KC-2206

CHOK1-CTLA4-delta23 Cell Line

23596

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Background of CHOK1-CTLA4-delta23 Cell Line

CTLA4, also known as CD152, is a protein receptor that belongs to the immunoglobulin superfamily, which is expressed by activated T cells and transmits an inhibitory signal to T cells. CTLA4 is similar to the T-cell co-stimulatory protein, CD28, and both molecules bind to CD80 and CD86, also called B7-1 and B7-2 respectively, on antigen-presenting cells. CTLA4 transmits an inhibitory signal to T cells, whereas CD28 transmits a stimulatory signal. CTLA4 is also found in regulatory T cells and may be important to their function.

Specifications

Catalog Number	KC-2206
Cell Line Name	CHOK1-CTLA4-delta23 Cell Line
Host Cell Line	CHOK1
Description	Stable CHOK1 cell line expressing exogenous human CTLA4 delta23 gene
Quantity	Two vials of frozen cells (≥2-10⁶/vial)
Stability	Stable in culture over a minimum of 10 passages
Application	Drug screening and biological assays
Freezing Medium	70% RPMI1640 + 20% FBS + 10% DMSO
Propagation Medium	RPMI1640 + 10% FBS + 10μg/ml Puromycin
Selection Marker	Puromycin
Morphology	Epithelial
Subculture	Split saturated culture 1:4-1:5 every 2-3 days; seed out at about 1-2 × 10⁵ cells/ml
Incubation	37 °C with 5% CO₂
Storage	Liquid nitrogen immediately upon receiving
Doubling Time	Approximately 30 hours
Mycoplasma Status	Negative
In Vivo Validation	NA

Cell Line Generation

CHOK1 human CTLA4 delta23 Cell Line was generated using a lentiviral vector expressing the human CTLA4 delta23 sequence.

Characterization

Figure 1: Characterization of human CTLA4 delta23 overexpression in the CHO-K1 human CTLA4 delta23 stable clone using FACS.

Cell Resuscitation

1. Prewarm culture medium (RPMI1640 + 10% FBS + 10μg/ml Puromycin)in a 37°C water bath.
2. Thaw the frozen vial in a 37°C water bath for 1-2 minutes.
3. Transfer the vial into biosafety cabinet, and wipe the surface with 70% ethanol.
4. Unscrew the top of the vial and transfer the cell suspension gently into a sterile centrifuge tube containing 9.0mL complete culture medium.
5. Spin at ~ 125 × g for 5-7 minutes at room temperature, and discard the supernatant without disturbing the pellet.
6. Resuspend cell pellet with the appropriate volume of complete medium and transfer the cell suspension into a T25 culture flask.
7. Incubate the flask at 37°C, 5% CO₂ incubator.
8. Split saturated culture 1:4-1:5 every 2-3 days; seed out at about 1-2 × 10⁵ cells/mL.

Cell Freezing

1. Prepare the freezing medium (70% RPMI1640 + 20% FBS + 10% DMSO) fresh immediately before use.
2. Keep the freezing medium on ice and label cryovials.
3. Transfer cells to a sterile, conical centrifuge tube, and count the cells.
4. Centrifuge the cells at 250×g for 5 minutes at room temperature and carefully aspirate off the medium.
5. Resuspend the cells at a density of at least 3×10⁶ cells/mL in chilled freezing medium.
6. Aliquot 1 mL of the cell suspension into each cryovial.
7. Freeze cells in the CoolCell freezing container overnight in a -80°C freezer.
8. Transfer vials to liquid nitrogen for long-term storage.

References

1. Syn NL, Teng MW, Mok TS, Soo RA (December 2017). "De-novo and acquired resistance to immune checkpoint targeting". The Lancet. Oncology. 18 (12): e731–e741.
2. Krummel MF, Allison JP (August 1995). "CD28 and CTLA-4 have opposing effects on the response of T cells to stimulation". The Journal of Experimental Medicine. 182 (2): 459–65.