What is CAR-T?
CAR-T is the abbreviation of Chimeric Antigen Receptor T-cell. It works by genetically modifying the body's own T cells so that they have antigen specificity against tumor cells, thereby enhancing the immune system's ability to attack tumor cells. The process of CAR-T treatment is roughly divided into the following steps:
- T cell collection:Extract T cells from the patient’s blood;
- Gene modification:Apply genetic engineering technology to T cells and transduce them into cells carrying CAR (chimeric antigen receptor);
- In vitro expansion: Expand the modified CAR-T cells in vitro to increase their number;
- Therapeutic injection:Re-inject a large number of CAR-T cells into the patient;
- Killing tumors:CAR-T cells recognize and bind to specific antigens on the surface of tumor cells, release cytotoxins, and kill tumor cells.
- Continuous Observation:The patient is closely observed to monitor the effectiveness of the treatment and possible side effects.
CAR-T immunotherapy process
Molecular design of CAR
At the molecular level, CAR-T cells kill tumor cells based on
- The extracellular antigen-binding domain of the CAR molecule specifically recognizes tumor antigens;
- Recognizes the intracellular domain that signals to the CAR molecule;
- The intracellular domain activates T cells, causing them to proliferate, synthesize perforin and granzymes, release cytokines, etc., and kill tumor cells.
Therefore, in order to maximize its function, the structural design of CAR molecules is crucial.
The CAR molecule is composed of 4 main components:
- Extracellular antigen-binding domain : Confers target-specific functions to CAR molecules. Its principle is to connect the variable heavy chain (VH) and variable light chain (VL) of the antibody to form a single-chain variable segment (scFv), which is used to specifically recognize tumor surface antigens.
- Hinge region: The structural region connecting the transmembrane domain and the extracellular unit. The role of the hinge is to provide steric flexibility that can overcome steric hindrance and have a suitable length to allow the antigen-binding domain to access the target epitope.
- Transmembrane domain: The main function is to anchor the CAR molecule to the cell membrane of T cells. Studies have shown that the transmembrane region may affect the expression level and stability of CAR molecules and play a role in signal transduction.
- Intracellular signaling domain : The co-stimulation effect of CAR molecules is the focus of much attention in CAR engineering. The main difference between the 1st and 3rd generation CAR molecules comes from the intracellular costimulatory domain. The two most common, FDA-approved costimulatory domains, CD28 and 4-1BB, both have efficient T cell activation effects and can induce T cells to perform different functions.
CAR molecular design blueprint
Limitations of CAR-T cell therapy and challenges in the treatment of solid tumors
The limitations of CAR-T cell therapy mainly include life-threatening cytokine storm (CRS), neurotoxicity, antigen escape, and durability of therapeutic effects. Especially for the treatment of solid tumors, due to the influence of factors such as the tumor microenvironment, no breakthrough success has been achieved in clinical practice.
The limitations of CAR-T cell therapy include: A. Antigen escape; B. Off-target effects; C. CAR-T cell transport and infiltration; D. Immunosuppressive microenvironment; E. CAR-T cell-related toxicity.
CAR-T cell therapy is an emerging immunotherapy in the past decade. In the past, it was mainly used to treat blood tumors and achieved great success. However, it later encountered many difficulties in the treatment of solid tumors. Mainly including tumor antigen heterogeneity, cell reinfusion and infiltration into tumor tissue
(1)Tumor antigen heterogeneity
Tumor antigen heterogeneity is one of the obstacles for CAR-T cell therapy against solid tumors. Tumor antigens are mainly divided into two types: tumor-associated antigens (TAA) and tumor-specific antigens (TSA): TAA is highly expressed in tumor cells and also expressed in normal tissue cells, but at a low level; TSA is only expressed in tumor cells It is not expressed in normal tissue cells, so it is also the most ideal antigen target. Since the discovery and screening of TSA is extremely difficult, the most commonly used recognition target of CAR molecules is TAA. Therefore, the diverse expression of TAA by different types of tumor cells may affect the recognition of cancer cells by CAR-T cells and reduce the cost of CAR-T therapy. Effect.
