Filter Unit Harvesting Poxviruses Reducing DNA Contaminants
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing and purifying poxviruses, such as Vaccinia and Modified Vaccinia Virus Ankara (MVA), face challenges in achieving low levels of host cell contaminants, particularly DNA, which are stringent under new regulatory requirements, especially when transitioning from primary to continuous cell lines, and existing processes for harvesting and disrupting host cells in suspension cultures are not optimal for aseptic processing and yield.
Innovation Solution
A method involving culturing host cells expressing poxviruses in suspension, collecting them on a filter unit, disrupting the cells in situ, and eluting the virus to separate it from the cell culture medium, allowing for a closed, aseptic process that maximizes yield and minimizes impurities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If host cells are lysed in suspension culture followed by filtration steps, then virus recovery is achieved, but host cell contaminants particularly DNA remain at high levels
Solution Approach 1:
The patent applies preliminary action by performing cell collection and lysis in a specific sequence before contamination occurs. Host cells are first collected onto a filter unit, then lysed in situ, ensuring that DNA and other contaminants are contained and removed during the subsequent washing steps before they can contaminate the virus preparation
Solution Approach 2:
The process is segmented into distinct functional zones: the filter unit separates cell collection from virus elution, allowing independent optimization of each step. The filter acts as a physical barrier that segments the contaminant-containing cell debris from the virus preparation, enabling thorough washing of the cell layer without affecting the eluted virus
2Productivity
If traditional open processing methods are used for cell harvesting and disruption, then cell lysis is efficient, but aseptic processing requirements are not met
Solution Approach 1:
The filter unit serves as an intermediary device that enables closed-system processing. Cells are lysed while contained on the filter within a closed apparatus, acting as a mediator between the need for efficient lysis and the requirement for aseptic conditions. The filter allows lysis reagents to contact cells effectively while maintaining containment
Solution Approach 2:
The invention extracts the cell lysis step from open conventional methods and relocates it to a closed system environment. By taking out the lysis process and performing it within a closed apparatus on the filter unit, the method maintains lysis efficiency while eliminating exposure to contaminants, thus satisfying GMP requirements
3Manufacturing precision
If multiple filtration and purification steps are applied, then virus purity increases, but processing complexity and cost increase
Solution Approach 1:
The method merges multiple functions into the filter unit: cell collection, cell lysis containment, contaminant removal via washing, and virus elution all occur in sequence on the same filter. This consolidation reduces the number of separate devices and steps needed compared to traditional methods requiring separate centrifugation, filtration, and purification units
Solution Approach 2:
The filter unit is designed as a multi-functional element that performs collection, containment, and separation functions. This universal component replaces multiple specialized devices, simplifying the overall process while achieving high purity through integrated washing and elution steps
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables efficient recovery of poxviruses with reduced impurities and adherence to GMP principles, facilitating scalable and cost-effective production while maintaining aseptic processing, even in large-scale industrial settings.
Implementation Method 1
collecting said host cell in/on a filter unit
Implementation Method 2
separating said poxvirus by eluting the poxvirus from said filter unit
Data Source
AI summary
The present invention provides a method for recovering an essentially cell-associated expression product from a host cell comprising (a) culturing said host cell under conditions that allow expression of said expression product; (b) collecting said host cell in/on a filter unit; (c) disrupting said host cell in/on the filter unit; and (d) separating said expression product from said disrupted host cell. Said host cell is preferably a vertebrate cell, more preferably an avian cell, which is preferably cultured in suspension. Furthermore, the present invention provides for the use of a filter unit characterized in that said filter unit is (i) suitable to retain a host cell which expresses an expression product; and (ii) suitable for elution of said expression product from the filter unit after cell disruption in/on said filter unit for recovering said expression product from said host cell as well as for a system for recovering an expression product from a host cell comprising said filter unit. The present invention also provides an expression product obtainable by said method, said expression product being preferably a virus, specifically a poxvirus, in particular selected from the group consisting of fowlpoxvirus, vaccinia virus and, more preferably, modified vaccinia virus Ankara, MVA.