TARGATT™ Knock-in Master Cell Line
Use our TARGATT™ Master Cell Lines (HEK293, CHO, and iPSC) and kits to generate site-specific knock-in cell lines efficiently (even large transgene). TARGATT™’s safe harbor locus-based gene integration overcomes challenges associated with random integration methods.
- Higher knock-in efficiency compared to other knock-in technologies, with or without clonal selection
- No integration of bacterial backbone which might reduce gene expression
- Single copy integration is compatible with gene amplification
- Uniform, high level gene expression
- Fast and simple gene knock-in protocol
The TARGATT™ Master Cell Lines are ideal for large isogenic cell library construction for antibody and recombinant protein expression and high-yield bioproduction studies.
ASC's Custom Services for Cell Line and Animal Model Generation, and Downstream Assays for Drug/ Toxicity Testing
TARGATT™ System in HEK293T Cells:
Figure 1. Schematic representation of site-specific gene insertion using TARGATT™ Master Cell Lines. The TARGATT™ Master Cell Line is engineered with the attP landing pad (or docking site) at a safe harbor locus (hROSA26/ hH11/ hAAVS1). The TARGATT™ PhiC31 integrase catalyzes an irreversible reaction between the attP sites on genome and the attB sites on the donor vector, resulting in integration of a single copy of the GFP reporter gene (positive control) at the preselected locus.
Figure 2. GFP expression in TARGATT™ HEK293T Master Cell Lines The CAG-GFP vector was used to verify fast knock-in in the TARGATT™-HEK293T Master Cell Line. An enriched GFP signal was shown under fluorescence microscopy. (Left) bright field microscopy. (Right) Immunofluorescence; GFP channel.
Figure 3. TARGATT™-HEK293T Master Cell Line transfected with donor plasmid containing GFP and attB. (a) Parental HEK293T cell line only (control); (b) Parental HEK293T cell line was transfected with donor plasmid containing GFP reporter by random insertion (+GFP); (c) TARGATT™-HEK293T Master Cell Line was transfected with GFP donor plasmid before GCV selection (+GFP); (d) TARGATT™-HEK293T Master Cell Line was transfected with GFP donor plasmid after GCV negative selection to eliminate clones without gene of interest (GFP+GCV).
The data indicates that the TARGATT™-HEK293 Master Cell Line system provides a robust, fast and efficient integration platform for generating a uniform cell population with stable transgene expression. This platform paves the way for homogeneous expression of GOI and subsequent biotherapeutic protein production.
The TARGATT™ 20 plasmid was designed specifically for the TARGATT™ Master Cell Lines to select for cells with site-specific, transgene knock-in at the docking site, without plasmid backbone. We can custom modify: (1) the TARGATT™ 20 plasmid that comes with the kit to include/ exclude specific sequence(s)/ expression elements, suitable for your project needs; or (2) customize our other TARGATT™ plasmids to enable its use with the master cell lines. However, any custom modifications will be a fee-for-service custom service. Please inquire for details..
The TARGATT™ Knock-in Master Cell Line Kit uses PhiC31 integrase to insert any gene of interest into a preselected intergenic and transcriptionally active genomic locus (hROSA26, hH11, hAAVS1 or other safe harbor locus).
The TARGATT™ technology can be utilized for generating knock-in cell lines and libraries for a variety of applications including reporter gene expression, gene knockdown, conditional/ inducible gene expression, gene overexpression, antibody expression libraries, pilot bioproduction of recombinant protein, and disease modeling.
Comparing TARGATT™ and existing gene editing technologies:
Potential Applications in Antibody Discovery:
- scFv screening
- Off-target screening with membrane protein library
Potential Applications in CAR-T, Ion Channels, GPCR and Other Library Screening includes but not limited to:
- CAR affinity/efficiency
- CAR specificity and safety screening
- “Universal” CAR-T cell
- Discover novel immune targets, checkpoints
- Receptor identification
- Ion Channels
- Off-target screening
- Non-membrane, non-secretory protein library
- Protein evolution
- Enzyme activity and specificity
- AAV capsid specificity and efficiency
TARGATT™ Master Cell Line
- Chi, X., Zheng, Q., Jiang, R., Chen-Tsai, R. Y., & Kong, L. J. (2019). A system for site-specific integration of transgenes in mammalian cells. PLOS ONE, 14(7), e0219842.
