Biology subjects

Zhu, Y. P.

Publications and source records attributed to Zhu, Y. P..

4 recordsLinked to original sources

bioRxiv2024

Comparative single-cell lineage bias in human and murine hematopoietic stem cells

The commitment of hematopoietic stem cells (HSC) to myeloid, erythroid, and lymphoid lineages is influenced by microenvironmental cues, and governed by cell-intrinsic and epigenetic characteristics that are unique to the HSC population. To investigate the nature of lineage commitment bias in human HSC, mitochondrial single cell (sc) ATAC-Sequencing (mt-scATAC-Seq) was used to identify somatic mutations in mitochondrial DNA to act as natural genetic barcodes for tracking the ex vivo differentiation potential of HSC to mature cells. Clonal lineages of human CD34+ cells and their mature progeny were normally distributed across the hematopoietic lineage tree without evidence of significant skewing. To investigate commitment bias in vivo, mice were transplanted with limited numbers of long-term HSC (LT-HSC). Variation in the ratio of myeloid and lymphoid cells between donors, although suggestive of a skewed output, was not altered by increasing numbers of LT-HSC. These data suggest that the variation in myeloid and lymphoid engraftment is a stochastic process influenced by the irradiated recipient niche and not a cell-intrinsic lineage bias of LT-HSC.

genomics↗

bioRxiv2023

The lung employs an intrinsic surfactant-mediated inflammatory response for viral defense

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) causes an acute respiratory distress syndrome (ARDS) that resembles surfactant deficient RDS. Using a novel multi-cell type, human induced pluripotent stem cell (hiPSC)-derived lung organoid (LO) system, validated against primary lung cells, we found that inflammatory cytokine/chemokine production and interferon (IFN) responses are dynamically regulated autonomously within the lung following SARS-CoV-2 infection, an intrinsic defense mechanism mediated by surfactant proteins (SP). Single cell RNA sequencing revealed broad infectability of most lung cell types through canonical (ACE2) and non-canonical (endocytotic) viral entry routes. SARS-CoV-2 triggers rapid apoptosis, impairing viral dissemination. In the absence of surfactant protein B (SP-B), resistance to infection was impaired and cytokine/chemokine production and IFN responses were modulated. Exogenous surfactant, recombinant SP-B, or genomic correction of the SP-B deletion restored resistance to SARS-CoV-2 and improved viability.

immunology↗

bioRxiv2019

CyTOF reveals phenotypically-distinct human blood neutrophil populations differentially correlated with melanoma stage

Understanding neutrophil heterogeneity and its relationship to disease progression has become a recent focus of cancer research. Indeed, several studies have identified neutrophil subpopulations associated with pro- or anti-tumoral functions. However, this work has been hindered by the lack of widely-accepted markers with which to define neutrophil subpopulations. To identify markers of neutrophil heterogeneity in cancer, we utilized single-cell cytometry by time-of-flight (CyTOF) coupled with high-dimensional analysis on blood samples from treatment-naive, melanoma patients. Our efforts allowed us to identify 7 blood-neutrophil clusters, including 2 previously identified individual populations. Interrogation of these neutrophil subpopulations revealed a positive trend between specific clusters and disease stage. Finally, we recapitulated these 7 blood-neutrophil populations via flow cytometry and found that they exhibit diverse capacities for phagocytosis and reactive oxygen species (ROS) production in vitro. In summary, our data provide a refined consensus on neutrophil-heterogeneity markers, enabling a prospective functional evaluation in patients with solid tumors. KEY POINTSO_LICyTOF analysis reveals 7 blood neutrophil clusters correlating with melanoma stage in treatment-naive patients. C_LIO_LINeutrophil clusters by unbiased-calling are recapitulated by flow cytometry and harbor diverse phagocytic and ROS-producing capacities. C_LI

immunology↗

bioRxiv2019

Bone marrow transplantation rescues monocyte recruitment defect and improves cystic fibrosis in mice

One Sentence SummaryIn this study, we demonstrate that correcting the monocyte adhesion defect in CFTR{Delta}F508 mice (CF mice) by bone marrow transplantation significantly improved survival and reduced inflammation.\n\nAbstractCystic fibrosis (CF) is an inherited life-threatening disease accompanied by repeated lung infections and multi-organ inflammation that affects tens of thousands of people worldwide. The causative gene, cystic fibrosis transmembrane conductance regulator (CFTR), is mutated in CF patients. Monocytes from CF patients show a deficiency in integrin activation and adhesion. Since monocytes play critical roles in controlling infections, defective monocyte function may contribute to CF progression. In this study, we demonstrate that monocytes from CFTR{Delta}F508 mice (CF mice) show defective adhesion under flow. Transplanting CF mice with wild-type bone marrow after sublethal irradiation replaced most (60-80%) CF monocytes with wild-type monocytes, significantly improved survival, and reduced inflammation. Wild-type/CF mixed bone marrow chimeras directly demonstrated defective CF monocyte recruitment to the bronchoalveolar lavage and the intestinal lamina propria in vivo. Our findings show that providing wild-type monocytes by bone marrow transfer rescues gastrointestinal (GI) mortality in CF mice, suggesting that wild-type bone marrow stem cells might mitigate CF inflammation.

immunology↗