Combined data now show that splenic stroma of both human and murine origin provides a mesenchymal stromal cell microenvironment which is WNT pathwayвЂ“dependent, and which supports in vitro myelopoiesis with production of specific subsets of myeloid and dendritic-like cells.

However, the 5C6 stroma which failed to support hematopoiesis uniquely expressed several inhibitors of the WNT pathway. Gene profiling revealed both stromal lines to reflect perivascular reticular cells with osteogenic characteristics. Transcriptome analysis compared two stromal lines differing in myelopoietic support capacity. Human bone marrow progenitors gave rise to myelopoiesis from hematopoietic progenitors, while human cord blood supported limited myelopoiesis from existing myeloid precursors. Human splenocytes gave production of predominantly myeloid dendritic-like cells, with minor subsets resembling conventional dendritic cells (cDC) cells, and myeloid or monocyte-derived DC. When human progenitor populations from spleen, bone marrow and cord blood were employed as a source of progenitors for co-culture above splenic stromal lines, myelopoiesis was supported. Similar stromal lines have now been isolated from long-term cultures (LTC) of human spleen. Murine spleen has been shown to harbour stromal cells that support hematopoiesis with production of myeloid antigenвЂ“presenting cells.

Flowjo compensation matrix