NKG2D-Mediated Marrow Injury in Paroxysmal Nocturnal Hemoglobinuria and Its Related Disorders.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3674-3674
Author(s):  
Nobuyoshi Hanaoka ◽  
Tatsuya Kawaguchi ◽  
Kentaro Horikawa ◽  
Shoichi Nagakura ◽  
Sonoko Ishihara ◽  
...  

Abstract Immune mechanism is considered to exert in the pathogenesis of marrow failure in paroxysmal nocturnal hemoglobinuria (PNH), idiopathic aplastic anemia (AA) and myelodysplastic syndromes (MDS); however, the molecular events are unknown. We have currently reported the appearance of NKG2D ligands such as cytomegalovirus glycoprotein UL16 binding proteins (ULBPs) and MHC class I-related chains A and B (MICA/B) on granulocytes and CD34+ marrow cells of some patients with PNH and its related diseases (Hanaoka N, et al. Blood. 2006;107:1184–1191). ULBP and MICA/B are stress-inducible membrane proteins that appear in infection and transformation. The ligands share NKG2D receptor on lymphocytes such as NK, CD8+ T, and γδ T-cells and promote activation of the lymphocytes. Cells expressing the ligands are then deadly injured by NKG2D+ lymphocytes (Groh, PNAS 1996; Cosman, Immunity 2001). Indeed, cells expressing NKG2D ligands were killed in vitro by autologous NKG2D+ lymphocytes of our patients (Hanaoka N, et al. Blood. 2005;106:304a; Blood. 2006;108:295a). In further analysis, ligands were detected on granulocytes in 47 (53%) of 88 patients: 11 (58%) of 19 PNH, 28 (60%) of 47 AA, and 8 (36%) of 22 refractory anemia. Ligands were also detected on immature bone marrow cells in all 11 patients (3 PNH, 5 AA, and 3 refractory anemia) who permitted analysis of their marrow cells. In the patients, it is conceivable that blood cells were exposed to a certain stress to induce NKG2D ligands, leading to NKG2D-mediated marrow injury. We also observed a close association of the ligand expression with pancytopenia and favorable response to immunosuppressive therapy by prospective analysis of 5 patients (3 AA-PNH syndrome and 2 AA) for more than one year up to 5 years. Thus, we here propose that NKG2D-mediated immunity, which drives both NK and T-cells, is critically implicated in the pathogenesis of bone marrow failure of PNH and its related disorders.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 990-990
Author(s):  
Nobuyoshi Hanaoka ◽  
Tatsuya Kawaguchi ◽  
Kentaro Horikawa ◽  
Shoichi Nagakura ◽  
Yasuchika Tsuzuki ◽  
...  

Abstract Bone marrow failure syndromes (BFS) including aplastic anemia (AA), myelodysplastic syndromes (MDS), and paroxysmal nocturnal hemoglobinuria (PNH) are considered to harbor immune-mediated marrow injury. Indeed, immunosuppressive therapy (IST) with antithymocyte globulin and cyclosporine ameliorates the hematopoiesis in BFS patients, despite its limit: infrequent relapse of marrow failure after IST, resistance of some patients to IST, and untoward effects like infection. To overcome the difficulties, molecular targeted therapy is alternative. However, neither incitement of marrow injury nor target molecules on marrow cells recognized by cytotoxic lymphocytes has been identified. We have currently suggested that NKG2D ligands such as ULBP and MICA/B serve as triggers for immune-mediated marrow injury in PNH (Hanaoka, Blood2006;107:1184). ULBP and MICA/B are stress-inducible membrane proteins that appear in infection and transformation. The ligands share NKG2D receptor on lymphocytes such as NK, CD8+ T, and γδ T cells and promote activation of the lymphocytes. Cells expressing the ligands are then deadly injured by NKG2D+ cells (Groh, PNAS USA 1996; Cosman, Immunity 2001). In this background, we attempted to confirm the clinical significance of the expression of NKG2D ligands in BFS. The ligands were detected by flow cytometry on the granulocytes and marrow cells in 47 (53%) of 89 patients with BFS: 28 (56%) of 50 patients with AA; 11 (65%) of 17 patients with PNH; 8 (36%) of 22 patients with MDS; and none of 17 healthy individuals. The membrane expression of the ligands was supported by their increase in plasma. It is then conceivable that blood cells were exposed to a certain stress to induce NKG2D ligands in the patients, leading to NKG2D-mediated marrow injury. There was a close association of the expression of NKG2D ligands with both progression of marrow failure and favorable response to IST. Thus, we propose that the NKG2D ligands not only are feasible predictors for both immune-mediated marrow injury and IST effects, but also serve for potential targeted therapy in BFS.


