Posttransplant cyclophosphamide (PTCy) is associated with a low incidence of chronic graft-versus-host disease (cGVHD) following hematopoietic stem cell (HSC) transplantation. Previous studies have shown the important roles of B cell immunity in cGVHD development. Here, we investigated the long-term reconstitution of B lymphopoiesis after PTCy using murine models. We first demonstrated that the immune homeostatic abnormality leading to cGVHD is characterized by an initial increase in effector T cells in the bone marrow and subsequent B and Treg cytopenia. PTCy, but not cyclosporine A or rapamycin, inhibits the initial alloreactive T cell response, which restores intra-bone marrow B lymphogenesis with a concomitant vigorous increase in Tregs. This leads to profound changes in posttransplant B cell homeostasis, including decreased B cell activating factors, increased transitional and regulatory B cells, and decreased germinal center B cells. To identify the cells responsible for PTCy-induced B cell tolerance, we selectively depleted Treg populations that were graft or HSC derived using DEREG mice. Deletion of either Treg population without PTCy resulted in critical B cytopenia. PTCy rescued B lymphopoiesis from graft-derived Treg deletion. In contrast, the negative effect of HSC-derived Treg deletion could not be overcome by PTCy, indicating that HSC-derived Tregs are essential for maintaining favorable B lymphopoiesis following PTCy. These findings define the mechanisms by which PTCy restores homeostasis of the B cell lineage and reestablishes immune tolerance.
Yuichi Sumii, Takumi Kondo, Shuntaro Ikegawa, Takuya Fukumi, Miki Iwamoto, Midori Filiz Nishimura, Hiroyuki Sugiura, Yasuhisa Sando, Makoto Nakamura, Yusuke Meguri, Takashi Matsushita, Naoki Tanimine, Maiko Kimura, Noboru Asada, Daisuke Ennishi, Yoshinobu Maeda, Ken-ichi Matsuoka
Loss of function mutations in the DNA methyltransferase 3A (DNMT3A) are seen in a large number of AML patients with normal cytogenetics and are frequently associated with poor prognosis. DNMT3A mutations are an early pre-leukemic event, which when combined with other genetic lesions result in full blown leukemia. Here, we show that loss of Dnmt3a in HSC/Ps results in myeloproliferation, which is associated with hyperactivation of the PI3Kinase pathway. PI3Kα/β or the PI3Kα/δ inhibitor treatment partially corrects myeloproliferation, although the partial rescue is more efficient in response to the PI3Kα/β inhibitor treatment. In vivo RNA-seq analysis on drug treated Dnmt3a–/– HSC/Ps showed a reduction in the expression of genes associated with chemokines, inflammation, cell attachment and extracellular matrix compared to controls. Remarkably, drug treated leukemic mice showed a reversal in the enhanced fetal liver HSC like gene signature observed in vehicle treated Dnmt3a–/– LSK cells as well as a reduction in the expression of genes involved in regulating actin cytoskeleton-based functions including the RHO/RAC GTPases. In a human PDX model bearing DNMT3A mutant AML, PI3Kα/β inhibitor treatment prolonged their survival and rescued the leukemic burden. Our results identify a new target for treating DNMT3A mutation driven myeloid malignancies.
Lakshmi Reddy Palam, Baskar Ramdas, Katelyn M. Pickerell, Santhosh Kumar Pasupuleti, Rahul Kanumuri, Annamaria Cesarano, Megan Szymanski, Bryce M. Selman, Utpal P. Davé, George Sandusky, Fabiana Perna, Sophie Paczesny, Reuben Kapur
To better characterize the heterogeneity of multiple myeloma (MM), we profiled plasma cells (PCs) and their B cell lymphopoiesis in the BM samples from patients with monoclonal gammopathy of undetermined significance, smoldering MM, and active MM by mass cytometry (CyTOF) analysis. Characterization of intra- and interneoplastic heterogeneity of malignant plasmablasts and PCs revealed overexpression of the MM SET domain (MMSET), Notch-1, and CD47. Variations in upregulation of B cell signaling regulators (IFN regulatory factor 4 [IRF-4], CXCR4, B cell lymphoma 6 [Bcl-6], c-Myc, myeloid differentiation primary response protein 88 [MYD88], and spliced X box-binding protein 1 [sXBP-1]) and aberrant markers (CD319, CD269, CD200, CD117, CD56, and CD28) were associated with different clinical outcomes in clonal PC subsets. In addition, prognosis was related to heterogeneity in subclonal expression of stemness markers, including neuroepithelial stem cell protein (Nestin), SRY-box transcription factor 2 (Sox2), Krüppel-like factor 4 (KLF-4), and Nanog. Furthermore, we have defined significantly elevated levels of MMSET, MYD88, c-Myc, CD243, Notch-1, and CD47 from hematopoietic stem cells to PCs in myeloma B cell lymphopoiesis, noted even in premalignant conditions, with variably modulated expression of B cell development regulators, including IRF-4, Bcl-2, Bcl-6, and sXBP-1; aberrant PC markers (such as CD52, CD44, CD200, CD81, CD269, CD117, and CXCR4); and stemness-controlling regulators, including Nanog, KLF-4, octamer-binding transcription factor 3/4 (Oct3/4), Sox2, and retinoic acid receptor α2 (RARα2). This study provides the rationale for precise molecular profiling of patients with MM by CyTOF technology to define disease heterogeneity and prognosis.
