While platelets are the cellular mediators of thrombosis, platelets are also immune cells. Platelets interact both directly and indirectly with immune cells, impacting their activation and differentiation, as well as all phases of the immune response. Megakaryocytes (Mks) are the cell source of circulating platelets, and until recently Mks were typically only considered as bone marrow (BM) resident cells. However, platelet producing Mks also reside in the lung, and lung Mks express greater levels of immune molecules compared to BM Mks. We therefore sought to define the immune functions of lung Mks. Using single cell RNA-Seq of BM and lung myeloid enriched cells, we found that lung Mks (MkL) had gene expression patterns that are similar to antigen presenting cells (APC). This was confirmed using imaging and conventional flow cytometry. The immune phenotype of Mks was plastic and driven by the tissue immune environment as evidenced by BM Mks having a MkL like phenotype under the influence of pathogen receptor challenge and lung associated immune molecules, such as IL-33. Our in vitro and in vivo assays demonstrated that MkL internalized and processed both antigenic proteins and bacterial pathogens. Furthermore, MkL induced CD4+ T cell activation in a MHC II dependent manner both in vitro and in vivo. These data indicated that Mks in the lung had key immune regulatory roles dictated in part by the tissue environment.
Daphne N. Pariser, Zachary T. Hilt, Sara K. Ture, Sara K. Blick-Nitko, Mark R. Looney, Simon J. Cleary, Estheany Roman-Pagan, Jerry Saunders II, Steve N. Georas, Janelle M. Veazey, Ferralita Madere, Laura Tesoro Santos, Allison M. Arne, Nguyen PT Huynh, Alison C. Livada, Selena M. Guerrero-Martin, Claire E. Lyons, Kelly A. Metcalf Pate, Kathleen E. McGrath, James Palis, Craig Morrell
Gene editing of the erythroid-specific BCL11A enhancer in hematopoietic stem and progenitor cells (HSPCs) from sickle cell disease (SCD) patients induces fetal hemoglobin (HbF) without detectable toxicity as assessed by mouse xenotransplant. Here, we evaluated autologous engraftment and HbF induction potential of erythroid-specific BCL11A enhancer edited HSPCs in four non-human primates. We utilized a single guide RNA (sgRNA) with identical human and rhesus target sequences to disrupt a GATA1 binding site at the BCL11A +58 erythroid enhancer. Cas9 protein and sgRNA ribonucleoprotein complex (RNP) was electroporated into rhesus HSPCs, followed by autologous infusion after myeloablation. We found that gene edits persisted in peripheral blood (PB) and bone marrow (BM) for up to 101 weeks similarly for BCL11A enhancer or control locus (AAVS1) targeted cells. Biallelic BCL11A enhancer editing resulted in robust γ-globin induction, with the highest levels observed during stress erythropoiesis. Indels were evenly distributed across PB and BM lineages. Off-target edits were not observed. Non-homologous end-joining repair alleles were enriched in engrafting HSCs. In summary, we find that edited HSCs can persist for at least 101 weeks post-transplant, and biallelic edited HSCs provide substantial HbF levels in PB red blood cells, together supporting further clinical translation of this approach.
Selami Demirci, Jing Zeng, Yuxuan Wu, Naoya Uchida, Anne H. Shen, Danilo Pellin, Jackson Gamer, Morgan Yapundich, Claire Drysdale, Jasmine Bonanno, Aylin C. Bonifacino, Allen Krouse, Nathaniel Seth Linde, Theresa Engels, Robert E. Donahue, Juan J. Haro-Mora, Alexis Leonard, Tina Nassehi, Kevin Luk, Shaina N. Porter, Cicera R. Lazzarotto, Shengdar Q. Tsai, Mitchell Weiss, Shondra M. Pruett-Miller, Scot A. Wolfe, Daniel E. Bauer, John F. Tisdale
Germ cell tumors (GCTs) are the most common cancer in men between the ages of 15-40. While most patients are cured, those with disease arising in the mediastinum have distinctly poor outcomes. One in every 17 patients with primary mediastinal non-seminomatous GCTs develop an incurable hematologic malignancy and prior data intriguingly suggests a clonal relationship exists between hematologic malignancies and GCTs in these cases. To date however, the precise clonal relationship between GCTs and the diverse additional somatic malignancies arising in such individuals has not been determined. Here, we traced the clonal evolution and characterized the genetic features of each neoplasm from a cohort of fifteen patients with GCTs and associated hematologic malignancies. We discovered that GCTs and hematologic malignancies developing in such individuals evolved from a common shared precursor, nearly all of which harbored allelically imbalanced TP53 and/or RAS pathway mutations. Hematologic malignancies arising in this setting genetically resembled mediastinal GCTs rather than de novo myeloid neoplasms. Our findings argue that this scenario represents a unique clinical syndrome, distinct from de novo GCTs or hematologic malignancies, initiated by an ancestral precursor which gives rise to the parallel evolution of GCTs and blood cancers in these patients.
