Analysis of NK Cells Receptors and NK Cells Ligands in Acute Myeloid Leukemia: Comparisons Between the Blood and the Bone Marrow.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1643-1643
Author(s):  
Jerome Rey ◽  
Eloise Perrot ◽  
Caroline Veuillen ◽  
Thomas Prébet ◽  
Anne Etienne ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Acute Myeloid Leukemia ◽  
Healthy Volunteers ◽  
Nk Cells ◽  
Myeloid Leukemia ◽  
Immune Escape ◽  
Flow Cytometry Data ◽  
Nk Receptor ◽  
Acute Myeloid

Abstract Abstract 1643 Poster Board I-669 Background The significant role of NK cells in the control of acute myeloid leukemia (AML) has been demonstrated in the setting of allogeneic stem cell transplantation. However, the implication of NK cells against autologous leukemic cells needs to be clarified. We have previously described deficient expression of NK activatory receptors in AML at diagnosis, in particular the natural cytotoxicity receptors (NCR) namely NKp30 and NKp46. So, defective cytotoxicity of AML cells can be explained by abnormalities of activating NK-receptor expression allowing immune escape from NK cells. However, immune escape can be also due to defective activating NK receptor-ligand interactions due to abnormal expression of their ligands on blasts cells. These defects have been observed in particular on NK cells or blasts cells isolated from the blood. Few studies have analysed the bone marrow component although blasts cells concentrate here. We postulated that abnormalities of NK cells receptors or ligands expression are more severe in bone marrow, in near contact with the blasts, compared with blood. We sought to identify disparities between deficient expression of NK or ligands in the bone marrow in comparison with the blood. Methods We realized a phenotypic analysis of NK cells and blasts cells at the diagnosis of AML. The level of activatory NK receptors (NKRa) knew to mediate NK cell recognition and lysis of AML blasts cells (NCR (NKp30 and NKp46) and DNAM-1) was investigated by flow cytometry. The expression of NKG2D ligands (MICA/B and ULBP1-3) and DNAM-1 ligands (Nectin-2 and PVR) receptors were also analysed. These analyses were realised with coupled specimens obtained in the same patient at diagnosis of AML (n=19), peripheral blood and bone marrow samples in order to detect discrepancies between these two sites. A control group (age-matched; n=15) for blood samples was included for this study. All biological samples were obtained from patients and healthy volunteers after informed consent. Results A total of 19 patients were included in this study. We included 6 cases of AML 5, 4 cases of AML 4, 4 cases of AML 2, 4 cases of AML 1 and one case of AML 0. Flow cytometry data for NKRa were only available for 11 patients. We confirmed the deficient expression of NKp30 and NKp46 receptors (as determined by MFI) on NK cells from blood of AML patients. In AML patient, the ratio MFI (MFI receptor/MFI control isotype) of NKp30 (4.27 +/- 2.97; p<0.0001) and of NKp46 (5.96 +/- 5.67; p<0.0001) significantly differed from healthy volunteers (NKp30 26.65 +/- 6.12; NKp46 39.73 +/- 9.66). Moreover, the deficient expression of these receptors was also observed on NK cells from the bone marrow (NKp30 3.66 +/- 2.22, p<0.0001; NKp46 6.71+/- 6.42, p<0.0001). However, we can not demonstrated significant differences between the NKRa expression on NK cells from blood versus from bone marrow (NKp30 p= 0.8438; NKp46 p= 0.9476 and DNAM-1 p= 0.3579). The expression of the ligands for NKRa was analysed to compare the expression on blasts cells isolated from the blood compared to blasts cells isolated from the bone marrow. Flow cytometry data for ligands were only available for 17 patients. We observed a strong expression of HLA class I molecules on blasts cells that was equivalent in the blood and in bone marrow. DNAM-1 ligands (PVR, Nectin 2) were expressed on blasts cells (see figure). NKG2D ligands were also expressed but to a lesser extent with predominant ULBP1 expression. However, we can not observed significant differences in the expression of ligands between the blood and the bone marrow. Conclusions The deficiency of activating NK cells receptors expression at AML diagnosis is significant, present in a majority of patients, and consistent across the 2 components, ie blood and bone marrow. These defects are one component of the immune escape from NK cells. We have speculated that these abnormalities were more pronounced in bone marrow, near blasts cells, because these abnormalities are in part induced by blasts cells. However, we can not demonstrated significant differences in the expression of activating receptors or ligands between blood and bone marrow. We are accumulating more data in order to detect differences between sub-groups of AML. Disclosures No relevant conflicts of interest to declare.

