Novelty in improvement of CAR T cell-based immunotherapy with the aid of CRISPR system

Abstract Introduction Chimeric Antigen Receptor (CAR) T cells have tremendous potentials for cancer treatment; however, various challenges impede their universal use. These restrictions include the poor function of T cells in tumor microenvironments, the shortage of tumor-specific antigens and, finally, the high cost and time-consuming process, as well as the poor scalability of the method. Creative gene-editing tools have addressed each of these limitations and introduced next generation products for cell therapy. The clustered regularly interspaced short palindromic repeats-associated endonuclease 9 (CRISPR/Cas9) system has triggered a revolution in biology fields, as it has a great capacity for genetic manipulation. Method In this review, we considered the latest development of CRISPR/Cas9 methods for the chimeric antigen receptor T cell (CAR T)-based immunotherapy. Results The ability of the CRISPR/Cas9 system to generate the universal CAR T cells and also potent T cells that are persistent against exhaustion and inhibition was explored. Conclusion: We explained CRISPR delivery methods, as well as addressing safety concerns related to the use of the CRISPR/Cas9 system and their potential solutions.

Progress of gene-mediated precision immunotherapy in the treatment of acute myeloid leukemia / 中国药科大学学报

@#Acute myeloid leukemia (AML) is a disease caused by abnormal cloning of hematopoietic stem cells in the bone marrow, which leads to accumulation of a large number of abnormally differentiated myeloid cells. It is difficult to cure by traditional treatment. The successful application of chimeric antigen receptor T cell (CAR-T) immunotherapy indicates that the treatment of hematological tumors has entered a new stage of precision immunotherapy. However, CAR-T immunotherapy has been found to have many problems in clinical applications, including long treatment cycle, expensive prices, off-target effects, cytokine release syndrome, etc. Therefore, it is necessary to expand the application of CAR or adopt improved measures to enhance the therapeutic effect. This article reviews the new strategies for genetic engineering modification of CAR immune cells and the research progress and application of in situ programming to generate CAR-T, and besides, briefly introduces the new methods about the delivery of gene drugs in vivo, aiming to provide new ideas and theoretical basis for expanding and improving the application of precision immunotherapy in AML.

Control effect of Dasatinib on the treatment of acute myeloid leukemia and adverse events of CD123 targeting CAR-T:a case report and literature review / 陆军军医大学学报

Objective To preliminarily explore the efficacy of chimeric antigen receptor T cells(CAR-T)targeting CD 123 in the treatment of acute myeloid leukemia(AML)and the role of dasatinib in the treatment of CD123 targeting CAR-T induced side effects.Methods Clinical data of 1 patient with relapsed AML admitted to No.920 Hospital of PLA Joint Logistic Support Force in September,2019 were collected.The patient relapsed after previous multi-line chemotherapy and was treated with CD123 targeting CAR-T therapy.The routine blood changes of the patient after treatment were observed.Dasatinib was used when agranulocytosis occurred,40 mg orally 3 times per day,and was stopped when agranulocytosis was relieved.Changes in blood cells,CAR-T amplification,and disease control were observed.The patient was followed up for over 1 year.Results Flow cytometry for bone marrow showed that minimal residual disease negative result was observed in 30 d after infusion.The patient remained disease-free for over 1 year.After CD 123 CAR-T cells infusion,significant expansion of CAR-T cells was observed,accompanied by granulocyte deficiency and cytokine release syndrome(CRS).After using dasatinib,inhibition of CAR-T cell expansion was observed,accompanied by blood cell recovery,and CRS symptoms were alleviated.After stop of dasatinib,CAR-T cells expanded again and blood cells decreased again.Conclusion CAR-T cells targeting CD 123 have certain efficacy in the treatment for relapsed AML.Dashatinib has a blocking effect on the amplification and function of CAR-T,which can alleviate bone marrow suppression caused by CD 123 targeting CAR-T and avoid severe CRS.

