scholarly journals The Infection-Driven Production/Secretion of Inflammatory Cytokines By Circulating Monocytes of Myelofibrosis Is Defective and Is Reactivated after In VivoJAK1/2 Inhibition

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1686-1686
Author(s):  
Martina Barone ◽  
Francesca Ricci ◽  
Marco Romano ◽  
Dorian Forte ◽  
Giuseppe Auteri ◽  
...  

Introduction: Myelofibrosis (MF) is a chronic myeloproliferative neoplasm characterized by hyper-activation of the JAK-STAT pathway. More than half of the patients carries the JAK2V617F mutation. Cytokine overproduction, which is the hallmark of MF, is driven by multiple signaling pathways (NF-KB and MAPK) beyond JAK-STAT and is reduced but not abrogated by Ruxolitinib (RUX). RUX, which is the only JAK1/2 inhibitor approved for the treatment of splenomegaly and symptoms associated with MF, suppresses myeloproliferation (JAK2-driven) and release of pro-inflammatory cytokines (JAK1-driven). Microvesicles (MVs), which have a role in the inflammatory network and are critical players in the regulation of immunity through cytokine signaling, are released from a broad variety of cells with effects on communication among cells. Infections are one of the main causes of morbidity and mortality in MF. The increased infectious risk is thought to arise from dysfunction of key immune cells, including T, natural killer and dendritic cells, which further aggravates after JAK1/2 inhibition therapy. In this scenario, even though MF monocytes (Mo) are over-activated and show inflammatory features, their contribution still needs to be clarified. Aims: To study the role of circulating Mo in the inflammatory network of MF and to investigate whether and to what extent in vivoJAK1/2 inhibition may affects their in vitro cytokine producing ability. Methods: EDTA-anticoagulated peripheral blood was collected from 12 JAK2V617F mutatedMF patients before (Baseline) and after 6 months of RUX therapy and from 10 age/sex-matched healthy donors (HD). After 4 hours in vitro stimulation of mononuclear cells (PBMCs) with lipopolysaccharides (LPS) and in the presence of brefeldin A, the Interleukin (IL)-1β, -6, -10 and Tumor Necrosis Factor (TNF)-α producing Mo (CD14+ cells) were measured by intracellular staining and flow cytometry analysis. In parallel experiments, upon LPS stimulation, free and MVs-bound cytokines (IL-1β, IL-6, IL-10 and TNF-α) have been measured in the supernatants of immunomagnetically isolated HD/MF-Mo by flow cytometry. In addition, after isolation with ultracentrifugation from platelet poor plasma, titrating doses of circulating HD/MF MVs were co-cultured for 24 hours with immunomagnetically isolated HD-Mo and, upon LPS stimulation, inflammatory cytokines secretion was analysed in the supernatants by flow cytometry. Results: To characterize the cytokine producing ability of Mo we analyzed the IL1-β, TNF-α, IL-6 and IL-10 positive MF/HD Mo in response to LPS stimulation. At baseline, the percentages of MF-Mo producing pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) after 4 hours LPS stimulation was highly reduced as compared with the HD counterparts (Fig. 1). No IL-10-positive cells were detected with LPS stimulation (data not shown). To confirm the data, we analysed the free and MVs-bound cytokines in the culture supernatants upon LPS stimulation. At baseline, MF-Mo showed defective capacity to secrete free (Fig.2) and MVs-bound (Fig.3) IL-1β, IL-6, TNF-α and IL-10. Interestingly, the isolated circulating MF-MVs inhibited the LPS-driven inflammatory cytokines in vitro secretion of HD-Mo (Fig.4). Six months-RUX therapy reactivated the in vitro MF-Mo ability to produce intracellular inflammatory cytokines (Fig.1) and to secrete MVs-bound inflammatory cytokines in response to LPS stimulation (Fig.3). Conversely, the MF-Mo ability to secrete free cytokines in the supernatants in response to LPS stimulus remained lower than the HD counterparts (Fig.2). Conclusions: These data further refine the immune dysfunction of MF by demonstrating defective cytokine production/secretion of circulating Mo in response to infectious stimulus (LPS). This defect might be due, at least in part, to the inhibitory activity of circulating MF-MVs. Importantly, in vivoJAK1/2 inhibition ameliorates Mo cytokines production and promotes the MVs-based inflammatory cytokine signaling, suggesting that the increased infectious risk of MF patients undergoing RUX therapy is not due to defective inflammatory signals of circulating Mo. These findings contribute to better interpreting the off-target efficacy of JAK1/2 inhibition and to envisaging strategies aimed at facilitating the immune surveillance in MF. Disclosures Martinelli: BMS: Consultancy; Pfizer: Consultancy; ARIAD: Consultancy; Novartis: Consultancy; Roche: Consultancy. Cavo:janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel accommodations, Speakers Bureau; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; novartis: Honoraria; sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; bms: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Palandri:Novartis: Consultancy, Honoraria.

