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33 result(s) for "Fló, Juan"
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Safety and immunogenicity of a SARS-CoV-2 Gamma variant RBD-based protein adjuvanted vaccine used as booster in healthy adults
A Gamma Variant RBD-based aluminum hydroxide adjuvanted vaccine called ARVAC CG was selected for a first in human clinical trial. Healthy male and female participants (18-55 years old) with a complete COVID-19-primary vaccine scheme were assigned to receive two intramuscular doses of either a low-dose or a high-dose of ARVAC CG. The primary endpoint was safety. The secondary objective was humoral immunogenicity. Cellular immune responses were studied as an exploratory objective. The trial was prospectively registered in PRIISA.BA (Registration Code 6564) and ANMAT and retrospectively registered in ClinicalTrials.gov (NCT05656508). Samples from participants of a surveillance strategy implemented by the Ministry of Health of the Province of Buenos Aires that were boosted with BNT162b2 were also analyzed to compare with the booster effect of ARVAC CG. ARVAC CG exhibits a satisfactory safety profile, a robust and broad booster response of neutralizing antibodies against the Ancestral strain of SARS-CoV-2 and the Gamma, Delta, Omicron BA.1 and Omicron BA.5 variants of concern and a booster effect on T cell immunity in individuals previously immunized with different COVID-19 vaccine platforms. Here the authors show in a phase 1 trial that a recombinant subunit vaccine based on the gamma variant of SARS-CoV-2 exhibits a satisfactory safety profile, and induces a broad booster response of neutralizing antibodies and a booster effect on T cell immunity in individuals previously immunized with different SARS-CoV-2 vaccine platforms.
Non-Clinical Safety Studies of IMT504, a Unique Non-CpG Oligonucleotide
IMT504 is a non-CpG 24-mer oligodeoxynucleotide (ODN) with immunomodulatory as well as tissue repair activity. IMT504 has been previously proven to be effective in animal models of vaccine potency, chronic lymphocytic leukemia, tissue regeneration, and sepsis. Here, we assessed the safety, including pharmacokinetics and toxicity studies in rats and monkeys, of IMT504 in a single- or repeated-dose administration by the subcutaneous (SC) or intravenous (IV) routes. In rats, the maximum tolerated dose was determined to be 50 mg/kg when administered SC. Adverse effects at 50 mg/kg were mild and reversible liver injury, revealed as lobular inflammation, focal necrosis, and small changes in the transaminase profile. Dose-dependent splenomegaly and lymphoid hyperplasia, most probably associated with immune stimulation, were commonly observed. Rats and monkeys were also IV injected with a single dose of 10 or 3.5 mg/kg, and no adverse effects were observed. Rats injected IV with 10 mg/kg showed a transient increase in spleen weight, together with a slight increase in the marginal zone of the white pulp and in leukocyte count 2 days post-administration. In monkeys, this dosage caused slight changes in total serum complement and leukocyte count on day 14. No adverse effects were observed at 3.5 mg/kg IV in rats or monkeys. Therefore, this dose was defined as the “no observed adverse effect level” for this route. Furthermore, repeated-dose toxicity studies were performed in these species using 3.5 or 0.35 mg/kg/day IV for 6 weeks. A transient increase in the spleen and liver weight was observed at 3.5 mg/kg/day only in female rats. No changes in clotting time and activation of the alternative complement pathway were observed. The toxicity profile of IMT504 herein reported suggests a dose range in which IMT504 can be used safely in clinical trials.
Immunogenicity and safety of monovalent and bivalent SARS-CoV-2 variant adapted RBD-based protein booster vaccines in adults previously immunized with different vaccine platforms: A phase II/III, randomized clinical trial
A randomized, placebo-controlled, crossover, double-blind, phase II/III study was conducted to evaluate the immunogenicity, safety, and tolerability of a recombinant booster vaccine (ARVAC) containing the SARS-CoV-2 spike protein receptor binding domain in three versions: ARVACGamma, ARVACOmicron, and ARVACBivalent in adults with ≤3 previous SARS-CoV-2 booster doses. Primary endpoint was seroconversion rate of neutralizing antibodies compared to placebo and to a > 75 % seroconversion rate to vaccine antigen homologous variants. All vaccine versions significantly increased seroconversion rates to SARS-CoV-2 variants compared to placebo. In participants aged 18–60 years, all versions met the primary endpoint; in those over 60 years old, ARVACOmicron and ARVACBivalent met this endpoint. No vaccine-related serious adverse events were recorded, and most adverse events were mild. Plasma levels of anti-spike-specific IgG and anti-S1-specific IgA in saliva increased in participants receiving any vaccine. The increase in plasma neutralizing antibodies induced by the vaccine was independent of the number of previous booster doses (0, 1 or 2), the primary vaccine platform (adenovirus, single-dose adenovirus, mRNA, inactivated virus, heterologous vaccination, and virus-like particle [VLP]) and the history of previous COVID-19. The neutralizing Ab response induced by the vaccine in healthy participants was similar to that triggered in participants with underlying medical conditions associated with an increased risk of severe COVID-19. ARVACBivalent induced high seroconversion rates (>90 %) against multiple variants and was superior to other ARVAC-versions. It increased neutralizing antibodies against SARS-CoV-2 variants (Ancestral, Gamma, Omicron, XBB and JN.1) and SARS-CoV-1. (NCT05752201).
