Expansion and differentiation of CD14+CD16− and CD14++CD16+ human monocyte subsets from cord blood CD34+ hematopoietic progenitors

Abstract

To determine whether monocytes can be generated from CD34+ hematopoietic progenitors in large numbers, cord blood CD34+ cells were first expanded for 3-10 days in X-VIVO 10 medium supplemented with FCS, stem cell factor (SCF), thrombopoietin (TPO), and Flt-3 Ligand (Flt-3L), and then differentiated in IMDM medium supplemented with FCS, SCF, Flt-3L, IL-3 and M-CSF for 7-14 days. These two step cultures resulted in up to a 600-fold mean increase of total CD14+ cells. Using this approach, two subpopulations of monocytes were obtained: CD14+CD16(-) and CD14++CD16+ occurring at 2:1 ratio. 1.25(OH)2 Vitamin D3 added to the differentiation medium altered this ratio by decreasing proportion of CD14++CD16+ monocytes. In comparison to CD14+CD16(-), the CD14++CD16+ cells showed different morphology and an enhanced expression of CD11b, CD33, CD40, CD64, CD86, CD163, HLA-DR, and CCR5. Both subpopulations secreted TNF and IL-12p40 but little or no IL-10. CD14++CD16+ monocytes released significantly more IL-12p40, were better stimulators of MLR but showed less S. aureus phagocytosis. These subpopulations are clearly different from those present in the blood and may be novel monocyte subsets that represent different stages in monocyte differentiation with distinct biological function.

Placental/umbilical cord blood-derived mesenchymal stem cell-like stromal cells support hematopoietic recovery of X-irradiated human CD34+ cells

“…However, a significant increase of CD14 expressing monocyte/macrophages was observed in the co-culture of X-irradiated cells in comparison to the stroma-free culture. These results may be due to the large increase of CFU-GM, monocyte/macrophage progenitors, in the culture (Ruzicka et al 2004;Stec et al 2007).…”

Expression of human cytokines dramatically improves reconstitution of specific human-blood lineage cells in humanized mice

“…Cytokines play a key role during their differentiation and maintenance. For example, IL-15 is required for development and survival of NK cells (11), GM-CSF and IL-4 for DC development (12), macrophage colony stimulating factor (M-CSF) for monocyte/ macrophage development and maintenance (13), and erythropoietin (EPO) and IL-3 for erythrocyte development (14). However, because of evolutionary divergence between human and mouse, these cytokines are species-specific (i.e., the mouse cytokines do not function on human cells).…”

Influence of Cholecalciferol Supplementation in Hemodialysis Patients on Monocyte Subsets: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

“…Nonetheless, a potential effect of 25(OH)D on monocyte CD14/CD16 subpopulations has not been studied yet. There is merely preliminary evidence in 4 non-renal cases that 1,25(OH) 2 D affects monocyte maturation of CD34+ cord blood hematopoietic progenitor cells towards CD16-negative phenotypes [15]. …”