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 18-19
Author(s):  
Guillermo Montalban Bravo ◽  
Rashmi Kanagal-Shamanna ◽  
Faezeh Darbaniyan ◽  
Irene Ganan-Gomez ◽  
Koji Sasaki ◽  
...  

INTRODUCTION: Myelodysplastic/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T) is a rare hematological disorder characterized by anemia, bone marrow dysplasia with ring sideroblasts and persistent thrombocytosis, and high frequency of SF3B1 and JAK2 mutations. Despite clinical, histological and molecular similarities with MDS with ring sideroblasts (MDS-RS), the clinical outcomes of these entities are diverse. To date, there is no data evaluating specific functional pathways which might explain phenotypic and clinical differences beyond diverse frequencies of JAK2 mutation. METHODS: We evaluated a total of 24 patients (pts) with MDS/MPN-RS-T and 27 pts with MDS-RS. Diagnosis was based on WHO 2017 criteria and confirmed by two independent hematopathologists. Whole bone marrow DNA was subject to 81 gene targeted next-generation sequencing (NGS) analysis. CD34+ cells from bone marrow samples of 4 pts with MDS/MPN-RS-T, 7 pts with MDS-RS and 17 healthy individuals obtained from AllCells (Emeryville, CA) were isolated using the CD34 MicroBead Kit and RNA was isolated using the PicoPure RNA isolation kit. Fastq files were mapped to the human genome (build GRCh38) in TopHat2 using the default options. Differential gene expression analysis was conducted using DESeq2 in R version 3.6.2. Pathway enrichment analysis was performed using gene set enrichment analysis, with the fgsea library in R. RESULTS: Patients with MDS/MPN-RS-T had higher median bone marrow ring sideroblast percentage (47% vs 32%, p=0.04) and absolute neutrophil count (4.34x109/L vs 2.99x109/L, p=0.001). Frequency of identified mutations and their VAFs compared to MDS-RS are shown in Figure 1A. The median number of mutations was higher in MDS/MPN-RS-T than in MDS-RS (3 vs 2, p<0.001). SF3B1 mutations were the most frequent in both entities (MDS/MPN-RS-T: 92%, MDS-RS: 82%), had similar median VAF (34% vs 32%, p=0.619), and involved the hot spot codon K700E in 64% and 43% of MDS-RS and MDS/MPN-RS-T (p=0.227), respectively. As expected, 58% of pts with MDS/MPN-RS-T had JAK2 V617F mutations but were also more likely to have mutations in kinase signaling genes (NF1, SETBP1, CBL, CBLB, FLT3 TKD, MPL) compared to MDS-RS (29% vs 4%, p=0.019). Four (40%) of JAK2 negative MDS/MPN-RS-T had mutations in kinase signaling genes. There were no differences in frequency of TET2 mutations between both entities. However, there was a trend for the median VAF of TET2 mutations in MDS/MPN-RS-T to be lower than in MDS-RS (1.5% vs 21.1%, p=0.177) suggesting a likely subclonal nature of these mutations compared to MDS-RS in which they appeared as dominant events. MDS/MPN-RS-T showed distinct transcriptomic profile compared to both healthy controls and MDS-RS. Compared to healthy controls, a total of 2 pathways were significantly upregulated and 58 were downregulated in MDS/MPN-RS-T while 5 pathways were upregulated and 69 were downregulated in MDS-RS. Compared to MDS-RS, a total of 29 pathways were significantly upregulated and 26 were downregulated in MDS/MPN-RS-T. The most significantly upregulated pathways in MDS/MPN-RS-T included genes involved in platelet activation and aggregation, cytokine signaling, and signaling through GPC receptors (Figure 1C). Compared to both healthy control and MDS-RS, MDS/MPN-RS-T was characterized by downregulation of genes involved in DNA damage response, regulation of apoptosis, telomere maintenance and RNA synthesis (Figure 1D). MDS-RS was characterized by downregulation of genes involved in signaling by GPC receptors and MAPK signaling, mRNA splicing, cytokine signaling and signaling through interleukins compared to both control and MDS/MPN-RS-T (Figure 1C). CONCLUSIONS: MDS/MPN-RS-T is characterized by co-dominance of SF3B1 and JAK2 mutations and presence of minor kinase signaling mutations not observed in MDS-RS. Upregulation of cytokine and interleukin signaling mediated through GPC receptors, and downregulation of genes involved in apoptosis and DNA damage are unique transcriptomic features of MDS/MPN-RS-T likely driven by genotype. These unique genomic and transcriptomic characteristics of MDS/MPN-RS-T supports the classification of MDS/MPN-RS-T based on genomic features beyond presence of SF3B1 mutation, and might represent potential therapeutic avenues for this rare disease. Figure Disclosures Sasaki: Otsuka: Honoraria; Pfizer Japan: Consultancy; Novartis: Consultancy, Research Funding; Daiichi Sankyo: Consultancy. Kantarjian:Sanofi: Research Funding; Abbvie: Honoraria, Research Funding; Janssen: Honoraria; BMS: Research Funding; Actinium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive biotechnologies: Honoraria; Aptitute Health: Honoraria; Immunogen: Research Funding; Jazz: Research Funding; Daiichi-Sankyo: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; BioAscend: Honoraria; Novartis: Honoraria, Research Funding; Delta Fly: Honoraria; Pfizer: Honoraria, Research Funding; Oxford Biomedical: Honoraria; Ascentage: Research Funding. Garcia-Manero:Astex Pharmaceuticals: Consultancy, Honoraria, Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Amphivena Therapeutics: Research Funding; Acceleron Pharmaceuticals: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Research Funding; Onconova: Research Funding; Merck: Research Funding; Novartis: Research Funding; H3 Biomedicine: Research Funding; Helsinn Therapeutics: Consultancy, Honoraria, Research Funding; Jazz Pharmaceuticals: Consultancy.


