scholarly journals Functional effects of chimeric antigen receptor co-receptor signaling domains in human Tregs

2019 ◽  
Author(s):  
Nicholas A.J. Dawson ◽  
Isaac Rosado-Sánchez ◽  
German E. Novakovsky ◽  
Vivian C.W. Fung ◽  
Qing Huang ◽  
...  

SummaryAntigen-specific regulatory T cells (Tregs) engineered with chimeric antigen receptor (CARs) are a potent immunosuppressive cellular therapy in multiple disease models. To date the majority of CAR Treg studies employed second generation CARs, encoding a CD28 or 4-1BB co-receptor signaling domain and CD3ζ, but it was not known if this CAR design was optimal for Tregs. Using an HLA-A2-specific CAR platform and human Tregs, we compared ten CARs with different co-receptor signaling domains and systematically tested their function. Tregs expressing a CAR encoding wild-type CD28 were markedly superior to all other CARs tested in anin vivomodel of graft-versus-host disease. In vitro assays revealed stable expression of Helios and ability to suppress CD80 expression on DCs as keyin vitropredictors ofin vivofunction. This comprehensive study of CAR signaling-domain variants in Tregs can be leveraged to optimize CAR design for use in antigen-specific Treg therapy.

2020 ◽  
Vol 12 (557) ◽  
pp. eaaz3866 ◽  
Author(s):  
Nicholas A. J. Dawson ◽  
Isaac Rosado-Sánchez ◽  
German E. Novakovsky ◽  
Vivian C. W. Fung ◽  
Qing Huang ◽  
...  

Antigen-specific regulatory T cells (Tregs) engineered with chimeric antigen receptors (CARs) are a potent immunosuppressive cellular therapy in multiple disease models and could overcome shortcomings of polyclonal Treg therapy. CAR therapy was initially developed with conventional T cells, which have different signaling requirements than do Tregs. To date, most of the CAR Treg studies used second-generation CARs, encoding a CD28 or 4-1BB co-receptor signaling domain and CD3ζ, but it was not known if this CAR design was optimal for Tregs. Using a human leukocyte antigen–A2–specific CAR platform and human Tregs, we compared 10 CARs with different co-receptor signaling domains and systematically tested their function and CAR-stimulated gene expression profile. Tregs expressing a CAR encoding CD28wt were markedly superior to all other CARs tested in an in vivo model of graft-versus-host disease. In vitro assays revealed stable expression of Helios and an ability to suppress CD80 expression on dendritic cells as key in vitro predictors of in vivo function. This comprehensive study of CAR signaling domain variants in Tregs can be leveraged to optimize CAR design for use in antigen-specific Treg therapy.


2013 ◽  
Vol 1 (1) ◽  
pp. 43-53 ◽  
Author(s):  
Evripidis Lanitis ◽  
Mathilde Poussin ◽  
Alex W. Klattenhoff ◽  
Degang Song ◽  
Raphael Sandaltzopoulos ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Béatrice Clémenceau ◽  
Sandrine Valsesia-Wittmann ◽  
Anne-Catherine Jallas ◽  
Régine Vivien ◽  
Raphaël Rousseau ◽  
...  

The present work was designed to compare two mechanisms of cellular recognition based on Ab specificity: firstly, when the anti-HER2 mAb trastuzumab bridges target cells and cytotoxic lymphocytes armed with a Fc receptor (ADCC) and, secondly, when HER2 positive target cells are directly recognized by cytotoxic lymphocytes armed with a chimeric antigen receptor (CAR). To compare these two mechanisms, we used the same cellular effector (NK-92) and the same signaling domain (FcεRIγ). The NK-92 cytotoxic cell line was transfected with either a FcγRIIIa-FcεRIγ(NK-92CD16) or a trastuzumab-based scFv-FcεRIγchimeric receptor (NK-92CAR). In vitro, the cytotoxic activity against HER2 positive target cells after indirect recognition byNK-92CD16was always inferior to that observed after direct recognition byNK-92CAR. In contrast, and somehow unexpectedly, in vivo, adoptive transfer ofNK-92CD16+ trastuzumab but not ofNK-92CARinduced tumor regression. Analysis of the in vivo xenogeneic system suggested that the human CH2-CH3 IgG2 used as a spacer in our construct was able to interact with the FcR present at the cell surface of the few NSG-FcR+ remaining immune cells. This interaction, leading to blockage of theNK-92CARin the periphery of the engrafted tumor cells, stresses the critical role of the composition of the spacer domain.


