Upper airways are lined with a pseudostratified mucociliary epithelium maintained by basal cells. To investigate functional and phenotypic heterogeneity within the human basal cell compartment, we used a combination of limiting dilution assays and surface marker profiling on primary cultures of basal cells with verified progenitor activity. The limiting dilution assay suggested functional heterogeneity in the ability of basal cells to repopulate a filter and maintain a barrier at ALI. The frequency of cells with this activity varied between patient strains and ranged from 0.08%-1% of basal cells. Validation of large-scale comprehensive surface marker profiling on basal cells led to identification of 74 antigens demarking consistent subpopulations. Preliminary functional analyses suggest differences in differentiation potential of some subpopulations. This work supports the idea that the basal cell compartment may be functionally heterogeneous, and provides new molecular tools for interrogation of human basal cells.

Upper airways are lined with a pseudostratified mucociliary epithelium maintained by basal cells. To investigate functional and phenotypic heterogeneity within the human basal cell compartment, we used a combination of limiting dilution assays and surface marker profiling on primary cultures of basal cells with verified progenitor activity. The limiting dilution assay suggested functional heterogeneity in the ability of basal cells to repopulate a filter and maintain a barrier at ALI. The frequency of cells with this activity varied between patient strains and ranged from 0.08%-1% of basal cells. Validation of large-scale comprehensive surface marker profiling on basal cells led to identification of 74 antigens demarking consistent subpopulations. Preliminary functional analyses suggest differences in differentiation potential of some subpopulations. This work supports the idea that the basal cell compartment may be functionally heterogeneous, and provides new molecular tools for interrogation of human basal cells.