2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Dan Li ◽  
Chenyu Li ◽  
Yan Xu

Abstract Background and Aims Acute kidney injury (AKI), commonly appeared in cardiac arrest, surgery and kidney transplantation which involved in ischemia-reperfusion (IR) injury of kidney. However, the mechanisms underlying inflammatory response in IR AKI is still unclear. Method Public dataset showed kruppel-like factor 6 (KLF6) was significantly highly expressed (P<0.05) in AKI, implies KLF6 might be associated with AKI. To evaluate the mechanism of KLF6 on IR AKI, 30 rats were randomly divided into sham and IR group, and were sacrificed at 0 h, 3 h, 6 h, 12 h or 24 h after IR. Results The results showed KLF6 expression was peaking at 6 h after IR, and the expression of pro-inflammatory cytokines MCP-1 and TNF-α were increased both in serum and kidney tissues after IR, while anti-inflammatory cytokine IL-10 was decreased after IR. Furthermore, in vitro results showed KLF6 knock-down reduced the pro-inflammatory cytokines expression and increased the anti-inflammatory cytokines expression. Conclusion These results suggest that (1) KLF6 might be a novel biomarker for early diagnosis of AKI and (2) targeting KLF6 expression may offer novel strategies to protect kidneys from IR AKI Figure KLF6, AKI, Control Inflammation


2016 ◽  
Vol 11 (6) ◽  
pp. 1934578X1601100
Author(s):  
Anna K Gazha ◽  
Lyudmila A. Ivanushko ◽  
Eleonora V. Levina ◽  
Sergey N. Fedorov ◽  
Tatyana S. Zaporozets ◽  
...  

The action of seven polyhydroxylated sterol mono- and disulfates (1-7), isolated from ophiuroids, on innate and adaptive immunity was examined in in vitro and in vivo experiments. At least, three of them (1, 2 and 4) increased the functional activities of neutrophils, including levels of oxygen-dependent metabolism, adhesive and phagocytic properties, and induced the expression of pro-inflammatory cytokines TNF-α and IL-8. Compound 4 was the most active for enhancing the production of antibody forming cells in the mouse spleen.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4094-4094
Author(s):  
Dorian Forte ◽  
Daria Sollazzo ◽  
Nicola Polverelli ◽  
Romano Marco ◽  
Lara Rossi ◽  
...  

