Hepatitis C virus (HCV) infection is a major worldwide problem. Chronic hepatitis C is recognized as one of the major causes of cirrhosis, hepatocellular carcinoma, and liver failure. Although new, directly acting antiviral therapies are suggested to overcome the low efficacy and adverse effects observed for the current standard of treatment, an effective vaccine would be the only way to certainly eradicate HCV infection. Recently, polyhydroxybutyrate beads produced by engineered Escherichia coli showed efficacy as a vaccine delivery system. Here, an endotoxin-free E. coli strain ( Hepatitis C virus (HCV) is an etiologic agent of chronic hepatitis C (1). Chronic HCV infection affects more than 170 million people worldwide and is responsible for approximately 350,000 deaths each year (2). Viral exposure results in acute disease in a small proportion of cases, while the majority (80%) progress to chronic infection, causing liver inflammation that slowly progresses to cirrhosis, liver failure, hepatocellular carcinoma, and death (3).Despite a substantial decline in HCV transmission due to improved prevention strategies and the introduction of new and powerful targeted therapies, hepatitis C remains a huge health problem, justifying further endeavors to develop new vaccines. Indeed, the pool of asymptomatic chronic HCV carriers who represent an infectious reservoir will remain substantial for many years. Less than 30% of patients with chronic hepatitis C are aware of the infection, and only about 10% of patients are currently treated (4, 5). Therefore, even if new antivirals could cure 90% of patients, there would still be a considerable percentage of patients who would be excluded (6). Hence, development of a vaccine to prevent infection or to at least prevent progression to chronicity represents a significant unmet medical need and is of high priority.Since 1% of infected patients show an immune response clearing the infection and the rate of spontaneous resolution is higher in the case of reinfected patients, this demonstrates that the induction of protective immunity which prevents development of chronic disease is a feasible goal for the development of a preventive vaccine against HCV (7,8).The role of HCV-specific T cell responses in the outcome of primary HCV infection has been widely studied, although a single correlate of protection has not been determined. However, it is known that this type of immune response is a determinant in the clearance of the virus. Comparative studies in humans and chimpanzees have shown that widespread and long-lasting CD8 ϩ and CD4 ϩ T cell responses against multiple HCV regions are linked to spontaneous viral clearance (9, 10).However, there is also strong evidence that rapid induction of high-titer cross-neutralizing antibodies targeting HCV envelope proteins correlates with viral clearance and protects against reinfection (11, 12). Therefore, an optimal HCV vaccine probably needs to elicit broad cross-reactive cellular immune responses together with cross-neutralizing antibo...

Inflammation and atherosclerosis are intimately associated via the production of dysfunctional high-density lipoproteins (HDL) and modification of apolipoprotein (apo) A-I. A putative interaction between CIGB-258 and apoA-I was investigated to provide mechanistic insight into the protection of HDL. The protective activity of CIGB-258 was tested in the CML-mediated glycation of apoA-I. The in vivo anti-inflammatory efficacy was compared in paralyzed hyperlipidemic zebrafish and its embryo in the presence of CML. Treatment of CML induced greater glycation extent of HDL/apoA-I and proteolytic degradation of apoA-I. In the presence of CML, however, co-treatment of CIGB-258 inhibited the glycation of apoA-I and protected the degradation of apoA-I, exerting enhanced ferric ion reduction ability. Microinjection of CML (500 ng) into zebrafish embryos resulted in acute death with the lowest survivability with severe developmental defects with interleukin (IL)-6 production. Conversely, a co-injection of CIGB-258 or Tocilizumab produced the highest survivability with a normal development speed and morphology. In hyperlipidemic zebrafish, intraperitoneal injection of CML (500 μg) caused the complete loss of swimming ability and severe acute death with only 13% survivability 3 h post-injection. A co-injection of the CIGB-258 resulted in a 2.2-fold faster recovery of swimming ability than CML alone, with higher survivability of approximately 57%. These results suggest that CIGB-258 protected hyperlipidemic zebrafish from the acute neurotoxicity of CML. Histological analysis showed that the CIGB-258 group had 37% lower infiltration of neutrophils in hepatic tissue and 70% lower fatty liver changes than those of the CML-alone group. The CIGB-258 group exhibited the smallest IL-6 expression in the liver and the lowest blood triglyceride level. CIGB-258 displayed potent anti-inflammatory activity in hyperlipidemic zebrafish by inhibiting apoA-I glycation, promoting rapid recovery from the paralysis of CML toxicity and suppression of IL-6, and lowering fatty liver changes.