Study on mechanism of Tim-3 on immune escape in benzene-induced acute myeloid leukemia

2020 ◽  
Author(s):  
qiong Ning ◽  
xiangxin li ◽  
Xiangdong Jian ◽  
Xiaopeng He
Keyword(s):  
Bone Marrow ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Immune Escape ◽  
Serum Levels ◽  
Control Group ◽  
M2 Macrophages ◽  
Experimental Group ◽  
Group Serum ◽  
Acute Myeloid

Abstract To study the mechanism of Tim-3 on immune escape in benzene-induced acute myeloid leukemia (AML), to provide potential targets of clinical monitoring and intervention of hematological toxicity in benzene-induced AML . C3H/He mice were randomly divided into control group and experimental group. Serum levels of IL-12 in the experimental group were significantly lower than that in the control group. Serum levels of TGF-β1 in the experimental group were significantly higher than that in the control group( p <0.05). The proportion of Tim-3 positive CD14 + monocytes of bone marrow and spleen in the experimental group were both significantly higher than that in the control group ( p <0.05) by Flow cytometry (FCM). Compared with the control group, the expression of Tim-3 on (M1+M2) macrophages of bone marrow in the experimental group significantly increased by immunofluorescence assay. The expression of type M2 macrophages in (M1+M2) macrophages of bone marrow and spleen tissues in the experimental group were both higher than that in the control group. The expression levels of p-PI3K, p-AKT and p-mTOR in the experimental group were all significantly higher than that in the control group. Tim-3 was highly expressed in macrophages in benzene-induced AML. It promoted the activation of PI3K/AKT/mTOR signaling pathway, stimulated the secretion of anti-inflammatory cytokines, and inhibited the secretion of pro-inflammatory cytokines. High expression of Tim-3 changed the phenotype and function of macrophages by promoting the macrophages polarization, thus inducing negative immune response in the tumor microenvironment and tumor immune escape.

scholarly journals Characterization of the DNAM-1, TIGIT and TACTILE Axis on Circulating NK, NKT-Like and T Cell Subsets in Patients with Acute Myeloid Leukemia

Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2171
Author(s):  
Isabel Valhondo ◽  
Fakhri Hassouneh ◽  
Nelson Lopez-Sejas ◽  
Alejandra Pera ◽  
Beatriz Sanchez-Correa ◽  
...  
Keyword(s):  
T Cells ◽  
Acute Myeloid Leukemia ◽  
T Cell ◽  
Healthy Volunteers ◽  
Nk Cells ◽  
Myeloid Leukemia ◽  
Cell Activation ◽  
Nk Cell ◽  
T Cell Subsets ◽  
Acute Myeloid

Background: Acute myeloid leukemia (AML) remains a major clinical challenge due to poor overall survival, which is even more dramatic in elderly patients. TIGIT, an inhibitory receptor that interacts with CD155 and CD112 molecules, is considered as a checkpoint in T and NK cell activation. This receptor shares ligands with the co-stimulatory receptor DNAM-1 and with TACTILE. The aim of this work was to analyze the expression of DNAM-1, TIGIT and TACTILE in NK cells and T cell subsets in AML patients. Methods: We have studied 36 patients at the time of diagnosis of AML and 20 healthy volunteers. The expression of DNAM-1, TIGIT and TACTILE in NK cells and T cells, according to the expression of CD3 and CD56, was performed by flow cytometry. Results: NK cells, CD56− T cells and CD56+ T (NKT-like) cells from AML patients presented a reduced expression of DNAM-1 compared with healthy volunteers. An increased expression of TIGIT was observed in mainstream CD56− T cells. No differences were observed in the expression of TACTILE. Simplified presentation of incredibly complex evaluations (SPICE) analysis of the co-expression of DNAM-1, TIGIT and TACTILE showed an increase in NK and T cells lacking DNAM-1 and co-expressing TIGIT and TACTILE. Low percentages of DNAM-1−TIGIT+TACTILE+ NK cells and DNAM-1− TIGIT+TACTILE+ CD56− T cells were associated with a better survival of AML patients. Conclusions: The expression of DNAM-1 is reduced in NK cells and in CD4+ and CD8+ T cells from AML patients compared with those from healthy volunteers. An increased percentage of NK and T cells lacking DNAM-1 and co-expressing TIGIT and TACTILE is associated with patient survival, supporting the role of TIGIT as a novel candidate for checkpoint blockade.