Jana Jakubikova, Danka Cholujova, Gabor Beke, Teru Hideshima, Lubos Klucar, Merav Leiba, Krzysztof Jamroziak, Paul G. Richardson, Efstathios Kastritis, David M. Dorfman, Kenneth C. Anderson
Reactivation of human cytomegalovirus (HCMV) from latency is a frequent complication following hematopoietic stem cell transplantation (HSCT). The development of acute graft-versus-host disease (GVHD) is a significant risk factor for HCMV disease. Using a murine GVHD model in animals latently infected with murine CMV (MCMV) we studied preventive and therapeutic interventions in this high-risk scenario of HSCT. Mice latently infected with MCMV reactivated MCMV and developed disseminated MCMV infection concomitant with the manifestations of GVHD. Dissemination was accompanied by accelerated mortality. We demonstrate that MCMV reactivation and dissemination was modulated by MCMV-specific antibodies, thus demonstrating in vivo protective activity of antiviral antibodies. However, the efficacy of serum therapy required repetitive doses of high titer immune serum secondary to the shortened serum half-life of IgG in animals with GvHD. In a complementary approach, treatment of GVHD by adoptive transfer of donor-derived regulatory T cells facilitated production of MCMV-specific antibodies from newly developing donor-derived B cells. Together, our findings strongly suggest that antibodies play a major role in controlling recurrent MCMV infection that follows GVHD and argue for reassessing the potential of antibody treatments as well as therapeutic strategies that enhance de novo antibody development against HCMV.
Martina Seefried, Nadine Hundhausen, Irena Kroeger, Maike Büttner-Herold, Petra Hoffmann, Matthias Edinger, Evelyn Ullrich, Friederike Berberich-Siebelt, William J. Britt, Michael Mach, Thomas H. Winkler
Primary atopic disorders are a group of inborn errors of immunity that skew the immune system toward severe allergic disease. Defining the biology underlying these extreme monogenic phenotypes reveals shared mechanisms underlying common polygenic allergic disease and identifies potential drug targets. Germline gain-of-function (GOF) variants in JAK1 are a cause of severe atopy and eosinophilia. Modeling the JAK1GOF (p.A634D) variant in both zebrafish and human induced pluripotent stem cells (iPSCs) revealed enhanced myelopoiesis. RNA-Seq of JAK1GOF human whole blood, iPSCs, and transgenic zebrafish revealed a shared core set of dysregulated genes involved in IL-4, IL-13, and IFN signaling. Immunophenotypic and transcriptomic analysis of patients carrying a JAK1GOF variant revealed marked Th cell skewing. Moreover, long-term ruxolitinib treatment of 2 children carrying the JAK1GOF (p.A634D) variant remarkably improved their growth, eosinophilia, and clinical features of allergic inflammation. This work highlights the role of JAK1 signaling in atopic immune dysregulation and the clinical impact of JAK1/2 inhibition in treating eosinophilic and allergic disease.