Research progress in targeted therapies of chronic lymphocytic leukemia / 上海交通大学学报（医学版）

Chronic lymphocytic leukemia(CLL)is one of small B-cell lymphomas and leukemias,characterized as a clonal disease of mature B cells.The disease is remarkably heterogeneous,with the majority of patients having an indolent course,yet they are currently incurable.Abnormal signaling pathways are indispensable in the pathogenesis of CLL.In CLL,the common abnormalities of signaling pathways include B-cell receptor(BCR)signaling,apoptosis,nuclear factor kappa B(NF-κB)signaling and Notch signaling.According to the target in signaling pathways,a series of targeted drugs,such as Bruton's tyrosine kinase(BTK)inhibitors(ibrutinib,zanubrutinib),phosphorylate phosphoinositide 3-kinase(PI3K)inhibitor(duvelisib)and B-cell leukemia/lymphoma 2(BCL2)inhibitor(venetoclax),which have significantly changed the prognosis of patients in clinic.Other targeted drugs,such as fenebrutinib,nemtabrutinib and umbralisib,as well as chimeric antigen receptor T-cell(CAR-T)therapy developed in the field of immuno-oncology and T cell engineering,are currently under trial,with more personalized treatment modalities being explored,which may become potential drug targets in the future.In this paper,relevant literature of CLL was reviewed,and recent research progress in molecular pathogenesis and targeted therapies of chronic lymphocytic leukemia was reviewed.

Care of a child with human herpesvirus-6B encephalitis after chimeric antigen receptor T-cell therapy / 中国实用护理杂志

Summarizing the nursing experience of a child with HHV-6B encephalitis after umbilical cord blood transplantation and CAR-T therapy. The child was 4 years old and was diagnosed with acute T lymphocytic leukemia on May 28, 2021. Nursing points: meticulously observe symptoms for early diagnosis and treatment; develop a specialized management plan, implement individualized care; enhance medication management to improve the quality of care; establish a shared decision-making communication model to prevent hospital-acquired infections; provide patient-centered care for lumbar puncture; assess the needs of the child and family, alleviate negative emotions; improve pre-discharge preparation, emphasize continuity of care. With proactive treatment and careful nursing, the child′s condition improved, and they were discharged. Follow-up for six months showed the child in a sustained remission state with no adverse sequelae, and normal life resumed.

Study on the anti-tumor effect of CD30 CAR-T cells based on multi-chain structure / 安徽医科大学学报

Objective @#To develop a CD30-targeted CAR-T cell drug based on the multi-chain chimeric antigen re- ceptor T cells (CAR-T) of the bridging protein DAP12 , and to study the in vitro and in vivo preclinical efficacy of CD30 CAR-T on Hodgkin lymphoma tumor cells .@*Methods @#Through gene synthesis and molecular cloning tech- niques , a CAR plasmid targeting CD30 was designed and constructed , and the obtained lentivirus was packaged . The T cells were transfected with the lentivirus , where the multi-chain CAR-T targeting CD30 was the CD30 - KIRS2/Dap12-BB group , the single-chain second-generation CAR-T was the CD30-41BBζgroup , and the T cells without virus infection were the NTD group . The positive rate of CAR was detected by flow cytometry , the cytotoxic- ity of the cells was detected by lactate dehydrogenase (LDH) release assay , the secretion level of the cytokine in- terferon γ(IFN-γ) was detected by enzyme-linked immunosorbent assay ( ELISA) , and the antitumor activity of CD30 CAR-T in mice was further detected by a mouse xenograft tumor model . @*Results @#A comparison was made between the multi-chain CAR-T targeting CD30 and the single-chain second-generation CAR-T. It was found that the antitumor effect of the multi-chain CAR-T was similar to that of the single-chain CAR-T. However , it was worth noting that the IFN-γsecretion level of the multi-chain CAR-T was higher (P < 0 . 001) . More importantly , in the mouse tumor model experiment , the multi-chain CAR-T achieved complete tumor regression . @*Conclusion @#The multi-chain CAR-T targeting CD30 is superior to the traditional single-chain CAR-T in terms of antitumor activity .