Abstract Introduction. Myelofibrosis (MF), an acquired clonal disorder of the hematopoietic stem/progenitor cell (HSPC) with a dysregulation in JAK/STAT signalling (mutations in JAK2, MPL and Calreticulin (CALR) genes), is characterized by a state of chronic inflammation. It is argued that the up-regulated production of proinflammatory cytokines by both HSPCs and the surrounding stromal cells generates a microenvironment that selects for the malignant clone. Only recently, it has been hypothesized that the sustained inflammatory microenvironment of MF can alter crucial biological processes, leading to genomic instability and cancer progression. Here we tested the in vitro functional effects of pivotal players of the inflammatory microenvironment (the extracellular ATP nucleotide and selected cytokines, such as Interleukin (IL)-1β, Tumor Necrosis Factor (TNF)-α or the Tissue Inhibitor of Metalloproteinases-1 (TIMP-1)) on the HSPCs from MF patients. Methods: Circulating CD34+/CD34+ CD38- cells from MF patients (JAK2V617F (17 cases) and CALR (9 cases) mutations) or cord blood (CB; 8 samples) were phenotypically and functionally characterized after in vitro incubation with or without ATP (1000 μM), IL-1β (10 ng/mL), TNF-α (10 ng/mL) or TIMP-1 (100 ng/mL) (alone or in combination). Cells were then analyzed for survival/apoptosis (Annexin-V/Propidium Iodide staining), phenotype (evaluation of CD63 (TIMP-1 receptor), CXCR4 and CD38 expression), cell cycle and clonogenic capacity. Migration was assessed first towards a CXCL12 gradient in the presence or absence of the pro-inflammatory factors. In parallel experiments, CD34+ cells from MF patients were co-cultured with normal mesenchymal stromal cells (MSCs) in the presence or absence of the pro-inflammatory cytokines and then evaluated for their ability to migrate towards a CXCL12 gradient. Plasma TIMP-1, TNF-α, IL-1β and CXCL12 were measured by ELISA assay. Results: The plasma levels of TIMP-1, TNF-α, IL-1β, CXCL12 and the number of circulating CD34+, CD34+ CD38-, CD34+ CD63+, CD34+ CD184+ cells were increased in MF patients. According to mutational status, the CD34+ CD63+ cells were higher in the CALR+ patients. The survival of MF CD34+ cells was strongly stimulated by in vitro incubation with TNF-α or IL-1β as compared with the CB-derived CD34+ cells or untreated cells. By multiple cytokine combinations, IL-1β/TIMP-1, IL-1β /ATP or IL-1β /TNF-α treatments significantly promote the survival of MF CD34+ cells as compared with the normal counterparts or the untreated cells. Various combinations with IL-1β were also effective in stimulating survival of CD34+CD38- cells. IL-1β/TIMP-1 and IL-1β/TNF-α/TIMP-1, but not factors alone, significantly increased the CFU-C growth of MF patients as compared with the CB-derived counterparts and the untreated cells. Moreover, comparing CALR+ vs JAK2V617F+ patients, the colony formation of JAK2V617F+ patients was mainly promoted by the IL-1β/TNF-α treatment. Along with clonogenic capacity stimulation, exposure of CD34+ cells from MF patients to IL-1β/TNF-α/TIMP-1 significantly increases the S-phase cells, suggesting that these pro-inflammatory factors stimulated cell-cycle progression in dormant CD34+ MF cells. Migration of CD34+ cells from MF was significantly increased in CXCL12 treated cells. In addition, exposure of MF CD34+ cells to IL-1β/TNF-α, IL-1β/TIMP-1 or IL-1β/TNF-α/TIMP-1 significantly promotes cell migration in comparison with the CB-derived counterparts or SDF-1 alone. MF migrated cells in the presence of IL-1β/TNF-α significantly upregulate CD63 expression. Intriguingly, colony formation of MF migrated CD34+ cells in the presence of IL-1β/TNF-α or IL-1β/TNF-α/TIMP-1 was potently increased. Finally, co-culture systems with normal MSCs in the presence of pro-inflammatory factors revealed that MF CD34+ cells display increased migration ability toward CXCL12 gradient. Conclusions: Altogether our findings suggest that in MF the inflammatory niche plays a key role in the maintenance of the malignant clone. Thus, the interplay between the pro-inflammatory cytokines promote and select the HSPCs with higher proliferative activity, clonogenic potential and migration capability. Targeting these microenvironmental interactions may be a clinically relevant approach. D.F. and D.S. equally contributed Disclosures Martinelli: Pfizer: Consultancy; Ariad: Consultancy; Novartis: Consultancy, Speakers Bureau; MSD: Consultancy; AMGEN: Consultancy; BMS: Consultancy, Speakers Bureau; ROCHE: Consultancy.


