Dynabeads® CD3CD28 CTS

实验原理

 

Dynabeads® CD3⁄CD28 CTS™ offer a simple method for isolation, activation and expansion of human T cells. Firstly, CD3 T cells are separated and concentrated from the apheresis product by magnetic cell separation using Dynabeads® CD3⁄CD28 CTS™. Following separation, the CD3 T cells are cultured in the presence of the beads. By combining anti-CD3 and anti-CD28 antibodies on Dynabeads®, the beads will provide both the primary and co-stimulatory signals that are required for activation and expansion of T cells. The activated T cells have been shown to produce IL2, GM-CSF, IFN-γ and TNF. T cells activated with these Dynabeads® can be expanded 100- 1000 fold over a 9-14 day culture period. The T cell expansion process can be scaled up using a bioreactor-based process. It has been shown that the T cell expansion protocol can be optimized to include expansion of antigen-specific T cells.

实验试剂

 

10 ml of Dynabeads® CD3⁄CD28 CTS™

Dynabeads® ClinExVivo™ Epoxy

DynaMag™ CTS™ (Magnetic Particle concentrator)

Dynal® MPC™-1 (Magnetic Particle concentrator)

PBS (Gibco ) [Note: PBS must be calcium and magnesium free.]

Anti-coagulant solution e.g. ACD-A, Baxter)

Pooled Human Serum (HS) (Cambrex or Valley Biomedical) heat inactivated at 56°C for 1 hour or autologous serum [Note: autologous serum may be used, although significant donor to donor variation should be expected]

OpTmizerTM T-Cell Expansion SFM (Gibco) serum free 1x formulation designed to support the culture and expansion of human T cells (or equivalent).

L-glutamine, (Gibco).

HEPES buffer, (Gibco)

IL-2, Proleukin® (Chiron)

实验设备

 

1-Bags (Baxter Lifecell® or CellGenix Vuelife™)

3-L Culture Bags (Baxter Lifecell® or CellGenix Vuelife™)

Sampling site coupler with female luer (Charter Medical)

Terumo TSCD® Sterile Tubing Welder

40μm - 80μm In-line Transfusion Filter (Pall)

10-lead harness sets (compatible with Terumo SCD 312 welder), (Charter Medical)

Hemostats tube clamp

COBE 2991 Cell Washer Disposable Set (COBE/Gambro) or Cytomate Disposable Set (Baxter)

Cell mixer (e.g. Heidolph Polymax 2040)

Plasma thawing device (e.g. Thermogenesis MT202)

Bioreactor (e.g. Wave Bioreactor)

实验步骤

 

1.        Dynabeads® Washing Protocol

1)        Wash Dynabeads® CD3⁄CD28 CTS™ twice before use to avoid potential transfer of residual antibody. Vials of Dynabeads® CD3⁄CD28 CTS™ are at negative pressure – liquid must be displaced with air and vice versa.

2)        Place one 10 ml vial of Dynabeads® CD3⁄CD28 CTS™ on the MPC-1 for 1 min.

3)        Aseptically remove the supernatant.

4)        Remove the vial from the MPC-1.

5)        Aseptically add 10 ml Buffer 1 to the vial and mix.

6)        Place the vial on the MPC-1 for 1 min.

7)        Aseptically remove the supernatant.

8)        Repeat steps 4 to 6.

9)        Resuspend the beads in 10 ml of Buffer 1 and keep the washed beads in a refrigerator until further use.

2.        Thawing and Washing of Cryopreserved Apheresis Cells

1)        Remove the required number of bags containing cryopreserved apheresis cells from liquid N vapour storage.

2)        Thaw the bag(s) in a plasma thawing device or by equivalent methods.

3)        To prevent cell clumping, add anti-coagulant solution aseptically to thawed cells to a final concentration of 10%.

4)        Slowly dilute the cell suspension 1:1 in Buffer 1.

5)        Wash the cells in Buffer 1 according to the cell washer manufacturer’s recommendations.

6)        Resuspend the cells in 50-60 ml of Buffer 1. If the volume exceeds 60 ml, perform a centrifugation step to reduce the volume.