Currently, there are many methods to target CAR-T cells to recognize multiple tumor-related antigens, such as co-expressing multiple CAR molecules on a single T cell, programmable CAR expression regulation, etc. Expressing two or more antigen recognition domains allows a single CAR-T cell to recognize multiple antigens expressed on tumor cells, thereby eliminating the adverse effects of antigen heterogeneity.
Immunosuppressive microenvironment in solid tumors: a. Effector cells and target cells; b. Immunosuppressive cells and cytokines; c. Physical barriers; d. Internal tumor microenvironment; e. Other immunosuppressive factors
(2) Infusion of CAR-T cells and infiltration into tumor tissue
CAR-T cells can exist in the blood and lymphatic system. Therefore, for hematological tumors, CAR-T cells have more opportunities to contact blood tumor cells, while in solid tumors, CAR-T cells are more difficult to penetrate through the blood system. tumor tissue. In addition, the lack of expression of chemokines involved in T cell penetration into tumor tissue, as well as the presence of dense fibrotic stroma in solid tumors, results in a reduced ability of CAR-T cells to migrate and invade tumor cells.
In many reports, CAR-T cells have been directly injected locally into tumor sites (Tumor sites), such as the brain, breast, pleura, liver, etc. Local injection of CAR-T cells may also reduce the risk of off-target effects. However, many solid tumors are metastatic, which is a major difficulty in local injection of CAR-T cells. On the other hand, some clinical studies use chemokines to mediate the trafficking of CAR-T cells and enhance tumor localization. For example, expression of macrophage colony-stimulating factor 1 receptor (CSF-1R) in CAR-T cells primes these cells to respond to CSF-1, a monocyte chemotactic factor that is enriched in many solid tumors. , while enhancing CAR-T cell proliferation signaling, it does not affect the cytotoxicity of the cells.
The tumor microenvironment of solid tumors promotes tumor growth and proliferation while causing immune suppression to CAR-T cells. Including immunosuppressive cells such as regulatory T cells (Treg), myeloid-derived suppressor cells (MDSC), tumor-associated macrophages (TAM), growth factors produced in solid tumors, local cytokines, CTLA-4 and PD-1, etc. Immune checkpoint molecules, etc., the tumor microenvironment in these complex environments will greatly limit the efficacy of CAR-T cells.
Recent advances in CAR-T research to break through solid tumors
In recent years, as scientists have continued to deepen their research on CAR-T therapy, scientific researchers have made new progress in the treatment of a variety of solid tumors through various transformation and upgrading methods.
1. Enhance the efficacy of CAR-T in the treatment of solid tumors through chimeric orthogonal cytokine receptors
In the past two years, there have been many studies on modifying CAR-T to treat solid tumors. The most worthy of in-depth understanding is the one conducted in 2022 by Christopher Garcia of Stanford University, Carl H. June of the University of Pennsylvania and the University of California, Los Angeles. Antoni Ribas, Anusha Kalbasi and others published a paper titled: Potentiating adoptive cell therapy using synthetic IL-9 receptors in the internationally renowned magazine Nature. Research Papers. In fact, as early as 2018, Christopher Garcia, also the corresponding author, had published a paper in Science. At that time, he had already proposed the concept of modifying CAR-T based on orthogonal cytokines and their receptors.
Orthogonal cytokine receptors are mutant forms of normal receptors that selectively bind mutated cytokines but not normal cytokines. In this study, the authors first replaced the ICD of the orthogonal mouse IL-2 receptor o2R with γc (receptors for common γ-chain) receptors for cytokines IL-4, IL-7, IL-9 and IL-21. Somatic ICD, creating chimeric orthogonal receptors. And oIL-2 clone 3A10 was selected as the receptor ligand. Analytical screening found that signal transduction through o9R leads to efficient phosphorylation of STAT1, STAT3, and STAT5. This effect is consistent with known signaling by wild-type IL-9 receptors. Subsequent further analysis found that o9R signaling was dose-dependent and specific for MSA-oIL2, and expression of o2R or o9R did not affect wild-type IL-2-induced STAT signaling.