Blood ◽  
2005 ◽  
Vol 106 (3) ◽  
pp. 841-851 ◽  
Author(s):  
Elaine M. Sloand ◽  
Lori Mainwaring ◽  
Monika Fuhrer ◽  
Shakti Ramkissoon ◽  
Antonio M. Risitano ◽  
...  

AbstractClinical observations and experimental evidence link bone marrow failure in myelodysplastic syndrome (MDS) with a T cell–dominated autoimmune process. Immunosuppressive therapy is effective in improving cytopenias in selected patients. Trisomy 8 is a frequent cytogenetic abnormality in bone marrow cells in patients with MDS, and its presence has been associated anecdotally with good response to immunotherapy. We studied 34 patients with trisomy 8 in bone marrow cells, some of whom were undergoing treatment with antithymocyte globulin (ATG). All had significant CD8+ T-cell expansions of one or more T-cell receptor (TCR) Vβ subfamilies, as measured by flow cytometry; expanded subfamilies showed CDR3 skewing by spectratyping. Sorted T cells of the expanded Vβ subfamilies, but not of the remaining subfamilies, inhibited trisomy 8 cell growth in short-term hematopoietic culture. The negative effects of Vβ-expanded T cells were inhibited by major histocompatibility complex (MHC) class 1 monoclonal antibody (mAb) and Fas antagonist and required direct cell-to-cell contact. Sixty-seven percent of patients who had de novo MDS with trisomy 8 as the sole karyotypic abnormality responded to ATG with durable reversal of cytopenias and restoration of transfusion independence, with stable increase in the proportion of trisomy 8 bone marrow cells and normalization of the T-cell repertoire. An increased number of T cells with apparent specificity for trisomy 8 cells is consistent with an autoimmune pathophysiology in trisomy 8 MDS.


Blood ◽  
1986 ◽  
Vol 67 (2) ◽  
pp. 479-483
Author(s):  
T Nagasawa ◽  
T Sakurai ◽  
H Kashiwagi ◽  
T Abe

We studied a patient with a rare complication of amegakaryocytic thrombocytopenia (AMT) associated with systemic lupus erythematosus (SLE). To investigate the underlying pathogenesis of AMT, the effects of peripheral blood T cells and serum on human megakaryocyte progenitor cells were studied using in vitro coculture techniques. Mononuclear bone marrow cells (2 X 10(5) from normal donors produced 33.6 +/- 8.8 (n = 10) colony-forming unit-megakaryocytes (CFU-M) in our plasma clot system. When 2 X 10(5) of the patient's T cells were added to the culture system, the number of CFU-M decreased to only 3.5 +/- 0.6/2 X 10(5) bone marrow cells. No evidence of inhibitory effects was found by the addition of the patient's serum and complement to the culture system. The T cells stored at -80 degrees C on admission were also capable of suppressing autologous CFU-M after recovery from AMT. These results indicate that in vitro suppression of CFU-M from allogenic and autologous bone marrow cells by this patient's T cells provides an explanation for the pathogenesis of AMT associated with SLE.


Blood ◽  
2000 ◽  
Vol 95 (2) ◽  
pp. 700-704 ◽  
Author(s):  
Kimberly A. Gush ◽  
Kai-Ling Fu ◽  
Markus Grompe ◽  
Christopher E. Walsh

