Materials and Reagents

Recombinant mouse IL-15 (rmIL15) (BioLegend, catalog number: 566302 )
RPMI-1640 medium (Life Technologies, Gibco^®, catalog number: 11875-119 )
Fetal bovine serum (Atlanta Biologicals, catalog number: S11055H )
Penicillin/streptomycin (Gemini Bio-Products, catalog number: F52M00E )
L-Glutamine (Life Technologies, Gibco^®, catalog number: 25030-081 )
100x 1 M Hepes (Life Technologies, Gibco^®, catalog number: 15630-080 )
100x MEM non-essential amino acids (Life Technologies, Gibco^®, catalog number: 11140-050 )
100x sodium pyruvate (100 mM) (Life Technologies, Gibco^®, catalog number: 11360-070 )
100x 2-mercaptoethanol (Life Technologies, Gibco^®, catalog number: 21985-023 )
OVA_257-264 synthetic peptide (Sigma-Aldrich, catalog number: S7951 )
Ficoll-Paque^TM Premium 1.084 (GE Healthcare, catalog number: 17-5446-02 )
Antibodies:
1. Anti-CD44 PerCpCy5.5 (clone: IM7) (eBioscience, catalog number: 45-0441 )
2. Anti-CD62L APC (clone: MEL-14) (eBioscience, catalog number: 17-0621 )
RBC lysis buffer (eBioscience, catalog number: 00-4333-57 )
Bovine serum albumin (Thermo Fisher Scientific, catalog number: BP1605-100 )
NaN₃ (Sigma-Aldrich, catalog number: S8032 )
T cell media (see Recipes)
Staining buffer (in PBS) (see Recipes)

Equipment

Centrifuge (Thermo Fischer Scientific, Sorvall^TM Legend RT)
70 µm cell strainer (BD Biosciences, Falcon^®, catalog number: 352350 )
15 ml and 50ml Falcon tubes
24 well plates (BD Biosciences, Falcon^®, catalog number: 353226 )
T75 culture flask (Corning, catalog number: 430641 )
37 °C, 5% CO₂ cell culture incubator

Procedure

CD44^hiCD62L^lo Memory T cell differentiation proceeds under sterile tissue culture conditions
1. Euthanize a OT-1 CD8 TCR transgenic mouse and take spleen, and (optional) lymph nodes.
2. Splenocytes are RBC lysed followed by washing with PBS twice.
OT-1 TCR stimulation with cognate peptide antigen
1. Resuspend cells in 1 ml of T cell media and add OVA_257-264 synthetic peptide to 1 µM.
2. Incubate in the 5% CO₂ at 37 °C for 1 h.
3. Spin down cells at 1,500 rpm for 3 min at 4 °C and wash once with T cell media.
4. Resuspend cells in 12 ml of T cell media and plate 1ml/well of a 24 well plate.
5. Incubate in the 5% CO₂ at 37 °C for 2 days.
6. Harvest the cells by pipetting up and down, and pellet cells.
7. Resuspend cells in 5 ml of T cell media, and load on to 2.5 ml of Ficoll.
8. Spin down at 400 x g for 15 min at 4 °C.
9. Transfer live cells on the interphase to a new 15 ml tube and fill up the tube with T cell media.
10. Spin down cells at 1,500 rpm for 3 min at 4 °C.
Memory T cell culture in the presence of IL-15
1. Resuspend cells in 24 ml of T cell media containing rmIL15 (20 ng/ml). Culture cells in T75 flask for four days.
2. Harvest and pellet cells for Ficoll gradient (repeat steps 9-12).
3. Resuspend cells in 40 ml of T cell media containing rmIL15 (20 ng/ml). Culture in T75 flask for two days.
4. Staining cells with anti-CD44 and CD62L antibodies in staining buffer for 15 min on ice.
5. Wash with staining buffer twice, then proceeds flow cytometry analysis.
  
  Figure 1. CD44 and CD62L expression of differentiated memory T cells

Recipes

T cell media
RPMI-1640
10% fetal bovine serum
1% penicillin/streptomycin
1% L-Glutamine
1x 1 M Hepes
1x MEM non-essential amino acids
1x sodium pyruvate 100 mM
1x 2-mercaptoethanol
Staining buffer (in PBS)
1% BSA
0.02% NaN₃

Acknowledgments

The protocol was adapted from a previously described study (Manjunath et al., 2001). This work was supported by the Starr Cancer Consortium (13-A123 to M.O.L. and M.Q.Z.), the Rita Allen Foundation (M.O.L.), the NBRPC (2012CB316503 to M.Q.Z), and the NIH (HG001696 to M.Q.Z.).

References

Kim, M. V., Ouyang, W., Liao, W., Zhang, M. Q. and Li, M. O. (2013). The transcription factor Foxo1 controls central-memory CD8⁺ T cell responses to infection. Immunity 39(2): 286-297.
Manjunath, N., Shankar, P., Wan, J., Weninger, W., Crowley, M., Hieshima, K., Springer, T., Fan, X., Shen, H. and Lieberman, J. (2001). Effector differentiation is not prerequisite for generation of memory cytotoxic T lymphocytes. J Clin Invest 108(6): 871-878.