Catherine M. Biggs, Anna Cordeiro-Santanach, Sergey V. Prykhozhij, Adam P. Deveau, Yi Lin, Kate L. Del Bel, Felix Orben, Robert J. Ragotte, Aabida Saferali, Sara Mostafavi, Louie Dinh, Darlene Dai, Katja G. Weinacht, Kerry Dobbs, Lisa Ott de Bruin, Mehul Sharma, Kevin Tsai, John J. Priatel, Richard A. Schreiber, Jacob Rozmus, Martin C.K. Hosking, Kevin E. Shopsowitz, Margaret L. McKinnon, Suzanne Vercauteren, Michael Seear, Luigi D. Notarangelo, Francis C. Lynn, Jason N. Berman, Stuart E. Turvey
BACKGROUND. Chronotherapy is a drug intervention at specific times of the day to optimize efficacy and minimize adverse effects. Its value in hematologic malignancy remains to be explored, in particular in adult patients. METHODS. We performed chronotherapeutic analysis using two cohorts of diffuse large B cell lymphoma (DLBCL) patients undergoing chemotherapy with a dichotomized schedule (morning or afternoon). The effect of a morning or afternoon schedule of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) on survival and drug tolerability were evaluated in a survival cohort (n = 210) and an adverse event cohort (n = 129), respectively. Analysis of ~14,000 healthy subjects was followed to identify the circadian variation in hematologic parameters. RESULTS. Both progression-free survival (PFS) and overall survival (OS) of female, but not male, patients were significantly shorter when patients received chemotherapy mostly in the morning (PFS hazard ratio [HR] 0.357; P = 0.033 and OS HR 0.141; P = 0.032). The dose intensity was reduced in female patients treated in the morning (cyclophosphamide 10%; P = 0.002, doxorubicin 8%; P = 0.002 and rituximab 7%; P = 0.003). This was mainly attributable to infection and neutropenic fever: female patients treated in the morning suffered from a higher incidence of infections (16.7% vs 2.4%) and febrile neutropenia (20.8% vs 9.8%) as compared to those treated in the afternoon. The sex-specific chronotherapeutic effects can be explained by the larger daily fluctuation of circulating leukocytes and neutrophils in females than in males. CONCLUSIONS. In female DLBCL patients, R-CHOP treatment in the afternoon can reduce the toxicity while it improves the efficacy and the survival outcome.
Dae Wook Kim, Ja Min Byun, Jeong-Ok Lee, Jae Kyoung Kim, Youngil Koh
Precision medicine can significantly improve outcomes for cancer patients, but implementation requires comprehensive characterization of tumor cells to identify therapeutically exploitable vulnerabilities. Here we describe somatic biallelic TET2 mutations in an elderly patient with acute myeloid leukemia (AML) that was chemoresistant to anthracycline and cytarabine (Ara-C), but acutely sensitive to 5’-azacitidine (5’-Aza) hypomethylating monotherapy resulting in long-term morphological remission. Given the role of TET2 as a regulator of genomic methylation, we hypothesized that mutant TET2 allele dosage affects response to 5’-Aza. Using an isogenic cell model system and an orthotopic mouse xenograft, we demonstrate that biallelic TET2 mutations confer sensitivity to 5’-Aza compared to cells with monoallelic mutation. Our data argue in favor of using hypomethylating agents for chemoresistant disease or as first line therapy in patients with biallelic TET2-mutated AML and demonstrate the importance of considering mutant allele dosage in the implementation of precision medicine for cancer patients.
Friedrich Stölzel, Sarah E. Fordham, Devi Nandana, Wei-Yu Lin, Helen J. Blair, Claire J. Elstob, Hayden L. Bell, Brigitte Mohr, Leo Ruhnke, Desiree Kunadt, Claudia Dill, Daniel A. Allsop, Rachel E. Piddock, Emmanouela-Niki Soura, Catherine Vida Park, Mohd Fadly, Thahira Rahman, Abrar A. Alharbi, Manja Wobus, Heidi Altmann, Christoph Röllig, Lisa Wagenführ, Gail L. Jones, Tobias Menne, Graham H. Jackson, Helen J. Marr, Jude Fitzgibbon, Kenan Onel, Manja Meggendorfer, Amber Robinson, Zuzanna Bziuk, Emily Bowes, Olaf Heidenreich, Torsten Haferlach, Sara Villar, Beñat Ariceta, Rosa Ayala Diaz, Steven J. Altschuler, Lani Wu, Felipe Prosper, Pau Montesinos, Joaquin Martinez-Lopez, Martin Bornhäuser, James M. Allan
Despite the efficacy of tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia (CML), malignant long-term hematopoietic stem cells (LT-HSC) persist as a source of relapse. However, LT-HSC are heterogenous and the most primitive, drug-resistant LT-HSC subpopulations are not well characterized. In normal hematopoiesis, self-renewal and long-term reconstitution capacity is enriched within LT-HSCs with low c-Kit expression (c-KitLow). Here, using a transgenic CML mouse model, we found that long-term engraftment and leukemogenic capacity were restricted to c-KitLow CML LT-HSC. CML LT-HSC demonstrated enhanced differentiation with expansion of mature progeny following exposure to the c-Kit ligand, stem cell factor (SCF). Conversely, SCF deletion led to depletion of normal LT-HSC but increase in c-KitLow and total CML LT-HSC with reduced generation of mature myeloid cells. CML c-KitLow LT-HSC showed reduced cell cycling, and expressed enhanced quiescence and inflammatory gene signatures. SCF administration led to enhanced depletion of CML primitive progenitors but not LT-HSC after TKI treatment. Human CML LT-HSC with low or absent c-Kit expression were markedly enriched after TKI treatment. We conclude that CML LT-HSC expressing low c-Kit levels are enriched for primitive, quiescent, drug-resistant leukemia initiating cells and represent a critical target for eliminating disease persistence.