Fanconi anemia (FA) is a genetic disorder characterized by bone marrow failure, congenital anomalies, and a predisposition to malignancy. FA cells demonstrate hypersensitivity to DNA cross-linking agents, such as mitomycin C (MMC). Mice with a targeted disruption of the FANCC gene (fancc −/− nullizygous mice) exhibit many of the characteristic features of FA and provide a valuable tool for testing novel therapeutic strategies. We have exploited the inherent hypersensitivity offancc −/− hematopoietic cells to assay for phenotypic correction following transfer of the FANCC complementary DNA (cDNA) into bone marrow cells. Murine fancc −/− bone marrow cells were transduced with the use of retrovirus carrying the humanfancc cDNA and injected into lethally irradiated recipients. Mitomycin C (MMC) dosing, known to induce pancytopenia, was used to challenge the transplanted animals. Phenotypic correction was determined by assessment of peripheral blood counts. Mice that received cells transduced with virus carrying the wild-type gene maintained normal blood counts following MMC administration. All nullizygous control animals receiving MMC exhibited pancytopenia shortly before death. Clonogenic assay and polymerase chain reaction analysis confirmed gene transfer of progenitor cells. These results indicate that selective pressure promotes in vivo enrichment offancc-transduced hematopoietic stem/progenitor cells. In addition, MMC resistance coupled with detection of the transgene in secondary recipients suggests transduction and phenotypic correction of long-term repopulating stem cells.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1489-1489
Author(s):  
Takamasa Katagiri ◽  
Zhirong Qi ◽  
Yu Kiyu ◽  
Naomi Sugimori ◽  
J. Luis Espinoza ◽  
...  

Abstract Abstract 1489 Poster Board I-512 The hematopoietic stem cell (HSC) differentiation pathway in humans remains largely unknown due to the lack of an appropriate in vivo assay allowing the growth of HSCs as well as of clonal markers that enable the tracing of their progenies. Small populations of blood cells deficient in glycosylphosphatidylinositol-anchored proteins (GPI-APs) such as CD55 and CD59 are detectable in approximately 50% of patients with aplastic anemia (AA) and 15% of patients with refractory anemia (RA) of myelodysplastic syndrome defined by the FAB classification. Such blood cells with the paroxysmal nocturnal hemoglobinuria (PNH) phenotype (PNH-type cells) are derived from single PIGA mutant HSCs and their fate depends on the proliferation and self-maintenance properties of the individual HSCs that undergo PIG-A mutation by chance (Blood 2008;112:2160, Br J Haematol 2009 in press) Analyses of the PNH-type cells from a large number of patients on the diversity of lineage combination may help clarify the HSC differentiation pathway in humans because PIG-A mutant HSCs in patients with bone marrow failure appear to reflect the kinetics of healthy HSCs. Therefore, different lineages of peripheral blood cells were examined including glycophorin A+ erythrocytes (E), CD11b+ granulocytes (G), CD33+ monocytes (M), CD3+ T cells (T), CD19+ B cells (B), and NKp46+ NK cells (Nk) from 527 patients with AA or RA for the presence of CD55−CD59− cells in E and G, and CD55−CD59−CD48− cells in M,T, B, Nk with high sensitivity flow cytometry. Two hundred and twenty-eight patients (43%) displayed 0.003% to 99.1% PNH-type cells in at least one lineage of cells. The lineage combination patterns of PNH-type cells in these patients included EGM in 71 patients (31%), EGMTBNk in 43 (19%), EG in 37 (16%), T alone 14 (6%), EGMBNk in 11 (5%), G alone in 10 (4%), GM in 10 (4%), EGMNk in 7 (3%), EGMT in 7 (3%), EGMB in 6 (3%), EM in 5 (2%), EGMTB in 3 (1%), EGNk in 1 (0.4%), EGMTNk in 1 (0.4%), GMTB in 1 (0.4%), and GT in 1 (0.4%) (Table). All patterns included G or M, except for 14 patients displaying PNH-type T cells alone. No patients showed TB or TBNk patterns suggestive of the presence of common lymphoid progenitor cells. Peripheral blood specimens from 123 patients of the 228 patients possessing PNH-type cells were examined again after 3 to 10 months and all patients showed the same combination patterns as those revealed by the first examination. PIG-A gene analyses using sorted PNH-type cells from 3 patients revealed the same mutation in G and Nk for 1 patient and in G and T for 2 patients. These findings indicate that human HSCs may take a similar differentiation pathway to that of murine HSCs, the ‘myeloid-based model’ that was recently proposed by Kawamoto et al. (Nature 2008; 10:452), though the cases with PNH-type T cells alone remain to be elucidated. Table. Lineages of cells containing PNH-type cells in patients with AA or RA. The number in the parenthesis denotes the proportion of patients showing each combination pattern in the total patients possessing PNH-type cells. (+ ; presence of PNH-type cells) Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 915-915
Author(s):  
Christine V. Ichim ◽  
Dzana Dervovic ◽  
Juan Carlo Zuniga-Pflucker ◽  
Richard A. Wells

