Research progress of universal cell therapy
CAR-T cell therapy brings new hope to cancer patients with its unique targeted therapy. At present, 10 CAR T drugs have been listed, mainly for CD19 or BCMA autologous CAR T cell transplantation treatment, according to statistics, a total of only 35,000 patients are treated, which is simply a fraction of the total number of patients in the world. One of the most important reasons is that personalized customization leads to the price is not close to the people. In addition, immunocell therapy is currently autologous transplantation treatment, so clinical treatment is also faced with a long preparation time, and patients need to clear the shower after bridge treatment and recover to the body state suitable for CAR T transfusion. More importantly, due to the influence of autoimmunity and chemotherapy, autologous T cells will be depleted, aging and functional defects in some patients, and it is not enough to prepare enough CAR T cells in vitro, thus affecting the final therapeutic effect. The cell therapy industry is rapidly iterating and commercializing technologies to meet the huge market demand. In particular, there are technical barriers to the underlying technology viral vectors and efficient gene editing, and they face long research and development cycles, high production costs, and low conversion rates, resulting in limited production capacity and high prices, resulting in great challenges on the road to commercialization. Therefore, the development of universal cell products is particularly important.
In order to enable more patients to benefit from immune cell therapy, researchers are now developing safe and effective allogeneic immune cells for the preparation of universal CAR-immune cells. The successful development of such products will greatly reduce the production cost, shorten the production time and better guarantee the efficacy of the product, so that more patients can benefit. The most important challenge of immune cell allotransplantation is graft-versus-host disease (GvHD) and host-versus-graft reaction (HvGR). To address this challenge, researchers have mainly addressed the following aspects [1] :
Figure 1. Universal CAR-T treatment strategy [8]
Figure 2. Universal NK cell strategy [7]
Shenzhen Cell Valley has achieved breakthroughs in the preparation process of NK, CAR-NK, γδT and CAR-γδT, especially in CAR-NK. Interested readers can review the scientific research enabling of 20231202, and welcome readers to communicate and guide our company to jointly promote the advent of new general-purpose cell products!
Reference：
[1] Ruella, Marco et al. Mechanisms of resistance to chimeric antigen receptor-T cells in haematological malignancies. Nature reviews. Drug discovery vol. 22,12 (2023): 976-995.
[2] Benjamin, R. et al. UCART19, a first-in-class allogeneic anti-CD19 chimeric antigen receptor T-cell therapy for adults with relapsed or refractory B-cell acute lymphoblastic leukaemia (CALM): a phase 1, dose-escalation trial. Lancet Haematol. 9, e833–e843 (2022)
[3] Eyquem, J. et al. Targeting a CAR to the TRAC locus with CRISPR/Cas9 enhances tumour rejection. Nature 543, 113–117 (2017).
[4] Mo, F. et al. Engineered of-the-shelf therapeutic T cells resist host immune rejection. Nat. Biotechnol. 39, 56–63 (2021).
[5] Nitsche, A. et al. Cytokine profiles of cord and adult blood leukocytes: diferences in expression are due to diferences in expression and activation of transcription factors. BMC Immunol. 8, 18 (2007)
[6] Merino, Aimee et al. Advances in NK cell therapy for hematologic malignancies: NK source, persistence and tumor targeting. Blood reviews vol. 60, 101073 (2023).
[7] Berrien-Elliott, Melissa M et al. Allogeneic natural killer cell therapy. Blood vol. 141,8 (2023): 856-868.
[8] Sadeqi Nezhad, et al. Induced Pluripotent Stem Cells (iPSCs) Provide a Potentially Unlimited T Cell Source for CAR-T Cell Development and Off-the-Shelf Products. Pharmaceutical Research. 38 (2021).
