RESUMEN
The vast majority of SARS-CoV-2 vaccines which are licensed or under development focus on the spike (S) protein and its receptor binding domain (RBD). However, the S protein shows considerable sequence variations among variants of concern. The aim of this study was to develop and characterize a SARS-CoV-2 vaccine targeting the highly conserved nucleocapsid (N) protein. Recombinant N protein was expressed in Escherichia coli, purified to homogeneity by chromatography and characterized by SDS-PAGE, immunoblotting, mass spectrometry, dynamic light scattering and differential scanning calorimetry. The vaccine, formulated as a squalane-based emulsion, was used to immunize Balb/c mice and NOD SCID gamma (NSG) mice engrafted with human PBMCs, rabbits and marmoset monkeys. Safety and immunogenicity of the vaccine was assessed via ELISA, cytokine titer assays and CFSE dilution assays. The protective effect of the vaccine was studied in SARS-CoV-2-infected Syrian hamsters. Immunization induced sustainable N-specific IgG responses and an N-specific mixed Th1/Th2 cytokine response. In marmoset monkeys, an N-specific CD4+/CD8+ T cell response was observed. Vaccinated Syrian hamsters showed reduced lung histopathology, lower virus proliferation, lower lung weight relative to the body, and faster body weight recovery. Convacell® thus is shown to be effective and may augment the existing armamentarium of vaccines against COVID-19.
RESUMEN
Organophosphates' toxic effect causes covalent binding to serine-198 in the active site of human plasma butyrylcholinesterase (BChE) with loss of enzymatic function (covalent inhibition). Mass spectrometric detection of modified FGESAGAAS peptide at the active site is a powerful exposure biomarker tool. The aim of this study was to develop mass spectrometry-based method for BChE adduct formation screening, avoiding the use of standard peptides. Immunomagnetic separation of proteins from plasma was optimized. Commercially available anti-butyrylcholinesterase monoclonal antibodies, immobilized on magnetic beads, resulted in stable and reusable affinity sorbent. The method was tested on horse serum BChE and real human plasma from healthy donors, treated with Russian VX (VR). The BChE isolated from blood plasma was digested with pepsin and analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS). The method was evaluated by using synthetic peptides and by comparison to the enzymatic activity Ellman's assay. The minimum concentration of VR exposure, resulting in detectable VR-adduct, was 0.2â¯ng/mL, which corresponded to the relative BChE inhibition of less than 2%. Adduct formation assessment was performed via monitoring of decrease in non-modified peptide LC-MS/MS signal and increase in VR-modified peptide signal. The designed approach was tested in a pilot study with 5 blood samples from healthy volunteers. Mass spectrometry-based method for BChE adduct formation was found to be in agreement with Ellman's inhibition assay, so the method is applicable for direct BChE inhibition assessment.
Asunto(s)
Butirilcolinesterasa/sangre , Organofosfatos/química , Proteoma/análisis , Animales , Butirilcolinesterasa/aislamiento & purificación , Butirilcolinesterasa/metabolismo , Cromatografía Liquida , Voluntarios Sanos , Caballos , Humanos , Organofosfatos/metabolismo , Espectrometría de Masas en TándemRESUMEN
New derivatives of phaeosphaeride A (PPA) were synthesized and characterized. Anti-tumor studies were carried out on the U937, HCT-116, PC3, MCF-7, A549, Ð562, NCI-H929, Jurkat, THP-1, RPMI8228 tumor cell lines, and on the HEF cell line. All the compounds synthesized were found to have better efficacy than PPA towards the tumor cell lines mentioned. Compound 6 (IC50â¯=â¯0.59⯱â¯0.27⯵M) was observed to be 11 times more active than PPA (IC50â¯=â¯6.5⯱â¯0.30⯵M) towards the NCI-H929 cell line, with a therapeutic index of 18. Compound 6 was determined to be over half and 16 times more active than etoposide towards the NCI-H929 (IC50â¯=â¯0.9⯱â¯0.05⯵M) and A549 (IC50â¯=â¯100⯱â¯7.0⯵M) cell lines, respectively.
Asunto(s)
Antineoplásicos/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Compuestos Bicíclicos Heterocíclicos con Puentes/síntesis química , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Línea Celular , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Estructura Molecular , Relación Estructura-ActividadRESUMEN
New derivatives of phaeosphaeride A (PPA) were synthesized and characterized. Anti-tumor activity studies were carried out on the HCT-116, PC3, MCF-7, A549, Ð562, NCI-Ð929, Jurkat, THP-1, RPMI8228 tumor cell lines, and on the HEF cell line. All of the compounds synthesized were found to have better efficacy than PPA towards the tumor cell lines mentioned. Compound 6 was potent against six cancer cell lines, HCT-116, PC-3, K562, NCI-H929, Jurkat, and RPMI8226, showing a 47, 13.5, 16, 4, 1.5, and 7-fold increase in anticancer activity comparative to those of etoposide, respectively. Compound 1 possessed selectivity toward the NCI-H929 cell line (IC50 = 1.35 ± 0.69 µM), while product 7 was selective against three cancer cell lines, HCT-116, MCF-7, and NCI-H929, each having IC50 values of 1.65 µM, 1.80 µM and 2.00 µM, respectively.