|Description||CTLA4 Ig-24 cells, derived from an adult female Chinese hamster (Cricetulus griseus), are a spontaneously immortalized cell line which have been genetically modified by introducing the human CTLA-4 gene, resulting in the expression of a fusion protein. The fusion protein possesses a dominant attribute of CTLA4Ig, making CTLA4 Ig-24 cells a unique and essential tool in immunology research. CTLA-4, a member of the immunoglobulin superfamily, is primarily expressed in activated T cells and acts as an inhibitory signal transmitter to regulate T cell function. It shares homology with CD28, a T-cell co-stimulatory protein, and both molecules bind to CD80 (B7-1) and CD86 (B7-2) proteins on antigen-presenting cells. CTLA-4 demonstrates a greater affinity and avidity for CD80 and CD86 than CD28, allowing it to outcompete CD28 for binding to these ligands. By doing so, CTLA-4 transmits an inhibitory signal to T cells, while CD28 transmits a stimulatory signal. This intricate regulatory mechanism is pivotal in maintaining immune balance and preventing excessive immune responses. Interestingly, CTLA-4 is also found in regulatory T cells (Tregs) and contributes to their inhibitory function. When T cells are activated through the T cell receptor (TCR) and CD28, the expression of CTLA-4 increases. Furthermore, CTLA-4 may influence cell motility and signal signalling through the PI3 kinase pathway.|
Identifiers / Biosafety / Citation
|Citation||CTLA4 Ig-24 (Cytion catalog number 305014)|
Expression / Mutation
|Medium supplements||10% FBS, w: 4.5 g/L Glucose, w: 4 mM L-Glutamine, w: 1.5 g/L NaHCO3, w: 1.0 mM Sodium pyruvate, 0.2 mM proline, 0.001 mM methotrexate|
|Subculturing||Remove medium and rinse the adherent cells using PBS without calcium and magnesium (3-5 ml PBS for T25, 5-10 ml for T75 cell culture flasks). Add Accutase (1-2 ml per T25, 2.5 ml per T75 cell culture flask), the cell sheet must be covered completely. Incubate at ambient temperature for 8-10 minutes. Carefully resuspend the cells with medium (10 ml), centrifuge for 3 min at 300 g, resuspend cells in fresh medium and dispense into new flasks which contain fresh medium.|
|Split ratio||1: 3 to 1: 4|
|Fluid renewal||2 to 3 times per week|
|Freeze medium||CM-1 (Cytion catalog number 800100) or CM-ACF (Cytion catalog number 806100)|
|Handling of cryopreserved cultures||The cells come deep-frozen shipped on dry ice. Please make sure that the vial is still frozen. If immediate culturing is not intended, the cryovial must be stored below -150 degree Celsius after arrival. If immediate culturing is intended, please follow the below instructions: Quickly thaw by rapid agitation in a 37 degree Celsius water bath within 40-60 seconds. The water bath should have clean water containing an antimicrobial agent. As soon as the sample has thawed, remove the cryovial from the water bath. A small ice clump should still remain and the vial should still be cold. From now on, all operations should be carried out under aseptic conditions. Transfer the cryovial to a sterile flow cabinet and wipe with 70% alcohol. Carefully open the vial and transfer the cell suspension into a 15 ml centrifuge tube containing 8 ml of culture medium (room temperature). Resuspend the cells carefully. Centrifuge at 300 x g for 3 min and discard the supernatant. The centrifugation step may be omitted, but in this case the remains of the freeze medium have to be removed 24 hours later. Resuspend the cells carefully in 10 ml fresh cell culture medium and transfer them into two T25 cell culture flasks. All further steps are described in the subculture section.|
|Handling of proliferating cultures||One or two cell culture flasks come filled with cell culture medium. Collect the entire medium in 1 or 2 x 50 ml centrifuge tubes, respectively. Carefully add 5 ml of cell culture medium to each T25 cell culture flask. Control the cell morphology and confluency under the microscope. Incubate at 37 degree Celsius for a minimum of 24 hours. Spin down the collected medium at 300 x g for 3 minutes to collect the cells which may have detached during transit. If a cell pellet is visible, resuspend the cells in 5 ml of cell culture medium and transfer to a T25 cell culture flask. Incubate at 37 degree Celsius for a minimum of 24 hours.|
Quality control / Genetic profile / HLA
|Sterility||Mycoplasma contaminations are ruled out through PCR-based and luminescence-based mycoplasma assays. The absence of bacterial, fungal or yeast contamination is controlled through daily visual cell monitoring.|
To identify mycoplasma contaminations we perform PCR-based and luminescence-based mycoplasma assays. We further determine any bacterial or fungal contamination through our standardized manufacturing processes.
Besides genomic DNA, RNA, cell pellets, and cell lysates, we can offer large quantities of assay-ready cells, plated cells in multiple formats, and frozen or growing cells. Contact us to receive a quote.
Each manufactured batch of cell lines* is authenticated via STR analysis. Contact us if you require a publication-ready STR report for your cells (*human, hamster, mouse, rat, and dog cells).
HLA characterization is available from more than 200 cell lines. HLA class I -A, B, C, and Class II HLA-DPA1, -DPB1, -DQA1, DQB1, and DRB1 alleles were obtained by next-generation sequencing methodologies (NGS) for class I and class II alleles.