Recent research on chimeric antigen receptor T cells in children with refractory/relapsed acute lymphoblastic leukemia / 中国当代儿科杂志

At present, the treatment of refractory/relapsed acute lymphoblastic leukemia is still in a difficult situation, and even if the intensity of chemotherapy is increased or it is combined with hematopoietic stem cell transplantation, some children may have a poor prognosis and a short survival time. Chimeric antigen receptor T-cell (CAR-T) immunotherapy uses genetically engineered T cells and does not rely on the human leukocyte antigen pathway to recognize tumor-specific antigens, and then CAR-T cells bind to target antigen cells to trigger immune response, thereby exerting a sustained anti-leukemia effect. As the most rapidly developed tumor immunotherapy, major breakthroughs have been made for CAR-T cells in the treatment of various hematological tumors, but there still lacks a comprehensive system for the research, development, and production of CAR-T cells and standardized diagnosis and treatment protocols in China. This article reviews the recent research on CAR-T cells in children with refractory/relapsed acute lymphoblastic leukemia.

Recent Progress of Nano-drug Combined with Chimeric Antigen Receptor T Cell Therapy in the Treatment of Soild Tumors / 中国肺癌杂志

Chimeric antigen receptor T cell (CAR-T) therapy has shown remarkable success in treating hematological malignancies. However, CAR-T therapy for solid tumors is still limited due to the unique solid-tumor microenvironment and heterogeneous target antigen expression, which leads to an urgent need of combining other therapies. At present, nano delivery system has become one of the most promising directions for the development of anti-tumor drugs. Based on the background of CAR-T and tumor treatment, we focus on the research progress of nanomedicine combined with CAR-T therapy, and systematically review the strategies and examples in recent years in the aspects of in vivo delivery of mRNA, regulation of tumor microenvironment, combination with photothermal therapy. And we also look forward to the future direction of this filed.
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Research progress of chimeric antigen receptor T cell and T cell antigen coupler modified T cell technology / 中国生物制品学杂志

@#At present,malignant tumor has become one of the public problems that seriously threaten human health. In addition to surgery,radiotherapy,chemotherapy,targeted therapy and other methods,with the development of molecular biology,immunotherapy has also developed rapidly,becoming an emerging method of cancer treatment. The most commonly used immune cells in clinical treatment are DC,NK,CIK,CTL and chimeric antigen receptor T cell(CAR-T). Among them,CAR-T technology is the initial technology for global research,while due to its off-target,neurotoxicity,transfection vector defects and other problems,it also has certain limitations in clinical application. T cell antigen coupler modified T cell(TAC-T)technology is a new technology developed on the basis of CAR-T,which uses natural T cell receptor(TCR)to modify T cells and retarget the antigen of cancer cells. In this paper,the research status of CAR-T technology and the research progress of TAC-T technology are reviewed in order to provide reference for further study on the mechanism of TAC-T technology and its safety of clinical application.

Progress in Chimeric Antigen Receptor-Modified Natural Killer Cells for Multiple Myeloma / 中国医学科学院学报

Although the development of novel drugs has significantly improved the survival of patients with multiple myeloma (MM) over the past decades,the lack of effective therapeutic options for relapsed and refractory MM results in poor prognosis.The chimeric antigen receptor (CAR) T-cell therapy has achieved considerable progress in relapsed and refractory MM.Nevertheless,this therapy still has limitations such as cytokine release syndrome,neurotoxicity,and off-target effects.Natural killer (NK) cells,as a critical component of the innate immune system,play an essential role in tumor immunosurveillance.Therefore,CAR-modified NK (CAR-NK) cells are put forward as a therapeutic option for MM.The available studies have suggested that multiple targets can be used as specific therapeutic targets for CAR-NK cell therapy and confirmed their antitumor effects in MM cell lines and animal models.This review summarizes the anti-tumor mechanisms,biological characteristics,and dysfunction of NK cells in the MM tumor microenvironment,as well as the basic and clinical research progress of CAR-NK cells in treating MM.