Justin Taylor, Mark T.A. Donoghue, Caleb Ho, Kseniya Petrova-Drus, Hikmat A. Al-Ahmadie, Samuel A. Funt, Yanming Zhang, Umut Aypar, Pavitra Nagesh Rao, Shweta S. Chavan, Michael Haddadin, Roni Tamari, Sergio Giralt, Martin S. Tallman, Raajit K. Rampal, Priscilla Baez, Rajya Kappagantula, Satyajit Kosuri, Ahmet Dogan, Satish K. Tickoo, Victor E. Reuter, George J. Bosl, Christine A. Iacobuzio-Donahue, David B. Solit, Barry S. Taylor, Darren R. Feldman, Omar Abdel-Wahab
Background. Chimeric antigen receptor (CAR) T cell immunotherapy has achieved complete remission and durable response in highly refractory patients. However, logistical complexity and high costs of manufacturing autologous viral products limit CAR T cell availability. Methods. We reported the early results of a phase I/II trial in B-cell acute lymphoblastic leukemia (B-ALL) patients relapsed after allogeneic hematopoietic stem cell transplantation (HSCT) using donor-derived CD19 CAR T cells generated with the Sleeping Beauty (SB) transposon and differentiated into cytokine induced killer cells (CIK). Results. The cellular product was produced successfully for all patients from the donor peripheral blood (PB) and consisted mostly of CD3+ lymphocytes with 43% CAR expression. Four pediatric and 9 adult patients were infused with a single dose of CAR T cells. Toxicities reported were two grade I and a grade II cytokine release syndrome (CRS) cases at the highest dose, in the absence of graft-versus-host disease (GvHD), neurotoxicity, or dose-limiting toxicities. Six out of 7 patients, receiving the highest doses, achieved CR and CRi at day 28. Five out of 6 patients in CR were also minimal residual disease (MRD)-negative. Robust expansion was achieved in the majority of the patients. CAR T cells were measurable by transgene copy PCR up to 10 months. Integration site analysis showed a positive safety profile and highly polyclonal repertoire in vitro and at early time points after infusion. Conclusion. SB-engineered CAR T cells expand and persist in pediatric and adult B-ALL patients relapsed after HSCT. Anti-leukemic activity was achieved without severe toxicities. Trial registration. clinicaltrials.gov NCT03389035.Funding. This study was supported by grants from AIRC; CRUK; FC AECC; Ministero della salute; FRRB.
Chiara F. Magnani, Giuseppe Gaipa, Federico Lussana, Daniela Belotti, Giuseppe Gritti, Sara Napolitano, Giada Matera, Benedetta Cabiati, Chiara Buracchi, Gianmaria Borleri, Grazia Fazio, Silvia Zaninelli, Sarah Tettamanti, Stefania Cesana, Valentina Colombo, Michele Quaroni, Giovanni Cazzaniga, Attilio Rovelli, Ettore Biagi, Stefania Galimberti, Andrea Calabria, Fabrizio Benedicenti, Eugenio Montini, Silvia Ferrari, Martino Introna, Adriana Balduzzi, Maria Grazia Valsecchi, Giuseppe Dastoli, Alessandro Rambaldi, Andrea Biondi
Store-operated calcium entry (SOCE) is the major route of Ca2+ influx in platelets. The Ca2+ sensor stromal interaction molecule 1 (STIM1) triggers SOCE by forming puncta structures with the Ca2+ channel Orai1 and the inositol trisphosphate receptor (IP3R), thereby linking the endo-/sarcoplasmic reticulum to the plasma membrane. Here, we identified the BAR domain superfamily member bridging integrator 2 (BIN2) as an interaction partner of STIM1 and IP3R in platelets. Deletion of platelet Bin2 (Bin2fl/fl,Pf4-Cre mice) resulted in reduced Ca2+ store release and Ca2+ influx in response to all tested platelet agonists. These defects were a consequence of impaired IP3R function in combination with defective STIM1-mediated SOC channel activation, while Ca2+ store content and agonist-induced IP3 production were unaltered. These defects translated into impaired thrombus formation under flow and a protection of Bin2fl/fl,Pf4-Cre mice in models of arterial thrombosis and stroke. These results establish BIN2 as a central regulator of platelet activation in thrombosis and thrombo-inflammatory disease settings.
