis
  • Scientists are working on making proteins from the hepatitis C virus (HCV) to help create vaccines or treatments against the virus.
  • They produced a special version of a protein called E2 in yeast cells, which is important for studying how the virus interacts with the immune system.
  • Experiments showed that when they used this E2 protein to immunize mice, it triggered a strong immune response, which means it could help in fighting HCV in humans.
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Development of heterologous systems to produce useful HCV vaccine candidates is an important part of HCV research. In this study different HCV structural region variants were designed to express the first 120 aa, 176 aa, 339 aa, and 650 aa of HCV polyprotein, and aa 384 to 521, or aa 384-605 or aa 384-746 of HCV E2 protein fused to the leader sequence of sucrose invertase 2 allowing the secretion of recombinant E2 proteins. Low expression levels were observed for HCV core protein (HCcAg) variants expressing the first 120 aa and 176 aa (HCcAg.

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In the present study, recombinant HCV (hepatitis C virus) core proteins enhanced the immune response elicited by a co-delivered DNA vaccine encoding HCV core and envelope proteins. A mixture of the plasmid pIDKE2 and Co.173, a protein comprising the first 173 amino acids of HCV core, in particular induces a strong humoral response, including antibodies that recognized peptides representing hypervariable region I from different viral isolates.

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Little is known about the assembly pathway or structure of the hepatitis C virus (HCV). In this work a truncated HCcAg variant covering the first 120 aa (HCcAg.120) with a 32 aa N-terminal fusion peptide (6x Histag-Xpress epitope) was purified as a monomer under strong denaturing conditions.

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Understanding the mechanism of hepatitis C virus (HCV) pathogenesis is an important part of HCV research. Recent experimental evidence suggests that the HCV core protein (HCcAg) has numerous functional activities. These properties suggest that HCcAg, in concert with cellular factors, may contribute to pathogenesis during persistent HCV infection.

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Different variants of hepatitis C virus core protein (HCcAg) have proved to self-assemble in vitro into virus-like particles (VLPs). However, difficulties in obtaining purified mature HCcAg have limited these studies. In this study, a high degree of monomeric HCcAg purification was accomplished using chromatographic procedures under denaturing conditions.

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Little is known about the in vivo assembly pathway or structure of the hepatitis C virus nucleocapsid. In this work the intermediates of HCcAg multimerization in Pichia pastoris cells and the nucleic acid binding properties of structured nucleocapsid-like particles (NLPs) were studied. Extensive cross-linking was observed for HCcAg after glutaraldehyde treatment.

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The hepatitis C virus (HCV) core protein-encoding sequence (HCcAg) is the most conserved gene in HCV genome and therefore may be useful to study broadly reacting T-cell epitopes. In this study BALB/c and C57BL/6 mice were immunized with a DNA based vaccine expressing the first 176 aa of HCcAg (pIDKCo). After i.

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Mucosal vaccination is currently arousing a great deal of interest, since mucosally induced immunity is able to protect not only against microorganisms using mucosa as a door of entry, but also against those parenterally transmitted. Hepatitis C virus (HCV) is considered a worldwide health problem and a current vaccine is not available. In the present work, immunogenicity of particulate HCcAg was evaluated, administered alone and also in formulations with the main protective antigen of HBV, the surface antigen (HBsAg), both by mucosal (i.

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Little is known about the life cycle of hepatitis C virus. Determination of the subcellular localization of HCV proteins may contribute to our understanding of the in vivo functions of the viral proteins. HCV core protein regulates multiple functions in host cells and it has been detected both in the cytoplasm and in the nucleus using different expression systems.

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The relationship between HCV core protein (HCcAg) processing and the structural composition and morphogenesis of nucleocapsid-like particles (NLPs) produced in Pichia pastoris cells was studied. At early stages of heterologous expression, data suggest that HCcAg (in the P21 form) was transported soon after its synthesis in the cytoplasm into the nucleus. HCcAg assembly into nucleocapsid-like particles with 20-30 nm in diameter took place primary in the cell nucleus.

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In this study, 13 samples of liver biopsies from patients with chronic hepatitis C were studied by transmission electron microscopy (EM) and immunoelectron microscopy (IEM). The 13 biopsies showed ultrastructural cell damage typical of acute viral hepatitis. In four of the 13 liver biopsies enveloped virus-like particles (VLPs) inside cytoplasmic vesicles and in the cytoplasm of hepatocytes were observed.

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High-level expression from one particular heterologous gene in Escherichia coli generally requires the optimization of codon usage. Genes encoding for Hepatitis C virus core protein (HCcAg), human interferon alpha2 and 8 subtypes (HUIFNalpha2 and HUIFNalpha8) show a high content of AGA/AGG codons. These are encoded by the product of the dnaY gene in E.

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The expression and processing of the Hepatitis C virus core protein (HCcAg) were analyzed in the methylotrophic yeast Pichia pastoris. Two proteins with 21 (p21) and 23 kDa (p23) were detected in immunoblot with a serum from a chronic carrier patient, as the major products for HCcAg. Both proteins, p21 and p23, produced by proteolytic processing in P.

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Plasmids expressing variants of the hepatitis C virus (HCV) core, E1 and E2 proteins individually or as polyproteins were administered to BALB/c mice. All plasmids induced a detectable and specific antibody response. Antibody titres against core, E1 and E2 proteins, 19 weeks after primary immunization, ranged from 1:50 to 1:4500 depending on the inoculated plasmid and the HCV antigen evaluated.

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The in vitro self-assembly properties of the entire hepatitis C virus core protein (HCcAg) obtained from Pichia pastoris cells and the induction of specific antibody immune response were studied. HCcAg was purified as a low-molecular-weight species by electroelution under denaturing conditions for confirmation of its self-assembly properties. After renaturalization, electron microscopy showed that HCcAg assembled into spherical particles of 30 nm.

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