Construction and functional analysis of EGFRvIII CAR-T cells co-expressing IL-15 and CCL19 / 生物工程学报

The aim of this study was to investigate the functional characteristics and in vitro specific killing effect of EGFRvIII CAR-T cells co-expressing interleukin-15 and chemokine CCL19, in order to optimize the multiple functions of CAR-T cells and improve the therapeutic effect of CAR-T cells targeting EGFRvIII on glioblastoma (GBM). The recombinant lentivirus plasmid was obtained by genetic engineering, transfected into 293T cells to obtain lentivirus and infected T cells to obtain the fourth generation CAR-T cells targeting EGFRvIII (EGFRvIII-IL-15-CCL19 CAR-T). The expression rate of CAR molecules, proliferation, chemotactic ability, in vitro specific killing ability and anti-apoptotic ability of the fourth and second generation CAR-T cells (EGFRvIII CAR-T) were detected by flow cytometry, cell counter, chemotaxis chamber and apoptosis kit. The results showed that compared with EGFRvIII CAR-T cells, EGFRvIII-IL-15-CCL19 CAR-T cells successfully secreted IL-15 and CCL19, and had stronger proliferation, chemotactic ability and anti-apoptosis ability in vitro (all P < 0.05), while there was no significant difference in killing ability in vitro. Therefore, CAR-T cells targeting EGFRvIII and secreting IL-15 and CCL19 are expected to improve the therapeutic effect of glioblastoma and provide an experimental basis for clinical trials.

Advances in Allogeneic Chimeric Antigen Receptor T Cells / 中国医学科学院学报

Autologous chimeric antigen receptor(CAR)T-cell therapy has improved the prognosis of hematological malignancies.Nevertheless,allogeneic CAR-T cells have potential advantages over the autologous approach available on the market.However,allogeneic CAR-T cells may cause life-threatening graft-versus-host disease(GVHD)or be rapidly eliminated by the host immune system.In this review,we analyze the different sources of T cells for optimal allogeneic CAR-T cell therapy,describe the different approaches,and introduce the gene editing measures to produce allogeneic CAR-T cells with limited potential for GVHD and improved anti-tumor effect.

Study on construction of c-Met specific CAR-T cells and its killing effect on non-small cell lung carcinoma / 中华肿瘤杂志

Objective: To produce chimeric antigen receptor T cells (CAR-T) targeting human hepatocyte growth factor/c-Met (HGF/c-Met) protein and detect its cytotoxicity against non-small cell lung cancer (NSCLC) cells H1975 in vitro. Methods: The whole gene sequence of c-Met CAR containing c-Met single-chain fragment variable was synthesized and linked to lentiviral vector plasmid, plasmid electrophoresis was used to detect the correctness of target gene. HEK293 cells were transfected with plasmid and the concentrated solution of the virus particles was collected. c-Met CAR lentivirus was transfected into T cells to obtain second-generation c-Met CAR-T and the expression of CAR sequences was verified by reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) and western blot, and the positive rate and cell subtypes of c-Met CAR-T cells were detected by flow cytometry. The positive expression of c-Met protein in NSCLC cell line H1975 was verified by flow cytometry, and the negative expression of c-Met protein in ovarian cancer cell line A2780 was selected as the control. The cytotoxicity of c-Met CAR-T to H1975 was detected by lactate dehydrogenase (LDH) cytotoxicity assay at 1∶1, 5∶1, 10∶1 and 20∶1 of effector: target cell ratio (E∶T). Enzyme-linked immunosorbent assay (ELISA) was used to detect the release of cytokines such as TNF-α, IL-2 and IFN-γ from c-Met CAR-T co-cultured with H1975. Results: The size of band was consistent with that of designed c-Met CAR, suggesting that the c-Met CAR plasmid was successfully constructed. The results of gene sequencing were consistent with the original design sequence and lentivirus was successfully constructed. CAR molecules expression in T cells infected with lentivirus was detected by western blot and RT-qPCR, which showed c-Met CAR-T were successfully constructed. Flow cytometry results showed that the infection efficiency of c-Met CAR in T cells was over 38.4%, and the proportion of CD8(+) T cells was increased after lentivirus infection. The NSCLC cell line H1975 highly expressed c-Met while ovarian cancer cell line A2780 negatively expressed c-Met. LDH cytotoxicity assay indicated that the killing efficiency was positively correlated with the E∶T, and higher than that of control group, and the killing rate reached 51.12% when the E∶T was 20∶1. ELISA results showed that c-Met CAR-T cells released more IL-2, TNF-α and IFN-γ in target cell stimulation, but there was no statistical difference between c-Met CAR-T and T cells in the non-target group. Conclusions: Human NSCLC cell H1975 expresses high level of c-Met which can be used as a target for immunotherapy. CAR-T cells targeting c-Met have been successfully produced and have high killing effect on c-Met positive NSCLC cells in vitro.

