Biology subjects

Terreaux, A.

Publications and source records attributed to Terreaux, A..

2 recordsLinked to original sources

bioRxiv2024

Clonal analysis of fetal hematopoietic stem/progenitor cell subsets reveals how post-transplantation capabilities are distributed

It has been proposed that adult haematopoiesis is sustained by multipotent progenitor (MPP) clones that are specified during development. From an immunophenotypic perspective, it is known that hematopoietic stem cell (HSC) and MPPs are present in the fetal liver yet our understanding of how fetal MPPs functionally compare to those in the adult bone marrow is incomplete. Using acute-term transplantations, we found that at a population-level fetal immunophenotypic MPP classes exhibited similar lineage biases as adult cells, albeit with some difference in lymphoid output. Clonal assessment of fetal MPPs engraftment revealed that lineage biases largely resulted from differences in the pattern of single-or bi-lineage differentiation. Immunophenotypic long-term (LT)-and short-term (ST)-HSCs in the fetal liver were distinguished from MPPs according to propensity for clonal multi-lineage differentiation. We also discovered that a large cohort of long-term repopulating units (LT-RU) were within the immunophenotypic ST-HSC population, a significant portion of these were labelled using Flt3-cre. This finding has two implications: (1) use of the CD150+ LT-HSC immunophenotype alone will systematically underestimate the size and diversity of the fetal LT-RU pool; and, (2), given fetal LT-RUs with a ST-HSC immunophenotype have the functional attributes required to persist into adulthood.

developmental biology↗

bioRxiv2022

Analysis of organelle content supports a membrane budding model of platelet biogenesis

Understanding how in vivo platelet biogenesis is undertaken is critical to making on-demand platelet production for clinical use feasible. We recently described the discovery of plasma membrane budding as a major in vivo platelet-producing pathway. In vitro recapitulation of this finding could pave the way towards efficient laboratory-based platelet production. The plausibility of the plasma membrane budding model has been called into question. The foundation of this is the contention that the size and payload composition of plasma membrane buds are not consistent with bona fide platelets. Thus, membrane buds likely represent stages in megakaryocyte-derived microparticle formation. Using 3D super-resolution imaging, we have performed a quantitative comparison of size and organelle content of plasma membrane buds, platelets, and microparticles in the adult mouse bone marrow. We unequivocally demonstrate that the structures we previously described as membrane buds exhibit the same size range as free platelets, that all buds contain organelles, and that membrane buds and free platelets contained an equivalent number of organelles. Crucially, membrane buds and microparticles are completely distinct from each other. To prevent future confusion between the processes of microparticle formation and platelet biogenesis, we propose using the more specific term "pre-platelet membrane buds".

cell biology↗