7)        Incubate the cells for 60 min in Buffer 1 at room temperature to allow dead or dying cells to aggregate and subsequently be removed via a blood filter as described below.

8)        Filter the cells through an In-line Transfusion Filter with cut-off between 40-80 μm. The cells are now ready for further processing.

9)        Remove 1 ml of the sample from the leukapheresis bag. Calculate the number of CD3 T cells by flow cytometry, and determine the viability of the cells with trypan blue staining.

3.        Magnetic Separation and Culture of CD3 T Cells

It has been shown that magnetic pre-selection of CD3 T cells can improve subsequent T cell expansion (1, 2). The recommended standard procedure described below uses a ratio of three Dynabeads® CD3⁄CD28 CTS™ per CD3 T cell. [If the starting sample contains less than 25% CD3 T cells, replace Buffer 1 with Incomplete Medium in the procedures below.]

1)        Dilute the cells to approx. 1 x 10⁷ CD3 T cells/ml in Buffer 1. For the standard procedure of processing 5 x 10⁸ T cells, dilute the sample in 50-60 ml of Buffer 1.

2)        Use a 1L bag for CD3 T cell separation. Add 100 ml of air to the bag.

3)        Add 5 x 10⁸ CD3 T cells to the 1L bag in 50-60 ml Buffer 1.

4)        Add 4.0 ml (corresponding to 1.6 x 10⁹ Dynabeads®) of washed Dynabeads® CD3⁄CD28 CTS™ per 5 x 10⁸ CD3 T cells and immediately proceed to the next step.

5)        Place the bag on a cell mixer and mix for 30 min at room temperature to gently mix the cells and the Dynabeads®. [If the starting sample contains less than 25% CD3 T cells it may be beneficial to mix the sample for 1-2 hours in Incomplete Medium instead of Buffer 1. Optimise the mixing temperature between 4-25°C for each application.]

6)        Prepare 150 ml of Buffer 1 in a 300 ml bag.

7)        After mixing, remove the 1L bag from the mixer and drain 150 ml of Buffer 1 into the bag. [Note: Handle the 1L bag very gently, to not disrupt the bead/cell complexes.] Place the 1L bag directly on the DynaMag™ CTS™. Adjust the magnet to a 60° angle.

8)        Leave the bag on the DynaMag™ CTS™ for 1 min to capture the bead-bound CD3 T cells. While on the magnet, open the 1L bag containing the captured cells and drain waste fluid out in waste bag via gravity. Remove the bag containing the captured cells from the magnet immediately after all waste fluid has been drained.

9)        Immediately add approximately 300 ml Complete Medium to the 1L bag containing the captured cells and gently resuspend the cell/bead complexes.

10)    Obtain a 3L bag

11)    Transfer the cell/bead complexes from the 1L bag into a 3L bag. Wash the 1L bag with Complete Medium and transfer the residual cells to the 3L bag.

12)    Repeat media wash of the 1L bag and transfer the residual cells to the 3L bag until the volume in the 3L bag has reached 1000 ml.

13)    Place the 3L bag in an incubator at 37°C/ 5% CO₂ until Day 3 of culture. [Note; Using a bioreactor, e.g. Wave Bioreactor, will increase expansion efficiency via perfusion and improved aeration (rocking). Whereas typical cell densities rarely exceed 2-3 x 10⁶ T cells/ml in static cultures, bioreactor systems can readily maintain viable T cells at densities of 2-4 x 10⁷ T cells/ml.]

14)    Collect a sample of the non-captured cell fraction and manually count the number of non-captured cells.

15)    Stain the non-captured cells for CD3 expression and evaluate by flow cytometry to calculate depletion efficacy.

4.        Counting and Splitting of Cultures

The cell concentration should be evaluated daily beginning on day 3 of culture.

1)        Gently mix the bag to help dissociate cell/bead complexes and to resuspend the cells before removing 1-2 ml cell suspension for counting.

2)        Again, mix the sample well to resuspend cells so as to ensure maximum dissociation of beads from cells. This will improve cell count accuracy.