Julia Volz, Charly Kusch, Sarah Beck, Michael Popp, Timo Vögtle, Mara Meub, Inga Scheller, Hannah S. Heil, Julia Preu, Michael K. Schuhmann, Katherina Hemmen, Thomas Premsler, Albert Sickmann, Katrin G. Heinze, David Stegner, Guido Stoll, Attila Braun, Markus Sauer, Bernhard Nieswandt
Tissue factor (TF) is the primary initiator of blood coagulation in vivo and the only blood coagulation factor for which a human genetic defect has not been described. As there are no routine clinical assays that capture the contribution of endogenous TF to coagulation initiation, the extent to which reduced TF activity contributes to unexplained bleeding is unknown. Using whole genome sequencing, we identified a heterozygous frameshift variant (p.Ser117HisfsTer10) in F3, the gene encoding TF, causing premature termination of TF ("TFshort") in a woman with unexplained bleeding. Routine hematological laboratory evaluation of the proposita was normal. CRISPR-edited human induced pluripotent stem cells recapitulating the variant were differentiated into vascular smooth muscle and endothelial cells that demonstrated haploinsufficiency of TF. The variant F3 transcript is eliminated by nonsense-mediated decay. Neither overexpression nor addition of exogenous recombinant TFshort inhibited factor Xa or thrombin generation, excluding a dominant negative mechanism. F3+/- mice provide an animal model of TF haploinsufficiency and exhibited prolonged bleeding times, impaired thrombus formation, and reduced survival following major injury. Heterozygous TF deficiency is present in at least 1 in 25,000 individuals and could limit coagulation initiation in undiagnosed individuals with abnormal bleeding but a normal routine laboratory evaluation.
Sol Schulman, Emale El-Darzi, Mary HC Florido, Max Friesen, Glenn Merrill-Skoloff, Marisa A. Brake, Calvin R. Schuster, Lin Lin, Randal J. Westrick, Chad A. Cowan, Robert Flaumenhaft, NIHR BioResource, Willem H. Ouwehand, Kathelijne Peerlinck, Kathleen Freson, Ernest Turro, Bruce Furie
During hemolysis, macrophages in the liver phagocytose damaged erythrocytes to prevent the toxic effects of cell-free hemoglobin and heme. It remains unclear how this homeostatic process modulates phagocyte functions in inflammatory diseases. Using a genetic mouse model of spherocytosis and single-cell RNA sequencing, we found that erythrophagocytosis skewed liver macrophages into a unique anti-inflammatory phenotype that we defined as Marcohigh/Hmoxhigh/MHC-class IIlow erythrophagocytes. This phenotype transformation profoundly mitigated disease expression in a model of an anti-CD40-induced hyperinflammatory syndrome with necrotic hepatitis and in a non-alcoholic steatohepatitis model, representing two macrophage-driven sterile inflammatory diseases. We reproduced the anti-inflammatory erythrophagocyte transformation in vitro by heme-exposure of mouse and human macrophages, yielding a distinctive transcriptional signature that segregated heme-polarized from M1- and M2-polarized cells. Mapping transposase-accessible chromatin in single cells by sequencing (scATAC-seq) defined the transcription factor NFE2L2/NRF2 as a critical driver of erythrophagocytes, and Nfe2l2/Nrf2-deficiency restored heme-suppressed inflammation. Our findings point to a pathway that regulates macrophage functions to link erythrocyte homeostasis with innate immunity.
Marc Pfefferlé, Giada Ingoglia, Christian A. Schaer, Ayla Yalamanoglu, Raphael M. Buzzi, Irina L. Dubach, Ge Tan, Emilio Y. López-Cano, Nadja Schulthess, Kerstin Hansen, Rok Humar, Dominik J. Schaer, Florence Vallelian
Fibrinolysis is initiated by tissue-type plasminogen activator (tPA) and inhibited by plasminogen activator inhibitor 1 (PAI-1). In obese humans, plasma PAI-1 and tPA proteins are increased, but PAI-1 dominates, leading to reduced fibrinolysis and thrombosis. To understand tPA–PAI-1 regulation in obesity, we focused on hepatocytes, a functionally important source of tPA and PAI-1 that sense obesity-induced metabolic stress. We showed that obese mice, like humans, had reduced fibrinolysis and increased plasma PAI-1 and tPA, due largely to their increased hepatocyte expression. A decrease in the PAI-1 (SERPINE1) gene corepressor Rev-Erbα increased PAI-1, which then increased the tPA gene PLAT via a PAI-1/LRP1/PKA/p-CREB1 pathway. This pathway was partially counterbalanced by increased DACH1, a PLAT-negative regulator. We focused on the PAI-1/PLAT pathway, which mitigates the reduction in fibrinolysis in obesity. Thus, silencing hepatocyte PAI-1, CREB1, or tPA in obese mice lowered plasma tPA and further impaired fibrinolysis. The PAI-1/PLAT pathway was present in primary human hepatocytes, and associations among PAI-1, tPA, and PLAT in livers from obese and lean humans were consistent with these findings. Knowledge of PAI-1 and tPA regulation in hepatocytes in obesity may suggest therapeutic strategies for improving fibrinolysis and lowering the risk of thrombosis in this setting.
