Chimeric Antigen Receptors Targeting Human Cytomegalovirus.
Ontology highlight
ABSTRACT:
SUBMITTER: Ali A
PROVIDER: S-EPMC7399702 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:As a stress-inducible natural killer (NK) cell ligand, B7H6 plays a role in innate tumor immunosurveillance and is a fairly tumor selective marker expressed on a variety of solid and hematologic cancer cells. Here, we describe the isolation and characterization of a new family of single chain fragment variable (scFv) molecules targeting the human B7H6 ligand. Through directed evolution of a yeast surface displayed non-immune human-derived scFv library, eight candidates comprising a single family of clones differing by up to four amino acid mutations and exhibiting nM avidities for soluble B7H6-Ig were isolated. A representative clone re-formatted as an scFv-CH1-Fc molecule demonstrated specific binding to both B7H6-Ig and native membrane-bound B7H6 on tumor cell lines with a binding avidity comparable to the previously characterized B7H6-targeting antibody, TZ47. Furthermore, these clones recognized an epitope distinct from that of TZ47 and the natural NK cell ligand NKp30, and demonstrated specific activity against B7H6-expressing tumor cells when expressed as a chimeric antigen receptor (CAR) in T cells.
| S-EPMC5914360 | biostudies-literature
Project description:Purpose: CD70 expression in normal tissues is restricted to activated lymphoid tissues. Targeting CD70 on CD70-expressing tumors could mediate "on-target, off-tumor" toxicity. This study was to evaluate the feasibility and safety of using anti-human CD70 CARs to treat cancer patients whose tumors express CD70.Experimental Design: Seven anti-human CD70 CARs with binding moieties from human CD27 combined with CD3-zeta and different costimulatory domains from CD28 and/or 41BB were constructed. In vitro functionality of these receptors was compared and in vivo treatment efficacy was evaluated in a xenograft mouse model. A homologous, all murine anti-CD70 CAR model was also used to assess treatment-related toxicities.Results: The CAR consisting of the extracellular binding portion of CD27 fused with 41BB and CD3-zeta (trCD27-41BB-zeta) conferred the highest IFN? production against CD70-expressing tumors in vitro, and NSG mice bearing established CD70-expressing human tumors could be cured by human lymphocytes transduced with this CAR. In the murine CD27-CD3-zeta CAR model, significant reduction of established tumors and prolonged survival were achieved using CAR-transduced splenocytes in a dose-dependent manner. Host preirradiation enhanced treatment efficacy but increased treatment-related toxicities such as transient weight loss and hematopoetic suppression. The treatment did not appear to block adaptive host immune responses.Conclusions: Preclinical testing supports the safety and efficacy of a CD27-containing CAR targeting CD70-expressing tumors. Clin Cancer Res; 23(9); 2267-76. ©2016 AACR.
| S-EPMC5411349 | biostudies-literature
Project description:Chimeric antigen receptor (CAR) T cells have emerged as a promising class of therapeutic agents, generating remarkable responses in the clinic for a subset of human cancers. One major challenge precluding the wider implementation of CAR therapy is the paucity of tumor-specific antigens. Here, we describe the development of a CAR targeting the tumor-specific isocitrate dehydrogenase 2 (IDH2) with R140Q mutation presented on the cell surface in complex with a common human leukocyte antigen allele, HLA-B*07:02. Engineering of the hinge domain of the CAR, as well as crystal structure-guided optimization of the IDH2R140Q-HLA-B*07:02-targeting moiety, enhances the sensitivity and specificity of CARs to enable targeting of this HLA-restricted neoantigen. This approach thus holds promise for the development and optimization of immunotherapies specific to other cancer driver mutations that are difficult to target by conventional means.
| S-EPMC8421441 | biostudies-literature
Project description:Chimeric antigen receptor (CAR) therapy is a promising immunotherapeutic strategy for treating multiple refractory blood cancers, but further advances are required for solid tumor CAR therapy. One challenge is identifying a safe and effective tumor antigen. Here, we devise a strategy for targeting hepatocellular carcinoma (HCC, one of the deadliest malignancies). We report that T and NK cells transduced with a CAR that recognizes the surface marker, CD147, also known as Basigin, can effectively kill various malignant HCC cell lines in vitro, and HCC tumors in xenograft and patient-derived xenograft mouse models. To minimize any on-target/off-tumor toxicity, we use logic-gated (log) GPC3-synNotch-inducible CD147-CAR to target HCC. LogCD147-CAR selectively kills dual antigen (GPC3+CD147+), but not single antigen (GPC3-CD147+) positive HCC cells and does not cause severe on-target/off-tumor toxicity in a human CD147 transgenic mouse model. In conclusion, these findings support the therapeutic potential of CD147-CAR-modified immune cells for HCC patients.