Advances of Targeted Therapy for Acute Myeloid Leukemia--Review / 中国实验血液学杂志

Acute myeloid leukemia (AML) has highly heterogeneous clinical manifestations and poor prognosis, and traditional chemotherapy is the main treatment. In recent years, with the in-depth development of next-generation sequencing technology, the treatment of AML is gradually exploring the precise targeted therapy in the direction of molecular biology and immunophenotype. The advent of various small-molecule inhibitors and immune-targeted drugs has brought hope to patients who cannot tolerate intensive chemotherapy or with relapsed/refractory AML. Compared with traditional chemotherapy, targeted therapy has the advantages of significant curative effect and fewer adverse effects. This article reviews the latest research progress of targeted drug therapy for AML.

Novel CD19-KIRS2/Dap12-BB CAR-T Treatment for 3 Patients with Relapsed and Refractory B-Cell Tumors / 中国实验血液学杂志

OBJECTIVE@#To investigate the safety and efficacy of novel CD19-KIRS2/Dap12-BB chimeric antigen receptor T cells (CAR-T cells) in the treatment of relapsed/refractory B-cell malignancy (R/R BCM).@*METHODS@#Three patients with R/R BCM treated with novel CD19-KIRS2/Dap12-BB CAR-T cells from June 2020 to November 2020 were enrolled, including 1 case of B-cell acute lymphoblastic leukaemia (B-ALL) and 2 cases of non-Hodgkin's lymphoma (NHL), and the efficacy and adverse reactions were observed.@*RESULTS@#After CAR-T cells infusion, patient with B-ALL achieved complete remission (CR) and minimal residual disease (MRD) turned negative, and 2 patients with NHL achieved partial remission (PR). Grade 2 cytokine release syndrome (CRS) occurred in B-ALL patient, grade 1 CRS occurred in 2 NHL patients, and grade II to IV hematologic adverse reactions occurred in 3 patients, all of which were controllable and reversible. The progression-free survival (PFS) of the 3 patients was 143, 199, and 91 days, and overall survival (OS) was 282, 430, and 338 days, respectively.@*CONCLUSION@#The novel CD19-KIRS2/Dap12-BB CAR-T cells in treatment of 3 patients with R/R BCM have significant short-term efficacy and controllable adverse reactions, but the long-term efficacy needs to be further improved.

Research Progress of Chimeric Antigen Receptor Modified NK Cells in the Treatment of Acute Myeloid Leukemia --Review / 中国实验血液学杂志

Chimeric Antigen Receptor (CAR) is a research hotspot in the field of cellular immunotherapy in recent years, and CAR-T cells therapy are developing rapidly in hematological malignant tumors, but their clinical application is still limited by related risks. It is particularly important to find more optimized immunoreactive cells. Natural killer (NK) cells, as key effector cells of innate immunity, can kill tumor or infected cells quickly without prior sensitization. Autologous or allogeneic NK cell infusion has become an effective cell therapy for acute myeloid leukemia (AML). CAR-NK cells combine the advantages of CAR targeting tumor specific antigens and enhancing immune cells activity with the innate antitumor function of NK cells to enhance the targeting and lytic activity of NK cells to AML primordial cells. At present, most of the CAR-NK treatments for AML are still in the stage of specific target screening and verification. This article reviews the latest research progress of CAR-NK cell therapy in the field of AML therapy.