Ze Zheng, Keiko Nakamura, Shana Gershbaum, Xiaobo Wang, Sherry Thomas, Marc Bessler, Beth Schrope, Abraham Krikhely, Rui-Ming Liu, Lale Ozcan, José A. López, Ira Tabas
The congenital sideroblastic anemias (CSAs) can be caused by primary defects in mitochondrial iron-sulfur cluster (Fe-S) biogenesis. HSCB (heat shock cognate B), which encodes a mitochondrial co-chaperone, also known as HSC20 (heat shock cognate protein 20), is the partner of mitochondrial heat shock protein A9 (HSPA9). Together with glutaredoxin 5 (GLRX5), HSCB and HSPA9 facilitate the transfer of nascent two-iron, two-sulfur ([2Fe-2S]) clusters to recipient mitochondrial proteins. Mutations in both HSPA9 and GLRX5 have previously been associated with CSA. Therefore, we hypothesized that mutations in HSCB could also cause CSA. We screened patients with genetically undefined CSA and identified a frameshift mutation and a rare promoter variant in HSCB in a female patient with non-syndromic CSA. We found that HSCB expression was decreased in patient-derived fibroblasts and K562 erythroleukemia cells engineered to have the patient-specific promoter variant. Furthermore, gene knockdown and deletion experiments performed in K562 cells, zebrafish, and mice demonstrate that loss of HSCB results in impaired Fe-S cluster biogenesis, a defect in red blood cell hemoglobinization, the development of siderocytes, and more broadly perturbs hematopoiesis in vivo. These results further affirm the involvement of Fe-S biogenesis in erythropoiesis and hematopoiesis and define HSCB as a CSA gene.
Andrew Crispin, Chaoshe Guo, Caiyong Chen, Dean R. Campagna, Paul J. Schmidt, Daniel A. Lichtenstein, Chang Cao, Anoop K. Sendamarai, Gordon J. Hildick-Smith, Nicholas C. Huston, Jeanne Boudreaux, Sylvia S. Bottomley, Matthew M. Heeney, Barry H. Paw, Mark D. Fleming, Sarah Ducamp
Acute myeloid leukemia (AML) disrupts the generation of normal blood cells, predisposing patients to hemorrhage, anemia, and infections. Differentiation and proliferation of residual normal hematopoietic stem and progenitor cells (HSPCs) are impeded in AML-infiltrated bone marrow (BM). The underlying mechanisms and interactions of residual hematopoietic stem cells (HSCs) within the leukemic niche are poorly understood, especially in the human context. To mimic AML infiltration and dissect the cellular crosstalk in human BM, we established humanized ex vivo and in vivo niche models comprising AML cells, normal HSPCs, and mesenchymal stromal cells (MSCs). Both models replicated the suppression of phenotypically defined HSPC differentiation without affecting their viability. As occurs in AML patients, the majority of HSPCs were quiescent and showed enrichment of functional HSCs. HSPC suppression was largely dependent on secreted factors produced by transcriptionally remodeled MSCs. Secretome analysis and functional validation revealed MSC-derived stanniocalcin 1 (STC1) and its transcriptional regulator HIF-1α as limiting factors for HSPC proliferation. Abrogation of either STC1 or HIF-1α alleviated HSPC suppression by AML. This study provides a humanized model to study the crosstalk among HSPCs, leukemia, and their MSC niche, and a molecular mechanism whereby AML impairs normal hematopoiesis by remodeling the mesenchymal niche.
Alexander Waclawiczek, Ashley Hamilton, Kevin Rouault-Pierre, Ander Abarrategi, Manuel Garcia Albornoz, Farideh Miraki-Moud, Nourdine Bah, John Gribben, Jude Fitzgibbon, David Taussig, Dominique Bonnet