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Science Immunology Mar 2023Chimeric antigen receptor (CAR) T cell therapy relies on T cells that are guided by synthetic receptors to target and lyse cancer cells. CARs bind to cell surface...
Chimeric antigen receptor (CAR) T cell therapy relies on T cells that are guided by synthetic receptors to target and lyse cancer cells. CARs bind to cell surface antigens through an scFv (binder), the affinity of which is central to determining CAR T cell function and therapeutic success. CAR T cells targeting CD19 were the first to achieve marked clinical responses in patients with relapsed/refractory B cell malignancies and to be approved by the U.S. Food and Drug Administration (FDA). We report cryo-EM structures of CD19 antigen with the binder FMC63, which is used in four FDA-approved CAR T cell therapies (Kymriah, Yescarta, Tecartus, and Breyanzi), and the binder SJ25C1, which has also been used extensively in multiple clinical trials. We used these structures for molecular dynamics simulations, which guided creation of lower- or higher-affinity binders, and ultimately produced CAR T cells endowed with distinct tumor recognition sensitivities. The CAR T cells exhibited different antigen density requirements to trigger cytolysis and differed in their propensity to prompt trogocytosis upon contacting tumor cells. Our work shows how structural information can be applied to tune CAR T cell performance to specific target antigen densities.
Topics: United States; Humans; Antigens, CD19; Adaptor Proteins, Signal Transducing; Antigens, Surface; B-Lymphocytes; Cell Death
PubMed: 36867678
DOI: 10.1126/sciimmunol.adf1426 -
Nature Sep 2019Fibrosis is observed in nearly every form of myocardial disease. Upon injury, cardiac fibroblasts in the heart begin to remodel the myocardium by depositing excess...
Fibrosis is observed in nearly every form of myocardial disease. Upon injury, cardiac fibroblasts in the heart begin to remodel the myocardium by depositing excess extracellular matrix, resulting in increased stiffness and reduced compliance of the tissue. Excessive cardiac fibrosis is an important factor in the progression of various forms of cardiac disease and heart failure. However, clinical interventions and therapies that target fibrosis remain limited. Here we demonstrate the efficacy of redirected T cell immunotherapy to specifically target pathological cardiac fibrosis in mice. We find that cardiac fibroblasts that express a xenogeneic antigen can be effectively targeted and ablated by adoptive transfer of antigen-specific CD8 T cells. Through expression analysis of the gene signatures of cardiac fibroblasts obtained from healthy and diseased human hearts, we identify an endogenous target of cardiac fibroblasts-fibroblast activation protein. Adoptive transfer of T cells that express a chimeric antigen receptor against fibroblast activation protein results in a significant reduction in cardiac fibrosis and restoration of function after injury in mice. These results provide proof-of-principle for the development of immunotherapeutic drugs for the treatment of cardiac disease.
Topics: Animals; Antigens, Surface; CD8-Positive T-Lymphocytes; Endomyocardial Fibrosis; Fibroblasts; Humans; Immunotherapy, Adoptive; Male; Mice; Ovalbumin; Wound Healing
PubMed: 31511695
DOI: 10.1038/s41586-019-1546-z -
Nature Medicine Feb 2022Chimeric antigen receptors (CARs) are receptors for antigen that direct potent immune responses. Tumor escape associated with low target antigen expression is emerging...
Chimeric antigen receptors (CARs) are receptors for antigen that direct potent immune responses. Tumor escape associated with low target antigen expression is emerging as one potential limitation of their efficacy. Here we edit the TRAC locus in human peripheral blood T cells to engage cell-surface targets through their T cell receptor-CD3 complex reconfigured to utilize the same immunoglobulin heavy and light chains as a matched CAR. We demonstrate that these HLA-independent T cell receptors (HIT receptors) consistently afford high antigen sensitivity and mediate tumor recognition beyond what CD28-based CARs, the most sensitive design to date, can provide. We demonstrate that the functional persistence of HIT T cells can be augmented by constitutive coexpression of CD80 and 4-1BBL. Finally, we validate the increased antigen sensitivity afforded by HIT receptors in xenograft mouse models of B cell leukemia and acute myeloid leukemia, targeting CD19 and CD70, respectively. Overall, HIT receptors are well suited for targeting cell surface antigens of low abundance.