Disclaimer: Shenzhen Cell Valley is committed to the research of cell and gene therapy, in order to promote emerging technologies, so that more people understand the new development of biomedicine. The content of this article is only used for information exchange, and the platform remains neutral on the content, statements and opinions of the article, and does not represent the position and views of Shenzhen Cell Valley. The relevant information in this article should not be used as a diagnosis or treatment, is not a substitute for professional medical advice, and the company's website will not assume any responsibility. The final interpretation of the content of the above statement belongs to the company's website, this statement will apply to the company's website all the time to share the article, thank you for your cooperation! Copyright description: The copyright of the article belongs to Shenzhen Cell Valley, individuals are welcome to forward to the circle of friends, media or institutions without authorization, reproduced in any form to other platforms, will be regarded as infringement. For reprinting, please contact email: contact@sz-cell.com
In order to enable more patients to benefit from immune cell therapy, researchers are now developing safe and effective allogeneic immune cells for the preparation of universal CAR-immune cells. The successful development of such products will greatly reduce the production cost, shorten the production time and better guarantee the efficacy of the product, so that more patients can benefit. The most important challenge of immune cell allotransplantation is graft-versus-host disease (GvHD) and host-versus-graft reaction (HvGR). To address this challenge, researchers have mainly addressed the following aspects [1] :
1.T cells can destroy GvHD by knockout TRAC, and other additional gene editing can resist host rejection, such as modification of graft MHC-I associated sites (B2M-HLAI); The combination of alenzumab and other drugs can also inhibit the CD52 target and escape the killing of allogeneic NK cells [2].
2. Selecting γδT cells, NK cells, etc. from healthy donors can avoid or reduce GvHD.
Based on the above theories, we summarize the research progress of universal cell therapy by researchers:
一、Universal CAR-T and TCR-T cells
The researchers used CRISPR-Cas9 to site-integrate CD19-CAR into the TRAC site, aiming to knock out the TCR of donor cells and introduce specific CAR molecules targeting CD19 at the same time, so that the transplantation of general-purpose CAR T cells avoided GvHD, and CD19-CAR was expressed under the natural TCR promoter. This genetic engineering enhanced the function of CAR-T cells to better control the disease progression of pre-B-ALL [3]. However, there are also related problems. For example, among the 21 patients treated with 'UCART19', 14 patients achieved complete remission or complete remission with incomplete blood response at 28 days after infusion, but there was no significant amplification of UCART19 in 4 patients who did not receive alenzumab targeting CD52 [2]. Therefore, host rejection of allogeneic CAR-T remains a major factor. The main way to avoid the rejection of allogeneic cells by the host is to prevent the auto-immune cells from recognizing the transplanted cells as foreign cells and thus killing them. For example, Caribou bioscience's CB011 and CB012 series both insert B2M-HLA-E while knocking out the B2M of donor cells to escape the attack of host T lymphocytes and NK cells. Some researchers have also constructed an alloimmune defense receptor (ADR) through genetic engineering, which can selectively recognize 4-1BB, a cell surface receptor that is temporarily upregulated on the surface of activated lymphocytes. ADR expressing CAR T cells can effectively resist alloreactive T cells in vitro and in vivo. In both hematoma and solid tumor mouse models, ADR-expressing allogeneic CD19-CAR-T therapy showed lasting tumor elimination [4]. This method may have a good prospect for the development of general purpose CAR-T in the future.
Based on the above theories, we summarize the research progress of universal cell therapy by researchers:
一、Universal CAR-T and TCR-T cells
The researchers used CRISPR-Cas9 to site-integrate CD19-CAR into the TRAC site, aiming to knock out the TCR of donor cells and introduce specific CAR molecules targeting CD19 at the same time, so that the transplantation of general-purpose CAR T cells avoided GvHD, and CD19-CAR was expressed under the natural TCR promoter. This genetic engineering enhanced the function of CAR-T cells to better control the disease progression of pre-B-ALL [3]. However, there are also related problems. For example, among the 21 patients treated with 'UCART19', 14 patients achieved complete remission or complete remission with incomplete blood response at 28 days after infusion, but there was no significant amplification of UCART19 in 4 patients who did not receive alenzumab targeting CD52 [2]. Therefore, host rejection of allogeneic CAR-T remains a major factor. The main way to avoid the rejection of allogeneic cells by the host is to prevent the auto-immune cells from recognizing the transplanted cells as foreign cells and thus killing them. For example, Caribou bioscience's CB011 and CB012 series both insert B2M-HLA-E while knocking out the B2M of donor cells to escape the attack of host T lymphocytes and NK cells. Some researchers have also constructed an alloimmune defense receptor (ADR) through genetic engineering, which can selectively recognize 4-1BB, a cell surface receptor that is temporarily upregulated on the surface of activated lymphocytes. ADR expressing CAR T cells can effectively resist alloreactive T cells in vitro and in vivo. In both hematoma and solid tumor mouse models, ADR-expressing allogeneic CD19-CAR-T therapy showed lasting tumor elimination [4]. This method may have a good prospect for the development of general purpose CAR-T in the future.
