CD8α+ mouse spleen dendritic cells do not originate from the CD8α- dendritic cell subset

Although previous studies had indicated that the CD8alpha(-) and CD8alpha(+) subtypes of murine dendritic cells (DCs) differ in immediate origin, a recent study found that intravenous transfer of CD8alpha(-) DCs led to CD8alpha(+) DCs in the spleen several days later, suggesting a direct precursor-product relationship. We have repeated these experiments with a balance sheet approach. We find that though a few CD8alpha(+) DCs can be generated in such experiments, this is a rare event and could be the result of a contaminant precursor. Most of the immediate precursors of CD8alpha(+) DCs are cells that lack the phenotype of a recognizable DC. CD8alpha(-) DCs and CD8alpha(+) DCs are not precursor-product related, though these sublineages may be connected further upstream. (C) 2003 by The American Society of Hematology.