2011 ◽  
Vol 49 (2) ◽  
pp. 168-173
Author(s):  
F. Sachse ◽  
K. Becker ◽  
T.J. Basel ◽  
D. Weiss ◽  
C. Rudack

BACKGROUND: Nasal polyposis (NP) is considered a subgroup within chronic rhinosinusitis. NP can be further subdivided into aspirin sensitive- and aspirin tolerant types (ASNP/ ATNP). Although the true etiology of NP has not been identified so far, it is agreed that NP represents an inflammatory disease of the nasal mucosa. Alterations of cellular kinase activities including that of IKK-2 might play a role in this inflammatory process. METHODS: Paraffin sections of ASNP, ATNP and controls were immunostained with Phospho-IkB-α antibody that detects the direct IKK-2 product (IkB-α. Intensity of epithelial staining was analysed semi-quantitatively by two independent observers. In cultured nasal polyp epithelial cells (NPECs) epithelial derived cytokines IL-8 and GRO α were induced by TNF-α or Staphylococcal supernatants and subsequently repressed by IKK-2 inhibitor TPCA-1. RESULTS: Significant Phospho-IkB-α staining was observed in the nasal epithelium of ASNP compared to ATNP and controls suggesting strong IKK-2 activation in patients with ASNP in vivo. In vitro, pro-inflammatory cytokines IL-8 and GRO-α in NPECs were significantly repressed by TPCA-1. CONCLUSION: IKK-2 activity is increased in the subgroup of ASNP. IL-8 and GRO-α responses were repressed by IKK-2 inhibitor TPCA-1 in vitro. IKK-2 inhibitors might represent a potential target for anti-inflammatory intervention in ASNP.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3141-3141
Author(s):  
Seamus B Hughes ◽  
David Spiciarich ◽  
Richard D. Press ◽  
Sarah L Thompson ◽  
Jerald P. Radich ◽  
...  

Abstract Mutations in CSF3R (aka GCSFR) occur in the majority of patients with Chronic Neutrophilic Leukemia (CNL) and also are rarely found in adult and pediatric Acute Myeloid Leukemia. The most common CSF3R mutation in CNL is T618I (aka T595I), a point mutation in the membrane-proximal extracellular domain that causes ligand independence. Mutations that lead to a premature stop in the cytoplasmic domain are also found in CNL and result in increased expression of CSF3R on the cell surface. Understanding the biology of other novel mutations in CSF3R may lead to insight into both receptor biology and oncogenesis. The CSF3R N610H mutation was identified in a patient with a myeloproliferative neoplasm, which was most consistent with a JAK2, CALR, MPL mutation negative primary myelofibrosis. This patient had a history of mild leukocytosis for several years with most recent white blood cell counts between 13.3 and 15.3 x 103/uL. A bone marrow biopsy revealed 90% cellularity with mildly increased reticulin fibrosis, increased myeloid to erythroid ratio, no overt dysplasia, and less than 5% blasts. The cells were karotypically normal with a micro deletion of the 3' end of PDGFRB (5q) identified by FISH at 59%. The patient has had minimal symptoms with no anemia or thrombocytopenia and is currently being monitored but not receiving any intervention. The patient's bone marrow was next-generation sequenced using a 42-gene myeloid malignancy targeted mutation hotspot panel which revealed a mutation at N610H in CSF3R at a 50% mutant allele frequency. Given its proximity to the most common CSF3R mutation found in Chronic Neutrophilic Leukemia (T618I, aka T595I), we were interested in understanding whether the N610H mutation might contribute to disease biology. N610 (also known as N586 in the traditional numbering system that does not include the signal peptide) is part of an N-X-T motif, which is a consensus sequence for N-linked glycosylation. Haniu et al (Biochemistry 1996) demonstrated that N610 is one of 8 sites that are N-glycosylated on CSF3R. We confirm by mass spectrometry (MS) based analysis that N610 is occupied with a bisecting complex N-glycan (in vitro). We further found that the N610H mutation and a more conservative N610Q substitution are highly activating in CSF3R, leading to cytokine-independent growth in the murine Ba/F3 cell line. Furthermore, like the T618I mutation, these mutations render the receptor ligand-independent. N610H and N610Q lead to a robust increase in downstream signaling through the JAK/STAT pathway as demonstrated by an increase in the levels of phospho-STAT3. The loss of N-glycosylation in the membrane-proximal region of CSF3R may therefore increase ligand-independent receptor activation and promote oncogenesis. This study highlights the insight that rare human mutations can provide into the relationship between receptor structure and function. Disclosures Radich: Ariad: Consultancy; Novartis: Consultancy, Research Funding; Gilliad: Consultancy; Incyte: Consultancy. Bertozzi:GlaxoSmithKline: Membership on an entity's Board of Directors or advisory committees; Catalent Biologics: Membership on an entity's Board of Directors or advisory committees; Verily: Membership on an entity's Board of Directors or advisory committees; Enable Bioscience: Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Oh:CTI: Research Funding; Janssen: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2466-2466 ◽  
Author(s):  
Praveen Kaudlay ◽  
Haiying Hua ◽  
Guansheng He ◽  
Darren J Newton ◽  
Abraham M Varghese ◽  
...  