scholarly journals Immunoistochemical expression of PD-1 and PD-L1 in bone marrow biopsies of patients with acute myeloid leukemia

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Francesco Romano ◽  
Antonino Giulio Giannone ◽  
Sergio Siragusa ◽  
Rossana Porcasi ◽  
Ada Maria Florena
Keyword(s):  
Bone Marrow ◽  
Immune Response ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Immune Escape ◽  
Medical Community ◽  
Immune Checkpoints ◽  
Bone Marrow Biopsies ◽  
Underlying Mechanisms ◽  
Acute Myeloid

tumor immunotherapy is a rapidly evolving field. The discovery of the ability of neoplasms to evade the immune response has shifted the attention of the medical community to the underlying mechanisms of the immune response to tumors, highlighting the importance of so-called immune check points, including CTLA4, TIM-3 and PD-1.  an immune escape mechanism is the activation of the immune checkpoint pathway that contributes to the creation of an immunosuppressive microenvironment and therefore to tumor proliferation.although immune checkpoints have been extensively investigated in solid tumors, the same is not true for hematologic neoplasms, particularly for myeloid malignancies. our study is based on the evaluation of the activation of the PD-1 and PD-L1 pathway in the context of the bone marrow tumor microenvironment of patients with acute myeloid leukemia. To do so we evaluated  34 bone marrow biopsies of patients with acute myeloid leukemia comparing them to 10 controls using immunohistochemical methods.

The Growth Inhibition and Apoptosis Induction of Acute Myeloid Leukemia Blast Population by the Blocking IGF-IR Pathway.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4515-4515
Author(s):  
Si Sun ◽  
Yanli He ◽  
Xingbing Wang ◽  
Wei Liu ◽  
Jun Liu ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Bone Marrow Cells ◽  
Pi3k Pathway ◽  
Leukemia Cell Line ◽  
Free System ◽  
Acute Myeloid ◽  
Marrow Cells

Abstract The insulin-like growth factor-1receptor (IGF-1R) is overexpressed in a variety of tumors and has been associated with cancer development. Here, we analysis the IGF-IR expression on the bone marrow cells from 45 newly diagnosed patients with acute myeloid leukemia (AML) by flow cytometry. IGF-1R universally expressed on AML blasts and the leukemia cell line HL-60, did not show significant correlation with FAB subtypes. However, the bone marrow cells from AML patients with high myeloblast counts (&gt;80%) generally showed brighter IGF-IR expressions, which indicated the IGF-IR pathway might play an important role for AML blast proliferation and survival. Indeed, blocking the IGF-1R pathway by neutralizing monoclonal antibodies could reduce the proliferation of HL-60 cells by 38.28% at 48 hr. This inhibitory effect on blast growth was observed in 4 of 5 AML samples. In the same IGF-1R blocking treatment, the apoptosis of HL-60 cells was significantly induced, resulting in apoptosis of 57% of the cell population with the measurement of Annexin V vs PI staining by flow cytometry. The control contained only 20% apoptotic cells. We also demonstrated that the blockade of the IGF-1R pathway inhibited the phophorylation of the PI3K pathway component Akt in HL-60 cells when cultured in a serum free system with a supplement of 50ng/ml exogenous IGF. Since PI3K pathway activation greatly contributes to the proliferation, survival and drug resistance of AML, it is of interest to study whether blockading IGF-IR could also inhibit the PI3K pathway in primary AML blasts and synergize other anti-leukemia agents to improve the therapeutic effectiveness. Conclusions: IGF-IR may play an important role in the proliferation and survival of the AML blast population; Blocking the IGF-IR pathway could significantly inhibit the growth of AML blasts and considerably induce the apoptosis of AML blasts; IGF-IR could become a critical molecular target in anti-leukemia drug discovery.