2021 ◽  
Author(s):  
Yannick D. Muller ◽  
Leonardo M.R. Ferreira ◽  
Emilie Ronin ◽  
Patrick Ho ◽  
Vinh Nguyen ◽  
...  

Infusion of regulatory T cells (Tregs) engineered with a chimeric antigen receptor (CAR) targeting donor-derived human leukocyte antigen (HLA) is a promising strategy to promote transplant tolerance. Here, we describe an anti-HLA-A2 CAR (A2-CAR) generated by grafting the complementarity-determining regions (CDRs) of a human monoclonal anti-HLA-A2 antibody into the framework regions of the Herceptin 4D5 single-chain variable fragment and fusing it with a CD28-zeta signaling domain. The CDR-grafted A2-CAR maintained the specificity of the original antibody. We then generated HLA-A2 mono-specific human CAR Tregs either by deleting the endogenous T-cell receptor (TCR) via CRISPR/Cas9 and introducing the A2-CAR using lentiviral transduction or by directly integrating the CAR construct into the TCR alpha constant locus using homology-directed repair. These A2-CAR+TCRdeficient human Tregs maintained both Treg phenotype and function in vitro. Moreover, they selectively accumulated in HLA-A2-expressing islets transplanted from either HLA-A2 transgenic mice or deceased human donors. A2-CAR+TCRdeficient Tregs did not impair the function of these HLA-A2+ islets, whereas similarly engineered A2-CAR+TCRdeficientCD4+ conventional T cells rejected the islets in less than 2 weeks. A2-CAR+TCRdeficient Tregs delayed graft-versus-host disease only in the presence of HLA-A2, expressed either by co-transferred peripheral blood mononuclear cells or by the recipient mice. Altogether, we demonstrate that genome-engineered mono-antigen-specific A2-CAR Tregs localize to HLA-A2-expressing grafts and exhibit antigen-dependent in vivo suppression, independent of TCR expression. These approaches may be applied towards developing precision Treg cell therapies for transplant tolerance.


2019 ◽  
Vol Volume 12 ◽  
pp. 9341-9350 ◽  
Author(s):  
Xiaojun Tang ◽  
Qi Tang ◽  
Yuan Mao ◽  
Xiaochen Huang ◽  
Lizhou Jia ◽  
...  

2021 ◽  
Author(s):  
Katherine Mueller ◽  
Nicole Piscopo ◽  
Matthew Forsberg ◽  
Louise Saraspe ◽  
Amritava Das ◽  
...  

Chimeric antigen receptor (CAR) T cells traditionally harbor viral vectors that encode the CAR transgene in the genome. However, viral vector manufacturing typically is resource intensive, suffers from batch-to-batch variability, and includes several animal components, adding regulatory and supply chain pressures. Here, CAR T cells were generated within nine days using recombinant SpCas9 protein and nucleic acids, without any viral vectors or animal components. In comparison to traditional retroviral CAR T cells, nonviral CRISPR CAR T cells exhibit TRAC-targeted genomic integration of the CAR transgene, higher frequency of gene expression signatures associated with a memory phenotype, low receptor signaling prior to infusion, and potent cytotoxicity against GD2+ neuroblastoma in vitro and in vivo. This proof-of-principle study eliminating viral vectors and animal components during CAR gene transfer could enable more flexible and scalable manufacturing of clinically-relevant, high-quality CAR T cells to treat cancers, including solid tumors.


2017 ◽  
Vol 35 (7_suppl) ◽  
pp. 150-150
Author(s):  
Sergei Kusmartsev ◽  
Johaness Vieweg ◽  
Victor Prima

150 Background: NKG2D is a lectin-like type 2 transmembrane receptor that expressed by natural killer cells and some T cell subsets. Stimulation of NKG2D receptor with specific agonistic ligands produces activating signals through signaling adaptor protein DAP10 leading to the enhanced cytokine production, proliferation, and cytotoxicity against tumor cells. There is strong evidence that NKG2D ligands are expressed in many human tumors, including melanoma, leukemia, myeloma, glioma, and carcinomas of the prostate, breast, lung, and colon. Recent studies also demonstrated that T cells bearing chimeric antigen receptor (CAR) NKG2D linked to CD3ζ (zeta) chain produce marked in vitro and in vivo anti-tumor effects. The aim of current study was to determine whether human T cells bearing chimeric antigen receptor (CAR) NKGD2 linked to CD3ε (epsilon) chain could be activated by the NKG2D-specific stimulation and able to kill human cancer cells. Given the important role of CD3ε in activation and survival of T cells, we hypothesized that NKG2D-CDε-bearing T cells could exert strong in vitro and in vivo anti-tumor effects. Methods: NKG2D CAR was produced by linking human NKG2D to DAP10 and the cytoplasmic portion of the CD3ε chain. Original full-length human cDNA clones were obtained from NIH Mammalian Gene Collection (MGC). Functional domain analysis and oligonucleotide design in the in-Fusion system of DNA cloning (Clontech) was used to generate the retroviral expression constructs. Results: Human PBMC-derived T cells were retrovirally transduced with newly generated NKG2D-CD3ε CAR DNA construct. These NKG2D CAR-expressing human T cells responded to NKG2D-specific activation by producing IFN-γ and exhibited significant cellular cytotoxicity against human tumor cells in vitro. In vivo studies demonstrated that NKG2D-CD3ε-bearing cells are capable of inhibiting growth of DU-145 human prostate cancer in the immunodeficient mice. Conclusions: Collectively, our data indicate the feasibility of developing chimeric antigen receptor NKG2D-CD3ε for T cells and suggest that adoptive transfer of T cells bearing NKG2D-CD3ε CAR could be potentially effective for immunotherapy of cancer patients.


