Genetically Engineered T-cells最新文献

{"title":"Abstract A045: Chlorotoxin redirects T-cells for specific and effective targeting against glioblastomas","authors":"Dongrui Wang, Vanessa D. Jonsson, Sarah L Wright, W. Chang, Xin Yang, R. Starr, Alfonso Brito, B. Aguilar, A. Sarkissian, L. Weng, S. Forman, M. Barish, Christine E. Brown","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A045","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A045","url":null,"abstract":"Glioblastoma (GBM) is the most common type of primary brain tumor, with the standard therapy only modestly improving the prognosis, highlighting the necessity to develop advanced treatments. We and others have established the platform to potentiate immune response against GBMs using chimeric antigen receptor (CAR) engineered T-cells. Specifically, we have shown that intracranial administration of CAR T-cells can be well tolerated in patients with recurrent GBMs, together with some early clinical evidence of antitumor response. However, CAR T-cell therapy against GBMs is complicated by the inter- and intratumoral heterogeneity, while the single-targeting therapies only respond to a subset of tumor cells. The development of new CAR therapy would thus aim for targeting a wider range of tumor cells and bypassing antigen escape. Here, we took an approach different from conventional strategies of tumor antigen discovery, exploiting the tumor-binding potential of a natural peptide to develop CAR T-cells that broadly target GBMs. Chlorotoxin (CLTX) is a 36-amino acid peptide with demonstrated GBM-binding capability. Inspired by the utilization of CLTX in GBM tumor imaging, we used a fluorescence-conjugated CLTX to screen the freshly-dispersed primary GBM cells and patient-derived GBM neurospheres, and found that CLTX binding was more homogeneous than the expression of other GBM-associated antigens including EGFR, HER2 and IL13Rα2. Although CLTX has limited inhibitory effect on GBM growth, its broad binding to GBM cells illustrates the potential to be conjugated with a cytotoxic agent. Therefore, we generated CAR T-cells bearing CLTX as the antigen targeting domain. CLTX-CAR T-cells were able to get activated after stimulating with GBM cells, as indicated by their degranulation, cytokine production and immuno-synapse formation. Modification of CAR constructs revealed that CLTX-CAR T-cells with CD28 costimulatory signal exhibited potent effector activity, while the 4-1BB costimulation resulted in inadequate CAR activation. In both in vitro and in vivo models, CLTX-CAR T-cells effectively eliminated GBM cells and tumors, including the ones with no/low expression of EGFR, HER2 and IL13Rα2. Importantly, CLTX peptide exhibited negligible binding to a panel of normal cells from neural and other tissues, and CLTX-CAR T-cells showed no off-target effect against normal organs in tumor-bearing mouse models. Screening on patient-derived GBM neurospheres, we discovered that the expression of metalloproteinase (MMP)-2 on targeT-cells was correlated with the effector function of CLTX-CAR T-cells. Further, the antitumor function of CLTX-CAR T-cells was severely diminished against GBMs with MMP-2 knockdown. Consistent with the cytotoxicity of CLTX-CAR T-cells, MMP-2 expression was also present in a subgroup of GBM cells with undetectable levels of EGFR, HER2 and IL13Rα2 expression. Our results demonstrate for the first time that a peptide toxin can be successfully used a","PeriodicalId":254712,"journal":{"name":"Genetically Engineered T-cells","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122656286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A043: Anti-CD19 CAR T-cells with a CRISPR/Cas9-mediated T-cell receptor knockout show high functionality in the absence of alloreactivity in vitro","authors":"D. Stenger, Tanja A. Stief, Theresa Käuferle, Semjon Willier, F. Rataj, Kilian Schober, R. Lotfi, Beate Wagner, D. Busch, S. Kobold, F. Blaeschke, T. Feuchtinger","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A043","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A043","url":null,"abstract":"Overall survival of pediatric B-precursor ALL patients reached 90% in recent years. However, the outcome for refractory or relapsed children remains very poor. Anti-CD19 chimeric antigen receptor T-cells (CD19-CAR) showed significant antileukemic activity in relapsed and refractory B-precursor ALL. Especially in children, isolation of a suitable T-cell amount for autologous