The integrin αvβ6: a novel target for CAR T-cell immunotherapy?

2016 ◽  
Vol 44 (2) ◽  
pp. 349-355 ◽  
Author(s):  
Lynsey M. Whilding ◽  
Sabari Vallath ◽  
John Maher

Immunotherapy of cancer using chimeric antigen receptor (CAR) T-cells is a rapidly expanding field. CARs are fusion molecules that couple the binding of a tumour-associated cell surface target to the delivery of a tailored T-cell activating signal. Re-infusion of such genetically engineered T-cells to patients with haematological disease has demonstrated unprecedented response rates in Phase I clinical trials. However, such successes have not yet been observed using CAR T-cells against solid malignancies and this is, in part, due to a lack of safe tumour-specific targets. The αvβ6 integrin is strongly up-regulated in multiple solid tumours including those derived from colon, lung, breast, cervix, ovaries/fallopian tube, pancreas and head and neck. It is associated with poorer prognosis in several cancers and exerts pro-tumorigenic activities including promotion of tumour growth, migration and invasion. By contrast, physiologic expression of αvβ6 is largely restricted to wound healing. These attributes render this epithelial-specific integrin a highly attractive candidate for targeting using immunotherapeutic strategies such as CAR T-cell adoptive immunotherapy. This mini-review will discuss the role and expression of αvβ6 in cancer, as well as its potential as a therapeutic target.

Cancers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 5445
Author(s):  
Pauline Thomas ◽  
Natacha Galopin ◽  
Emma Bonérandi ◽  
Béatrice Clémenceau ◽  
Sophie Fougeray ◽  
...  

Malignant central nervous system tumors are the leading cause of cancer death in children. Progress in high-throughput molecular techniques has increased the molecular understanding of these tumors, but the outcomes are still poor. Even when efficacious, surgery, radiation, and chemotherapy cause neurologic and neurocognitive morbidity. Adoptive cell therapy with autologous CD19 chimeric antigen receptor T cells (CAR T) has demonstrated remarkable remission rates in patients with relapsed refractory B cell malignancies. Unfortunately, tumor heterogeneity, the identification of appropriate target antigens, and location in a growing brain behind the blood–brain barrier within a specific suppressive immune microenvironment restrict the efficacy of this strategy in pediatric neuro-oncology. In addition, the vulnerability of the brain to unrepairable tissue damage raises important safety concerns. Recent preclinical findings, however, have provided a strong rationale for clinical trials of this approach in patients. Here, we examine the most important challenges associated with the development of CAR T cell immunotherapy and further present the latest preclinical strategies intending to optimize genetically engineered T cells’ efficiency and safety in the field of pediatric neuro-oncology.


Blood ◽  
2021 ◽  
Author(s):  
Hardikkumar Jetani ◽  
Almudena Navarro-Bailón ◽  
Marius Maucher ◽  
Silke Frenz ◽  
Christina Mathilde Verbruggen ◽  
...  

Acute myeloid leukemia (AML) is attractive for the development of CAR T-cell immunotherapy because AML blasts are susceptible to T-cell-mediated elimination. Here, we introduce sialic-acid-binding immunoglobulin-like lectin (Siglec)-6 as a novel target for CAR T-cells in AML. We designed a Siglec-6-specific CAR with a targeting-domain derived from a human monoclonal antibody JML‑1. We found that Siglec-6 is prevalently expressed on AML cell lines and primary AML blasts, including the subpopulation of AML stem cells. Treatment with Siglec-6-CAR T-cells confers specific anti-leukemia reactivity that correlates with Siglec-6-expression in pre-clinical models, including induction of complete remission in a xenograft AML model in immunodeficient mice (NSG/U937). In addition, we confirmed Siglec-6-expression on transformed B-cells in chronic lymphocytic leukemia (CLL) and show specific anti-CLL-reactivity of Siglec-6-CAR T-cells in vitro. Of particular interest, we found that Siglec-6 is not detectable on normal hematopoietic stem and progenitor cells (HSC/P) and that treatment with Siglec-6-CAR T-cells does not affect their viability and lineage differentiation in colony-formation assays. These data suggest that Siglec-6-CAR T-cell therapy may be used to effectively treat AML without a need for subsequent allogeneic hematopoietic stem cell transplantation. In mature normal hematopoietic cells, we detected Siglec-6 in a proportion of memory (and naïve) B-cells and basophilic granulocytes, suggesting the potential for limited on-target/off-tumor reactivity. The lacking expression of Siglec-6 on normal HSC/P is a key differentiator from other Siglec-family members (e.g. Siglec-3=CD33) and other CAR target antigens, e.g. CD123, that are under investigation in AML and warrants the clinical investigation of Siglec-6-CAR T-cell therapy.


