By SIRION Biotech…
SIRION Biotech Lentiviral Services
SIRION Biotech offers a world-leading portfolio of lentivirus services that enable clients to perfect stable constitutive as well as inducible lentiviral vectors for overexpression and gene knockdown.
SIRION’s multicistronic vector design and distinctive all-in-one TET-inducible lentivector system can produce highly homogeneous, stable cell line expression models that avoid time-consuming post-transduction clonal selection and radically accelerate progress in working with difficult, cytotoxic genes and shRNA strategies.
Within less than one month, SIRION can offer optimized monocistronic and bicistronic lentiviral vector designs featuring broad selections of promotor, selection markers, and fluorescent tags. SIRION lentivirus vectors facilitate fast, stable and strong gene overexpression or knockdown, together with reliable gene delivery into dividing and non-dividing cells.
Choice of inducible LV technologies
Sirion Biotech offers a continuously growing portfolio of virus modifications and understanding of game-changing modalities like CRISPR/Cas, shRNA knockdown, inducible expression systems, etc.
SIRION Biotech’s inducible expression platform is based on the TET technology. Together with the latest third generation lentivirus backbone, this guarantees high sensitivity without leakiness. Moreover, this inducible TET-lentivirus platform delivers knockdown efficiency of at least 80% on mRNA level when used in combination with SIRION’s RNAiONE™ technology for algorithmic identification of small hairpin RNA (shRNA) sequences. This serves as a guaranteed path to define the most effective target identification and validation that can be further translated into SIRION’s viral vector platform.
SIRION offers a choice of TET-inducible lentiviral ONE-vector and TWO-vector systems for large lentiviral constructs that can be used to establish stable inducible cell models, circumvent cell adaption to stable genetic modification and enable characterization of toxic gene modulations.
Vector optimization strategies
Apart from identifying the most appropriate vector system, the SIRION lentivirus development service can also be optimized in three further ways to reach higher transduction levels with viral vectors.
The first is through use of transduction boosters – reagents added to the transduction medium to increase success rates. One such reagent is LentiBOOST™, which improves the general physicochemical interactions taking place between cell membrane and virion during transduction, increasing transduction efficiencies by up to 90%.
A second optimization strategy is to amend a protocol to recognise that susceptibilities to virus particles can differ greatly between cell types. Small changes, such as increasing viral load or incubation time can exert significant effects, as can integration of a centrifugation step during lentiviral transduction, which can double the proportion of transduction-positive cells to more than 80%. As a technology expert and service provider for vector customization, SIRION Biotech has amassed a treasure trove of vector experience, containing optimized transduction protocols for >150 cell type/virus pairings.
The third optimization route is to modify the virion, the different ‘flavors’ of viral vectors determined by cell surface antigens that greatly influence what cells the virus can interact with, its immunogenicity and how easy it is to produce. SIRION Biotech offers a wide range of options to alter surface antigens for lentiviruses.
Third generation lentivirus vector engineering
Based on SIRION’s deep expertise in vector engineering, the lentiviral vector service employs latest self-inactivating 3’SIN technology as part of a 3G lentivirus vector engineering approach. This technology ensures safety of Lentivirus vectors and prevents virus generation.
Further service features include cloning of cDNA/ shRNA into an inducible lentiviral expression vector, verification of cloning success by DNA-Sequencing, lentivirus production in HEK 293 cells, purification, concentration, QC and lentivirus titration by qRT-PCR and determination of the functional titer on TU level and infectious lentivirus titer [IU/ml].
SIRION’s highly skilled specialists offer personal consultancy and planning for each project This expert consultancy combined with a flexible engineering service, enables clients to generate virtually any desired expression construct. Guaranteed standards for reliable batch-to-batch consistency at various scales and quality levels are designed to fit any project stage, from R&D and preclinical to clinical development. All projects are thoroughly planned with customers to ensure that the resulting particles are designed to fit the desired final application.