CAR T-cell manufacturing can be challenging due to low blood volume, low T-cell counts and clinical condition. In this case, the adoptive transfer of CAR T-cells from an unmatched healthy third-party donor provides a promising strategy. In order to prevent life-threatening graft-versus-host disease, a knockout (KO) of the endogenous T-cell receptor (TCR) has to be performed. Here, we generated CD19-CARs with a CRISPR/Cas9 mediated TCR KO, which remain highly functional and show strongly reduced alloreactivity compared to conventional CAR T-cells introduced into third-party T-cells. T-cells were isolated from peripheral blood mononuclear cells (PBMCs) of healthy donors and activated via anti-CD3/anti-CD28 stimulation. Retroviral transduction of a second generation anti-CD19 CAR (containing CD3zeta and 4-1BB stimulatory domains) was performed, followed by CRISPR/Cas9 mediated KO of the T-cell receptor beta chain via electroporation. After eleven days of expansion in the presence of IL-7 and IL-15, cells were purified for TCR KO-CD19-CAR T-cells via magnetic separation. Finally, the cell product was analyzed for cellular characteristics, functionality and alloreactivity by flow cytometry. A mean transduction rate of 37% for CD19-CARs and 40% for TCR KO-CD19-CARs was reached as well as a mean TCR KO rate of 78%. Both CD19-CARs as well as TCR KO-CD19-CARs showed suitable amounts of CD4- (45% vs. 33%) and CD8-T-cells (37% vs. 48%). The phenotype of CD19-CARs and TCR KO-CD19-CARs were comparable with mainly central memory (CM) (38% vs. 40%) and effector memory (EM) (57% vs. 51%) T-cells. The expansion of TCR KO-CD19-CARs was significantly reduced compared to conventional CD19-CARs (54-fold vs. 109-fold). This effect was not mediated by the loss of the TCR, but due to electroporation procedure. While CD19-CARs with or without TCR KO showed almost no background expression of the activation marker CD25 (2% vs 1%), contact with CD19-expressing targeT-cells resulted in a comparable upregulation of CD25 in both groups (95% vs. 94%). Co-culture with a CD19-expressing targeT-cell line led to an increased Interferon-γ secretion compared to unstimulated CARs, which was not significantly altered by the TCR KO (17% CD19-CAR vs. 14% TCR KO-CD19-CAR). CD19-dependent proliferative capacity of CAR T-cells was not influenced by loss of the TCR, as in both cases 97% of the T-cells proliferated after antigen recognition. Both CD19-CARs as well as TCR KO-CD19-CARs showed high, antigen-specific killing of 86% vs. 87% of the CD19-expressing targeT-cells at a 1:1 effector to target ratio. To evaluate the a","PeriodicalId":254712,"journal":{"name":"Genetically Engineered T-cells","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125654961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A034: High-throughput identification of naturally occurring T-cell receptors with therapeutic potential against tumor-associated, viral and neoantigens","authors":"M. Klinger, Peter Ebert, E. Osborne, R. Taniguchi, Joyce K. Hu, Tim Hayes, S. Benzeno, Adria Carbo, Melanie B Laur, Erica L. Eggers, H. Robins","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A034","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A034","url":null,"abstract":"The growing use of immunotherapy to treat advanced cancers has brought about a revolution in techniques to mobilize the immune system to antitumor effect. Chimeric antigen receptor (CAR) T-cells targeting CD19 constitute the first modified T-cell products to garner FDA approval for clinical use. However, CAR technologies can only targeT-cell surface antigens, representing approximately one quarter of potential targets. In contrast, T-cell receptor (TCR) therapies can target peptides presented by the major histocompatibility complex (MHC), including those derived from intracellular antigens. Hitherto, such receptors have generally been identified through low-throughput techniques using cancer patients’ blood, followed by affinity-maturation of TCRs, a step that can decrease safety. Here, we demonstrate a novel pipeline for the identification of potential therapeutic TCRs from the naive repertoire of healthy individuals. Using a technique called Multiplexed Identification of T-cell Receptor Antigen specificity (MIRA), we input hundreds of antigens of interest, including tumor-associated antigens, viral antigens and neoantigens, and identify thousands of TCRs to these antigens. These TCRs then undergo evaluation for