Chimeric orthogonal IL-2 receptor reveals properties of IL-9R signaling in T cells
Following experiments, the authors found that among these γc cytokines, IL-9 was more worthy of study—unlike other γc cytokines, IL-9 signaling is not active in naturally occurring T cells. Therefore, the synthetic chimeric orthogonal IL-9 receptor (o9R) will make adoptive T cells more powerful in fighting tumors. Further research found that T cells signaling through o9R were distinguished by concomitant activation of STAT1, STAT3, and STAT5, and presented a unique hybrid profile of stem cells and killer cells. Compared with the previous o2R T cells, o9R T cells have better anti-tumor effects in two refractory melanoma and pancreatic cancer mouse solid tumor models, with the highest cure rate exceeding 50%!
The authors next set out to study o9R signaling in vivo in adoptive cell therapy of solid tumors, using T cells from transgenic pmel mice that express endogenous T cell receptors specific for gp100, a melanocyte antigen. Overexpressed in B16. The study found that STAT signaling and cell proliferation of o2R and o9R in pmel T cells can reflect the status of o2R and o9R T cells in wild-type mice. The evaluation found that in the absence of lymphodepletion, o9R pmel T cells could prolong the survival of mice and achieve better anti-tumor effects in this model. Although the proliferative effect of o9R signaling is weak, o9R can improve T cell infiltration in tumors, increase IFN-γ expression, and o9R pmel T cells have higher cytolytic ability in vitro. The authors also confirmed these phenotypes through RNA-seq. In addition to changes related to stem cell-like memory T cells, the authors also observed an enrichment of genes related to the classical activation phenotype of T cells. This suggests that this population of cells has a mixed phenotype.
o9R signaling confers antitumor efficacy to pmel T cells without lymphocyte depletion.
Finally, the authors constructed a CAR-based adoptive therapy model in an immunotherapy-resistant mesothelin-expressing pancreatic cancer model. Combination treatment of CAR-o9R with an adenoviral vector encoding oIL2 (Ad-oIL-2) plus CAR-o2R resulted in complete regression in 8 of 12 mice (67%), and no cytokine release syndrome or tumor lysis was observed syndrome. Finally, the authors demonstrated that this therapy was effective whether the cytokines were delivered systemically to mice or injected directly into tumors. In each case, T cells engineered with synthetic orthogonal IL-9 receptors performed better and were able to cure some difficult-to-treat solid tumors.
Overall, this study demonstrates that synthetic orthogonal IL-9 and its receptor IL-9R can activate CAR-T cells without the need for chemotherapy or radiotherapy to clear the immune system, allowing them to gain new benefits. Function and enhanced anti-tumor activity against refractory solid tumors. These findings will open a new door for the treatment of solid tumors in humans.
2. Tumor-specific receptor signaling assists CAR-T in entering cold tumors
Another blockbuster study last year on modifying CAR-T was conducted by Professor Wendell A. Lim’s research group at the University of California, San Francisco in "Science"In the magazine, a paper titled "Synthetic cytokine circuits that drive T cells into immune-excluded tumors" was published. This study specifically targets chimeric antigen receptor (CAR) T cells, which are ineffective in treating solid tumors (cold tumors) with an immunosuppressive microenvironment. The authors designed a tumor-specific synNotch receptor to locally induce the cytokine IL-2 The resulting signal loop.
These signaling circuits effectively enhance CAR T cell infiltration and clear immune-rejection tumors without systemic toxicity. The most potent IL-2 induction circuits bypass inhibitory mechanisms to act in an autocrine and T cell receptor (TCR), or CAR-independent manner. These engineered cells establish a foothold in the target tumor and synthesize Notch-induced IL-2 production to initiate CAR-mediated T cell expansion and cell killing. Therefore, it may be possible to reconstitute synthetic T cell circuits to activate the outputs ultimately required for an antitumor response, but in a manner that avoids key points of tumor suppression.
Synthetic synNotch→IL-2 circuits can drive local T cell proliferation independently of TCR activation or synergistically with T cell killing.