Research Progress in Treatment of Chronic Lymphocytic Leukemia --Review / 中国实验血液学杂志

Chronic lymphocytic leukemia (CLL) is a low-grade lymphoproliferative tumor that occurs frequently in middle-aged and elderly people. Early and precise intervention can effectively improve the clinical prognosis of CLL patients. In the past, chemotherapy was the main treatment plan. With the development of molecular biology and the continuous advent of immune targeting drugs, targeted drugs targeting B cell receptor signaling pathway have shown high clinical application value in the diagnosis and treatment path of CLL. Cellular immunotherapies such as CAR-T also offer hope for patients with relapsed and refractory CLL. Allogeneic hematopoietic stem cell transplantation and multi-drug combination have also shown remarkable results in clinical practice. The purpose of this article is to review the latest research progress in the treatment of CLL.

Relationship of cytokines to adverse reaction of chimeric antigen receptor T cell immunotherapy and targeted drug intervention / 中国生物制品学杂志

@#Chimeric antigen receptor T cell(CAR-T)immunotherapy is the most potential adoptive immunotherapy for malignant tumors,which needs no antigen presenting cells(APC)and is not limited by major histocompatibiliy complex(MHC). CAR-T immunotherapy not only recognizes and kills tumor cells directly,but also forms memory T cells and establishs long-term anti-tumor mechanism,of which the effect in leukemia,multiple myeloma and other non-solid tumors as well as the great potential in solid tumors have been widely verified. However,a variety of adverse reactions such as cytokine release syndrome(CRS),neurotoxicity(NT)and miss target effect are produced during CAR-T immunotherapy,of which the occurrence of CRS and NT may be related to the abnormal level of cytokines. Remarkable increase of cytokine level is a major characteristics of CRS. However,the increase of cytokines is neither the root cause nor the only result of CAR-T adverse reaction. CAR-T immunotherapy has a high incidence of adverse reaction which may even endanger the life of patients. Cytokine targeted drugs such as Anakinra and Tocilizumab may decrease the incidence of adverse reaction and improve the prognosis of patients. This paper reviews the correlation of cytokines with CRS and NT in CAR-T immunotherapy and the effect of cytokine targeting drugs,so as to provide a reference for the basic research,quality control and clinical application of CAR-T immunotherapy.

Advance in chimeric antigen receptor-T cell immunotherapy for multiple myeloma / 中国生物制品学杂志

@#In recent years,considerable progress has been made in the treatment of multiple myeloma(MM).However,despite the current improved prognosis of this malignancy,it always ends in relapse and therefore new therapeutic approaches are urgently needed to overcome it.The chimeric antigen receptor(CAR)-T cells targeting B cell maturation antigen(BCMA),cluster of differentiation 19(CD19),cluster of differentiation 38(CD38) and kappa light chains have been evaluated,and have achieved remarkable results in clinical trials.However,even when MM is treated with CAR-T cell therapy,most patients eventually relapse,which is the greatest limitation of this therapy.This paperreviewedthe research progress,limitations and optimization of CAR-T cell immunotherapy in the treatment of MM.

Advances in application of regulatory T cells in transplant immune tolerance: from basic to clinical research / 器官移植

Regulatory T cells (Treg) are important inhibitory immune cells to establish immune tolerance, which play a pivotal role in regulating excessive immune response and autoimmune diseases of the host. Previous studies related to transplant immune tolerance have confirmed that increasing the number of Treg in vivo or enhancing the function of Treg serve as a therapeutic strategy to induce transplant immune tolerance. At present, Treg-based induction methods for transplant immune tolerance include adoptive infusion of Treg, in vivo amplification of Treg and utilization of antigen-specific Treg. In this article, the characteristics and mechanism of Treg, the latest research progress on basic experiments and clinical practice of Treg related to transplant immune tolerance at home and abroad were reviewed, and future challenges and development of Treg therapy were prospected, aiming to unravel the significance and application prospect of Treg in transplant immune tolerance, explore the advantages and limitations of Treg therapeutic strategies, and provide reference and evidence for subsequent research in this field.