Abstract Introduction Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired bone marrow disorder characterised by intravascular hemolysis and hemoglobinuria, potentially life-threatening thrombosis and an association with aplastic anemia. Most of the clinical features and complications of PNH are due to the unopposed activity of complement due to the absence of CD59 and CD55, two key regulators of complement. Eculizumab prevents the cleavage of C5 complement thereby preventing terminal complement activity and protecting PNH cells from lysis. The inhibition of C5 preserves the early part of complement pathway and leads to the build up of C3 on the PNH red cells, perhaps in part due to their lack of CD55. The majority of PNH patients receiving eculizumab have evidence of extravascular haemolysis that can be clinically significant, including with anemia, hyperbilirubinemia and in some a continued requirement for transfusions. This extravascular hemolysis in thought to be due to the C3 loading of PNH red cells. Methods We report the C3-loading of the PNH red cells from 119 patients treated with eculizumab and correlate this with hemoglobin, LDH, bilirubin, reticulocytes and transfusions. We have studied genetic polymorphisms that affect both C3 and FCγR. We have genotyped 46 eculizumab patients for a functional mutation in the C3 gene (rs2230199). The two alleles of this gene can be distinguished by the presence or absence of a HindIII restriction site that distinguishes the electophoretically slow (arg80) from the electrophoretically fast (gly80) allotype. The fast (C3F) allotype allele of this snp is associated with a range of disorders including age-related macular degeneration, IgA nephropathy, systemic vasculitis and partial lipodystrophy. APL-1 is a small cyclic peptide that binds to and inhibits the activation of complement C3. APL-2 is a large conjugate of APL-1 with enhanced bioactivity and a long systemic half-life. APL-1 and APL-2 molecules as well as other complement inhibitors were studied for lysis of red cells and C3 loading in vitro in a modified Ham test in which flow cytometry was used to identify non-lysed cells. Results Out of the 119 Eculizumab treated patients, 55 (46.2%) required at least one transfusion on treatment. 110 patients had C3 detectable by flow cytometry on their PNH red cells (mean of 19.8%; range: <0.1 to 64.6%). C3-loading was not seen on the normal red cells from the same patients on treatment nor on the PNH red cells in patients not receiving eculizumab. The mean LDH (735IU/l) and reticulocyte count (193 x 109/l) were not statistically significantly different for the transfused group compared to the non-transfused group (518 and 163 respectively). Mean PNH C3 and RBC C3 did not differ stastistically between the transfused and non-transfused groups (26.20 Vs 24.78 PNH C3;15.96 vs 15.09 RBC C3 respectively). We studied one functional polymorphism in the Fcγ receptor but this showed no correlation with haemolytic parameters. Conversely, for the C3 polymorphism eculizumab-treated patients homozygous for the slow (C3S) allele had a significantly higher degree of C3 loading on PNH red blood cells with C3S/C3S having a mean of 33.7% C3 loaded PNH red cells (n=26), C3S/C3F 19.0% (n=19) and C3F/C3F 12.8% (n=3)(all P<0.01). Homozygote C3S also had increased reticulocytes (P<0.01) and bilirubin (P<0.01). The C3S allele has previously been shown to be more efficient in a haemolysis assay using sheep erythrocytes. This polymorphism appears to explain much of the variation in C3 loading between different patients with PNH. In vitro experiments show that inhibitors of C5, such as eculizumab, protect the PNH red cells from lysis but lead to a very rapid deposition of C3 on the PNH red cells. However both APL1 and APL2 demonstrated similar protection of PNH red cell lysis with virtually no C3 loading on PNH red cells. Conclusion A significant proportion of patients on eculizumab experience extravascular haemolysis with the majority of patients developing C3 loading. We show for the first time that a functional polymorphism in the C3 gene is associated parameters of hemolysis. The S(low) allele alters the function of C3 protein and appears to be associated with extravascular haemolysis in patients with PNH. The C3 inhibitors, APL-1 and APL-2, protect PNH red cells and prevent C3 loading in vitro and if safe to be given chronically would be expected to reduce extravascular hemolysis significantly. Disclosures: Hill: Alexion Pharmaceuticals: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau. Kelly:Alexion: Honoraria. Richards:Alexion Pharmaceuticals: Honoraria, Membership on an entity’s Board of Directors or advisory committees. Hillmen:Alexion: Honoraria, Membership on an entity’s Board of Directors or advisory committees.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 237-237 ◽  
Author(s):  
Michael P. Rettig ◽  
Matthew Holt ◽  
Julie Prior ◽  
Sharon Shacham ◽  
Michael Kauffman ◽  
...  