Subsequently, the researchers designed a new AND gate for synNotch-IL-2 loop T cells. The therapeutic T cells need to recognize two antigens before triggering their full cytotoxic response: the TCR antigen required for T cell activation and synNotch antigen required for induction of IL-2 production. In this case, the authors used the anti-GFP-synNotch→sIL-2 synthetic cytokine circuit. By requiring the simultaneous presence of TCR antigen (NYESO-1) and synNotch antigen. When mice were treated with T cells expressing both the anti-NY-ESO-1 TCR and the anti-GFP synNotch→sIL-2 loop, the dual-targeted NY-ESO+/GFP+ tumors were significantly reduced in size.
To study the impact of local IL-2 production in a fully immunocompetent mouse tumor model, the researchers constructed anti-mesothelin CAR and synNotch-IL-2 loops for simultaneous expression in primary mouse T cells. The authors subsequently found that the killing effect mediated by the modified CAR-T cells caused tumor regression.
An autocrine synthetic IL-2 circuit significantly enhances T cell cytotoxicity in multiple immune-depleted syngeneic tumor models.
Cell-delivered IL-2 is a powerful tool for synergy with therapeutic T cells, and cytokines such as IL-2 have long been recognized as powerful stimulators of anti-tumor immunity. However, systemic IL-2 delivery is known to be highly toxic, leading to a wide range of side effects, thus greatly limiting its therapeutic use. The authors exploited the ability of the engineered cells to identify tumors and deliver IL-2 locally and accurately where needed. Cell-mediated local cytokine (IL-2) delivery can effectively overcome immune suppression and enhance CAR-T cells to effectively clear multiple immune-rejection tumor models (pancreatic cancer and melanoma).
The different ways in which the body produces cytokines are critical to its successful function. First, cytokine production must be dynamically regulated (inducible), but continued production of IL-2 may exacerbate off-target toxicity. Second, to bypass TCR/CAR inhibition by the tumor microenvironment, induction of IL-2 production must be independent of the TCR activation pathway. The authors found that a powerful solution to this constraint is to engineer a synthetic signal transduction pathway that is tumor-triggered but bypasses the native CAR/TCR activation pathway. Using tumor-detecting synNotch receptors to drive IL-2 production provides a simple and modular approach to achieving this goal.
3. Create stem cell-like CAR-T to exert lasting anti-tumor effects
In 2023, two recently published research results on modified CAR-T cells both achieved better therapeutic effects on different solid tumors. One of the studies was titled: "TSTEM-like CAR- T cells exhibit improved persistence and tumor control compared with conventional CAR-T cells in preclinical models”.
Although the FDA has currently approved five CAR-T cell therapies for the treatment of hematological tumors such as leukemia, lymphoma, and myeloma, the effectiveness of CAR-T cell therapy is limited in the more major cancer types of solid tumors. This is related to various factors such as poor expansion, poor persistence and T cell exhaustion of CAR-T cells. In order to solve this problem, the authors developed a new CAR-T cell therapy based on stem cell-like T cells (TSTEM). Compared with CAR-T cells based on traditional T cells, TSTEM CAR-T cells have stronger expansion capabilities. , and has been shown to be effective against solid tumors in preclinical studies. At the same time, this is also an important breakthrough in CAR-T cell therapy in the treatment of solid tumors.
Early phenotype CAR-T cells exhibit a TSTEM-like phenotype and lack expression of immune checkpoint molecules.
Compared with traditional CAR-T therapy, cancer patients who receive memory T cell-enriched CAR-T cell therapy can show better cancer control effects due to the expansion and persistence of CAR-T cells. Human memory T cells include stem cell-like CD8+ memory T cell progenitors that can become functional stem cell-like T cells (TSTEM) or dysfunctional exhausted precursor T cells (T-PEX). The research team demonstrated in a phase 1 clinical trial of CAR-T cell therapy (NCT03851146) that stem cell-like T cells (TSTEM) were present at lower levels in the infused CAR-T cells and that the infused CAR-T cells were Exhibits poor durability.