Author(s):  
Muhammad Sadeqi Nezhad ◽  
Mahboubeh Yazdanifar ◽  
Meghdad Abdollahpour-Alitappeh ◽  
Arash Sattari ◽  
Alexander seifalian ◽  
...  

Adoptive cell immunotherapy with chimeric antigen receptor (CAR) T cell has brought a revolutionary means of treatment for aggressive diseases such as hematologic malignancies and solid tumors. Over the last decade, FDA approved three types of CAR-T cells against CD19 hematologic malignancies, including Tisagenlecleucel (Kymriah), Axicabtagene ciloleucel (Yescarta), and Brexucabtagene autoleucel (Tecartus). Despite outstanding results gained from different clinical trials, CAR-T cell therapy is not free from side effects and toxicities, and needs careful investigations and improvements. Gene-editing technology, clustered regularly interspaced short palindromic repeats (CRISPR)/ CRISPR-associated protein 9 (Cas9) system has emerged as a promising tool to address some of the CAR-T therapy hurdles. Using CRISPR/Cas9 technology, CAR expression as well as other cellular pathways can be modified in various ways to enhance CAR-T cell’s anti-tumor function and persistence in immunosuppressive tumor microenvironment. CRISPR/Cas9 technology can also be utilized to reduce CAR-T cells toxicity and side effects. Hereby, we discuss the practical challenges and hurdles related to the accuracy, efficiency, efficacy, safety and delivery of CRISPR/Cas9 technology to the genetically engineered-T cells. Combining of these two state-of-the-art technologies, CRISPR/Cas9 and CAR-T cells, the field of oncology has an extraordinary opportunity to enter a new era of immunotherapy, which offers novel therapeutic options for different types of tumors.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Noah H. Richardson ◽  
Jordan B. Luttrell ◽  
Jonathan S. Bryant ◽  
Damian Chamberlain ◽  
Saleem Khawaja ◽  
...  

Abstract Background Simultaneous advances in gene editing, T cell engineering and biotechnology currently provide an opportunity for rapid progress in medicine. The approval of chimeric antigen receptor (CAR) T cell therapies by the US Food and Drug Administration (FDA) and the European Commission have generated substantial momentum for these first-in-class therapies to be used in patients with B cell malignancies. Main body Considerable efforts focus on improved outcomes and reduced side effects of the newly approved therapies. Using innovative strategies, researchers aim to extend CAR T cell use to tackle difficulties inherent in solid tumors. Efforts are underway to broaden the applications of CAR T cells, and the strategy has been successful in chronic viral infections and preclinical models of autoimmunity. Research is in progress to generate “off-the-shelf” CAR T cells, an advance, which would greatly increase patient availability and reduce treatment cost. Conclusions In this thematic review, we highlight advances that may help develop genetically engineered cells into a new category of medical therapies.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 3034-3034 ◽  
Author(s):  
Yajing Zhang

3034 Background: Chimeric antigen receptor T (CAR T) cells targeting CD19 have been used to achieve breakthroughs in the treatment of hematological malignancies, however, a high recurrence rate is the main obstacle to durable remission following CAR T cell therapy. Methods: As an open-label and single-arm phase I/IIa trial (ClinicalTrials.gov number, NCT03097770), we screened 99 patients with r/r B-NHL—including DLBCL, PMBCL, CLL/SLL, MCL, TFL and FL—according to the 2008 WHO Classification of Tumors of Hematopoietic and Lymphoid Tissue, and a total of 87 patients received an infusion of one dose tandem CD19/CD20 CAR-engineered T cells on day 0 in the range of 0.5×106-10×106 cells per kilogram of body weight after conditioning chemotherapy. The primary objective was to evaluate the safety and tolerability of CAR T cells. Efficacy, progression-free survival (PFS) and overall survival (OS) were evaluated as secondary objectives. Our clinical trials is registered with ClinicalTrials.gov, NCT03097770. Safety was assessed by CTCAE Version 5.0, and clinical response by PET-CT referred to standard international criteria. The trial remains open, and recruitment to extension cohorts with alternative endpoints is underway. Results: Between May 11, 2017, and Jan 31, 2020, 99 patients were enrolled and 87 received tandem CD19/CD20 CAR-engineered T cells across phases I/IIa. As of the cutoff date, 74 assessable patients were followed up for a median of 13.5 months (IQR 33.2 - 3.3), 62 (84%) had an objective response, and 55 (74%) had a complete response. The median progression-free survival and overall survival were all not reached. Cytokine release syndrome (CRS) occurred in 62 patients (71%), with 61% grade 1 or 2 and 10% grade 3 or more. CAR-T-cell-related encephalopathy syndrome (CRES) of grade 3 occurred in 2 patients (2%) . Three treatment-related deaths (2 in pulmonary infection and 1 in deposition of CART cells in pulmonary alveoli). Conclusions: In this study, optimized tandem CD19/CD20 CAR-engineered T cells induced a potent and durable anti-tumour response with controllable CRS and CRES. Clinical trial information: NCT03097770 .