Production of immunogenic hepatitis C virus (HCV) envelope proteins will assist in the future development of preventive or therapeutics applications. Only properly folded monomeric E2 protein is able to bind a putative cellular co-receptor CD81, but this interaction may modulate cell immune function. Recombinant E2 proteins, similar to the native form, but lacking undesirable immunoregulatory features, might be promising components of vaccine candidates against HCV. To obtain E2 suitable for structural as well as functional studies, a recombinant E2 variant (E2680) was produced in Pichia pastoris cells. E2680, comprising amino acids 384 to 680 of the HCV polyprotein, was secreted into the culture supernatant in the N-glycosilated form and was mainly composed of disulfide-linked multimers. Both monomeric and oligomeric forms of E2680 were recognized by conformational-sensitive MAb H53. In addition, antibodies in sera from 70% of HCVpositive patients were reactive against E2680. By immunizing E2680 in BALB/c mice, both a specific cellular immune response and anti-E2680 IgG antibody titers of 1:200,000 were induced. Our data suggest that recombinant E2680 could be useful to successfully induce strong anti-HCV immunity.

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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. Lipid droplets (LDs) have been proposed to link viral RNA synthesis and virion assembly by physically associating these viral processes. HCV assembly, envelopment, and maturation have been shown to take place at specialized detergent-resistant membranes in the ER, rich in cholesterol and sphingolipids, supporting the synthesis of luminal LDs-containing ApoE. HCV assembly involves a regulated allocation of viral and host factors to viral assembly sites. Then, virus budding takes place through encapsidation of the HCV genome and viral envelopment in the ER. Interaction of ApoE with envelope proteins supports the viral particle acquisition of lipids and maturation. HCV secretion has been suggested to entail the ion channel activity of viral p7, several components of the classical trafficking and autophagy pathways, ESCRT, and exosome-mediated export of viral RNA. Here, we review the most recent advances in virus morphogenesis and the interplay between viral and host factors required for the formation of HCV virions.

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Hyperinflammation distinguishes COVID-19 patients who develop a slight disease or none, from those progressing to severe and critical conditions. CIGB-258 is a therapeutic option for the latter group of patients. This drug is an altered peptide ligand (APL) derived from the cellular stress protein 60 (HSP60). In preclinical models, this peptide developed anti-inflammatory effects and increased regulatory T cell (Treg) activity. Results from a phase I clinical trial with rheumatoid arthritis (RA) patients indicated that CIGB-258 was safe and reduced inflammation. The aim of this study was to examine specific biomarkers associated with hyperinflammation, some cytokines linked to the cytokine storm granzyme B and perforin in a cohort of COVID-19 patients treated with this peptide. All critically ill patients were under invasive mechanical ventilation and received the intravenous administration of 1 or 2 mg of CIGB-258 every 12 h. Seriously ill patients were treated with oxygen therapy receiving 1 mg of CIGB-258 every 12 h and all patients recovered from their severe condition. Biomarker levels associated with hyperinflammation, such as interleukin (IL)-6, IL-10, tumor necrosis factor (TNF-α), granzyme B, and perforin, significantly decreased during treatment. Furthermore, we studied the ability of CIGB-258 to induce Tregs in COVID-19 patients and found that Tregs were induced in all patients studied. Altogether, these results support the therapeutic potential of CIGB-258 for diseases associated with hyperinflammation. Clinical trial registry: RPCEC00000313

Hepatitis C virus (HCV) infection is a worldwide health problem. Vaccines against this pathogen are not available and advances in this field are limited because of the high genetic variability of the virus, inaccessibility of animal models, and incomplete definition of immunological correlates of protection. In the present work, a chimeric protein, Eq1, encompassing HCV amino acid regions from structural antigens, was generated. Eq1 was expressed in GC-366 bacterial cells. After cell disruption, Eq1 was purified from the insoluble fraction by sequential steps of differential solubilization and metal chelating affinity chromatography. Eq1 was specifically recognized by anti-HCV positive human sera. Moreover, immunization of BALB/c mice with different doses of Eq1 formulated either in Alum or Freund's incomplete adjuvant elicited both humoral- and cellular-specific immune responses. Doses of 20 µg of Eq1 induced the strongest cell-mediated immune responses and only the formulation of this dose in Alum elicited a neutralizing antibody response against heterologous cell culture HCV. All these data together indicate that Eq1 is immunogenic in mice and might be an interesting component of vaccine candidates against HCV infection.