Abstract Abstract 915 The orphan nuclear receptor NR2F6 is a mammalian homologue of the Drosophila seven-up gene that plays key roles in decisions of cell fate in neuroblast and retinal cells. We have previously described a novel role for NR2F6 in decisions of cell fate of mammalian haematopoietic cells of the myeloid cell lineage. We have shown that over-expression of NR2F6 in bone marrow cells impairs differentiation and extends the proliferative capacity of myeloid and early progenitor cells eventually leading to acute myeloid leukaemia (AML), while silencing of NR2F6 expression in AML cell lines causes terminal differentiation and apoptosis. A role of NR2F6 in lymphopoiesis has yet to be identified. Here we describe for the first time a role for NR2F6 in the specification of lymphoid cells. NR2F6 expression is heterogeneous throughout the haematopoietic hierarchy, with expression being highest in long-term repopulating HSCs and generally declining with the differentiation of progenitor cells. We report that over-expression of NR2F6 abrogates the developmental program necessary for T-cell lymphopoiesis. We assessed the effects of NR2F6 on lymphopoiesis in vivo by competitive bone marrow transplantation of NR2F6-IRES-GFP or GFP retrovirally transduced grafts (n=43). Competitive repopulation of lethally irradiated murine hosts with GFP transduced bone marrow cells resulted in successful engraftment and T-cell development, with GFP+ T-cells present in the thymus, and periphery at rates comparable to the percent marked cells in the original graft. However over-expression of NR2F6 placed developing T-cells at a dramatic competitive disadvantage. Six weeks post transplant the proportion of CD3+ cells derived from NR2F6 transduced bone marrow cells was greatly diminished relative to control (more than 10 fold), while at 12 weeks post-transplant we observed an abrogation of CD3+ cells derived from NR2F6 transduced T-cells (with the percentage of NR2F6 transduced CD3+ cells being comparable to staining with IgG control) in both the thymus and periphery. This stark competitive disadvantage was observed in all recipients of NR2F6 transduced grafts. We confirmed that this is not a phenomenon specific to the marker CD3 by analysing a portion of the animals for expression of CD4 and CD8, which again showed a lack of mature t-cells. In a second series of bone marrow transplants, cells transduced with NR2F6 or GFP were purified by fluorescence-activated cell sorting and grafts of 100% transduced cells were transferred by tail vein injection into lethally irradiated recipients. Animals transplanted with NR2F6 transduced bone marrow demonstrated a gross decrease in their thymic size and cellularity (∼10 fold decrease, n=17). Furthermore, the thymus of NR2F6 transduced animals contained a larger proportion of non-transduced, GFP negative residual haematopoietic cells than the vector control animals, corroborating the competitive disadvantage that NR2F6 transduced bone marrow cells face in the thymus. As observed in our previous experiments these animals demonstrated a gross reduction in the proportion of CD3+ cells in the thymus, spleen, lymph nodes and peripheral blood. To rule out the possibility that over-expression of NR2F6 is preventing the trafficking of progenitor cells to the thymus we differentiated NR2F6 or GFP transduced haematopoietic stem cells (lin-,c-kit+,sca-1+) into T-cells in vitro on OP9-DL1 cells. We observed a drastic reduction in the number of cells generated from NR2F6 transduced stem/progenitor cells (>50 fold at day 23), suggesting that expression of NR2F6 greatly impairs T-cell development. Mechanistically, others have shown that NR2F6 functions as a transcriptional repressor inhibiting the transactivating ability of genes such as Runx1. We conjecture that in lymphoid progenitors as well NR2F6 functions as a transcriptional repressor preventing the activation of pathways necessary for T-cell survival, proliferation and lymphopoiesis. Taken together, these data establish that the orphan nuclear receptor NR2F6 is a novel negative regulator of T-cell lymphopoiesis, and demonstrate that down-regulation of NR2F6 is important for the survival and proliferation of T-cell progenitors. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2404-2404
Author(s):  
Santhosh Dhanraj ◽  
Sethu Madhava Rao Gunja ◽  
Adam P Deveau ◽  
Mikael Nissbeck ◽  
Boonchai Boonyawat ◽  
...  