2020 ◽  
Vol 14 (4) ◽  
pp. 312-323
Author(s):  
Romeo G. Mihăilă

Background: Patients with refractory or relapsed diffuse large B-cell lymphoma have a poor prognosis with the current standard of care. Objective: Chimeric Antigen Receptor T-cells (CAR T-cells) are functionally reprogrammed lymphocytes, which are able to recognize and kill tumor cells. The aim of this study is to make progress in this area. Method: A mini-review was achieved using the articles published in Web of Science and PubMed in the last year and the new patents were made in this field. Results: The responses to CAR T-cell products axicabtagene ciloleucel and tisagenlecleucel are promising; the objective response rate can reach up to 83%, and the complete response rate ranges between 40 and 58%. About half of the patients may have serious side effects, such as cytokine release syndrome and neurotoxicity. Current and future developments include the improvement of CAR T-cell expansion and polyfunctionality, the combined use of CAR T-cells with a fusion protein between interferon and an anti-CD20 monoclonal antibody, with checkpoint inhibitors or small molecule sensitizers that have apoptotic-regulatory effects. Furthermore, the use of IL-12-expressing CAR T-cells, an improved technology for the production of CAR T-cells based on targeted nucleases, the widespread use of allogeneic CAR T-cells or universal CAR T-cells obtained from genetically engineered healthy donor T-cells are future developments actively considered. Conclusion: CAR T-cell therapy significantly improved the outcome of patients with relapsed or refractory diffuse large B-cell lymphoma. The advances in CAR T-cells production technology will improve the results and enable the expansion of this new immunotherapy.


2021 ◽  
Vol 22 (5) ◽  
pp. 2476
Author(s):  
Kento Fujiwara ◽  
Masaki Kitaura ◽  
Ayaka Tsunei ◽  
Hotaka Kusabuka ◽  
Erika Ogaki ◽  
...  

T cells that are genetically engineered to express chimeric antigen receptor (CAR) have a strong potential to eliminate tumor cells, yet the CAR-T cells may also induce severe side effects due to an excessive immune response. Although optimization of the CAR structure is expected to improve the efficacy and toxicity of CAR-T cells, the relationship between CAR structure and CAR-T cell functions remains unclear. Here, we constructed second-generation CARs incorporating a signal transduction domain (STD) derived from CD3ζ and a 2nd STD derived from CD28, CD278, CD27, CD134, or CD137, and investigated the impact of the STD structure and signaling on CAR-T cell functions. Cytokine secretion of CAR-T cells was enhanced by 2nd STD signaling. T cells expressing CAR with CD278-STD or CD137-STD proliferated in an antigen-independent manner by their STD tonic signaling. CAR-T cells incorporating CD28-STD or CD278-STD between TMD and CD3ζ-STD showed higher cytotoxicity than first-generation CAR or second-generation CARs with other 2nd STDs. The potent cytotoxicity of these CAR-T cells was not affected by inhibiting the 2nd STD signals, but was eliminated by placing the STDs after the CD3ζ-STD. Our data highlighted that CAR activity was affected by STD structure as well as by 2nd STD signaling.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Laura Castelletti ◽  
Dannel Yeo ◽  
Nico van Zandwijk ◽  
John E. J. Rasko