Identifying Small Molecules That Overcome HoxA9-Mediated Differentiation Arrest in Acute Myeloid Leukemia

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3513-3513
Author(s):  
David B. Sykes ◽  
Mark K Haynes ◽  
Nicola Tolliday ◽  
Anna Waller ◽  
Julien M Cobert ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Acute Myeloid Leukemia ◽  
Small Molecules ◽  
Cell Line ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Myeloid Differentiation ◽  
Prostacyclin Receptor ◽  
Acute Myeloid

Abstract Abstract 3513 AML in adults is a devastating disease with a 5-year survival rate of 25%. We lack new treatments for AML, and the chemotherapy standard of care remains unchanged in thirty years. One success story in the treatment of AML has been the discovery of drugs that trigger the differentiation of leukemic blasts in the small subset of patients with acute promyelocytic leukemia. However, differentiation therapy is unfortunately not available for the remaining 90% of non-APL acute myeloid leukemia patients. Understanding and targeting the mechanism of differentiation arrest in AML has been under investigation for more than four decades. There is growing evidence to support the role of the homeobox transcription factors in normal hematopoietic differentiation as well as malignant hematopoiesis. The persistent, and inappropriate, expression of the homeobox gene HoxA9 has been described in the majority of acute myeloid leukemias. This implicates HoxA9 dysregulation as a common pathway of differentiation arrest in myeloid leukemias and suggests that by understanding and targeting this pathway, one might be able to overcome differentiation arrest. In cultures of primary murine bone marrow, constitutive expression of HoxA9 blocks myeloid differentiation and results in the outgrowth of immature myeloid cell lines. The mechanism by which HoxA9 causes differentiation arrest is not known and no compounds exist that inhibit HoxA9. We developed a murine cell line model in which the cells were blocked in differentiation by a conditional version of HoxA9. In this system, an estrogen-dependent ER-HoxA9 protein was generated by fusion with the estrogen receptor hormone-binding domain. When expressed in cultures of primary murine bone marrow, immortalized myeloblast cell lines can grow indefinitely in the presence of stem cell factor and beta-estradiol. Upon removal of beta-estradiol, and inactivation of HoxA9, these cell lines undergo synchronous and terminal myeloid differentiation. We took advantage of an available transgenic mouse model in which GFP was expressed downstream of the lysozyme promoter, a promoter expressed only in mature neutrophils and macrophages. Cell lines derived from the bone marrow of this lysozyme-GFP mouse were GFP-negative at baseline and brightly GFP-positive upon differentiation. In this manner, we generated a cell line with a built-in reporter of differentiation. These cells formed the basis of a high-throughput screen in which cells were incubated with small molecules for a period of four days in 384-well plate format. The cells were assayed by multi-parameter flow cytometry to assess for toxicity and differentiation. Compounds that triggered green fluorescence were scored as “HITS” and their pro-differentiation effects confirmed by analysis of morphology and cell surface markers. Given the availability of cells and the simple and reliable assay, we performed both a pilot screen of small molecules at The Broad Institute as well as an extensive screen of the NIH Molecular Libraries Small Molecule Repository. The screen of more than 350,000 small molecules was carried out in collaboration with the University of New Mexico Center for Molecular Discovery. We have identified one lead class of compounds - prostacyclin agonists – capable of promoting myeloid differentiation in this cell line model of AML. Using a parallel cell line derived from a prostacyclin receptor knock-out mouse, we confirmed that activity was due to signaling through the prostacyclin receptor. The role of prostacyclin signaling in myeloid differentiation has not been previously described. Analysis of gene expression demonstrated that the expression of the prostacyclin receptor is seen in ∼60% of in primary human AML samples. This is a potentially exciting finding as prostacyclin agonists (e.g. treprostinil) are clinically relevant as well as FDA-approved. Their potential role in the treatment of acute myeloid leukemia is unknown. Here we present the details of our high-throughput flow cytometry system and preliminary identification of pro-differentiation agents in AML. If successful, we anticipate that one of these small molecules may offer insight into a mechanism for overcoming differentiation arrest, and may also translate into a novel, clinically relevant treatment for acute myeloid leukemia. Disclosures: Sklar: IntelliCyt: Founder of IntelliCyt, the company that sells the HyperCyt high-throughput flow cytometry system. Other. Zon:Fate Therapeutics: Founder Other.