Figure 1. Universal CAR-T treatment strategy [8]
二、Universal NK and CAR-NK cells
Studies have found that, compared with peripheral blood stem cell transplantation, patients receiving allogeneic cord blood transplantation have lower levels of pro-inflammatory cytokines, significantly reducing GVHD[5]. Other sources of immune effector cells, such as induced pluripotent stem cells, are also being explored.
NK cells are cytotoxic cells that play an important role in the innate immune response against viral or bacterial infection or damage to cells. Because they do not perform a killing function by recognizing allogeneic HLA and do not cause GVHD, NK cells have potential as allogeneic immunotherapies. The activation of NK cells is regulated by a variety of transmembrane receptors, including activating receptors, inhibiting receptors, cytokine receptors and chemokine receptors. Down-regulation of MHC, a common feature of tumor cells, provides an activation and killing mechanism for NK cells. When the NK cell surface inhibitory killer immunoglobulin receptor KIR binds to the MHC-I down-regulated tumor cells, the NK inhibitory signal is weakened and the killing function of NK cells is induced. NK cell surface inhibitory receptor CD94 (NKG2A or NKG2C heterodimer) can recognize non-classical HLA-E molecules, malignant tumors or virus-infected cells can escape the immune system through this molecular pathway. The activation signal of NKG2C can activate NK cells to play a killing function, so NKG2C positive NK cells can better enable NK cells to resist the escape of HLA-E positive tumors. In addition, CAR-NK not only has the natural killing ability of NK cells, but also can specifically recognize tumor antigens through CAR molecules to play an anti-tumor role [6]. But allogeneic NK cells are still vulnerable to allogeneic rejection by the host immune system. The most commonly used protocol is to gene knockout class HLA-1 molecules (B2M gene) in NK cells and express single chain HLA-E molecules, so as to escape the killing of host T cells, NK and macrophages, and also prevent the cannibalization of transplanted NK cells [7].
Studies have found that, compared with peripheral blood stem cell transplantation, patients receiving allogeneic cord blood transplantation have lower levels of pro-inflammatory cytokines, significantly reducing GVHD[5]. Other sources of immune effector cells, such as induced pluripotent stem cells, are also being explored.
NK cells are cytotoxic cells that play an important role in the innate immune response against viral or bacterial infection or damage to cells. Because they do not perform a killing function by recognizing allogeneic HLA and do not cause GVHD, NK cells have potential as allogeneic immunotherapies. The activation of NK cells is regulated by a variety of transmembrane receptors, including activating receptors, inhibiting receptors, cytokine receptors and chemokine receptors. Down-regulation of MHC, a common feature of tumor cells, provides an activation and killing mechanism for NK cells. When the NK cell surface inhibitory killer immunoglobulin receptor KIR binds to the MHC-I down-regulated tumor cells, the NK inhibitory signal is weakened and the killing function of NK cells is induced. NK cell surface inhibitory receptor CD94 (NKG2A or NKG2C heterodimer) can recognize non-classical HLA-E molecules, malignant tumors or virus-infected cells can escape the immune system through this molecular pathway. The activation signal of NKG2C can activate NK cells to play a killing function, so NKG2C positive NK cells can better enable NK cells to resist the escape of HLA-E positive tumors. In addition, CAR-NK not only has the natural killing ability of NK cells, but also can specifically recognize tumor antigens through CAR molecules to play an anti-tumor role [6]. But allogeneic NK cells are still vulnerable to allogeneic rejection by the host immune system. The most commonly used protocol is to gene knockout class HLA-1 molecules (B2M gene) in NK cells and express single chain HLA-E molecules, so as to escape the killing of host T cells, NK and macrophages, and also prevent the cannibalization of transplanted NK cells [7].
