Project description:The success of chimeric antigen receptor (CAR) T cells in treating B cell malignancies comes at the price of eradicating normal B cells. Even though T cell malignancies are aggressive and treatment options are limited, similar strategies for T cell malignancies are constrained by the severe immune suppression arising from bystander T cell aplasia. Here, we show the selective killing of malignant T cells without affecting normal T cell-mediated immune responses in vitro and in a mouse model of disseminated leukemia. Further, we develop a CAR construct that carries the single chain variable fragment of a subtype-specific antibody against the variable TCR β-chain region. We demonstrate that these anti-Vβ8 CAR-T cells are able to recognize and kill all Vβ8+ malignant T cells that arise from clonal expansion while sparing malignant or healthy Vβ8- T cells, allowing sufficient T cell-mediated cellular immunity. In summary, we present a proof of concept for a selective CAR-T cell therapy to eradicate T cell malignancies while maintaining functional adaptive immunity, which opens the possibility for clinical development.
Project description:Gamma delta T (γδT) lymphocytes are primed for rapid function, including cytotoxicity toward cancer cells, and are a component of the immediate stress response. Following activation, they can function as professional antigen-presenting cells. Chimeric antigen receptors (CARs) work by focusing T cell function on defined cell surface tumor antigens and provide essential costimulation for robust activation. Given the natural tropism of γδT cells for the tumor microenvironment, we hypothesized that their transduction with CARs might enhance cytotoxicity while retaining their ability to migrate to tumor and act as antigen-presenting cells to prolong the intratumoral immune response. Using a GD2-targeting CAR as a model system, we showed that γδT cells of both Vδ1 and Vδ2 subsets could be expanded and transduced to sufficient numbers for clinical studies. The CAR added to the cells' innate cytotoxicity by enhancing GD2-specific killing of GD2-expressing cancer cell lines. Migration toward tumor cells in vitro was not impaired by the presence of the CAR. Expanded CAR-transduced Vδ2 cells retained the ability to take up tumor antigens and cross presented the processed peptide to responder alpha beta T (αβT) lymphocytes. γδ CAR-T cell products show promise for evaluation in clinical studies of solid tumors.
Project description:Over the last decade, the emergence of several novel therapeutic approaches has changed the therapeutic perspective of human malignancies. Adoptive immunotherapy through chimeric antigen receptor T cell (CAR-T), which includes the engineering of T cells to recognize tumor-specific membrane antigens and, as a result, death of cancer cells, has created various clinical benefits for the treatment of several human malignancies. In particular, CAR-T-cell-based immunotherapy is known as a critical approach for the treatment of patients with hematological malignancies such as acute lymphoblastic leukemia (ALL), multiple myeloma (MM), chronic lymphocytic leukemia (CLL), acute myeloid leukemia (AML), Hodgkin lymphoma (HL), and non-Hodgkin's lymphoma (NHL). However, CAR-T-cell therapy of hematological malignancies is associated with various side effects. There are still extensive challenges in association with further progress of this therapeutic approach, from manufacturing and engineering issues to limitations of applications and serious toxicities. Therefore, further studies are required to enhance efficacy and minimize adverse events. In the current review, we summarize the development of CAR-T-cell-based immunotherapy and current clinical antitumor applications to treat hematological malignancies. Furthermore, we will mention the current advantages, disadvantages, challenges, and therapeutic limitations of CAR-T-cell therapy.
Project description:BackgroundChimeric antigen receptor engineered T cells (CAR-T) have demonstrated promising clinical efficacy in B-cell malignancies, and the approach has been extended to T-cell malignancies. However, the use of allogeneic T cells in CAR therapy poses a challenge due to the risk of graft-versus-host disease. Recently, natural killer (NK) cells have exhibited "off‑the‑shelf" availability. The nanobody-based CAR structures have attracted much attention for their therapeutic potential owing to the advantages of nanobody, including small size, optimal stability, high affinity and manufacturing feasibility. CD5, a common surface marker of malignant T cells, has three scavenger receptor cysteine-rich domains (D1-D3) in the extracellular region. The present study aims to construct "off‑the‑shelf" CAR-NK cells targeting the membrane-proximal domain of CD5 derived from nanobody against T-cell malignancies.MethodsAnti-CD5-D3 nanobody was screened by phage display technology, followed by constructing fourth-generation CAR plasmids ectopically producing IL-15 to generate CD5 CAR-NK cells derived from peripheral blood. And the second-generation CD5 CAR-T cells based on nanobody were generated, referred to as 5D.b CAR-T and 12 C.b CAR-T. Furthermore, CAR-NK cells without IL-15 (IL-15△ CAR-NK) were generated to assess the impact on cytotoxicity of CAR-NK cells. Cytotoxic activity against CD5+ hematologic malignant cell lines and normal T cells was exerted in vitro and NOD/ShiLtJGpt-Prkdcem26Cd52Il2rgem26Cd22/Gpt mouse model transplanted with Jurkat-Luc cells was used to evaluate the antitumor efficacy of CD5 CAR-NK cells in vivo.ResultsTwo nanobodies (5D and 12 C) competed for binding to the epitope of CD5-D3. 12 C CAR-NK cells were superior to 5D CAR-NK cells in antitumor potential and 12 C.b CAR-T cells exhibited superior cytotoxic activity than 5D CAR-T cells ex vivo. So, 12 C was regarded as the optimal nanobody. 12 C CAR-NK cells and IL-15△ CAR-NK cells exhibited robust cytotoxicity against CD5+ malignant cell lines and controlled disease progression in xenograft mouse model. 12 C CAR-NK cells demonstrated greater antitumor activity compared to that of IL-15△ CAR-NK cells in vitro and in vivo.ConclusionsTaken together, the fourth-generation nanobody-derived anti-CD5 CAR-NK cells may be a promising therapeutic against T-cell malignancies.
