Hi, I usually culture 1-2x104 DCs and 1x105 T cells (1:5-10) in 200 μl of complete medium in round-bottomed 96-well plates for 72-96 hr at 37ºC. You can add any peptide to the cultures at optimal concentration. Hope this helps.

The choice of DC population is going to be important. While it may be easier to use BM-derived DCs, how they are generated can influence outcome of T cell response and may not represent DCs found under "normal" conditions. Splenic DCs exist as different subpopulations, which would also have different effects on T cell populations. Finally, what T cell populations are being used. Are you using whole T cell populations or are you separating them based on naive (CD44loCD62Lhi), CD4, or CD8?

GM-CSF differentiation of murine bone marrow cells into DCs requires long-term culture (1-2 weeks) to acquire dendritic cells and usually these cultures contain a heterogeneous population of macrophages, early precursors and immature and spontaneously matured DCs. In my opinion splenic DCs (that include CD8+ and CD8- DCs) is a more uniform and reproducible population that you can get by CD11c positive selection. Activation of naive T cells by dendritic cells requires interaction TCR and peptide-loaded class II or class I MHC molecules to the DC surface. Thus, you could characterize OT-II or OT-I cells activated by OVA peptide-loaded DCs or use other TCR transgenic mice. I usually get OTII or OTI T cells by CD4 or CD8 positive selection.

Great answers, all, thank you! This agrees well with what I've been able to dig out of the literature. In my case, I'd like to use single cell suspensions made from lymph nodes which would presumably contain multiple DC subsets. I'd infect these cells with virus and culture them with P14 CD8 T cells (from the P14 TCR transgenic system), measuring expression of markers on the CD8s following co-culture.