PyNTTTTGT and CpG Immunostimulatory Oligonucleotides: Effect on Granulocyte/Monocyte Colony-Stimulating Factor (GM-CSF) Secretion by Human CD56+ (NK and NKT) Cells
CD56+ cells have been recognized as being involved in bridging the innate and acquired immune systems. Herein, we assessed the effect of two major classes of immunostimulatory oligonucleotides (ODNs), PyNTTTTGT and CpG, on CD56+ cells. Incubation of human peripheral blood mononuclear cells (hPBMC) with some of these ODNs led to secretion of significant amounts of interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α) and granulocyte/monocyte colony-stimulating factor (GM-CSF), but only if interleukin 2 (IL2) was present. IMT504, the prototype of the PyNTTTTGT ODN class, was the most active. GM-CSF secretion was very efficient when non-CpG ODNs with high T content and PyNTTTTGT motifs lacking CpGs were used. On the other hand, CpG ODNs and IFNα inhibited this GM-CSF secretion. Selective cell type removal from hPBMC indicated that CD56+ cells were responsible for GM-CSF secretion and that plasmacytoid dendritic cells (PDCs) regulate this process. In addition, PyNTTTTGT ODNs inhibited the IFNα secretion induced by CpG ODNs in PDCs by interference with the TLR9 signaling pathway. Since IFNα is essential for CD56+ stimulation by CpG ODNs, there is a reciprocal interference of CpG and PyNTTTTGT ODNs when acting on this cell population. This suggests that these synthetic ODNs mimic different natural alarm signals for activation of the immune system.
Addition of the Immunostimulatory Oligonucleotide IMT504 to a Seasonal Flu Vaccine Increases Hemagglutinin Antibody Titers in Young Adult and Elder Rats, and Expands the Anti-Hemagglutinin Antibody Repertoire
Flu vaccines are partially protective in infants and elder people. New adjuvants such as immunostimulatory oligonucleotides (ODNs) are strong candidates to solve this problem, because a combination with several antigens has demonstrated effectiveness. Here, we report that IMT504, the prototype of a major class of immunostimulatory ODNs, is a potent adjuvant of the influenza vaccine in young adult and elderly rats. Flu vaccines that use virosomes or whole viral particles as antigens were combined with IMT504 and injected in rats. Young adult and elderly animals vaccinated with IMT504-adjuvated preparations reached antibody titers 20-fold and 15-fold higher than controls, respectively. Antibody titers remained high throughout a 120 day-period. Animals injected with the IMT504-adjuvated vaccine showed expansion of the anti-hemagglutinin antibody repertoire and a significant increase in the antibody titer with hemagglutination inhibition capacity when confronted to viral strains included or not in the vaccine. This indicates that the addition of IMT504 in flu vaccines may contribute to the development of significant cross-protective immune response against shifted or drifted flu strains.
Development of bivalent RBD adapted COVID-19 vaccines for broad sarbecovirus immunity
COVID-19 vaccine adaptation is critical to respond to continuously emerging SARS-CoV-2 variants with enhanced immune evasion. The ARVAC protein subunit vaccine, based on the receptor binding domain of the spike protein of SARS-CoV-2, has been adapted to XBB.1.5 and JN.1 variants, as monovalent and bivalent formulations. Preclinical studies in mice showed that ARVAC XBB.1.5 and JN.1 monovalent vaccines induced strong neutralizing antibodies against XBB and JN.1 lineages, though with limited efficacy against phylogenetically distant variants. By contrast, bivalent formulations combining Gamma antigen with either XBB.1.5 or JN.1 antigens demonstrated superior cross-neutralizing activity, covering variants from Ancestral to JN.1. Additionally, Gamma-containing bivalent vaccines elicited neutralizing antibodies against SARS-CoV-1, highlighting their potential for broad-spectrum immunity. Cellular immune studies confirmed robust CD4 + T cell activation across all formulations. These findings support the continued adaptation of ARVAC to current circulant variants and propose ARVAC bivalent vaccines containing the Gamma antigen as a strategy for induction of pan-sarbecovirus immunity.