affinity, avidity, cytokine release, cytotoxicity and safety. Cytotoxicity is demonstrated using both peptide-loaded and endogenously presented peptides. Safety is evaluated using alanine-glycine scans; evaluation of reactivity of TCRs againsT-cell lines and primary cells is planned. We have fully characterized several TCRs targeting clinically relevant targets, which demonstrated improved avidity and cytolysis relative to a benchmark TCR, and a promising preliminary safety profile. In the recent year, cancer neoantigens as targets for natural and therapeutic antitumor responses have also gained momentum given their attractive product profile. Hereto, we also show data for TCRs against shared neoantigens. Citation Format: Mark Klinger, Peter Ebert, Edward Osborne, Ruth Taniguchi, Joyce Hu, Tim Hayes, Sharon Benzeno, Adria Carbo, Melanie Laur, Erica Eggers, Harlan Robins. High-throughput identification of naturally occurring T-cell receptors with therapeutic potential against tumor-associated, viral and neoantigens [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A034.","PeriodicalId":254712,"journal":{"name":"Genetically Engineered T-cells","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132804056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A031: Engineering antigen density sensors for T-cell immunotherapy","authors":"R. Hernandez-Lopez, W. Lim, Wei Yu","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A031","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A031","url":null,"abstract":"T-cells can be redirected to kill tumor cells via synthetic T-cell receptors known as chimeric antigen receptors (CARs); this approach is becoming a highly promising therapeutic strategy for cancer treatment. Current CAR T-cells, while effective at killing cells expressing the target antigen, fail to discriminate between cells expressing high and low levels of common antigens. Potential target antigens are often also found on normal cells at lower expression levels, and CAR T-cells get activated even by low amounts of target antigen, resulting in potentially deadly toxic effects. We are approaching this problem of antigen density discrimination by using common biochemical mechanisms for cooperative recognition to design new synthetic T-cell receptors. CAR T-cells are highly sensitive to even low densities of the target antigen. Current strategies for generating CAR T-cells consist of selecting antibodies with high affinity since previous studies have shown that the CAR T-cell activity is inversely correlated with the antibody’s affinity. However, these CARs are unable to discriminate between cancer and normal cells based on antigen density. Recent studies suggest that lowering the receptor affinity on a CAR T-cell could increase its selectivity against targeT-cells with different antigen densities. Nevertheless, lowering the affinity is unlikely to provide a sharp density threshold of activation. Instead for a sharp threshold transition from off to on, one would require cooperativity and nonlinear recognition. We have designed a two-step recognition-activation circuit that involves two receptors. In this circuit an initial recognition event alters the potency of a subsequent response. We combined a weak receptor that turns on the activity of a high-affinity receptor that fully activates the cell. For this circuits we have made used of a new class of modular receptors called synthetic notch receptors (SynNotch). SynNotch receptors use antibody-based domains to recognize a target antigen, but when activated, they control transcription via a cleaved transcriptional domain. We have designed and expressed several synNotch/CAR circuits and have tested in vitro their ability to achieve antigen density sensing. These circuits use a synNotch receptor to control the expression of a CAR—all recognizing the same Her2 ligand. The constructs are introduced into T-cells via standard lentiviral infection, and sorted for receptor expression using flow cytometry (anti-myc stain). We have screened candidate receptors for expression and activation response in the human Jurkat T-cell line and human primary CD4+ and CD8+ T-cells from several donors, using standard flow-based assays (e.g. CD69 Activation, T-cell proliferation) and cytokine assays (e.g., IL-2, INF-γ). We are now taking the best circuit candidate and proceeding in mouse models. We have first characterized the growth curves of tumors made by engineered targeT-cells to measure the baseline