ABSTRACT
Introduction: Covid-19 epidemic results from an infection caused by SARS-CoV2. Evolution-based analyses on the nucleotide sequences show that SARS-CoV2 is a member of the genus Beta-coronaviruses and its genome consists of a single-stranded RNA, encoding 16 proteins. Among the structural proteins, the nucleocapsid is the most abundant protein in virus structure, highly immunogenic, with sequence conservatory. Due to a large number of mutations in the spike protein, the aim of this study was to investigate bioinformatics, expression of nucleocapsid protein and evaluate its immunogenicity as an immunogenic candidate Material(s) and Method(s): B and T cell epitopes of nucleocapsid protein were examined in the IEDB database. The PET28a-N plasmid was transferred to E. coli BL21(DE3) expression host, and IPTG induced recombinant protein expression. The protein was purified using Ni-NTA column affinity chromatography, and the Western blotting method was utilized to confirm it. Finally, mice were immunized with three routes of purified protein. Statistical analysis of the control group injection and test results was carried out by t-test from SPSS software. Result(s): The optimized gene had a Codon adaptation index (CAI) of 0/97 Percentage of codons having high-frequency distribution was improved to 85%. Expression of recombinant protein in E.coli led to the production of BoNT/B-HCC with a molecular weight of 45 kDa. The total yield of purified protein was 43 mg/L. Immunization of mice induced serum antibody response. Statistical analysis showed that the antibody titer ratio was significantly different compared to the control sample and the antibody titer was acceptable up to a dilution of 1.256000 Conclusion(s): According to the present study results, the protein can be used as an immunogenic candidate for developing vaccines against SARS-CoV2 in future research.Copyright © 2022, Semnan University of Medical Sciences. All rights reserved.
ABSTRACT
Introduction: Covid-19 epidemic results from an infection caused by SARS-CoV2. Evolution-based analyses on the nucleotide sequences show that SARS-CoV2 is a member of the genus Beta-coronaviruses and its genome consists of a single-stranded RNA, encoding 16 proteins. Among the structural proteins, the nucleocapsid is the most abundant protein in virus structure, highly immunogenic, with sequence conservatory. Due to a large number of mutations in the spike protein, the aim of this study was to investigate bioinformatics, expression of nucleocapsid protein and evaluate its immunogenicity as an immunogenic candidate Material(s) and Method(s): B and T cell epitopes of nucleocapsid protein were examined in the IEDB database. The PET28a-N plasmid was transferred to E. coli BL21(DE3) expression host, and IPTG induced recombinant protein expression. The protein was purified using Ni-NTA column affinity chromatography, and the Western blotting method was utilized to confirm it. Finally, mice were immunized with three routes of purified protein. Statistical analysis of the control group injection and test results was carried out by t-test from SPSS software. Result(s): The optimized gene had a Codon adaptation index (CAI) of 0/97 Percentage of codons having high-frequency distribution was improved to 85%. Expression of recombinant protein in E.coli led to the production of BoNT/B-HCC with a molecular weight of 45 kDa. The total yield of purified protein was 43 mg/L. Immunization of mice induced serum antibody response. Statistical analysis showed that the antibody titer ratio was significantly different compared to the control sample and the antibody titer was acceptable up to a dilution of 1.256000 Conclusion(s): According to the present study results, the protein can be used as an immunogenic candidate for developing vaccines against SARS-CoV2 in future research.Copyright © 2022, Semnan University of Medical Sciences. All rights reserved.
