Generation of large numbers of pro-DCs and pre-DCs in vitro.

The CD8(+), CD8(-), and plasmacytoid dendritic cell (DC) subtypes develop from progenitors that express surface fms-like tyrosine kinase 3 (Flt3). Recently, two developmentally sequential progenitors have been identified that give rise to these subtypes. This includes a transition from an earlier CD11c(-)MHC-II(-) "pro-DC," which divides and differentiates to give rise to CD11c(+)MHC-II(-) "pre-DC," en route to generating the three CD11c(+)MHC-II(+) DC subtypes - plasmacytoid DCs, CD8(+) DCs, and CD8(-) DCs. In this chapter, we describe the very simple method of generating large numbers of in vitro-derived pro-DCs and pre-DCs. As these precursors are largely DC-restricted, they can be used to either reconstitute a mouse with DCs of desired background, to study the developmental steps in vitro or in vivo, among other purposes.