3)        Take an aliquot of cells and mix 1:1 with trypan blue staining solution and manually count on a hematocytometer (do not remove the Dynabeads® before counting). Determine cell density and viability. [Caution: insufficient mixing of bead/cell complexes may result in cell count underestimates as they will not migrate efficiently under hemocytometer coverslips.]

4)        Stain cells for CD3 expression and evaluate by flow cytometry to calculate the number of CD3 T cells in the bag.

5)        Determine the total cell volume by weighing the bag.

6)        When CD3 T cell density exceeds 1 x 10⁶ cells/ml, dilute the cells to approximately 0.5 x 10⁶ CD3 T cells/ml in Complete Medium.

7)        Split the cultures to new 3L bags when needed. [Note: T cell growth typically slows as T cell concentrations increase above 1-2 x 10⁶ T cells/ml, so adjust T cell numbers to ~0.5 x 10⁶ /ml to help maintain the cells in log phase growth.]

8)        Repeat counting of cells daily and dilute cells in fresh Complete Medium to 0.5 x 10⁶ /ml.

5.        Harvesting of Expanded CD3 T Cells

1)        Harvest cells on an optimal day for your application (usually day 8-12).

2)        Remove the 3L bags from the incubator. Remove a sample from a representative number of bags for cell count and FACS analysis. Perform the cell counts as described above.

3)        Remove the beads by passing the cell culture over the DynaMag™ CTS™ using gravity driven flow. Determine the angle of the MPC empirically between 0-60°. To achieve a flow rate of up to 150 ml/min, the bags containing cells and beads must be suspended from the pole so that the fluid level is 85-90 cm above the cell collection bags.

4)        Concentrate the cells and washed using a cell washer.

5)        Perform a final bead removal twice by placing the bag on the DynaMag™ CTS™. Adjust the magnet to a 60° angle. After 1 min, drain the cells into a new bag via gravity.

6)        Determination of residual beads can be performed.

6.        Cryopreservation of Expanded CD3 T Cells

1)        Prepare cryopreservation medium and cryopreserve the expanded T Cells.

2)        Store the final product of expanded T cells in the vapour phase of a liquid N₂ storage unit.

7.        Separation and Expansion of Fresh (non-cryopreserved) Apheresis Cells

1)        Dilute PBMC to 5-10 x 10⁶ cells/ml in Incomplete Medium (pre-warmed to 37°C).

2)        Wash Dynabeads® ClinExVivo™ Epoxy as described above for Dynabeads® CD3⁄CD28 CTS™.

3)        Add Dynabeads® ClinExVivo™ Epoxy to the PBMC at a 1-2 beads per total nucleated cells in a sterile culture bag. It may be preferred to use 2 beads per nucleated cell when monocyte levels are >15% of total PBMC.

4)        Place the bag into a humidified incubator at 37°C/ 5% CO₂ for one hour. [During the one hour incubation, beads and cells come into contact via gravity at the bottom of the bag and monocytes will ingest beads.]

5)        Remove the bag of cells and beads from the incubator after 1 hour. Gently mix the cells and beads before removing Dynabeads® ClinExVivo™ Epoxy and any cells that have ingested beads using a Dynal® ClinExVivo™.

6)        Allow ~50mL of Incomplete Medium to flow into the bag containing the bead:cell complexes. Mix well and transfer the medium containing residual cells to the bag containing unbound cells.

7)        Count the cells in the bag, stain for CD3 and evaluate by flow cytometry to calculate the number of CD3 T cells in the sample.

8)        Adjust the cell concentration to 1 x 10⁷ CD3 T cells/ml in Incomplete Medium.

9)        Perform capture of CD3 T cells as described above. [Note: magnetic concentration should be done in Incomplete Medium in place of Buffer 1 after monocyte/phagocytic cell depletion using Dynabeads® ClinExVivo™ Epoxy.]

10)    Following capture of CD3 T cells, prepare cells for culture initiation.

11)    Place the bag with cells and Dynabeads® CD3⁄CD28 CTS™ in an incubator at 37°C/ 5% CO₂ until Day 3 of culture.

12)    Count and split cell culture as described above.