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@#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.
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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.
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New approaches to cancer immunotherapy have been developed, showing the ability to harness the immune system to treat and eliminate cancer. For many solid tumors, therapy with checkpoint inhibitors has shown promise. For hematologic malignancies, adoptive and engineered cell therapies are being widely developed, using cells such as T lymphocytes, as well as natural killer (NK) cells, dendritic cells, and potentially others. Among these adoptive cell therapies, the most active and advanced therapy involves chimeric antigen receptor (CAR)-T cells, which are T cells in which a chimeric antigen receptor is used to redirect specificity and allow T cell recognition, activation and killing of cancers, such as leukemia and lymphoma. Two autologous CAR-T products have been approved by several health authorities, starting with the U.S. Food and Drug Administration (FDA) in 2017. These products have shown powerful, inducing, long-lasting effects against B cell cancers in many cases. In distinction to the results seen in hematologic malignancies, the field of using CAR-T products against solid tumors is in its infancy. Targeting solid tumors and trafficking CAR-T cells into an immunosuppressive microenvironment are both significant challenges. The goal of this review is to summarize some of the most recent aspects of CAR-T cell design and manufacturing that have led to successes in hematological malignancies, allowing the reader to appreciate the barriers that must be overcome to extend CAR-T therapies to solid tumors successfully.
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@#[Abstract] Objective: To explore the anti-tumor activity of MUC16-targeted chimeric antigen receptor modified NK-92 (CARNK-92) cells against ovarian cancer. Methods: The expression of MUC16 in surgically resected tumor tissues of 15 patients with ovarian cancer treated in the Department of Obstetrics and Gynecology of Qingyang Hospital of Traditional Chinese Medicine and 4 ovarian tumor cell lines was detected by Immunohistochemistry and Flow cytometry. MUC CAR sequence was synthesized by gene synthesis, and its lentivirus expression vector were constructed. CARNK-92 cells targeting MUC16 (MUC-BBz) were obtained by lentivirus infection. The expression of CD107a in MUC-BBz was detected by Flow cytometry. The activation of MUC-BBz cells and its cytotoxicity against SKOV3 target cells were characterized by the release of LDH assay. The xenograft nude mouse model of SKOV3 cells was established to verify the in vivo anti-tumor activity of MUC-BBz cells. Results: MUC16 was highly expressed in ovarian cancer tissues and human ovarian cancer cells. MUC-BBz was successfully constructed by infecting NK-92 cells with lentivirus, with a positive rate of (42.79±2.58)%. MUC-BBz could be specifically activated by MUC16 over-expressing tumor cells. After co-incubation of effector cells and target cells, the expression of CD107a on MUC-BBz was upregulated significantly (P<0.01), and the ability of MUC-BBz secreting cytokines IFN-γ and perforin also increased (all P<0.01). The LDH test indicated that with the increase of effector-target ratio, the cytotoxicity of MUC-BBz against 4 ovarian cancer cells (hey, COC1, SKOV3 and A2780) also significantly enhanced. The results of transplanted tumor model showed that transfusion of MUC-BBz could significantly inhibit the growth of SKOV3 xenograft in mice (P<0.01). Conclusion: The CARNK-92 cells can significantly inhibit the growth of ovarian cancer cells in vitro and in vivo, which provides an important basis for further evaluation of its clinical application.
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Chimeric antigen receptor (CAR) T-cell therapy is an effective new treatment for hematologic malignancies. Currently, two CAR T-cell products have been approved for clinical use by the U. S. FDA. A barrier to widespread use of CAR T-cell therapy is post-infusion toxicity, including primarily cytokine release syndrome and neurologic toxicity, in which neurotoxicity is the main factor for incidence rate and mortality rate.As there is still a lack of pathophysiological research on this symptom, this review describes existing neurologic toxicity and insights into the pathophysiology of this syndrome, which provides new opportunities for targeted therapeutic interventions to modulate CAR T-cell therapy toxicities.
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China has the highest incidence of malignant tumors and associated mortality worldwide; efforts are underway to reduce their recurrence rate and fatality. However, single-target chimeric antigen receptor (CAR) T cells used in the treatment of malignant tumors are prone to antigen target loss, tumor recurrence, and other limitations. Presently, multi-target CAR-T cells that can identify and target two or more tumor-related antigens have been developed in China and in the rest of the world; these cells can be used to effectively avoid antigen escape and prevent tumor recurrence. In this review, we have focused on the progress in multi-target CAR-T strategies currently being developed and tested for the treatment of malignant tumors. We have also discussed the advantages of multi-targeted CAR-T cell therapies and measures to overcome limitations, such as tumor recurrence after single-targeted CAR-T-cell treatment; we have also analyzed the therapeutic effects of multi-targeted CAR-T-cell treatments combined with other regimen. The use of multi-target CAR-T cells as a new therapeutic option to improve anticancer efficacy and reduce cancer progression, has also been proposed.