Abstract Background Exportin 1 (XPO1) also called CRM1, is a widely expressed nuclear export protein, transporting a variety of molecules including tumor suppressor proteins and cell cycle regulators. Targeted inhibition of XPO1 is a new strategy to restore multiple cell death pathways in various malignant diseases. SINEs are novel, orally available, small molecule Selective Inhibitors of Nuclear Export (SINE) that specifically bind to XPO1 and inhibit its function. Methods We used WST-1 cell proliferation assays, flow cytometry, and bioluminescence imaging to evaluate the efficacy of multiple SINEs to induce apoptosis alone and in combination with cytarabine (AraC) or doxorubicin in vitro in chemotherapy sensitive and resistant murine acute promyelocytic leukemia (APL) cells. This murine model of APL was previously generated by knocking in the human PML-RARa cDNA into the 5’ regulatory sequence of the cathepsin G locus (Westervelt et al. Blood, 2003). The abnormal co-expression of the myeloid surface antigen Gr1 and the early hematopoietic markers CD34 and CD117 identify leukemic blasts. These Gr1+CD34+CD117+ APL cells partially retain the ability to terminally differentiate toward mature granulocytes (mimicking more traditional AML models) and can be adoptively transferred to secondary recipients, which develop a rapidly fatal leukemia within 3 weeks after tumor inoculation. To assess the safety and efficacy of SINEs in vivo, we injected cryopreserved APL cells intravenously via the tail vein into unconditioned genetically compatible C57BL/6 recipients and treated leukemic and non-leukemic mice (n=15/cohort) with 15 mg/kg of the oral clinical staged SINE KPT-330 (currently in Phase 1 studies in patients with solid tumors and hematological malignancies) alone or in combination with 200 mg/kg cytarabine every other day for a total of 2 weeks. Peripheral blood was obtained weekly from mice for complete blood counts and flow cytometry to screen for development of APL. Results The first generation SINE, KPT214, inhibited the proliferation of murine APL cell lines in a dose and time dependent manner with IC50 values ranging from of 95 nM to 750 nM. IC50 values decreased 2.4-fold (KPT-185) and 3.5-fold (KPT-249) with subsequent generations of the SINEs. Consistent with the WST-1 results, Annexin V/7-aminoactinomycin D flow cytometry showed a significant increase of APL apoptosis within 6 hours of KPT-249 application. Minimal toxicity against normal murine lymphocytes was observed with SINEs even up to doses of 500 nM. Additional WST-1 assays using AraC-resistant and doxorubicin-resistant APL cell lines demonstrated cell death of both chemotherapy-resistant cell lines at levels comparable to the parental chemosensitive APL cell lines. Combination therapy with low dose KPT-330 and AraC showed additive effects on inhibition of cell proliferation in vitro. This additive effect of KPT-330 and chemotherapy on APL killing was maintained in vivo. As shown in Figure 1, treatment with AraC or KPT-330 alone significantly prolonged the survival of leukemic mice from a median survival of 24 days (APL + vehicle) to 33 days or 39 days, respectively (P < 0.0001). Encouragingly, combination therapy with AraC + KPT-330 further prolonged survival compared to monotherapy (P < 0.0001), with some mice being cured of the disease. Similar in vivo studies with the AraC-resistant and doxorubicin-resistant APL cells are just being initiated. Conclusions Our data suggests that the addition of a CRM1 inhibitor to a chemotherapy regimen offers a promising avenue for treatment of AML. Disclosures: Shacham: Karyopharm Therapeutics Inc.: Employment, Equity Ownership, Membership on an entity’s Board of Directors or advisory committees, Patents & Royalties. Kauffman:Karyopharm Therapeutics Inc.: Employment, Equity Ownership, Membership on an entity’s Board of Directors or advisory committees, Patents & Royalties. McCauley:Karyopharm Therapeutics, Inc: Employment, Equity Ownership.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3592-3592
Author(s):  
Paola Delbini ◽  
Viola Ghiandai ◽  
Maria Domenica Cappellini ◽  
Lorena Duca ◽  
Isabella Nava ◽  
...  