To solve this problem, the research team developed a production protocol to rapidly generate stem cell-like T cells (TSTEM) that can generate fully functional TSTEM CAR-T cells in just 6 days, instead of the standard 14 days, which This opens the door to more economical and efficient CAR-T cell therapy in the future. Compared with traditional CAR-T, T-STEM CAR-T cells have stronger proliferation ability and increased cytokine secretion. These responses are dependent on the presence of CD4+ T cells during TSTEM CAR-T cell generation. Subsequently, the authors found in multiple preclinical animal models that adoptive transplantation of TSTEM CAR-T cells could better control mouse tumor growth and resist tumor recurrence. These more favorable outcomes were associated with increased persistence of TSTEM CAR-T cells and an increase in the memory T cell repertoire.
TSTEM-like CAR-T cells exhibit enhanced persistence and tumor control in vivo.
In summary, in this study we describe an easily replicable protocol to generate human stem cell-like CAR-T cells with enhanced proliferation and self-renewal capabilities. These stem cell-like CAR-T cells can also form effector CAR-T cells at the tumor site, and this effect can be enhanced by anti-PD-1 adjuvant therapy. Many clinical trials are investigating the use of CAR-T therapy in solid tumors, however limited clinical responses have been reported to date. Key mechanisms for suboptimal patient response include limited CAR-T cell persistence in the body. Here, the authors developed a novel CAR-T cell with strong proliferative potential that improves persistence in the body. Therefore, this CAR-T modification protocol proposed by the authors has immediate and broad implications, and also has the potential for future trial protocols combining stem cell-like CAR-T cells, especially in combination with immune checkpoint blockade, for more effective Treatment of solid tumors.
4. γδ CAR-T performs well in bone metastasis cancer
All the above studies focused on traditional αβ T cells, while another recently published in the journal "Science Advances" The article titled: "γδ-Enriched CAR-T cell therapy for bone metastatic castrate-resistant prostate cancer" achieves better anti-solid tumor effects by transforming another innate immune-like γδ CAR-T cell. . The T cells we often refer to actually refer to αβ T cells, accounting for about 65%-70% of the total number of T cells. The T cell receptors (TCRs) on their surface are composed of two glycoprotein chains, α chain and β chain. γδ T cells are a subset of T cells, accounting for 0.5%-5% of all T lymphocytes. Their TCRs are composed of γ chain and δ chain, and are mainly found in epithelial and mucosal tissues, such as skin, intestines, etc. Although not abundant, γδ T cells have no antigen specificity and therefore have a broader tumor killing effect.
In this study, the authors employed a combination strategy using gamma delta chimeric antigen receptor (CAR)-T cells and zoledronate (ZOL) to treat bone metastatic prostate cancer (mCRPC). In a preclinical mouse model of bone mCRPC, γδ CAR-T cells targeting prostate stem cell antigen (PSCA) induced rapid and significant tumor regression while increasing survival and reducing cancer-related bone disease. Ultimately, data from this study demonstrate that endogenous Vγ9Vδ2 T-cell receptor activity is retained in CAR-T cells, allowing dual-receptor recognition of tumor cells.
Impact of domain design within CAR.
To generate γδ CAR-T cells, the researchers first transduced Vγ9Vδ2-enriched T cells with a second-generation CD28 costimulatory CAR construct (28t28Z), which when transduced into αβ T cells has been previously shown to be effective in expressing PSCA anti-tumor effect on tumors. However, γδ T cell expression of a modified CAR was clearly superior, in which the CD28-derived hinge and transmembrane domains (but no signaling portion) were replaced by a CD8α-derived hinge/transmembrane (8t28Z). γδ T cells expressing these CARs exhibit higher expression of the β subunit of the interleukin 2 receptor (IL-2Rβ), and these results suggest that slight modifications of structural elements can greatly enhance CAR expression. While γδ T cells expressing CD28 costimulated second-generation CAR showed maximal IFN-γ (IFN-γ secretion can modulate the tumor microenvironment of solid tumors and increase the efficacy of CAR-T cells) secretion and targeting of prostate cancer cells. Cytotoxicity.