Description of the technology
- Zhu, F., Gamboa, M., Farruggio, A. P., Hippenmeyer, S., Tasic, B., Schüle, B., … Calos, M. P. (2014). DICE, an efficient system for iterative genomic editing in human pluripotent stem cells. Nucleic Acids Research, 42(5), e34. http://doi.org/10.1093/nar/gkt1290.
- Tasic, B., Hippenmeyer, S., Wang, C., Gamboa, M., Zong, H., Chen-Tsai, Y., & Luo, L. (2011). Site-specific integrase-mediated transgenesis in mice via pronuclear injection. Proceedings of the National Academy of Sciences of the United States of America, 108(19), 7902–7907. http://doi.org/10.1073/pnas.1019507108.
Commentary, comparison with other transgenic methods
- Rossant, J., Nutter, L. M., & Gertsenstein, M. (2011). Engineering the embryo. Proceedings of the National Academy of Sciences, 108(19), 7659-7660.
Tet inducible mice generated by TARGATT™
- Fan, X., Petitt, M., Gamboa, M., Huang, M., Dhal, S., Druzin, M. L., … Nayak, N. R. (2012). Transient, Inducible, Placenta-Specific Gene Expression in Mice. Endocrinology, 153(11), 5637–5644. http://doi.org/10.1210/en.2012-1556.
Advantage of Hipp11 (H11) locus
- Hippenmeyer, S., Youn, Y. H., Moon, H. M., Miyamichi, K., Zong, H., Wynshaw-Boris, A., & Luo, L. (2010). Genetic Mosaic Dissection of Lis1 and Ndel1 in Neuronal Migration. Neuron, 68(4), 695–709. http://doi.org/10.1016/j.neuron.2010.09.027.
Applications for TARGATT™ (and cited/published articles
- Matharu, N., Rattanasopha, S., Tamura, S., Maliskova, L., Wang, Y., Bernard, A., ... & Ahituv, N. (2018). CRISPR-mediated activation of a promoter or enhancer rescues obesity caused by haploinsufficiency. Science, eaau0629.
- Chen-Tsai, R. Y. (2019). Using TARGATT™ Technology to Generate Site-Specific Transgenic Mice. In Microinjection (pp. 71-86). Humana Press, New York, NY
- Barrett, R. D., Laurent, S., Mallarino, R., Pfeifer, S. P., Xu, C. C., Foll, M., ... & Hoekstra, H. E. (2018). The fitness consequences of genetic variation in wild populations of mice. bioRxiv, 383240.
- Ibrahim, L. A., Huang, J. J., Wang, S. Z., Kim, Y. J., Li, I., & Huizhong, W. (2018). Sparse Labeling and Neural Tracing in Brain Circuits by STARS Strategy: Revealing Morphological Development of Type II Spiral Ganglion Neurons. Cerebral Cortex, 1-14.
- Kumar, A., Dhar, S., Campanelli, G., Butt, N. A., Schallheim, J. M., Gomez, C. R., & Levenson, A. S. (2018). MTA 1 drives malignant progression and bone metastasis in prostate cancer. Molecular oncology.
- Jang, Y., Broun, A., Wang, C., Park, Y. K., Zhuang, L., Lee, J. E., ... & Ge, K. (2018). H3. 3K4M destabilizes enhancer H3K4 methyltransferases MLL3/MLL4 and impairs adipose tissue development. Nucleic acids research. https://doi.org/10.1093/nar/gky982
- Tang, Y., Kwon, H., Neel, B. A., Kasher-Meron, M., Pessin, J., Yamada, E., & Pessin, J. E. (2018). The fructose-2, 6-bisphosphatase TIGAR suppresses NF-κB signaling by directly inhibiting the linear ubiquitin assembly complex LUBAC. Journal of Biological Chemistry, jbc-RA118.
