Biology subjects

Kurtzberg, J.

Publications and source records attributed to Kurtzberg, J..

5 recordsLinked to original sources

bioRxiv2021

Characterizing Human Mesenchymal Stromal Cells Immune Modulatory Potency Using Targeted Lipidomic Profiling of Sphingolipids

Cell therapies are expected to increase over the next decade due to increasing demand for clinical applications. Mesenchymal stromal cells (MSCs) have been explored to treat a number of diseases, with some successes in early clinical trials. Despite early successes, poor MSC characterization results in lessened therapeutic capacity once in vivo. Here, we characterized bone-marrow (BM), adipose derived and umbilical cord tissue MSCs sphingolipids (SLs), a class of bioactive lipids, using liquid chromatography - tandem mass spectrometry. We found ceramide levels differed based upon donors sex in BM-MSCs. We detected fatty acyl chain variants in MSCs from all 3 sources. Linear discriminant analysis revealed that MSCs separated based on tissue source. Principal component analysis showed IFN-{gamma} primed and unstimulated MSCs separated according to their SL signature. Lastly, we detected higher ceramide levels in low IDO MSCs, indicating sphingomeylinase or ceramidase enzymatic activity may be involved in their immune potency.

bioengineering↗

bioRxiv2020

Single-Cell Transcriptomic Attributes and Unbiased Computational Modeling for the Prediction of Immunomodulatory Potency of Mesenchymal Stromal Cells

Mesenchymal stromal cells (MSCs) are currently being tested in numerous clinical trials as potential cell therapies for the treatment of various diseases and due to their potential immunomodulatory, pro-angiogenic, and regenerative properties. However, variabilities in tissue sources, donors, and manufacturing processes and the lack of defined critical quality attributes (CQAs) and clinically relevant mechanism of action (MoA) pose significant challenges to identify MSC cell therapy products with a predictable therapeutic outcome. This also hinders regulatory considerations and broad clinical translation of MSCs. MSC products are often administered to the patient immediately after thawing from cryopreserved vials (out-of-thaw). However, the qualifying quality-control assays are either performed before cryopreservation, or after culturing the post-thaw cells for 24-48 hours (culture-rescued), none of which represent the out-of-thaw product administered to patients. In this study, we performed a broad functional characterization of out-of-thaw and culture-rescue MSCs from bone marrow (BM-MSCs) and cord tissue (CT-MSCs) using macrophage activation and T cell proliferation-based in vitro potency assays and deep phenotypic characterization using single-cell RNA-sequencing. Using this data, we developed unbiased computational models, specifically symbolic regression (SR) and canonical correlation analysis (CCA) models to predict the immunomodulatory potency of MSCs. Overall, our results suggest that manufacturing conditions (OOT vs. CR) have a strong effect on MSC-function on MSC interactions with macrophages and T cells. Furthermore, single-cell RNA-seq analyses of out-of-thaw BM and CT-MSCs indicate a tissue of origin-dependent variability and heterogeneity in the transcriptome profile. Using symbolic regression modeling we identified specific single-cell transcriptomic attributes of MSCs that predict their immunomodulatory potency. In addition, CCA modeling predicted MSC donors with high or low immunomodulatory potency from their transcriptome profiles. Taken together, our results provide a broad framework for identifying predictive CQAs of MSCs that could ultimately help in better understanding of their MOAs and improved reproducibility and manufacturing control of MSCs.

immunology↗

bioRxiv2020

Single-Cell RNAseq of Out-of-Thaw Mesenchymal Stromal Cells Shows Striking Tissue-of-Origin Differences and Inter-donor Cell-Cycle Variations

Mesenchymal stromal cells (MSCs) from a variety of tissue sources are widely investigated in clinical trials, and the MSCs are often administered immediately after thawing the cryopreserved product. While previous reports have examined the transcriptome of freshly-cultured MSCs from some tissues, little is known about the single-cell transcriptomic profiles of out-of-thaw MSCs from different tissue sources. Such understanding could help determine which tissue origins and delivery methods are best suited for specific indications. Here, we characterized cryopreserved MSCs, immediately post-thaw, from bone marrow (BM) and cord tissue (CT), using single-cell RNA sequencing (scRNA-seq). We show that out-of-thaw BM-vs. CT-MSCs have significant differences in gene expression. Gene-set enrichment analyses implied divergent functional potential. In addition, we show that MSC-batches can vary significantly in cell cycle status, suggesting different proliferative vs. immunomodulatory potentials. Our results provide a comprehensive single-cell transcriptomic landscape of clinically and industrially relevant MSC products. HighlightsO_LISingle cell gene expression comparison between Bone-marrow derived MSCs and Cord-tissue derived MSCs C_LIO_LIDonor effects and cell heterogeneity on tissue-specific MSC gene expression C_LIO_LISingle Cell Pooling Enhances Differential Expression Analysis for Bone marrow and Cord tissue MSC samples C_LIO_LIGene ontology reveals tissue specific unique molecular function and pathways C_LI

cell biology↗

bioRxiv2019

Measuring Robustness of Brain Networks in Autism Spectrum Disorder with Ricci Curvature

Ricci curvature is a method for measuring the robustness of networks. In this work, we use Ricci curvature to measure robustness of brain networks affected by autism spectrum disorder (ASD). Subjects with ASD are given a stem cell infusion and are imaged with diffusion MRI before and after the infusion. By using Ricci curvature to measure changes in robustness, we quantify both local and global changes in the brain networks correlated with the infusion. Our results find changes in regions associated with ASD that were not detected via traditional brain network analysis.

neuroscience↗

bioRxiv2019

Human Umbilical Cord blood monocytes, but not adult blood monocytes, rescue brain cells from hypoxic-ischemic injury: Mechanistic and therapeutic implications

Cord blood (CB) mononuclear cells (MNC) are being tested in clinical trials to treat hypoxic-ischemic (HI) brain injuries. Although early results are encouraging, mechanisms underlying potential clinical benefits are not well understood. To explore these mechanisms further, we exposed mouse brain organotypic slice cultures to oxygen and glucose deprivation (OGD) and then treated the brain slices with cells from CB or adult peripheral blood (PB). We found that CB-MNCs protect neurons from OGD-induced death and reduced both microglial and astrocyte activation. PB-MNC failed to affect either outcome. The protective activities were largely mediated by factors secreted by CB-MNC, as direct cell-to-cell contact between the injured brain slices and CB cells was not essential. To determine if a specific subpopulation of CB-MNC are responsible for these protective activities, we depleted CB-MNC of various cell types and found that only removal of CB CD14+ monocytes abolished neuroprotection. We also used positively selected subpopulations of CB-MNC and PB-MNC in this assay and demonstrated that purified CB-CD14+ cells, but not CB-PB CD14+ cells, efficiently protected neuronal cells from death and reduced glial activation following OGD. Gene expression microarray analysis demonstrated that compared to PB-CD14+ monocytes, CB-CD14+ monocytes over-expressed several secreted proteins with potential to protect neurons. Differential expression of five candidate effector molecules, chitinase 3-like protein-1, inhibin-A, interleukin-10, matrix metalloproteinase-9 and thrombospondin-1, were confirmed by western blotting, and immunofluorescence. These findings suggest that CD14+ monocytes are a critical cell-type when treating HI with CB-MNC.

neuroscience↗