Gaucher disease type 1 is the most common inherited lysosomal storage disorder caused by the deficiency of lysosomal β-glucocerebrosidase (GBA, acid-β-glucosidase), required for the degradation of glycosphingolipids. The deficiency of the enzyme results in the widespread accumulation of glucosylceramide in macrophages, leading to anemia, thrombocytopenia and coagulopathy, visceral (hepatosplenomegaly, lungs) and skeletal manifestations (deformities, fractures, avascular osteonecrosis). However, GD manifestations are caused not only by the burden of glucosylceramide storage, but also by macrophage activation. It seems that GD reflects the downstream consequences of inappropriate macrophage activation, with the release of pro-inflammatory cytokines and other responses to storage material. The aim of this study is to assess in vitro phenotypic characterization, functional properties and gene expression anaysis of GD1 macrophages in order to understand their possible role in inflammation and in impairment of iron metabolism occurring in GD patients. Monocytes were isolated from buffy coats of GD patients (n=3) and controls (n=3) by applying an in vitro model protocol. Monocytes were expanded in ImmunoCult™ medium and 1% ZellShield® antibiotic cocktail. Differentiation was induced in ImmunoCult™ medium, 50 ng/mL M-CSF and 50 ng/mL GM-CSF. To mimic the in vivo condition, macrophage population was loaded with erythrocytes ghosts isolated from GD patients. Cell morphology was analyzed on cytocentrifuged preparations stained with May-Grünwald Giemsa (MGG). Surface marker expression (CD11, CD33, CD68, CD64) were examined by flow cytometry to evaluate macrophages differentiation and phenotype. Gene expression analysis of iron metabolism-related genes was evaluated through Real-Time Quantitative PCR. Biochemical indices (NTBI, GDF15, sTfR and chitotriosidase) were analyzed in supernatant through ELISA assay. Flow cytometry analysis (Fig.1) revealed that without erythrocytes ghosts (preM∅), the proportion of CD11+/CD68+ macrophage population was similar between GD patients and control. However, in GD macrophages, when loaded with Gaucher erythrocytes ghosts (M∅+ghosts), the proportion of CD11++/CD68++ cells increased (36.4%), as a reflection of a more pro-inflammatory phenotype. Treated controls showed no differences. To further characterize these different macrophages subpopulations in GD patients, we used an additional parameter, CD64, because CD64/CD68 markers are specific for M1/M2 polarization. GD M∅+ghosts showed an higher percentage of CD64++/CD68++ population (78%) in comparison of GD pre-M∅ (45%) and controls (36%), confirming a M1 proinflammatory phenotype of GD macrophages loaded with erythrocytes ghosts. Under microscope evaluation, GD M∅+ghosts presented high number of spindle-shaped fibroblastoid, typically M1 phenotype cells, rather than large flat-round cells (M2 cells). Moreover, morphological staining of these cells confirmed the typical features of GD cells with basophilic cytoplasm with characteristic crinkles. Controls showed no differences in macrophage features when loaded with erythrocytes ghosts. To confirm the pro-inflammatory potential of GD M∅+ghosts, high levels of pro-inflammatory mediators TNF-α, IL-1β and (s)TfR) were found in supernatant of GD M∅+ghosts (72,9±8,5, 24,7±2,7 and 3,1±4,4, respectively) compared to pre-M∅ and controls. High GDF15 expression in GD M∅+ghosts (14,77±5,87) respect to preM∅ (1,80±1,1) and controls (1,67±0,8) was observed. By gene expression analysis we observed in GD M∅+ghosts an higher HAMP expression (28,13±5,63) compared to preM∅ (2,49±1,5) and controls (0,71±0,02), and a lower SLC40A1 expression (0,01±0,00) compared to GD preM∅ (0,16±0,05) and controls (0,79±0,25). No significant differences in TFRC and GDF11 expression between GD preM∅ and M∅+ghosts in GD patients were observed. These preliminary data suggest that GD macrophages, when stimulated, display a proinflammatory potential. These activated M1 macrophages could contribute to an inflammatory-producing environment, triggering hepcidin and ferroportin expression by an autocrine/paracrine mechanism and leading to dysregulation of iron distribution. Disclosures Cappellini: CRISPR Therapeutics: Membership on an entity's Board of Directors or advisory committees; Vifor Pharmaceutical: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Honoraria; Genzyme/Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees. Motta:Sanofi-Genzyme: Honoraria, Membership on an entity's Board of Directors or advisory committees.


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