Hemopoietic precursor cells in human peripheral blood

Abstract

Human peripheral blood contains two types of stem cells that differentiate along the granulocytic pathway. They are separable by their ability to form colonies in agar in vitro (CFU-C) and in plasma clots in diffusion chambers in vivo (CFU-DG). Kinetic studies suggest that CFU-DG represents an intermediate between the still hypothetical human pluripotent stem cell and CFU-C.

Differentiation of subpopulations of human and murine hemopoietic stem cells by hypotonic lysis.

“…(b) The human CFU-DG and CFU-C behave quite differently in an in vivo culture. The number of CFU-DG decreases progressively during a 4-d period, whereas the CFU-C decline initially then increase above the original inoculum number (20). In this work the distinctiveness of CFU-C and CFU-DG is supported by the observed differences in response to hypotonicity.…”

“…Results fromii this and an earlier study (20) suggest that both human and murine CFU-DG are more primitive than CFU-C. Still unanswered remains the question of whether CFU-DG is an expression of differentiation of the pluripotent stem cell; i.e., is it identical with murine CFU-S or its human equivalent, or is it an intermediate stem cell that is not yet comitted to granulocytic differentiation.…”

“…3) marrow exposed to hypotonic lysis for 2 and 3 min, respectively, still contained a considerable number of CFU-C but formed no colonies on subsequent culture in diffusion chambers. On the other hand, in an earlier work (20) in most cases 2-d culture of human hemopoietic cells in vivo resulted in a cell suspension that gave rise to colonies in diffusion chambers (CFU-DG) but not in agar (CFU-C), this time suggesting that CFU-DG do not differentiate in agar.…”

Granulocyte progenitors (CFU-D) in neutrophilic leukemoid reaction are hyporesponsive to macrophage-induced inhibition

“…However, it should be emphasized that the results obtained in the present study do not exclude the possibility of an increased total concentration of CFU-D in NLR, because of higher marrow cellularity in these patients. Similar progenitor number in NLR and controls could also result from the fact that using the DC technique we have investigated the proliferation of a more primitive granulocyte progenitor population, different from that which forms colonies in vitro [18,29]. This cell compartment might be less affected during infection or could be already influenced by feedback inhibition of granulopoiesis [21,22].…”

Granulopoietic precursors in chronic neutropenia

“…In this study we monitored the early phases of granulocytopoiesis in patients with chronic neutropenia by determining the number of cells ' which form granulocyte-containing colonies in diffusion chambers in mice (CFU-DG) and the number of cells which form granulocytic colonies in agar in vitro (CFU-C). Several studies suggest the existence of a parent-progeny relationship between CFU-DG and CFU-C precursors (8)(9)(10). 11 white males employed by a chemical plant were referred to the University of Virginia Hospital for evaluation of chronic neutropenia.…”