13 research outputs found
Casamino acids facilitate the secretion of recombinant dengue virus serotype-3 envelope domain III in Pichia pastoris
Background: Dengue is a viral disease spread to humans by mosquitoes. Notably, there are four serotypes of Dengue Viruses (DENV) that places ∼40% of the global population at risk of infection. However, lack of a suitable drug or a preventive vaccine exacerbates the matter further. Envelope Domain-III (EDIII) antigen of Dengue Virus (DENV) has garnered much attention as a promising vaccine candidate for dengue, in addition to its use as a diagnostic intermediate. Hence developing a method for efficient production of high quality recombinant EDIII is important for research and industrial purpose. Results: In this work, a Pichia pastoris system was optimized for the secretory over-expression of DENV serotype-3 EDIII under the control of methanol inducible AOX1 promoter. Temperature alone had a significant impact upon the amount of secretory EDIII, with 2.5-fold increase upon reducing the induction temperature from 30 to 20 °C. However surprisingly, supplementation of culture media with Casamino Acids (CA), further augmented secretory EDIII titer, with a concomitant drop of intracellular EDIII levels at both temperatures. Though, reduction in intracellular retention of EDIII was more prominent at 20°C than 30°C. This suggests that CA supplementation facilitates overexpressing P. pastoris cells to secrete more EDIII by reducing the proportion retained intracellularly. Moreover, a bell-shaped correlation was observed between CA concentration and secretory EDIII titer. The maximum EDIII expression level of 187 mg/L was achieved under shake flask conditions with induction at 20°C in the presence of 1% CA. The overall increase in EDIII titer was ∼9-fold compared to un-optimized conditions. Notably, mouse immune-sera, generated using this purified EDIII antigen, efficiently neutralized the DENV. Conclusions: The strategy described herein could enable fulfilling the mounting demand for recombinant EDIII as well as lay direction to future studies on secretory expression of recombinant proteins in P. pastoris with CA as a media supplement
Ultrasensitive and Robust Point-of-Care Immunoassay for the Detection of Plasmodium falciparum Malaria.
Plasmodium falciparum malaria is widespread in the tropical and subtropical regions of the world. There is ongoing effort to eliminate malaria from endemic regions, and sensitive point-of-care (POC) diagnostic tests are required to support this effort. However, current POC tests are not sufficiently sensitive to detect P. falciparum in asymptomatic individuals. After extensive optimization, we have developed a highly sensitive and robust POC test for the detection of P. falciparum infection. The test is based on upconverting nanophosphor-based lateral flow (UCNP-LF) immunoassay. The developed UCNP-LF test was validated using whole blood reference panels containing samples at different parasite densities covering eight strains of P. falciparum from different geographical areas. The limit of detection was compared to a WHO-prequalified rapid diagnostic test (RDT). The UCNP-LF achieved a detection limit of 0.2-2 parasites/μL, depending on the strain, which is 50- to 250-fold improvement in analytical sensitivity over the conventional RDTs. The developed UCNP-LF is highly stable even at 40 °C for at least 5 months. The extensively optimized UCNP-LF assay is as simple as the conventional malaria RDTs and requires 5 μL of whole blood as sample. Results can be read after 20 min from sample addition, with a simple photoluminescence reader. In the absence of a reader device at the testing site, the strips after running the test can be transported and read at a central location with access to a reader. We have found that the test and control line signals are stable for at least 10 months after running the test. The UCNP-LF has potential for diagnostic testing of both symptomatic and asymptomatic individuals
Ultrasensitive and Robust Point-of-Care Immunoassay for the Detection of Plasmodium falciparum Malaria
Plasmodium falciparum malaria is widespread in the tropical and
subtropical regions of the world. There is ongoing effort to eliminate
malaria from endemic regions, and sensitive point-of-care (POC)
diagnostic tests are required to support this effort. However, current
POC tests are not sufficiently sensitive to detect P. falciparum
in asymptomatic individuals. After extensive optimization, we have
developed a highly sensitive and robust POC test for the detection of P. falciparum
infection. The test is based on upconverting nanophosphor-based lateral
flow (UCNP-LF) immunoassay. The developed UCNP-LF test was validated
using whole blood reference panels containing samples at different
parasite densities covering eight strains of P. falciparum from
different geographical areas. The limit of detection was compared to a
WHO-prequalified rapid diagnostic test (RDT). The UCNP-LF achieved a
detection limit of 0.2-2 parasites/μL, depending on the strain, which is
50- to 250-fold improvement in analytical sensitivity over the
conventional RDTs. The developed UCNP-LF is highly stable even at 40 °C
for at least 5 months. The extensively optimized UCNP-LF assay is as
simple as the conventional malaria RDTs and requires 5 μL of whole blood
as sample. Results can be read after 20 min from sample addition, with a
simple photoluminescence reader. In the absence of a reader device at
the testing site, the strips after running the test can be transported
and read at a central location with access to a reader. We have found
that the test and control line signals are stable for at least 10 months
after running the test. The UCNP-LF has potential for diagnostic
testing of both symptomatic and asymptomatic individuals.
