scholarly journals Production and control of a Brazilian tailor-made meningococcal B vaccine Short title: Brazilian meningococcal B vaccine production

2021 ◽  
Author(s):  
Ellen Jessouroun ◽  
Ana Paula Santos ◽  
Elza Scott Figueira ◽  
Marilza Batista Correia ◽  
Maria de Lourdes Moura Leal
Keyword(s):  
Total Protein ◽  
Public Health Problem ◽  
Membrane Vesicles ◽  
Pilot Scale ◽  
Good Manufacturing Practice ◽  
Outer Membrane Vesicles ◽  
Total Protein Content ◽  
Class 1 ◽  
Main Class ◽  
And Control

Meningococcal disease has been a public health problem in Brazil since the serogroups A and C epidemics occurred in the 1970s. The Oswaldo Cruz Foundation in Brazil has been working to develop a serogroup B meningococcal vaccine composed of detergent-treated outer membrane vesicles (OMV) and detoxified endotoxin (dLOS) from Neisseria meningitidis serogroup B prevalent strains. Experimental vaccine were produced in a pilot-scale under Good Manufacturing Practice condition (GMP). Physicochemical and biological controls were established based on what has been reported previously for OMV vaccines. The developed  vaccine contained the main class 1, 2, 3, and 5 proteins, some minor iron-regulated proteins, and 5–10% residual lipopolysaccharide related to total protein content. The dLOS was added, as a vaccine component, in half of the total protein amount. The pyrogenicity of the final products, based on the residual LOS in OMVs, varied from 1.01 to 2.24 ng LOS/kg rabbit. Three experimental vaccines, were highly immunogenic in mice with better performance using higher antigen concentrations.

scholarly journals New strategy to select cross-reactivity Meningococci strains: immunization with Outer membrane vesicles of serogroup C and cationic lipid as adjuvant

2021 ◽  
Author(s):  
Amanda Izeli Portilho ◽  
Gabriela Trzewikowski de Lima ◽  
Elizabeth De Gaspari
Keyword(s):  
Outer Membrane ◽  
Public Health Problem ◽  
Cationic Lipid ◽  
Humoral Response ◽  
Membrane Vesicles ◽  
Cross Reactivity ◽  
Outer Membrane Vesicles ◽  
High Avidity ◽  
Avidity Index ◽  
High Avidity Index

Background: Invasive meningococcal disease (IMD), caused by Neisseria meningitidis, is a public health problem, associated with high levels of morbidity and mortality, capable of causing outbreaks or epidemics, but preventable through vaccination. In Brazil, the main serogroups isolated are C and B. The last epidemic occurred in the 80s, in Sao Paulo, because of a B:4:P1.15 strain. Methods: Adult Swiss mice were immunized with outer membrane vesicles (OMV) of N. meningitidis strain C:4:P1.15, adjuvanted by the cationic lipid dioctadecyldimethylammonium bromide in bilayer fragments (DDA-BF), administered via prime-booster (intranasal/subcutaneous) scheme. The humoral response was accessed by Immunoblotting and ELISA, using homologous immunization strain and a different serogroup but equal serosubtype strain, N. meningitidis B:4:P1.15. Results: Immunoblotting revealed the recognition of antigens associated with the molecular weight of Porin A and Opacity proteins, which are immunogenic but highly heterogeneous, and Tbp and NspA, which are more homogeneous between meningococci strains. ELISA results showed antibody production that persisted after 190 days and recognized the C:4:P1.15 and the B:4:P1.15 strains, with high avidity index. The adjuvanted group recognized antigens following the IN prime and had a higher avidity index against the heterologous strain. Conclusions: DDA-BF improved the humoral response, but the OMV alone induced high avidity index antibodies as well. Even though these are preliminary results, we see it as a promising approach for affordable meningococcal immunization in developing countries, at outbreak or epidemic situations.

Drought stress and osmo-priming effects on physiological and biochemical characteristics of Ocimum basilicum

2016 ◽  
Vol 6 (1) ◽  
pp. 905-913
Author(s):  
Bahram Majd Nassiry ◽  
Neda Mohammadi
Keyword(s):  
Drought Stress ◽  
Total Protein ◽  
Catalase Activity ◽  
Seedling Emergence ◽  
Seed Priming ◽  
Ocimum Basilicum ◽  
Field Development ◽  
Physiological And Biochemical Characteristics ◽  
Germination Characteristics ◽  
And Control

    One of the effects of reducing water content on soil is reduction of growth and development of seedlings and variation of field development. Seed priming technique has been known as a challenge to improve germination and seedling emergence under different environmental stresses. The objectives of this research were to evaluate the effects of osmo-priming on germination characteristics and changes of proline, protein and catalase activity of Ocimum basilicum seeds. Results showed that drought stress reduced the germination characteristics and drought stress in -8 bar was the critical stress.  Priming treatments were include KNO3, PEG and NaCl by 0, -4 and -8 bar concentrations. The seeds were primed with those materials for 8 and 16 hours. The highest germination characteristics were obtained from nitrate potassium in -8 bar for 16 hours priming. Therefore the best seed treatment under drought stress during germination was obtained from the osmo-primed with -8 bar nitrate potassium for 16 hours. The drought stress increased proline and catalase activity but reduced total protein. Priming treatment increases proline, total protein and catalase activity under drought and control conditions. It is concluded that priming results in improvement in germination components of Ocimum basilicum in drought stress conditions and increases the resistance to drought stress with improvement of proline, protein and catalase activity in germination phase.

Electrophysiological Characterization of Transport Across Outer Membrane Channels from Gram-Negative Bacteria in Their Native Environment

2019 ◽  
Author(s):  
Jiajun Wang ◽  
Rémi Terrasse ◽  
Jayesh Arun Bafna ◽  
Lorraine Benier ◽  
Mathias Winterhalter
Keyword(s):  
Outer Membrane ◽  
Lipid Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Multi Drug Resistance ◽  
Gram Negative Bacteria ◽  
Membrane Channels ◽  
Gram Negative ◽  
Electrophysiological Characterization

Multi-drug resistance in Gram-negative bacteria is often associated with low permeability of the outer membrane. To investigate the role of membrane channels in the uptake of antibiotics, we extract, purify and reconstitute them into artificial planar membranes. To avoid this time-consuming procedure, here we show a robust approach using fusion of native outer membrane vesicles (OMV) into planar lipid bilayer which moreover allows also to some extend the characterization of membrane protein channels in their native environment. Two major membrane channels from <i>Escherichia coli</i>, OmpF and OmpC, were overexpressed from the host and the corresponding OMVs were collected. Each OMV fusion revealed surprisingly single or only few channel activities. The asymmetry of the OMV´s translates after fusion into the lipid membrane with the LPS dominantly present at the side of OMV addition. Compared to conventional reconstitution methods, the channels fused from OMVs containing LPS have similar conductance but a much broader distribution. The addition of Enrofloxacin on the LPS side yields somewhat higher association (<i>k<sub>on</sub></i>) and lower dissociation (<i>k<sub>off</sub></i>) rates compared to LPS-free reconstitution. We conclude that using outer membrane vesicles is a fast and easy approach for functional and structural studies of membrane channels in the native membrane.

Outer Membrane Vesicles Facilitate Trafficking of the Hydrophobic Signalling Molecule CAI-1 Between Vibrio harveyi Cells

2018 ◽  
Author(s):  
Sophie Brameyer ◽  
Laure Plener ◽  
Axel MMller ◽  
Andreas Klingl ◽  
Gerhard Wanner ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Vibrio Harveyi ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Signalling Molecule ◽  
I Cells
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