scholarly journals Stromal CYR61 Confers Resistance to Mitoxantrone Via Spleen Tyrosine Kinase Activation in Human Acute Myeloid Leukemia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2228-2228
Author(s):  
Xin Long ◽  
Laszlo Perlaky ◽  
Tsz-Kwong Chris Man ◽  
Michele S. Redell
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Acute Myeloid Leukemia ◽  
Cell Lines ◽  
Stromal Cells ◽  
Myeloid Leukemia ◽  
Stromal Cell ◽  
Chemotherapy Resistance ◽  
Induced Apoptosis ◽  
Acute Myeloid

Abstract Acute myeloid leukemia (AML) is a life-threatening bone marrow malignancy with a relapse rate near 50% in children, despite aggressive chemotherapy. Accumulating evidence shows that the bone marrow stromal environment protects a subset of leukemia cells and allows them to survive chemotherapy, eventually leading to recurrence. The factors that contribute to stroma-induced chemotherapy resistance are largely undetermined in AML. Our goal is to delineate the mechanisms underlying stroma-mediated chemotherapy resistance in human AML cells. We used two human bone marrow stromal cell lines, HS-5 and HS-27A, to study stroma-induced chemotherapy resistance. Both stromal cell lines are equally effective in protecting AML cell lines and primary samples from apoptosis induced by chemotherapy agents, including mitoxantrone, etoposide, and cytarabine. By gene expression profiling using the Affymetrix U133Plus 2 platform, we previously found that CYR61 was among the genes that were commonly upregulated in AML cells by both stromal cell lines. CYR61 is a secreted matricellular protein that is expressed at relatively low levels by AML cells, and at higher levels by stromal cells. CYR61 binds and activates integrins and enhances growth factor signaling in AML cells, and it has been associated with chemoresistance in other malignancies. Our current data provide functional evidence for a role for this protein in stroma-mediated chemoresistance in AML. First, we added anti-CYR61 neutralizing immunoglobulin (Ig), or control IgG, to AML-stromal co-cultures, treated with chemotherapy for 24 hours, and measured apoptosis with Annexin V staining and flow cytometry. In THP-1+HS-27A co-cultures treated with 50 nM mitoxantrone, the apoptosis rate was 33.0 ± 3.7% with anti-CYR61 Ig v. 16.3 ± 4.2% with control IgG; p=0.0015). Next, we knocked down CYR61 in the HS-5 and HS-27A stromal cell lines by lentiviral transduction of two individual shRNA constructs, and confirmed knockdown (KD) at the gene and protein levels for both cell lines. These CYR61-KD stromal cells provided significantly less protection for co-cultured AML cells treated with mitoxantrone, compared to stromal cells transduced with the non-silencing control. For example, the apoptosis rate for THP-1 cells co-cultured with CYR61-KD HS-27A cells was 10.8 ± 0.8%, compared to 6.8 ± 1.1% for THP-1 cells co-cultured with control HS-27A cells (p=0.02). Similar results were obtained with NB-4 AML cells. These results demonstrate that CYR61 contributes to stroma-mediated chemoresistance. CYR61 binds to integrin αvβ3 (Kireeva, et al, J. Biol. Chem., 1998, 273:3090), and this integrin activates spleen tyrosine kinase (Syk) (Miller, et al, Cancer Cell, 2013, 24:45). Using intracellular flow cytometry, we found that activated Syk (pSyk) increased in THP-1 and NB-4 cell lines, and in primary AML patient samples, upon exposure to control HS-27A cells. In primary samples, the mean fluorescence intensity (MFI) for pSyk averaged 11.7 ± 1.3 in co-culture v. 6.6 ± 0.6 for cells cultured alone (p=0.004, n=10). In contrast, pSyk did not significantly increase in AML cells co-cultured with CYR61-KD HS-27A cells (MFI for primary patient samples: 8.6 ± 0.8). This result implicates Syk as a downstream signaling mediator of CYR61. To determine the role of CYR61-induced Syk signaling in chemotherapy resistance, we treated AML-stromal cell co-cultures with 3 uM R406, a potent Syk inhibitor, or DMSO, then added 300 nM mitoxantrone, and measured apoptosis after 24 hours. In AML cells co-cultured with control HS-27A cells, mitoxantrone-induced apoptosis was significantly increased by Syk inhibition (THP-1 cells: 13.7 ± 0.7% with R406 v. 10.0 ± 0.3% with DMSO, p<0.05), consistent with reduced chemoresistance. Notably, R406 did not further increase mitoxantrone-induced apoptosis in AML cells co-cultured with CYR61-KD HS-27A stromal cells (THP-1 cells: 15.7 ± 0.2% with R406 v. 16.9 ± 0.4% with DMSO). Similar results were seen with NB-4 cells, as well. These results support the notion that CYR61 signals through the integrin-Syk pathway to protect AML cells from chemotherapy. Therefore, the CYR61 - integrin - Syk pathway may be a potential therapeutic target for overcoming stroma-induced chemotherapy resistance in AML. Disclosures No relevant conflicts of interest to declare.