2020 ◽  
Author(s):  
Liqing Kang ◽  
Jian Zhang ◽  
Minghao Li ◽  
Nan Xu ◽  
Wei Qi ◽  
...  

Abstract Background: Treatment with chimeric antigen receptor (CAR)-engineered T cells directed against the B-cell maturation antigen (BCMA) promoted transient recovery from multiple myeloma (MM). However, the absence of this antigen on immature plasma cells may limit the efficacy of this modality and facilitate relapse. The purpose of this study is to characterize a novel CAR that includes both a single-chain variable fragment (scFv)-BCMA and an scFv-CD19 in tandem orientation (tan-CAR) in an attempt to target both BCMA and CD19 expression on MM cells. Method: The scFv sequences from the anti-CD19 antibody FMC63 and the anti-BCMA antibody C11D5.3 were ligated in tandem with transmembrane and T-cell signaling domains to generate the tan-CAR construct. Specificity and efficacy of activated tan-CAR T cells were analyzed using in vitro proliferation, cytokine release, and cytolysis assays. We also evaluated the in vivo efficacy with a xenograft mouse model that included target tumor cells that expressed CD19 or BCMA and compared the results to those obtained with conventional CAR T cells. Results: The in vitro studies revealed specific activation of tan-CAR T cells by K562 cells that overexpressed CD19 and/or BCMA. Cell proliferation, cytokine release, and cytolytic activity were all comparable to the responses of single scFv CAR T cells. Importantly, in vivo studies of tan-CAR T cells revealed specific inhibition of tumor growth in the mouse xenograft model that included cells expressing both CD19 and BCMA. Systemic administration of tan-CAR T cells resulted in complete tumor remission, in contrast to the reduced efficacies of BCMA-CAR T and CD19-CAR T alone in this setting. Conclusion: We report the successful design and execution of novel tan-CAR T cells that promote significant anti-tumor efficacy against both CD19 and BCMA antigen-positive tumor cells in vitro and in vivo . The data from this study reveal a novel strategy that may help to reduce the rate of relapse in the treatment with single scFv-CAR T cells.


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Sudjit Luanpitpong ◽  
Jirarat Poohadsuan ◽  
Phatchanat Klaihmon ◽  
Surapol Issaragrisil

Natural killer (NK) cells are part of the first line of defense that rapidly respond to malignant transformed cells. Chimeric antigen receptor- (CAR-) engineered NK cells, although are still at the preliminary stage, have been shown to be alternative to CAR-T cells, mainly due to the absence of graft-versus-host disease and safer clinical profile. Allogeneic human NK cell line NK-92 cells, equipped by CAR, are being developed for clinical applications. Herein, we designed third-generation CARs, optimized the production protocol, and generated CAR-NK-92 cells, targeting CD19 and/or CD138 antigens that employ CD28, 4-1BB, and CD3ζ signaling, with >80% CAR expression, designated as CD19-NK-92, CD138-NK-92, and dual-NK-92 cells. The generated CAR-NK-92 cells displayed high and selective cytotoxicity toward various corresponding leukemia, lymphoma, and multiple myeloma cell lines in vitro. Multitargeting approach using a mixture of CD19-NK-92 and CD138-NK-92 cells was also evaluated at various ratios to test the idea of personalized formulation to match the patients’ antigen expression profile. Our data indicate that increasing the ratio of CD19-NK-92 to CD138-NK-92 could improve NK cytotoxicity in leukemia cells with a relatively higher expression of CD19 over CD138, supporting the personalized proof of concept. This information represents the basis for further in vivo studies and future progress to clinical trials.


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