ABSTRACT
Background: Mantle cell lymphoma (MCL) is a B-cell tumor which often relapses. BCR inhibitors (Ibrutinib, Acalabrutinib) and antiapoptotic BCL2-family members blockers BH3-mimetics (Venetoclax, ABT-199) are effective drugs to fight MCL. However, the disease remains incurable, due to therapy resistance, even to the promising Venetoclax and Ibrutinib combination. Therefore, there is a profound need to explore novel useful therapeutic targets. CK2 is a S/T kinase overexpressed in several solid and blood tumors. We demonstrated that CK2, operating through a 'non-oncogene addiction' mechanism promotes tumor cell survival, and counteracts apoptosis, by activating pro-survival signaling cascades, such as NF-κ B, STAT3 and AKT. CK2 could regulate also BCL2 family members. The CK2 chemical inhibitor CX-4945 (Silmitasertib, Sil) is already under scrutiny in clinical trials in relapsed multiple myeloma, solid tumors and COVID-19. Aims: In this work, we tested the effect of CK2 chemical inhibition or knock down on Venetoclax (Ven)-induced cytotoxicity in MCL pre-clinical models to effectively reduce MCL cell growth and clonal expansion. Methods: CK2 expression and BCR/BCL2 related signaling components were analyzed in MCL cells and control cells by Western blotting. CK2 and BCL2 inhibition was obtained with Sil and Ven, respectively and with CK2 gene silencing through the generation of anti-CK2 shRNA IPTG-inducible MCL cell clones. Survival, apoptosis, mitochondrial membrane depolarization and proliferation were investigated by FACS analysis of AnnexinV/PI and JC-10 staining. The synergic action of Ven and Sil was analyzed by the Chou-Talalay combination index (CI) method. CK2 knock down in vivo was obtained in xenograft NOD-SCID mouse models Results: CK2 inactivation (with Sil or CK2 silencing) determined a reduction in the activating phosphorylation of S529 p65/RelA and S473 and S129 AKT, important survival cascades for MCL. Sil or CK2 silencing caused BCL2 and related MCL1 protein reduction, causing cell death. Importantly, we confirmed these results also in an in vivo xenograft mouse model of CK2 knockdown in MCL. Sil +Ven combination increased MCL cell apoptosis, as judged by the augmented frequency of Annexin V positive cells and expression of cleaved PARP protein, and JC-10 mitochondrial membrane depolarization, with respect to the single treatments. Captivatingly, Sil or CK2 gene silencing led to a substantial reduction of the Ven-induced increase of MCL-1, potentially counteracting a deleterious Ven-induced drawback. Analysis of cell cycle distribution confirmed an increased frequency of apoptotic cells in the sub G1 phase in CK2-silenced cells and a modulation of the other phases of the cell cycle. Remarkably, the calculated CI less than 1 suggested a strong synergic cell-killing effect between Sil and Ven, on all the cell lines tested, including those less sensitive or resistant to Ven Summary/Conclusion: We demonstrated that the simultaneous inhibition/knock down of CK2 and BCL2 synergistically cooperates in inducing apoptosis and cell cycle arrest of MCL malignant B-lymphocytes and has the potential of reducing MCL clonal growth, also counterbalancing mechanism of resistance that may arise with Ven. Therefore, CK2 is a rational therapeutic target for the treatment of MCL to be tested in combination with Ibrutinib or Ven.
ABSTRACT
BACKGROUND AND AIM: E. coli are widely used for recombinant protein development, due to its low cost, ease of manipulation, and availability of well established molecular tools and techniques. Due to a lack of sophisticated machinery to undertake posttranslational modifications, the E. coli bacterial culture is limited in its ability to express more complex proteins, resulting in low solubility of the protein of interest that is generated as inclusion bodies. Although we were able to produce the recombinant SARS-CoV-2-S1 protein at high expression levels in our earlier investigation, we were also able to obtain nearly the whole protein as inclusion body. To overcome this problem, different solubility strategies have been tried. In this study, we developed an E.coli expression strategy based on the expression of the S1 protein as a fusion of SUMO fusion protein. METHODS: The DNA sequence of S1 protein was cloned into the pET SUMO expression vector, resulting in a construct expressing a N-terminal tag SUMO fusion protein. To achieve the high-level expression of S1, small scale expression conditions were optimized in E. coli BL21 (DE3) containing pET SUMO-S1 with different induction temperatures, times and IPTG concentrations. Additionally, different medium was also tested for the expression of S1 protein. For each parameter, solubility and expression of cell lysates from uninduced and induced cultures, plus the soluble and insoluble fractions from induced cultures were analyzed by SDS-PAGE and Western Blot. RESULTS: SDS-PAGE and Western Blot analysis showed the presence of a ∼83 kDa recombinant fusion protein. The maximum level of expression of the recombinant protein was observed at 30 , 4 h after induction with 0,55 mM IPTG. CONCLUSIONS: This study showed that the use of SUMO fusion tag partially increases the production of S1 protein in the form of soluble fractions and optimization studies continue.