Figure 2. Universal NK cell strategy [7]
三、General type γδT and CAR-γδT cells
T cells can be divided into αβT cells and γδT cells according to the difference of TCR. Human peripheral blood lymphocytes are mainly αβT cells, and γδT cells generally account for only 1%-5%. Although the proportion of γδT cells is small, γδT cells can directly kill tumor cells through the NK cell receptor on the cell surface, ADCC effect and secreted cytokines (IFN-γ, TNF-α). Moreover, γδT cells can also act as antigen-presenting cells to activate αβT cells, or induce anti-tumor cytotoxicity of NK cells by 4-1BB co-stimulation pathway, so as to achieve indirect killing of tumors. Moreover, γδT cells do not present the risk of GvHD during allogeneic cell transplantation, so they are safer. In addition to the natural anti-tumor effect, CAR-γδT can further specifically recognize tumor-associated antigens through CAR molecules, and play a direct role in killing tumors.
T cells can be divided into αβT cells and γδT cells according to the difference of TCR. Human peripheral blood lymphocytes are mainly αβT cells, and γδT cells generally account for only 1%-5%. Although the proportion of γδT cells is small, γδT cells can directly kill tumor cells through the NK cell receptor on the cell surface, ADCC effect and secreted cytokines (IFN-γ, TNF-α). Moreover, γδT cells can also act as antigen-presenting cells to activate αβT cells, or induce anti-tumor cytotoxicity of NK cells by 4-1BB co-stimulation pathway, so as to achieve indirect killing of tumors. Moreover, γδT cells do not present the risk of GvHD during allogeneic cell transplantation, so they are safer. In addition to the natural anti-tumor effect, CAR-γδT can further specifically recognize tumor-associated antigens through CAR molecules, and play a direct role in killing tumors.
Figure 3. Anti-tumor mechanism of γδT cells [9]
Shenzhen Cell Valley has achieved breakthroughs in the preparation process of NK, CAR-NK, γδT and CAR-γδT, especially in CAR-NK. Interested readers can review the scientific research enabling of 20231202, and welcome readers to communicate and guide our company to jointly promote the advent of new general-purpose cell products!
Reference：
[1] Ruella, Marco et al. Mechanisms of resistance to chimeric antigen receptor-T cells in haematological malignancies. Nature reviews. Drug discovery vol. 22,12 (2023): 976-995.
[2] Benjamin, R. et al. UCART19, a first-in-class allogeneic anti-CD19 chimeric antigen receptor T-cell therapy for adults with relapsed or refractory B-cell acute lymphoblastic leukaemia (CALM): a phase 1, dose-escalation trial. Lancet Haematol. 9, e833–e843 (2022)
[3] Eyquem, J. et al. Targeting a CAR to the TRAC locus with CRISPR/Cas9 enhances tumour rejection. Nature 543, 113–117 (2017).
[4] Mo, F. et al. Engineered of-the-shelf therapeutic T cells resist host immune rejection. Nat. Biotechnol. 39, 56–63 (2021).
[5] Nitsche, A. et al. Cytokine profiles of cord and adult blood leukocytes: diferences in expression are due to diferences in expression and activation of transcription factors. BMC Immunol. 8, 18 (2007)
[6] Merino, Aimee et al. Advances in NK cell therapy for hematologic malignancies: NK source, persistence and tumor targeting. Blood reviews vol. 60, 101073 (2023).
[7] Berrien-Elliott, Melissa M et al. Allogeneic natural killer cell therapy. Blood vol. 141,8 (2023): 856-868.
[8] Sadeqi Nezhad, et al. Induced Pluripotent Stem Cells (iPSCs) Provide a Potentially Unlimited T Cell Source for CAR-T Cell Development and Off-the-Shelf Products. Pharmaceutical Research. 38 (2021).
[9]Yuan Song, et al. Targeting Cytokine Signals to Enhance γδT Cell-Based Cancer Immunotherapy. Front. Immunol., (2022)
Disclaimer: Shenzhen Cell Valley is committed to the research of cell and gene therapy, in order to promote emerging technologies, so that more people understand the new development of biomedicine. The content of this article is only used for information exchange, and the platform remains neutral on the content, statements and opinions of the article, and does not represent the position and views of Shenzhen Cell Valley. The relevant information in this article should not be used as a diagnosis or treatment, is not a substitute for professional medical advice, and the company's website will not assume any responsibility. The final interpretation of the content of the above statement belongs to the company's website, this statement will apply to the company's website all the time to share the article, thank you for your cooperation! Copyright description: The copyright of the article belongs to Shenzhen Cell Valley, individuals are welcome to forward to the circle of friends, media or institutions without authorization, reproduced in any form to other platforms, will be regarded as infringement. For reprinting, please contact email: contact@sz-cell.com