| S-EPMC7511348 | biostudies-literature
Project description:PURPOSE:The outgrowth of antigen-negative variants is a significant challenge for adoptive therapy with T cells that target a single specificity. Chimeric antigen receptors (CAR) are typically designed with one or two scFvs that impart antigen specificity fused to activation and costimulation domains of T-cell signaling molecules. We designed and evaluated the function of CARs with up to three specificities for overcoming tumor escape using Designed Ankyrin Repeat Proteins (DARPins) rather than scFvs for tumor recognition. EXPERIMENTAL DESIGN:A monospecific CAR was designed with a DARPin binder (E01) specific for EGFR and compared with a CAR designed using an anti-EGFR scFv. CAR constructs in which DARPins specific for EGFR, EpCAM, and HER2 were linked together in a single CAR were then designed and optimized to achieve multispecific tumor recognition. The efficacy of CAR-T cells bearing a multispecific DARPin CAR for treating tumors with heterogeneous antigen expression was evaluated in vivo. RESULTS:The monospecific anti-EGFR E01 DARPin conferred potent tumor regression against EGFR+ targets that was comparable with an anti-EGFR scFv CAR. Linking three separate DARPins in tandem was feasible and in an optimized format generated a single tumor recognition domain that targeted a mixture of heterogeneous tumor cells, each expressing a single antigen, and displayed synergistic activity when tumor cells expressed more than one target antigen. CONCLUSIONS:DARPins can serve as high-affinity recognition motifs for CAR design, and their robust architecture enables linking of multiple binders against different antigens to achieve functional synergy and reduce antigen escape.
| S-EPMC6940018 | biostudies-literature
Project description:BackgroundImmunotherapy against solid tumors has long been hampered by the development of immunosuppressive tumor microenvironment, and the lack of a specific tumor-associated antigen that could be targeted in different kinds of solid tumors. Human leukocyte antigen G (HLA-G) is an immune checkpoint protein (ICP) that is neoexpressed in most tumor cells as a way to evade immune attack and has been recently demonstrated as a useful target for chimeric antigen receptor (CAR)-T therapy of leukemia by in vitro studies. Here, we design and test for targeting HLA-G in solid tumors using a CAR strategy.MethodsWe developed a novel CAR strategy using natural killer (NK) cell as effector cells, featuring enhanced cytolytic effect via DAP12-based intracellular signal amplification. A single-chain variable fragment (scFv) against HLA-G is designed as the targeting moiety, and the construct is tested both in vitro and in vivo on four different solid tumor models. We also evaluated the synergy of this anti-HLA-G CAR-NK strategy with low-dose chemotherapy as combination therapy.ResultsHLA-G CAR-transduced NK cells present effective cytolysis of breast, brain, pancreatic, and ovarian cancer cells in vitro, as well as reduced xenograft tumor growth with extended median survival in orthotopic mouse models. In tumor coculture assays, the anti-HLA-G scFv moiety promotes Syk/Zap70 activation of NK cells, suggesting reversal of the HLA-G-mediated immunosuppression and hence restoration of native NK cytolytic functions. Tumor expression of HLA-G can be further induced using low-dose chemotherapy, which when combined with anti-HLA-G CAR-NK results in extensive tumor ablation both in vitro and in vivo. This upregulation of tumor HLA-G involves inhibition of DNMT1 and demethylation of transporter associated with antigen processing 1 promoter.ConclusionsOur novel CAR-NK strategy exploits the dual nature of HLA-G as both a tumor-associated neoantigen and an ICP to counteract tumor spread. Further ablation of tumors can be boosted when combined with administration of chemotherapeutic agents in clinical use. The readiness of this novel strategy envisions a wide applicability in treating solid tumors.
