Hematopoietic multipotent progenitors (MPPs) regulate blood cell production to meet the evolving demands of an organism. Adult human MPPs remain ill defined, whereas mouse MPPs are well characterized, with distinct immunophenotypes and lineage potencies. Using multi-omic single-cell analyses and functional assays, we identified distinct human MPPs within Lin-CD34+CD38dim/lo adult bone marrow with unique biomolecular and functional properties. These populations were prospectively isolated based on expression of CD69, CLL1, and CD2 in addition to classical markers like CD90 and CD45RA. We identified a CD69+ MPP with long-term engraftment and multilineage differentiation potential, a CLL1+ myeloid-biased MPP, and a CLL1-CD69- erythroid-biased MPP. We used this updated hematopoietic stem and progenitor cell (HSPC) profile to study human and mouse bone marrow cells and observe unique cell-type-specific homology between species and cell-type-specific changes associated with human aging. By identifying and functionally characterizing adult MPP sub-populations, we provide a framework for future studies in hematopoiesis.
Copyright © 2025 The Author(s). Published by Elsevier Inc. All rights reserved.

Systemic inflammation is established as part of late-stage severe lung disease, but molecular, functional, and phenotypic changes in peripheral immune cells in early disease stages remain ill defined. Chronic obstructive pulmonary disease (COPD) is a major respiratory disease characterized by small-airway inflammation, emphysema, and severe breathing difficulties. Using single-cell analyses we demonstrate that blood neutrophils are already increased in early-stage COPD, and changes in molecular and functional neutrophil states correlate with lung function decline. Assessing neutrophils and their bone marrow precursors in a murine cigarette smoke exposure model identified similar molecular changes in blood neutrophils and precursor populations that also occur in the blood and lung. Our study shows that systemic molecular alterations in neutrophils and their precursors are part of early-stage COPD, a finding to be further explored for potential therapeutic targets and biomarkers for early diagnosis and patient stratification.
Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.

The dual interrogation of the transcriptome and proteome with single-cell resolution provides exquisite insights into immune mechanisms in health and disease. Here, we describe a cutting-edge protocol wherein we combine Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-Seq), a technique utilizing antibody-oligonucleotide conjugates (AOCs), with fluorescence-activated cell sorting to enrich rare cell populations. Our protocol incorporates co-staining of cells with both fluorescent antibodies and AOCs simultaneously for subsequent input into the cell sorting and CITE-Seq pipeline. For complete details on the use and execution of this protocol, please refer to Mair et al. (2020).
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