Characterization of Mast Cell-Committed Progenitors Present in Human Umbilical Cord Blood

Abstract

Human mast cells are derived from CD34+ hematopoietic cells present in cord blood, bone marrow, and peripheral blood. However, little is known about the properties of the CD34+ cells. We demonstrated here that mast cell progenitors that have distinct phenotypes from other hematopoietic cell types are present in cord blood by culturing single, sorted CD34+ cells in 96-well plates or unsorted cells in methylcellulose. The CD34+ mast cell-committed progenitors often expressed CD38 and often lacked HLA-DR, whereas CD34+ erythroid progenitors often expressed both CD38 and HLA-DR and CD34+ granulocyte-macrophage progenitors often had CD33 and sometimes expressed CD38. We then cultured single cord blood-derived CD34+CD38+ cells under conditions optimal for mast cells and three types of myeloid cells, ie, basophils, eosinophils, and macrophages. Of 1,200 CD34+CD38+ cells, we were able to detect 13 pure mast cell colonies and 52 pure colonies consisting of either one of these three myeloid cell types. We found 17 colonies consisting of two of the three myeloid cell types, whereas only one colony consisted of mast cells and another cell type. These results indicate that human mast cells develop from progenitors that have unique phenotypes and that committed mast cell progenitors develop from multipotent hematopoietic cells through a pathway distinct from myeloid lineages including basophils, which have many similarities to mast cells.

The immunophenotype of mast cells and its utility in the diagnostic work-up of systemic mastocytosis

“…Early reports by use of in vitro MC-differentiation models revealed that these progenitors circulate as CD34 + /CD117 + agranular mononuclear cells [25], which express the CD133 (prominin 1) stem cell-associated marker [26], together with myeloid-associated antigens, such as CD13 (aminopeptidase N) [24] and CD33 (siglec-3) [26], in the absence of the CD14 (LPS receptor) monocytic marker, CD17 (lactosylceramide) [27], and Fc«RI [13,25]. In addition, these precursors have been frequently shown to express CD38 and often to lack HLA-DR expression [28]. More recent ex vivo studies, based on the analysis of BM samples from healthy individuals and MDS patients, identified MCPs on phenotypic grounds as a minor subpopulation of CD34 + HPC, showing a CD117 high HLA-DR 2/int profile, the frequency of such MCPs ranging from ,0.001% to 0.02% of the whole CD34+ HPC compartment (mean of ,0.001% 6 0.005% BM cells) [29].…”

“…Despite this, relative consensus exists in the literature about the phenotypic pattern of expression of several molecules, during MC maturation. Accordingly, early MCPs are known to express a set of early hematopoietic (CD34, CD38, CD45, CD38, HLA-DR) and myeloid markers (CD13, CD33) [24,26,28], as well as multiple cytokine and chemokine receptors (CD116, CD117, CD123, CD126, CXCR1, CXCR2, CXCR4) [26,30,37] and adhesion molecules (CD29, CD49d, CD49e, CD11a, CD18, CD44, CD54, CD58; see Table 1) [26,30,38]. During MC maturation, expression of some of these molecules remains relatively unchanged (e.g., CD29, CD44, CD58, CXCR2, CXCR4) [26,37,38], or it is even up-regulated (e.g., CD117, CD13, CD45) [26], whereas other molecules show decreased expression levels (e.g., the adhesion-related molecules CD49d, CD49e, CD11a, and CD18) [38], or they even become undetected in more mature MCs (e.g., CD34, CD116, CD123, CD126; see Table 1) [30,37].…”

A protocol for generating high numbers of mature and functional human mast cells from peripheral blood

“…Mast cells (MCs) are multi-functional tissue-dwelling cells involved in various pathological conditions such as allergy and asthma, and their contribution to cardiovascular diseases and rheumatoid arthritis has also been suggested [1][2][3][4]. MCs are filled with cytoplasmic secretory granules that contain preformed mediators including cytokines, heparin, histamine, and two neutral serine proteases: tryptase and chymase [5][6][7][8]. Mature MCs can be distinguished from other cells by their expression of high-affinity IgE receptor [Fc epsilon receptor I (FceRI)] and c-kit (CD117) on their surface, and tryptase and heparin in their granules [1,9,10].…”

Luminal decoration of blood vessels by activated perivasal mast cells in allergic rhinitis

“…Human mast cells were differentiated from cord blood‐derived progenitor cells . In brief, stem cells were isolated from heparinized human cord blood by gradient centrifugation and magnetic enrichment for CD133‐positive cells (CD133 Micro Bead kit; Miltenyi Biotech, #130‐050‐801, Bergisch Gladbach, Germany).…”