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@#Objective: To explore the gene transduction method of chimeric antigen receptor (CAR) mediated by novel cationic polymer nanocarrier mPEG-P (Asp-AED-g-HFB) (PAEF) and PigyBac transposon system to modify natural killer (NK) cells, providing a new strategy for immunotherapy of cancer cells. Methods: PAEF/DNA (transposase+transposon) complex were prepared. The particle size distribution and surface potential of PAEF/DNA complexes were measured with Nano-ZSE Dynamic Light Scattering System (Malvern Instruments). The DNA encapsulation rate, release and stability of PAEF were evaluated by DNA gel electrophoresis, and then by combiningwithparticlesizeandsurfacepotentialtodeterminethepreferentialN/PratiotoenterNKcells.Thecell cytotoxicity of PAEF/DNA complexes under different N/P ratios was analyzed by CCK-8 cytotoxicity test. Transduction efficiency of NK cells was evaluated by Fluorescence microscopy and Flow cytometry, and the feasibility of PAEF gene transfection vectors was assessed. Results: PAEF could encapsulate DNA to form nano-complexes with the diameter of 100-150 nm, which was suitable to mediate DNA entering into cells. PAEF could completely encapsulate DNA with N/P ratio of 20. In the presence of reducing agent dithiothreitol (DTT), PAEF had a good ability to release DNA. NK-92 cells transfected with PAEF/DNA complex, which was formed at the N/P ratio of 80, attained a significantly higher cell viability than cells of lipofectamine transfection group [(72.50±3.9)% vs (64.03±1.8)%, P<0.05]; Fluorescence microscopic observation showed more fluorescence and higher fluorescence intensity in cells of PAEF/DNA group; Flow cytometry showed the highest transfection efficiency of 83.4%. Conclusions: Nanocarrier PAEF can encapsulate DNA well by electrostatic adsorption, and has good biocompatibility and high efficiency for gene transduction. It provides a good experimental basis for adoptive immunotherapy.
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Regulatory T cell (Treg) is a subset of T cells that negatively regulates immunity and has the function of inhibiting rejection. The specific modification of Treg by chimeric antigen receptor (CAR) technology can successfully chime donor-specific antigen onto the surface of Treg, thus regulating the immune function of the body in a real-time manner. It provides a novel and promising therapeutic option for inducing immune tolerance. In this article, research progresses on Treg in immune related diseases, main difficulties in the realization of CAR-Treg technology and its role in inducing transplantation immune tolerance were reviewed, and the opportunities and challenges of CAR-Treg application in the field of organ transplantation are prospected.
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multiple myeloma (MM), considered an incurable hematological malignancy, is characterized by its clonal evolution of malignant plasma cells. Although the application of autologous stem cell transplantation (ASCT) and the introduction of novel agents such as immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs) have doubled the median overall survival to eight years, relapsed and refractory diseases are still frequent events in the course of MM. To achieve a durable and deep remission, immunotherapy modalities have been developed for relapsed/refractory multiple myeloma (RRMM). Among these approaches, chimeric antigen receptor (CAR) T-cell therapy is the most promising star, based on the results of previous success in B-cell neoplasms. In this immunotherapy, autologous T cells are engineered to express an artificial receptor which targets a tumor-associated antigen and initiates the T-cell killing procedure. Tisagenlecleucel and Axicabtagene, targeting the CD19 antigen, are the two pacesetters of CAR T-cell products. They were approved by the US Food and Drug Administration (FDA) in 2017 for the treatment of acute lymphocytic leukemia (ALL) and diffuse large B-cell lymphoma (DLBCL). Their development enabled unparalleled efficacy in combating hematopoietic neoplasms. In this review article, we summarize six promising candidate antigens in MM that can be targeted by CARs and discuss some noteworthy studies of the safety profile of current CAR T-cell therapy.
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@#[Abstract] Objective: To construct CD33-CAR modified NK92 cells based on CD33-scFv sequence, and to explore its killing effect on CD33+ AML (acute myeloid leukemia) cells. Methods: DNA fragment encoding CD33-CAR was synthesized by gene synthesis and molecular cloning technology and then cloned into lentiviral vector. Lentivirus were packaged and used to transfect NK92 cells. The transfection efficiency was detected by flow cytometry, and puromycin was used to screen NK92 cells stably expressing CD33-CAR (CD33-CAR-NK92). Killing effect of CD33-CAR-NK92 cells on AML cells in vitro was examined with calcein-AM release assays. IFN-γ secretions of NK92 cells and CD33-CAR-NK92 cells were measured by ELISA. Results: The pCDH-CD33-CAR lentiviral vector was successfully constructed. After lentiviral transfection, about 18.7% of NK92 cells express CD33-CAR (referred as CD33-CARNK92 cells). The percentage of CD33-CAR+ NK92 cells was about 86.3% after puromycin selection. In contrast to unmodified NK92 cells, significantly higher cytotoxic effect against CD33+ MOLM-13 cells was found in CD33-CAR-NK92 cells (P<0.01); however, there was no significant difference in cytotoxicity against CD33- JURKAT cells between NK92 cells and CD33-CAR-NK92 cells (P> 0.05). After co-culture at an effect-target ratio of 2∶1 for 6 hours, the level of IFN-γ secreted by the CD33-CAR modified NK92 cells was significantly higher than that of the unmodified ([190.97±11.52] vs [88.41±2.75]pg/ml, P<0.01). Conclusion: The CD33-CARNK92 cells could specifically recognize CD33 antigen and kill CD33+ AML cells in comparison with the unmodified NK92 cells, which provides experimental basis for clinical transformation of CD33-CAR-NK92 cells in treatingAML.
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The great potential of cell therapy based on chimeric antigen receptor (CAR) has been demonstrated in the treatment of malignant tumors through 25 years of research .A large number of experimental and clinical data have been repor-ted in recent years .This review compares and analyzes these data to discuss how to enhance the efficacy of CAR-T cell therapy in the treatment of unresectable malignant tumors and to summarize the safety issues and solution strategies of CAR-T cell technology in the treatment of malignant tumors .