scholarly journals Impact of Minimal Residual Disease and Chimerism Monitoring at Different Timepoints after Allogeneic Stem Cell Transplantation for Acute Myeloid Leukemia

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 7-7
Author(s):  
Reyes María Martín-Rojas ◽  
Gillen Oarbeascoa ◽  
Rebeca Bailén ◽  
Ignacio Gómez-Centurión ◽  
Luis Miguel Juarez ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Acute Myeloid Leukemia ◽  
Stem Cell ◽  
Cumulative Incidence ◽  
Myeloid Leukemia ◽  
Residual Disease ◽  
Minimal Residual ◽  
Risk Of Relapse ◽  
Acute Myeloid

¶ Martin-Rojas RM and Oarbeascoa G contributed equally to this work. INTRODUCTION Relapse is the main cause of treatment failure after allogeneic hematopoietic stem cell transplantation (allo-HSCT) for acute myeloid leukemia (AML). The evaluation of minimal residual disease (MRD) could provide a more accurate assessment of the depth of response, and therefore identify patients with higher risk of relapse. AIMS The aim of our study was to analyze the impact of pre-HSCT flow cytometry (FCM) and molecular MRD together with chimerism and MRD in the early post-HSCT period in patients with AML. METHODS We conducted a retrospective study in patients with complete remission AML who underwent a HSCT between 2008 and 2019 in our center. MRD was analyzed by flow cytometry in bone marrow aspirates and by quantitative RT-PCR (NMP1, RUNX1-RUNX1T1, CBFB-MYH11, KMT2A-MLLT3, WT1) in bone marrow aspirates and/or peripheral blood. MRD was determined within the 30 days preceding the HSCT and at day +30 and +90 post-HSCT. Bone marrow and selected CD34+ lineage chimerism was analyzed by STR (AmpFISTR SGM Plus, Thermo Fisher) at days +30 and +90 post-HSCT. This study was approved by our Institutional Ethics Committee. Data were analyzed using IBM SPSS Statistics version 24 and R version 3.5.1. RESULTS A total of 115 patients were analyzed. Pre-HSCT MRD was negative in 58 patients (50.4%) and positive in 57 patients (49.6%). We found no statistically significant differences in the characteristics between the two groups (Table 1). Median follow up was 39 months (IQR 10.4-55.8). 3-year overall survival (OS) for patients with pre-HSCT negative MRD was 72.5% versus 70.3% in patients with positive MRD (p=0.41), with an event free survival (EFS) of 66.9% versus 66.1 (p=0.48) respectively (Figure 1). Median time to the beginning of immunosuppression withdrawal was 82.5 days (IQR 59-93) for patients with negative MRD and 68 days (IQR 55.3-85.3) for patients with positive MRD (p&lt;0.001). The cumulative incidence of grade II-IV acute graft versus host disease (aGVHD) and moderate-severe chronic GVHD did not show statistically significant differences based on the MRD status. Similarly, the cumulative incidence of relapse and the 2-year mortality was not significantly different between the two groups. Patients with negative MRD at day +30 showed a 2-year OS of 83.5% versus 58.1% in patients with