Next, they transferred their experiments to mouse models, and the results showed that CAR-T cells significantly reduced tumor size and improved survival rates with limited toxicity. To evaluate the anti-tumor activity of anti-PSCA γδ CAR-T cells in vivo, the researchers inoculated PSCA-expressing C4-2B prostate cancer cells (2.0 × 105 cells per injection) into the left and right tibiae of 6-week-old male NSG ( NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ) mice (n=10) and monitored by bioluminescence imaging as a readout of tumor burden.
ZOL enhances γδ-rich CAR-T cell-mediated regression of intratibial prostate tumors.
After 10 days, the mice were randomly divided into two groups based on the different detected light signals, one group served as the untreated control group, and the other group received anti-PSCA γδ CAR-T cells (1.5×107) via tail vein inoculation. Subsequent bioluminescence imaging revealed that mice treated with anti-PSCA γδ CAR-T therapy exhibited rapid and significant tumor regression (P = 0.009) that persisted for up to 30 days within 24 hours after T cell transfer. At later time points, two of the five anti-PSCA γδ CAR-T-treated mice relapsed, but these tumors were subsequently observed to grow significantly more slowly compared with untreated control tumors.
Overall, this study is the first to evaluate γδ T cells expressing CAR and treating bone metastatic prostate cancer. It has the potential to quickly achieve clinical transformation. It is speculated that it will not be long before a similar CAR-T is applied for clinical application for mCRPC.
summary
Whether through chimeric orthogonal cytokine receptors, tumor-specific synNotch receptors, or CAR-T cells that produce stem cell-like T cells, which are modifications to traditional αβ T cells; or by directly modifying γδ T cells (without MHC molecules) limitations) to improve its universality; we can all see that good results have been achieved in CAR-T modification for solid tumors in recent years. It can be said that these research results have provided us with ideas to promote CAR-T to kill tumor cells from different angles.
But in addition, the future development direction of CAR-T will still mainly focus on the following aspects:
1. Expand the scope of indications: Currently, CAR-T cell therapy is mainly used to treat hematological tumors, such as acute lymphoblastic leukemia and non-Hodgkin lymphoma. Although preliminary good results have been achieved in animal models, or there are good curative effects in some melanomas, the first priority for future CAR-T development still needs to expand the scope of indications and apply CAR-T cell therapy to more Types of solid tumors, such as lung cancer, breast cancer, colorectal cancer, etc. Researchers will work hard to find more tumor antigens and develop CAR-T cells with broader antigen specificity.
2. Improve treatment effect:CAR-T cell therapy has achieved significant clinical efficacy in some patients, but there are still patients who experience relapse or ineffectiveness. Future development trends will focus on improving the therapeutic effect and persistence of CAR-T cells. This may include improving the design of CAR-T cells to enhance their tumor recognition and killing capabilities, as well as developing combination treatment strategies, such as combination with other immunotherapies, radiotherapy, or chemotherapy.
3. Reduce side effects:CAR-T cell therapy may cause a series of side effects, including cytokine release syndrome (CRS) and CAR-T cell-related encephalopathy (CRES) . Future development trends will focus on mitigating side effects and improving the safety of treatment. Researchers will look for better ways to manage and prevent side effects, and improve CAR-T cell construction and regulation strategies to reduce unnecessary activation and side effects. With the development of precision medicine, CAR-T cell therapy will also develop towards personalized treatment. Through genetic testing and tumor characterization analysis, the most suitable CAR-T cell therapy strategy for the patient can be selected. This may include selecting specific CAR-T cell constructs, dosages, and treatment regimens to improve the specificity and effectiveness of the treatment.
4. Production and accessibility improvements:The production process of CAR-T cell therapy is complex and expensive, limiting the possibility of its widespread application. Future development trends will include improving production processes and reducing costs to increase the accessibility and sustainability of CAR-T cell therapy. The introduction of new production technologies and automated systems may accelerate the production and supply of CAR-T cells. Only by reducing costs can CAR-T bring substantial help to a wider range of tumor patients. Otherwise, it is just talk on paper. .