| S-EPMC8524382 | biostudies-literature
Project description:Adoptive cell transfer of tumor-specific T lymphocytes (T cells) is proving to be an effective strategy for treating established tumors in cancer patients. One method of generating these cells is accomplished through engineering bulk T cell populations to express chimeric antigen receptors (CARs), which are specific for tumor antigens. Traditionally, these CARs are targeted against tumor antigens using single-chain antibodies (scFv). Here we describe the use of a designed ankyrin repeat protein (DARPin) as the tumor-antigen targeting domain.We prepared second generation anti-HER2 CARs that were targeted to the tumor antigen by either a DARPin or scFv. The CARs were engineered into human and murine T cells. We then compared the ability of CARs to trigger cytokine production, degranulation and cytotoxicity.The DARPin CARs displayed reduced surface expression relative to scFv CARs in murine cells but both CARs were expressed equally well on human T cells, suggesting that there may be a processing issue with the murine variants. In both the murine and human systems, the DARPin CARs were found to be highly functional, triggering cytokine and cytotoxic responses that were similar to those triggered by the scFv CARs.These findings demonstrate the utility of DARPins as CAR-targeting agents and open up an avenue for the generation of CARs with novel antigen binding attributes.
| S-EPMC4678647 | biostudies-literature
Project description:Despite high remission rates following CAR-T cell therapy in B-ALL, relapse due to loss of the targeted antigen is increasingly recognized as a mechanism of immune escape. We hypothesized that simultaneous targeting of CD19 and CD22 may reduce the likelihood of antigen loss, thus improving sustained remission rates. A systematic approach to the generation of CAR constructs incorporating two target-binding domains led to several novel CD19/CD22 bivalent CAR constructs. Importantly, we demonstrate the challenges associated with the construction of a bivalent CAR format that preserves bifunctionality against both CD19 and CD22. Using the most active bivalent CAR constructs, we found similar transduction efficiency compared to that of either CD19 or CD22 single CARs alone. When expressed on human T cells, the optimized CD19/CD22 CAR construct induced comparable interferon ? and interleukin-2 in vitro compared to single CARs against dual-antigen-expressing as well as single-antigen-expressing cell lines. Finally, the T cells expressing CD19/CD22 CAR eradicated ALL cell line xenografts and patient-derived xenografts (PDX), including a PDX generated from a patient with CD19- relapse following CD19-directed CAR therapy. The CD19/CD22 bivalent CAR provides an opportunity to test whether simultaneous targeting may reduce risk of antigen loss.
| S-EPMC6300726 | biostudies-literature
Project description:Immune targeting of B-cell malignancies using chimeric antigen receptors (CARs) is a promising new approach, but critical factors impacting CAR efficacy remain unclear. To test the suitability of targeting CD22 on precursor B-cell acute lymphoblastic leukemia (BCP-ALL), lymphoblasts from 111 patients with BCP-ALL were assayed for CD22 expression and all were found to be CD22-positive, with median CD22 expression levels of 3500 sites/cell. Three distinct binding domains targeting CD22 were fused to various TCR signaling domains ± an IgG heavy chain constant domain (CH2CH3) to create a series of vector constructs suitable to delineate optimal CAR configuration. CARs derived from the m971 anti-CD22 mAb, which targets a proximal CD22 epitope demonstrated superior antileukemic activity compared with those incorporating other binding domains, and addition of a 4-1BB signaling domain to CD28.CD3 constructs diminished potency, whereas increasing affinity of the anti-CD22 binding motif, and extending the CD22 binding domain away from the membrane via CH2CH3 had no effect. We conclude that second-generation m971 mAb-derived anti-CD22 CARs are promising novel therapeutics that should be tested in BCP-ALL.
| S-EPMC3575759 | biostudies-literature
Project description:Chimeric antigen receptor (CAR)-expressing T cells targeting B-cell maturation antigen (BCMA) have activity against multiple myeloma, but improvements in anti-BCMA CARs are needed. We demonstrated recipient anti-CAR T-cell responses against a murine single-chain variable fragment (scFv) used clinically in anti-BCMA CARs. To bypass potential anti-CAR immunogenicity and to reduce CAR binding domain size, here we designed CARs with antigen-recognition domains consisting of only a fully human heavy-chain variable domain without a light-chain domain. A CAR designated FHVH33-CD8BBZ contains a fully human heavy-chain variable domain (FHVH) plus 4-1BB and CD3? domains. T cells expressing FHVH33-CD8BBZ exhibit similar cytokine release, degranulation, and mouse tumor eradication as a CAR that is identical except for substitution of a scFv for FHVH33. Inclusion of 4-1BB is critical for reducing activation-induced cell death and promoting survival of T cells expressing FHVH33-containing CARs. Our results indicate that heavy-chain-only anti-BCMA CARs are suitable for evaluation in a clinical trial.
| S-EPMC6962219 | biostudies-literature