Mansi Shah, Harish Kumar, Shaowei Qiu, Hui Li, Mason Harris, Jianbo He, Ajay Abraham, David K. Crossman, Andrew Paterson, Robert S. Welner, Ravi Bhatia
Diamond–Blackfan anemia (DBA) is a genetic blood disease caused by heterozygous loss-of-function mutations in ribosomal protein (RP) genes, most commonly RPS19. The signature feature of DBA is hypoplastic anemia occurring in infants, although some older patients develop multi-lineage cytopenias with bone marrow hypocellularity. The mechanism of anemia in DBA is not fully understood and even less is known about the pancytopenia that occurs later in life, in part because patient hematopoietic stem and progenitor cells (HSPCs) are difficult to obtain, and the current experimental models are suboptimal. We modeled DBA by editing healthy human donor CD34+ HSPCs with CRISPR/Cas9 to create RPS19 haploinsufficiency. In vitro differentiation revealed normal myelopoiesis and impaired erythropoiesis, as observed in DBA. After transplantation into immunodeficient mice, bone marrow repopulation by RPS19+/− HSPCs was profoundly reduced, indicating hematopoietic stem cell (HSC) impairment. The erythroid and HSC defects resulting from RPS19 haploinsufficiency were partially corrected by transduction with an RPS19-expressing lentiviral vector or by Cas9 disruption of TP53. Our results define a tractable, biologically relevant experimental model of DBA based on genome-editing of primary human HSPCs and they identify an associated HSC defect that emulates the pan-hematopoietic defect of DBA.
Senthil Velan Bhoopalan, Jonathan S. Yen, Thiyagaraj Mayuranathan, Kalin D. Mayberry, Yu Yao, Maria Angeles Lillo Osuna, Yoonjeong Jang, Janaka S.S. Liyange, Lionel Blanc, Steven R. Ellis, Marcin W. Wlodarski, Mitchell J. Weiss
Mutations in the BRCA1 tumor suppressor gene, such as 5382insC (BRCA15382insC), give carriers an increased risk for breast, ovarian, prostate and pancreatic cancers. We have previously reported that, in mice, Brca1 deficiency in the hematopoietic system leads to pancytopenia and, as a result, early lethality. Here we explore the cellular consequences of Brca1 null and BRCA1 5382insC alleles in combination with Tp53 deficiency in the murine hematopoietic system. We find that Brca1 and Tp53 co-deficiency leads to a highly penetrant erythroproliferative disorder that is characterized by hepatosplenomegaly and expanded megakaryocyte erythroid progenitor (MEP) and immature erythroid blast populations. The expanded erythroid progenitor populations in both bone marrow and spleen have the capacity to transmit the disease into secondary mouse recipients, suggesting Brca1 and Tp53 co-deficiency provides a new murine model of hematopoietic neoplasia. This Brca1/Tp53 model replicates Poly (ADP-ribose) polymerase (PARP) inhibitor olaparib sensitivity seen in existing Brca1/Tp53 breast cancer models and has the benefits of monitoring disease progression and drug responses via peripheral blood analyses without sacrificing experimental animals. In addition, this erythroid neoplasia develops much faster than murine breast cancer, allowing for increased efficiency of future preclinical studies.
Gerardo Lopez-Perez, Ranjula Wijayatunge, Kelly B. McCrum, Sam R. Holmstrom, Victoria E. Mgbemena, Theodora S. Ross
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