All in all, CAR-T therapy can overcome the limitations of solid tumor treatment and can be said to be one of the most pressing challenges currently facing the field. In fact, about 90% of cancer cases worldwide are solid tumors, and the unmet clinical needs are still huge. However, compared with hematological tumors, factors such as the lack of selective and highly expressed surface antigens on solid tumors, antigen heterogeneity, immunosuppressive microenvironment, and the thick physical barriers of solid tumors have made intravenous injection of CAR difficult. -T cells not only have difficulty entering tumors and binding to them in the numbers required to defeat cancer, but they also have difficulty surviving and functioning effectively in the unfavorable microenvironment formed by tumor lesions.
At present, CAR-T cell therapy, as an innovative tumor treatment method, has made encouraging progress with the joint efforts of global scientific researchers. It has not only achieved remarkable success in the treatment of hematological tumors, but also shows great potential in the field of solid tumors. However, CAR-T cell therapy still faces some challenges, including infiltration into solid tumors to increase therapeutic effect, cost and complexity of mass production, and management of side effects. With the advancement of technology and the accumulation of clinical experience, it is expected that CAR-T cell therapy will gradually be improved and optimized, can bring benefits to more patients with solid tumors, and become one of the important methods in the field of tumor treatment in the future.
[references]
[1] Sterner, R. C., & Sterner, R. M. (2021). CAR-T cell therapy: current limitations and potential strategies. Blood Cancer Journal, 11(4), 1-11.
[2] Bridgeman, J. S., Hawkins, R. E., Bagley, S., Blaylock, M., Holland, M., & Gilham, D. E. (2010). The optimal antigen response of chimeric antigen receptors harboring the CD3ζ transmembrane domain is dependent upon incorporation of the receptor into the endogenous TCR/CD3 complex. The Journal of Immunology, 184(12), 6938-6949.
[3] Guedan, S., Posey Jr, A. D., Shaw, C., Wing, A., Da, T., Patel, P. R., ... & June, C. H. (2018). Enhancing CAR T cell persistence through ICOS and 4-1BB costimulation. JCI insight, 3(1).
[4] Kalbasi A, Siurala M, Su LL, Tariveranmoshabad M, Picton LK, Ravikumar P, Li P, Lin JX, Escuin-Ordinas H, Da T, Kremer SV, Sun AL, Castelli S, Agarwal S, Scholler J, [ PubMed ] Song D, Rommel PC, Radaelli E, Young RM, Leonard WJ, Ribas A, June CH, Garcia KC. Potentiating adoptive cell therapy using synthetic IL-9 receptors. Nature. 2022 Jul;607(7918):360-365.
[5] Kalbasi A, Siurala M, Su LL, Tariveranmoshabad M, Picton LK, Ravikumar P, Li P, Lin JX, Escuin-Ordinas H, Da T, Kremer SV, Sun AL, Castelli S, Agarwal S, Scholler J, [ PubMed ] Song D, Rommel PC, Radaelli E, Young RM, Leonard WJ, Ribas A, June CH, Garcia KC. Potentiating adoptive cell therapy using synthetic IL-9 receptors. Nature. 2022 Jul;607(7918):360-365.
[6] Meyran D, Zhu JJ, Butler J, Tantalo D, MacDonald S, Nguyen TN, Wang M, Thio N, D'Souza C, Qin VM, Slaney C, Harrison A, Sek K, Petrone P, Thia K, Giuffrida L, Scott AM, Terry RL, Tran B, Desai J, Prince HM, Harrison SJ, Beavis PA, Kershaw MH, Solomon B, Ekert PG, Trapani JA, Darcy PK, Neeson PJ. TSTEM-like CAR-T cells exhibit improved persistence and tumor control compared with conventional CAR-T cells in preclinical models. Sci Transl Med. 2023 Apr 5;15(690):eabk1900.
[7] Frieling JS, Tordesillas L, Bustos XE, Ramello MC, Bishop RT, Cianne JE, Snedal SA, Li T, Lo CH, de la Iglesia J, Roselli E, Benzaïd I, Wang X, Kim Y, Lynch CC, Abate-Daga D. γδ-Enriched CAR-T cell therapy for bone metastatic castrate-resistant prostate cancer. Sci Adv. 2023 May 3;9(18):eadf0108.