positive MRD (p=0.03) and a EFS of 79.9% versus 48.6% (Figure 2). The cumulative incidence of relapse was more elevated in patients with positive MRD (29.8% versus 13.6%) at day +30. Patients with mixed chimerism (MC) at day +30 showed a significantly lower 3-year OS and EFS than patients with complete chimerism (CC). Likewise, the cumulative incidence of relapse was significantly higher in patients with MC, both if detected in bone marrow aspirate and in CD34+ cells. The multivariate analysis revealed that MRD status at day +30 post-HSCT was an independent prognostic factor for EFS (HR 3.74; 95% CI 1.38-10.1; p=0.009). CONCLUSIONS Patients with AML presenting a positive MRD in the early post-HSCT period and those who show a MC at day +30 post-HSCT have lower EFS, with positive MRD at day +30 being an independent prognostic factor for EFS. The evaluation of MRD and chimerism in the early post-HSCT period is useful to identify patients with higher risk of relapse, who may take advantage of preemptive measures. Disclosures Kwon: Gilead, Novartis, Pfizer, Jazz: Consultancy, Honoraria.

scholarly journals Acute myeloid leukemia immune escape by epigenetic CD48 silencing

2020 ◽  
Vol 134 (2) ◽  
pp. 261-271 ◽  
Author(s):  
Zhiding Wang ◽  
Yang Xiao ◽  
Wei Guan ◽  
Mengzhen Wang ◽  
Jinghong Chen ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Nk Cells ◽  
Immune Evasion ◽  
Myeloid Leukemia ◽  
Immune Escape ◽  
Nk Cell ◽  
Epigenetic Modification ◽  
High Expression ◽  
Hypomethylating Agent ◽  
Acute Myeloid

Abstract Acute myeloid leukemia (AML) is a malignant disorder of hemopoietic stem cells. AML can escape immunosurveillance of natural killer (NK) by gene mutation, fusions and epigenetic modification. The mechanism of AML immune evasion is not clearly understood. Here we show that CD48 high expression is a favorable prognosis factor that is down-regulated in AML patients, which can help AML evade from NK cell recognition and killing. Furthermore, we demonstrate that CD48 expression is regulated by methylation and that a hypomethylating agent can increase the CD48 expression, which increases the NK cells killing in vitro. Finally, we show that CD48 high expression can reverse the AML immune evasion and activate NK cells function in vivo. The present study suggests that a combination the hypomethylating agent and NK cell infusion could be a new strategy to cure AML.

scholarly journals Development of Somatic NRAS Mutation Associated with Rapid Transition from Germline GATA2 Mutation Associated Myelodysplastic Syndrome to Acute Myeloid Leukemia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3616-3616 ◽  
Author(s):  
Yanqin Yang ◽  
Yubo Zhang ◽  
Jun Zhu ◽  
Catherine E. Lai ◽  
Jingrong Tang ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Acute Myeloid Leukemia ◽  
Myelodysplastic Syndrome ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Bone Marrow Aspirate ◽  
Nras Mutation ◽  
Trisomy 8 ◽  
Acute Myeloid