AbstractMalignant mesothelioma (MM) is a treatment-resistant tumor originating in the mesothelial lining of the pleura or the abdominal cavity with very limited treatment options. More effective therapeutic approaches are urgently needed to improve the poor prognosis of MM patients. Chimeric Antigen Receptor (CAR) T cell therapy has emerged as a novel potential treatment for this incurable solid tumor. The tumor-associated antigen mesothelin (MSLN) is an attractive target for cell therapy in MM, as this antigen is expressed at high levels in the diseased pleura or peritoneum in the majority of MM patients and not (or very modestly) present in healthy tissues. Clinical trials using anti-MSLN CAR T cells in MM have shown that this potential therapeutic is relatively safe. However, efficacy remains modest, likely due to the MM tumor microenvironment (TME), which creates strong immunosuppressive conditions and thus reduces anti-MSLN CAR T cell tumor infiltration, efficacy and persistence. Various approaches to overcome these challenges are reviewed here. They include local (intratumoral) delivery of anti-MSLN CAR T cells, improved CAR design and co-stimulation, and measures to avoid T cell exhaustion. Combination therapies with checkpoint inhibitors as well as oncolytic viruses are also discussed. Preclinical studies have confirmed that increased efficacy of anti-MSLN CAR T cells is within reach and offer hope that this form of cellular immunotherapy may soon improve the prognosis of MM patients.


Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2941
Author(s):  
Luciana R. C. Barros ◽  
Emanuelle A. Paixão ◽  
Andrea M. P. Valli ◽  
Gustavo T. Naozuka ◽  
Artur C. Fassoni ◽  
...  

Immunotherapy has gained great momentum with chimeric antigen receptor T cell (CAR-T) therapy, in which patient’s T lymphocytes are genetically manipulated to recognize tumor-specific antigens, increasing tumor elimination efficiency. In recent years, CAR-T cell immunotherapy for hematological malignancies achieved a great response rate in patients and is a very promising therapy for several other malignancies. Each new CAR design requires a preclinical proof-of-concept experiment using immunodeficient mouse models. The absence of a functional immune system in these mice makes them simple and suitable for use as mathematical models. In this work, we develop a three-population mathematical model to describe tumor response to CAR-T cell immunotherapy in immunodeficient mouse models, encompassing interactions between a non-solid tumor and CAR-T cells (effector and long-term memory). We account for several phenomena, such as tumor-induced immunosuppression, memory pool formation, and conversion of memory into effector CAR-T cells in the presence of new tumor cells. Individual donor and tumor specificities are considered uncertainties in the model parameters. Our model is able to reproduce several CAR-T cell immunotherapy scenarios, with different CAR receptors and tumor targets reported in the literature. We found that therapy effectiveness mostly depends on specific parameters such as the differentiation of effector to memory CAR-T cells, CAR-T cytotoxic capacity, tumor growth rate, and tumor-induced immunosuppression. In summary, our model can contribute to reducing and optimizing the number of in vivo experiments with in silico tests to select specific scenarios that could be tested in experimental research. Such an in silico laboratory is an easy-to-run open-source simulator, built on a Shiny R-based platform called CARTmath. It contains the results of this manuscript as examples and documentation. The developed model together with the CARTmath platform have potential use in assessing different CAR-T cell immunotherapy protocols and its associated efficacy, becoming an accessory for in silico trials.


Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 743
Author(s):  
Aleksei Titov ◽  
Ekaterina Zmievskaya ◽  
Irina Ganeeva ◽  
Aygul Valiullina ◽  
Alexey Petukhov ◽  
...  

Adoptive cell immunotherapy (ACT) is a vibrant field of cancer treatment that began progressive development in the 1980s. One of the most prominent and promising examples is chimeric antigen receptor (CAR) T-cell immunotherapy for the treatment of B-cell hematologic malignancies. Despite success in the treatment of B-cell lymphomas and leukemia, CAR T-cell therapy remains mostly ineffective for solid tumors. This is due to several reasons, such as the heterogeneity of the cellular composition in solid tumors, the need for directed migration and penetration of CAR T-cells against the pressure gradient in the tumor stroma, and the immunosuppressive microenvironment. To substantially improve the clinical efficacy of ACT against solid tumors, researchers might need to look closer into recent developments in the other branches of adoptive immunotherapy, both traditional and innovative. In this review, we describe the variety of adoptive cell therapies beyond CAR T-cell technology, i.e., exploitation of alternative cell sources with a high therapeutic potential against solid tumors (e.g., CAR M-cells) or aiming to be universal allogeneic (e.g., CAR NK-cells, γδ T-cells), tumor-infiltrating lymphocytes (TILs), and transgenic T-cell receptor (TCR) T-cell immunotherapies. In addition, we discuss the strategies for selection and validation of neoantigens to achieve efficiency and safety. We provide an overview of non-conventional TCRs and CARs, and address the problem of mispairing between the cognate and transgenic TCRs. Finally, we summarize existing and emerging approaches for manufacturing of the therapeutic cell products in traditional, semi-automated and fully automated Point-of-Care (PoC) systems.


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