Abstract Background: Deadenylation is a major mechanism that regulates RNA function and fate. Several mammalian deadenylases have been identified. Poly (A)-specific ribonuclease (PARN) is one of the major mammalian deadenylases that trims single-stranded poly (A) tails of mRNAs and oligoadenylated tails of H/ACA box snoRNAs and microRNAs. RNA biogenesis has emerged as a mechanism underlying several inherited diseases including well known inherited bone marrow failure syndromes (IBMFSs) such as Diamond Blackfan anemia, dyskeratosis congenita and Shwachman-Diamond syndrome. Little is known about the biological significance of germline mutations in PARN. Methods: Genome-wide screen for copy number alterations was used to identify causal mutations in patients with hematological and neurological manifestations. Four patients were identified with deletions in the PARN gene. Genomic, biochemical, cellular and knockdown experiments in human bone marrow cells and in zebrafish have been performed to clarify the role of PARN in the human disease. Results: We identified large monoallelic deletions in PARN in four patients with developmental delay or mental illness. One patient in particular had a severe neurological phenotype, central hypomyelination, and severe bone marrow failure. This patient had an additional missense mutation on the non-deleted allele and had severely reduced PARN protein and deadenylation activity. Clonogenic assays of the patient's bone marrow cells showed reduced potential to generate hematopoietic colony. Fibroblasts from the patient with biallelic mutations showed markedly slow growth. Large proportion of the cells accumulated in the G1/G0 phase of cell cycle, suggesting impaired transition from G1 to the S phase. Cells from this patient also had impaired oligoadenylation of specific H/ACA box snoRNAs and scaRNAs, including the telomerase RNA component (TERC). Importantly, PARN-deficient patient cells manifested abnormalities in two pathways that are affected in IBMFSs: short telomeres and an aberrant ribosome profile. This combination of abnormalities is seen in patients with severe variants of dyskeratosis congenita (Hoyeraal-Hreidarsson syndrome). Knocking down PARN in human CD34+ marrow cells from healthy donors revealed marked defect in clonogenic potential. Morpholino knockdown of parn in zebrafish resulted in reduced formation of red blood cells and granulocytes. Conclusions: We report for the first time four patients from three different families with developmental delay or mental illness, who carried large monoallelic PARN deletions that have not been reported in healthy controls. This indicates that large PARN deletions in humans result in a neurological phenotype. Further, we showed that biallelic PARN mutations that results in markedly reduced protein, cause severe bone marrow failure and severe global central hypomyelination, similar to what is seen in patients with severe forms of dyskeratosis congenita. The identified defects suggest a new disease mechanism, in which PARN-deficiency disrupts the polyadenylated state of H/ACA box RNA molecules that in turn influences ribosome profile and telomere length and cause hematological and neurological defects. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2003 ◽  
Vol 101 (10) ◽  
pp. 3872-3874 ◽  
Author(s):  
Holger Tönnies ◽  
Stefanie Huber ◽  
Jörn-Sven Kühl ◽  
Antje Gerlach ◽  
Wolfram Ebell ◽  
...  

Abstract Fanconi anemia (FA) is a condition that induces susceptibility to bone marrow failure, myelodysplastic syndrome (MDS), and leukemia. We report on a high incidence of expanding clonal aberrations with partial trisomies and tetrasomies of chromosome 3q in bone marrow cells of 18 of 53 FA patients analyzed, detected by conventional and molecular cytogenetics. To determine the clinical relevance of these findings, we compared the cytogenetic data, the morphologic features of the bone marrow, and the clinical course of these patients with those of 35 FA patients without clonal aberrations of 3q. The 2 groups did not differ significantly with respect to age, sex, or complementation group. There was a significant survival advantage of patients without abnormalities of chromosome 3q. Even more pronounced was the risk assessment of patients with gains of 3q material with respect to the development of morphologic MDS and acute myeloid leukemia (AML). Thus, our data from 18 patients with 3q aberrations reveal that gains of 3q are strongly associated with a poor prognosis and represent an adverse risk factor in FA.


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