Induction of p19INK4d in response to ultraviolet light improves DNA repair and confers resistance to apoptosis in neuroblastoma cells
The genetic instability driving tumorigenesis is fuelled by DNA damage and by errors made by the DNA replication. Upon DNA damage the cell organizes an integrated response not only by the classical DNA repair mechanisms but also involving mechanisms of replication, transcription, chromatin structure dynamics, cell cycle progression, and apoptosis. In the present study, we investigated the role of p19INK4d in the response driven by neuroblastoma cells against DNA injury caused by UV irradiation. We show that p19INK4d is the only INK4 protein whose expression is induced by UV light in neuroblastoma cells. Furthermore, p19INK4d translocation from cytoplasm to nucleus is observed after UV irradiation. Ectopic expression of p19INK4d clearly reduces the UV-induced apoptosis as well as enhances the cellular ability to repair the damaged DNA. It is clearly shown that DNA repair is the main target of p19INK4d effect and that diminished apoptosis is a downstream event. Importantly, experiments performed with CDK4 mutants suggest that these p19INK4d effects would be independent of its role as a cell cycle checkpoint gene. The results presented herein uncover a new role of p19INK4d as regulator of DNA-damage-induced apoptosis and suggest that it protects cells from undergoing apoptosis by allowing a more efficient DNA repair. We propose that, in addition to its role as cell cycle inhibitor, p19INK4d is involved in maintenance of DNA integrity and, therefore, would contribute to cancer prevention.
Ganglioside GM1-binding peptides as adjuvants of antigens inoculated by the intranasal route
Forty-five GM1-binding peptides were identified using phage-displayed peptides libraries of random peptides. Most have a motif containing a hydrophobic amino acid followed by a serine (S). Based on a GM1-binding assays, two of these GM1-binding peptides (named 15 and 40) were chosen to investigate its immunostimulatory properties when chemically coupled to antigens. Mice intra-nasally (i.n.) vaccinated with some of these complexes developed a better local and systemic antibody response than mice i.n. vaccinated with the respective uncoupled antigens. The efficiency of the complex GM 1-binding peptide-antigen strongly depends on the composition and structure of both of the components of the complex.
Co-immunization with plasmids coding the full length and a soluble form of glycoprotein D of HSV-2 induces protective cellular and humoral immune response in mice
At present, the significance of antibody for protection of the female genital tract against infection with HSV-2 remains controversial. In the present study, the ability of a DNA vaccine encoding different forms of glycoprotein D (gD) of herpes simplex virus-2 (HSV-2) to induce simultaneously cellular and humoral responses was evaluated. Mice immunized with a plasmid encoding full length gD (pgD) developed a strong cellular immune response but weak antibody titers in serum and vaginal washings. On the other hand, mice immunized with a plasmid encoding soluble form of gD (pΔgD) showed high titers of antibodies but a very weak cell-mediated immune response. When mice were immunized simultaneously with both plasmids, cellular and humoral immune responses were elicited. This mice showed neutralizing antibodies in serum and vaginal washings as well as a high number of IFN-γ secreting cells in spleen. When challenged with 50 lethal doses of virus, mice immunized with pgD along with pΔgD showed a more complete protection than mice immunized with pgD alone. Collectively these results suggest that neutralizing antibodies help cell-mediated immune response for the protection against HSV-2 infection.
Jorge Luis Borges traductor de Die Verwandlung
Este trabajo se propone analizar la discutible autenticidad de la traducción de La metamorfosis de Kafka, publicada en 1933 por la Revista de Occidente (Madrid), sin nombre de autor, y publicada nuevamente en Buenos Aires en 1938 por la editorial Losada atribuyendo esta traducción a Jorge Luis Borges (y muchísimas veces reeditada, hasta el presente, con la misma atribución). Puesto que no disponemos de ningún documento absolutamente probatorio que sustente una conclusión definitiva, y cómo es posible incluir entre esos documentos insuficientes las declaraciones de Borges, se intenta interrogar aquí a los más diversos indicios -entre otros el concepto de traducción sustentado por Borges- y leerlos desde una perspectiva que no olvide los juegos borgianos.