tumor growth and","PeriodicalId":254712,"journal":{"name":"Genetically Engineered T-cells","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122251054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A030: Identification of α-fetoprotein-specific T-cell receptors for hepatocellular carcinoma immunotherapy","authors":"Yukai He, Wei Zhu, Yibing Peng, Lan Wang, Yuan Hong, Juan Wu, E. Celis","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A030","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A030","url":null,"abstract":"Hepatocellular carcinoma (HCC) is the major form of liver cancer for which there is no effective therapy. Genetic modification with T-cell receptors (TCR) specific for HCC-associated antigens, such as α-fetoprotein (AFP), can potentially redirect human T-cells to specifically recognize and kill HCC tumor cells to achieve antitumor effects. In this study, by using lentivector and peptide immunization, we identified a population of CD8-T-cells in HLA-A2 transgenic AAD mice that recognized AFP158 epitope on human HCC cells. Adoptive transfer of the AFP158-specific mouse CD8-T-cells eradicated HepG2 tumor xenografts as large as 2cm in diameter in immunocompromised NSG mice. We then established T-cell hybridoma clones from the AFP158-specific mouse CD8-T-cells and identified three sets of paired TCR genes out of 5 hybridomas. Expression of the murine TCR genes redirected primary human T-cells to bind HLA-A2/AFP158 tetramer. The TCR gene-engineered human T-cells (TCR-T) also specifically recognized HLA-A2+AFP+ HepG2 HCC tumor cells and produced effector cytokines. Importantly, the TCR-T-cells could specifically kill HLA-A2+AFP+ HepG2 tumor cells without significant toxicity to normal primary hepatocytes in vitro. Adoptive transfer of the AFP-specific human TCR-T-cells could eradicate HepG2 tumors in NSG mice. Conclusion: We have identified novel AFP-specific murine TCR genes that can redirect human T-cells to specifically recognize and kill HCC tumor cells, and those AFP158-specific TCRs have a great potential to engineer a patient’s autologous T-cells to treat HCC tumors. Citation Format: Yukai He, Wei Zhu, Yibing Peng, Lan Wang, Yuan Hong, Juan Wu, Esteban Celis. Identification of α-fetoprotein-specific T-cell receptors for hepatocellular carcinoma immunotherapy [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A030.","PeriodicalId":254712,"journal":{"name":"Genetically Engineered T-cells","volume":"220 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115653145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A026: Novel electroporation method for quick CAR-T-cell manufacture","authors":"Jian Chen, Xiaofeng Xia","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-A026","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-A026","url":null,"abstract":"CAR-T-cells are currently manufactured for clinical use by infection of human T-cells with viral vectors containing the CAR gene. T lymphocytes have to be stimulated and expanded ex vivo because the viral vectors infect fresh natural lymphocytes very poorly. The viral vector approach is extremely expensive due to the high cost of virus production and the high cost of long-term cell expansion that could take 10-14 days in a GMP facility. The viral vector approach also has a huge biologic downside: ex vivo expanded T-cells become bulky and lose efficacy against tumor cells. The use of electroporation technology in CAR-T-cell manufacturing has attracted increasing interests for its low cost and the wide range of applications, including transposon based stable CAR expression, transient expression and genome editing. However, actual clinical use of electroporation technology in CAR-T has been difficult and several clinical trials have met significant problems due to the poor transfection efficiency and decreased T-cell survival with traditional electroporation methods. Through theoretical analysis of the other existing electroporation technologies, we found that they all have problems in electrophysical design. The problems include physical design of devices, electrical pulse selection, and buffer composition. With a redesigned electroporation system, we can now achieve very high transfection efficiency for T-cells while maintaining cell survival. For Sleeping Beauty transposon-based CAR expression, we found that over a period of two to three weeks the efficiency can get to 60% to 90% with fasT-cell proliferation. The protein expression time