Previous studies have shown that purified dendritic cells (DCs) have cell-intrinsic, age-dependent differences in their response to TLR stimulation. To delineate which aspects of the age-dependent difference in innate immunity are cell intrinsic vs extrinsic, we searched for global differences to TLR7/8 stimulation in purified adult vs neonatal DC populations. We hypothesize that very few selected cell intrinsic differences in gene expression of key immune genes between these 2 age groups exist, and the bulk would be cell extrinsic differences. The results show that there are age-dependent differences in expression of several key genes involved in the immune response at baseline already. Upon stimulation, we identified a substantially larger fraction of age-dependent differentially expressed genes in conventional than plasmacytoid DCs. Bioinformatics analyses indicate that important immune pathways were significantly differentially expressed in DC subsets between the 2 age groups.

Total RNA was isolated from purified human conventional and plasmacytoid dendritic cells from 6 adult and 6 cord blood donors that were stimulated with 3M-003 at a final concentration of 5 uM for 1 and 6 hr.

human adult and neonatal dendritic cell subsets comparison to TLR7/8 stimulation