Project description:Chimeric antigen receptor (CAR) T cells are patient T cells that are transduced with genetically engineered synthetic receptors to target a cancer cell surface antigen. The remarkable clinical response rates achieved by adoptive transfer of T cells that target CD19 in patients with leukemia and lymphoma have led to a growing number of clinical trials exploring CAR T-cell therapy for solid tumors. Herein, we review the evolution of adoptive T-cell therapy; highlight advances in CAR T-cell therapy for thoracic malignancies; and summarize the targets being investigated in clinical trials for patients with lung cancer, malignant pleural mesothelioma, and esophageal cancer. We further discuss the barriers to successfully translating CAR T-cell therapy for solid tumors and present strategies that have been investigated to overcome these hurdles.
Project description:BackgroundThe unprecedented efficacy of chimeric antigen receptor T (CAR-T) cell immunotherapy of CD19+ B-cell malignancies has opened a new and useful way for the treatment of malignant tumors. Nonetheless, there are still formidable challenges in the field of CAR-T cell therapy, such as the biodistribution of CAR-T cells in vivo.MethodsNALM-6, a human B-cell acute lymphoblastic leukemia (B-ALL) cell line, was used as target cells. CAR-T cells were injected into a mice model with or without target cells. Then we measured the distribution of CAR-T cells in mice. In addition, an exploratory clinical trial was conducted in 13 r/r B-cell non-Hodgkin lymphoma (B-NHL) patients, who received CAR-T cell infusion. The dynamic changes in patient blood parameters over time after infusion were detected by qPCR and flow cytometry.ResultsCAR-T cells still proliferated over time after being infused into the mice without target cells within 2 weeks. However, CAR-T cells did not increase significantly in the presence of target cells within 2 weeks after infusion, but expanded at week 6. In the clinical trial, we found that CAR-T cells peaked at 7-21 days after infusion and lasted for 420 days in peripheral blood of patients. Simultaneously, mild side effects were observed, which could be effectively controlled within 2 months in these patients.ConclusionsCAR-T cells can expand themselves with or without target cells in mice, and persist for a long time in NHL patients without serious side effects.Trial registrationThe registration date of the clinical trial is May 17, 2018 and the trial registration numbers is NCT03528421 .
Project description:Chimeric antigen receptor (CAR)-T cell therapy is the next revolutionary advance in cancer therapy. By using ex vivo engineered T cells to specifically target antigens, a targeted immune reaction is induced. Chimeric antigen receptor-T cell therapy is approved for patients suffering from advanced and refractory B cell and plasma cell malignancies and is undergoing testing for various other haematologic and solid malignancies. In the process of triggering an anticancer immune reaction, a systemic inflammatory response can emerge as cytokine release syndrome (CRS). The severity of CRS is highly variable across patients, ranging from mild flu-like symptoms to fulminant hyperinflammatory states with excessive immune activation, associated multiorgan failure and high mortality risk. Cytokine release syndrome is also an important factor for adverse cardiovascular (CV) events. Sinus tachycardia and hypotension are the most common reflections, similar to what is seen with other systemic inflammatory response syndromes. Corrected QT interval prolongation and tachyarrhythmias, including ventricular arrhythmias and atrial fibrillation, also show a close link with CRS. Events of myocardial ischaemia and venous thromboembolism can be provoked during CAR-T cell therapy. Although not as closely related to CRS, changes in cardiac function can be observed to the point of heart failure and cardiogenic shock. This may also be encountered in patients with severe valvular heart disease in the setting of CRS. This review will discuss the pertinent CV risks of the growing field of CAR-T cell therapy for today's cardiologists, including incidence, characteristics, and treatment options, and will conclude with an integrated management algorithm.