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Legal aspects of the criminal offence of poaching
The purpose of this thesis is to provide a detailed analysis of a relatively narrow issue belonging to the criminal law, namely the criminal offence of poaching. The key part of this work examines the merits of § 304 of the Act no. 40/2009, The Criminal Code, and focuses also on its systematic inclusion in the head VIII, called Crimes against the Environment, constituting a part of the special section of the aforementioned code. I attempt to gather the existing conclusions of the doctrine as well as the jurisprudence and to present them in an organized way. I also endeavour to critically assess a number of selected passages and to add my own reflections. In addition, several practical examples are briefly highlighted in order to enrich this work. This thesis will be divided into four main chapters - the Introduction, the Poaching legislation de lege lata, the Poaching legislation de lege ferenda and the Conclusion. Regarding the introduction, the reasons which led me to choose and critically analyse this socially negative phenomenon are shortly outlined. Furthermore, I explain my view of poaching as a long-lasting problem in our society. With respect to the chapter dealing with the poaching legislation de lege lata, it forms the main part of this thesis. Firstly, I aim to consistently categorize..
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Targeting macrophage Syk enhances responses to immune checkpoint blockade and radiotherapy in high-risk neuroblastoma.
BackgroundNeuroblastoma (NB) is considered an immunologically cold tumor and is usually less responsive to immune checkpoint blockade (ICB). Tumor-associated macrophages (TAMs) are highly infiltrated in NB tumors and promote immune escape and resistance to ICB. Hence therapeutic strategies targeting immunosuppressive TAMs can improve responses to ICB in NB. We recently discovered that spleen tyrosine kinase (Syk) reprograms TAMs toward an immunostimulatory phenotype and enhances T-cell responses in the lung adenocarcinoma model. Here we investigated if Syk is an immune-oncology target in NB and tested whether a novel immunotherapeutic approach utilizing Syk inhibitor together with radiation and ICB could provide a durable anti-tumor immune response in an MYCN amplified murine model of NB.MethodsMyeloid Syk KO mice and syngeneic MYCN-amplified cell lines were used to elucidate the effect of myeloid Syk on the NB tumor microenvironment (TME). In addition, the effect of Syk inhibitor, R788, on anti-tumor immunity alone or in combination with anti-PDL1 mAb and radiation was also determined in murine NB models. The underlying mechanism of action of this novel therapeutic combination was also investigated.ResultsHerein, we report that Syk is a marker of NB-associated macrophages and plays a crucial role in promoting immunosuppression in the NB TME. We found that the blockade of Syk in NB-bearing mice markedly impairs tumor growth. This effect is facilitated by macrophages that become immunogenic in the absence of Syk, skewing the suppressive TME towards immunostimulation and activating anti-tumor immune responses. Moreover, combining FDA-approved Syk inhibitor, R788 (fostamatinib) along with anti-PDL1 mAb provides a synergistic effect leading to complete tumor regression and durable anti-tumor immunity in mice bearing small tumors (50 mm3) but not larger tumors (250 mm3). However, combining radiation to R788 and anti-PDL1 mAb prolongs the survival of mice bearing large NB9464 tumors.ConclusionCollectively, our findings demonstrate the central role of macrophage Syk in NB progression and demonstrate that Syk blockade can "reeducate" TAMs towards immunostimulatory phenotype, leading to enhanced T cell responses. These findings further support the clinical evaluation of fostamatinib alone or with radiation and ICB, as a novel therapeutic intervention in neuroblastoma
An accelerometry of tremor in multiple sclerosis
Public health is largely devoted to preventive medicine. Therefore this thesis focuses on a topic that can affect the consequences caused by the tremor in the case of multiple sclerosis. The aim of the thesis is to elaborate the fundamental knowledge of the process of this tremor. The thesis is structured as follows. First it deals with the general characteristics of the tremor and the specific characteristics of the tremor in multiple sclerosis. It also discusses the possibilities of testing the tremor, where the largest part relates accelerometric examination using an accelerometer on the basis of which can provide useful information to both patients with the tremor and provide better coexistence with this symptom. Finally the thesis describes the therapeutic procedures that help to alleviate the tremor, which is an integral part of the ergotherapy. Powered by TCPDF (www.tcpdf.org
Additional file 6: Figure S6. of Casamino acids facilitate the secretion of recombinant dengue virus serotype-3 envelope domain III in Pichia pastoris
Evaluating the proteolytic susceptibility of secreted EDIII in culture supernatant. Proteolytic degradation for secreted EDIII was monitored in cell-free culture supernatants to negate the balance between EDIII secretion and degradation. Culture supernatants from P. pastoris expressing EDIII in the absence of CA, were obtained after 6 days of induction at 20° and 30 °C. Retrieved supernatants were further incubated at their respective induction temperatures and samples were collected at 0, 28 and 93 h interval from both. Samples were thereafter separated on a denaturing polyacrylamide gel and visualized by Coomassie stain. No visible degradation was observed indicating negligible proteolysis of secreted EDIII. Lane 1: Prestained protein marker; Lane 2–4: 20 °C; Lane 5–7: 30 °C; Lane 2 & 5: 0 h; Lane 3 & 6: 28 h and Lane 4 & 7: 93 h. (PPTX 567 kb