after electroporation is very short. For simple GFP plasmids we can observe GFP expression after only 30 minutes. Unlike viral vectors, electroporation works well on fresh natural T-cells, thereby eliminating the need for expensive cell expansion and virus production altogether and cutting the huge economic burden of CAR-T therapy. By reinfusion of more natural T-cells, the antitumor efficacy of CAR-T-cells could be improved while the side effects of cytokine release syndrome could be minimized. Citation Format: Jian Chen, Xiaofeng Xia. Novel electroporation method for quick CAR-T-cell manufacture [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A026.","PeriodicalId":254712,"journal":{"name":"Genetically Engineered T-cells","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127681243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract IA17: Utilizing synthetic biology and high-dimensional probing to address therapeutic obstacles and empower engineered T cells with the capacity to eradicate tumors","authors":"K. Anderson, D. Egan, S. Hingorani, S. Oda, K. Paulson, R. Perret, L. Schmidt, Thomas M. Schmitt, Ingunn M. Stromnes, A. Chapuis, P. Greenberg","doi":"10.1158/2326-6074.CRICIMTEATIAACR18-IA17","DOIUrl":"https://doi.org/10.1158/2326-6074.CRICIMTEATIAACR18-IA17","url":null,"abstract":"We have been exploring in preclinical models and clinical trials methods to reproducibly provide therapeutic T cell responses by transfer of genetically engineered T cells. Our largest clinical experience is in treating human Acute Myelogenous Leukemia (AML). After identifying that WT1, a gene associated with promoting leukemic transformation, is over-expressed in human leukemic stem cells, and demonstrating in a clinical trial that in vitro expanded WT1-specific CD8 T cell clones can be safely transferred, exhibit anti-leukemic activity, and provide therapeutic benefit to AML patients, we extensively screened normal human repertoires and isolated a high affinity TCR specific for WT1 for genetically engineering CD8 T cells to reproducibly create cells with high avidity for leukemic cells. We have initially pursued this strategy in a 2 Arm trial for leukemia patients either at high risk of relapse (Arm 1) after hematopoietic cell transplant (HCT) or who have already relapsed after HCT (Arm 2). The prophylactic arm is now completed, with very encouraging results- all patients treated with engineered T cells remain alive and relapse free at a median of 38 months, compared to a relapse rate of ~50% in a concurrent matched cohort. Results in relapsed patients (Arm 2) have been less effective, and we have used high-dimensional analyses including single cell RNAseq both to elucidate the reasons for failure to eradicate the leukemia and to design strategies to overcome these obstacles. Our results have identified several mechanisms by which the leukemia escapes, and we have been testing approaches that employ further genetic modification of the T cells to enhance efficacy. The predominant reason for leukemia progression despite targeted therapy with T cells is the inability of the T cells to persist and maintain function in the context of encountering a rapidly proliferating myeloid leukemia. This reflects both engagement of pathways inhibitory to T cells by the leukemic cells, and apoptosis of the T cells from repetitive stimulation. We are addressing this issue by creating immuno-modulatory fusion proteins (IFPs) that have the ectodomain of an inhibitory or death receptor fused to a survival costimulatory domain. Results with two such IFPs will be discussed, a CD200R/CD28 fusion that binds the inhibitory ligand CD200 commonly expressed on leukemic cells but provides a CD28 costimulatory signal and a Fas/4-1BB fusion that binds FasL but rather than induce death promotes proliferation and survival. A more uncommon reason explaining progression is loss of expression of the WT1 epitope being targeted. This has occurred in 2 patients, but for distinct reasons. In one patient this reflected loss of a component of the immunoproteasome, and we have now isolated a TCR that recognizes an epitope not dependent on the immunoproteasome. In a second patient the level of WT1 expression declined- interestingly, this patient was treated with Vidaza, which can increase ","PeriodicalId":254712,"journal":{"name":"Genetically Engineered T-cells","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126860378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}