- Chen, M., Geoffroy, C. G., Meves, J. M., Narang, A., Li, Y., Nguyen, M. T., ... & Elzière, L. (2018). Leucine Zipper-Bearing Kinase Is a Critical Regulator of Astrocyte Reactivity in the Adult Mammalian CNS. Cell Reports, 22(13), 3587-3597
- Kido, T., Sun, Z., & Lau, Y.-F. C. (2017). Aberrant activation of the human sex-determining gene in early embryonic development results in postnatal growth retardation and lethality in mice. Scientific Reports, 7, 4113. http://doi.org/10.1038/s41598-017-04117-6.
- Nouri, N., & Awatramani, R. (2017). A novel floor plate boundary defined by adjacent En1 and Dbx1 microdomains distinguishes midbrain dopamine and hypothalamic neurons. Development, 144(5), 916-927.
- Li, K., Wang, F., Cao, W. B., Lv, X. X., Hua, F., Cui, B., ... & Yu, J. M. (2017). TRIB3 Promotes APL Progression through Stabilization of the Oncoprotein PML-RARα and Inhibition of p53-Mediated Senescence. Cancer Cell, 31(5), 697-710.
- Jiang, T., Kindt, K., & Wu, D. K. (2017). Transcription factor Emx2 controls stereociliary bundle orientation of sensory hair cells. eLife, 6, e23661.
- Booze, M. L., Hansen, J. M., & Vitiello, P. F. (2016). A Novel Mouse Model for the Identification of Thioredoxin-1 Protein Interactions. Free Radical Biology & Medicine, 99, 533–543. http://doi.org/10.1016/j.freeradbiomed.2016.09.013.
- Feng, D., Dai, S., Liu, F., Ohtake, Y., Zhou, Z., Wang, H., ... & Hayat, U. (2016). Cre-inducible human CD59 mediates rapid cell ablation after intermedilysin administration. The Journal of clinical investigation, 126(6), 2321-2333.
- Sun, N., Yun, J., Liu, J., Malide, D., Liu, C., Rovira, I. I., … Finkel, T. (2015). Measuring in vivo mitophagy. Molecular Cell, 60(4), 685–696. http://doi.org/10.1016/j.molcel.2015.10.009.
- Devine, W. P., Wythe, J. D., George, M., Koshiba-Takeuchi, K., & Bruneau, B. G. (2014). Early patterning and specification of cardiac progenitors in gastrulating mesoderm. eLife, 3, e03848. http://doi.org/10.7554/eLife.03848.
- Fogg, P. C. M., Colloms, S., Rosser, S., Stark, M., & Smith, M. C. M. (2014). New Applications for Phage Integrases. Journal of Molecular Biology, 426(15), 2703–2716. http://doi.org/10.1016/j.jmb.2014.05.014.
- Chen-Tsai, R. Y., Jiang, R., Zhuang, L., Wu, J., Li, L., & Wu, J. (2014). Genome editing and animal models. Chinese science bulletin, 59(1), 1-6.
- Park, K.-E., Park, C.-H., Powell, A., Martin, J., Donovan, D. M., & Telugu, B. P. (2016). Targeted Gene Knockin in Porcine Somatic Cells Using CRISPR/Cas Ribonucleoproteins. International Journal of Molecular Sciences, 17(6), 810. http://doi.org/10.3390/ijms17060810.
- Guenther, C. A., Tasic, B., Luo, L., Bedell, M. A., & Kingsley, D. M. (2014). A molecular basis for classic blond hair color in Europeans. Nature Genetics, 46(7), 748–752. http://doi.org/10.1038/ng.2991.
- Villamizar, C. A. (2014). Characterization of the vascular pathology in the acta2 r258c mouse model and cerebrovascular characterization of the acta2 null mouse. UT GSBS Dissertations and These (Open Access). Paper 508 (2014)