The cellular diversity of the hematopoietic system has been extensively studied, and a plethora of cell surface markers have been used to discriminate and prospectively purify different blood cell types. However, even within phenotypically identical fractions of hematopoietic stem and progenitor cells or lineage-restricted progenitors, significant functional heterogeneity is observed when single cells are analyzed. To address these challenges, researchers are now using techniques to follow single cells and their progeny to improve our understanding of the underlying functional heterogeneity. On November 19, 2015, Dr. David Kent and Dr. Leïla Perié, two emerging young group leaders, presented their recent efforts to dissect the functional properties of individual cells with a webinar series organized by the International Society for Experimental Hematology. Here, we provide a summary of the presented methods for cell labeling and clonal tracking and discuss how these different techniques have been employed to study hematopoiesis.
Cellular heterogeneity within defined populations is becoming increasingly evident, while examination of cellular cohorts at the population level may obscure unique properties of individual cells. For example, hematopoietic stem and progenitor cells (HSPCs) are defined as multipotent cells able to give rise to all hematopoietic (myeloid, lymphoid, and thrombo-erythroid) lineages. However, there is growing evidence that subpopulations with inherent lineage bias exist. In addition, it has been postulated that committed progenitor populations may be inherently heterogeneous. Given the heterogeneity of those cellular compartments, single-cell analysis is essential to define their functional potential.
Kokkaliaris, Konstantinos D., et al. “Understanding hematopoiesis from a single-cell standpoint.”Experimental hematology 44.6 (2016): 447-450.