Abstract There is increasing recognition of the role of inherited germline predisposition for myeloid disorders such as myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). The additional somatic genetic events required for development of a malignant phenotype are however poorly understood. A 25 year old woman was referred to the NHLBI hematology branch in March 2014 for a seven year history of pancytopenia. Her medical history included recurrent pneumonias, oral ulcers, severe varicella infection and arthralgias. Prior bone marrow examinations at ages 21 and 23 at outside institutions reported normocellular marrow, tri-lineage hematopoiesis and mild dyspoiesis. Cytogenetics were remarkable for trisomy 8 in 80% (aged 21) or 90% (aged 23) of metaphases. Previously unrecognized lymphedema was noted on examination. Peripheral blood counts showed WBC 2.28 K/ul [normal range: 3.98-10.04], HGB 9.9 g/dL [11.2-15.7], PLT: 67 K/ul [173-369], ALC: 0.36 K/ul [1.18-3.74] and AMC: 0.06 [0.24-0.86]. Peripheral blood flow cytometry demonstrated decreased CD3+ CD4+ (T) cells, CD19+ (B) cells and NK cells. HLA-DR15 negative. Bone marrow examination showed trilineage hematopoiesis, 50-60% cellularity, mild erythroid predominance and mildly increased, mildly atypical megakaryocytes. Blasts less than 5%. Bone marrow flow cytometry revealed severely decreased B-cells and monocytes, absent B-cell precursors, absent dendritic cells, inverted CD4:CD8 ratio, and atypical myeloid maturation pattern. Cytogenetics demonstrated stable trisomy 8 in 90% of metaphases. On the basis of this assessment the diagnosis of MDS was confirmed. Sanger sequencing revealed a GATA2 L375S mutation in the second zinc finger of known pathogenic significance. Four months later she developed increased fatigue and easy bruising with worsening thrombocytopenia (PLT: 10K/ul). Bone marrow was dramatically changed; now markedly hypercellular (90-100%) with diffuse sheets of immature cells consistent with blasts having fine chromatin, distinct or prominent nucleoli, and visible cytoplasm. Blasts were positive for CD33, CD56, CD64, CD123, and CD163; and were negative for CD34, CD14, and myeloperoxidase. Cytogenetics showed a new trisomy 20 in 65% of metaphases, in addition to previously seen trisomy 8 in 100%. A diagnosis of acute monoblastic leukemia (M5a subtype) was made. At both clinic visits bone marrow aspirate was collected on an IRB approved research sample acquisition protocol. Whole exome sequencing of 1ug DNA was performed using Agilent SureSelect v5 Exome enrichment Kits on an Illumina HiSeq 2000 with 100-bp paired-end reads (Macrogen, Rockville, MD). Data was mapped to hg19 (BWA) and processed using an in-house pipeline (Samtools/Picard/GATK/VarScan/Annovar). Mean read depth of target regions was 157 and 149. There was high correlation between both samples with the exception of a NRAS:NM_002524:exon3:c.C181A:p.Q61K mutation (57 of 180 reads) seen only in the later sample. Confirmatory ultra-deep sequencing for NRAS was performed using Illumina TruSight Myeloid Sequencing Panel on an Illumina MiSeq. No evidence of the NRAS Q61K mutation was found in the earlier March MDS bone marrow sample even when sequenced to a depth greater than 1750 reads (see figure). The mutation was confirmed in the August AML sample at a variant allele frequency of 35%. If heterozygous this would reflect a clone size of 70%, consistent with data from both cytogenetics (new trisomy 20 in 65% of metaphases) and the 76% blasts documented by bone marrow aspirate smear differential. We report here the rapid progression to AML in a patient with germline GATA2 MDS associated with development of a new trisomy 20 karyotype and a NRAS Q61K mutation. The NRAS mutation was not detectable after the patient achieved a complete remission following induction chemotherapy further supporting this association. This NRAS mutation has been implicated in the pathogenesis of multiple cancers by constitutive activation of proliferative signaling. GATA2 associated MDS is a high-risk pre-leukemic condition with the potential for rapid evolution to AML. This is the first report of acquired somatic mutations in the RAS/RTK signaling pathway in the context of germline GATA2 insufficiency associated with acute leukemic transformation. Figure 1. Figure 1. Disclosures Townsley: Novartis: Research Funding; GSK: Research Funding.

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