Topics: Animals; Antigens, CD19; Histocompatibility Antigens; Humans; Immunotherapy, Adoptive; Leukemia, Myeloid, Acute; Mice; Receptors, Antigen, T-Cell; Receptors, Chimeric Antigen; Xenograft Model Antitumor Assays
PubMed: 35027758
DOI: 10.1038/s41591-021-01621-1 -
Journal of Nuclear Medicine : Official... May 2021Prostate-specific membrane antigen (PSMA) is highly expressed on most prostate cancer (PCa) cells, and several PSMA ligands for PET imaging are now available worldwide.... (Review)
Review
Prostate-specific membrane antigen (PSMA) is highly expressed on most prostate cancer (PCa) cells, and several PSMA ligands for PET imaging are now available worldwide. Ga-PSMA-11 has already received U.S. Food and Drug Administration and European Medicines Agency approval, and use of PSMA PET is currently suggested by several international guidelines for investigating PCa in different clinical settings. In primary PCa, PSMA PET has been shown to be superior to cross-sectional imaging for the detection of pelvic lymph nodes and distant metastases with subsequent clinical management changes. Additionally, it might also have a role in intraprostatic tumor localization, especially when combined with multiparametric MRI. In a setting of PCa recurrence, higher detection rates have been observed than for any other available imaging techniques, especially at low prostate-specific antigen values. Furthermore, PSMA PET consistently led to a shift in clinical management, thus increasing the proportion of radiotherapy, surgery, or other focal therapies at the expense of systemic options or no treatment. In oligometastatic disease after radical surgery, PSMA PET may be relevant in guiding a metastasis-directed therapy approach, as preliminary data seem to suggest a benefit in terms of progression-free survival after treatment of PSMA PET-positive lesions. As a staging and gatekeeping technique, PSMA PET represents a reliable whole-body imaging procedure in combination with second-line therapy of castration-resistant PCa, as well as being pivotal when assessing patients eligible for radioligand therapy such as Lu-PSMA. This critical review aims at providing a comprehensive overview of the latest literature on the current or emerging main indications, as well as a general outlook on the recommended interpretation criteria for PSMA PET imaging.
Topics: Antigens, Surface; Glutamate Carboxypeptidase II; Humans; Male; Positron-Emission Tomography; Prostatic Neoplasms
PubMed: 33712536
DOI: 10.2967/jnumed.120.257238 -
Nucleic Acids Research Jul 2020Major histocompatibility complex (MHC) molecules are expressed on the cell surface, where they present peptides to T cells, which gives them a key role in the...
Major histocompatibility complex (MHC) molecules are expressed on the cell surface, where they present peptides to T cells, which gives them a key role in the development of T-cell immune responses. MHC molecules come in two main variants: MHC Class I (MHC-I) and MHC Class II (MHC-II). MHC-I predominantly present peptides derived from intracellular proteins, whereas MHC-II predominantly presents peptides from extracellular proteins. In both cases, the binding between MHC and antigenic peptides is the most selective step in the antigen presentation pathway. Therefore, the prediction of peptide binding to MHC is a powerful utility to predict the possible specificity of a T-cell immune response. Commonly MHC binding prediction tools are trained on binding affinity or mass spectrometry-eluted ligands. Recent studies have however demonstrated how the integration of both data types can boost predictive performances. Inspired by this, we here present NetMHCpan-4.1 and NetMHCIIpan-4.0, two web servers created to predict binding between peptides and MHC-I and MHC-II, respectively. Both methods exploit tailored machine learning strategies to integrate different training data types, resulting in state-of-the-art performance and outperforming their competitors. The servers are available at http://www.cbs.dtu.dk/services/NetMHCpan-4.1/ and http://www.cbs.dtu.dk/services/NetMHCIIpan-4.0/.
Topics: Amino Acid Motifs; Antigen Presentation; Histocompatibility Antigens Class I; Histocompatibility Antigens Class II; Ligands; Machine Learning; Peptides; Software
PubMed: 32406916
DOI: 10.1093/nar/gkaa379 -
Cancer Research Oct 2020Identification of tumor-specific cell surface antigens has proven challenging, as the vast majority of tumor-associated antigens are also expressed in normal tissues. In...
Identification of tumor-specific cell surface antigens has proven challenging, as the vast majority of tumor-associated antigens are also expressed in normal tissues. In mesothelioma, we identified a highly specific tumor cell surface antigen that can be targeted for therapy development. Mesothelioma is caused by malignant transformation of the mesothelium, is incurable, and can be categorized into three histologic subtypes: epithelioid, biphasic, and sarcomatoid. To identity novel mesothelioma cell surface antigens with broad subtype coverage and high tissue specificity, we have previously selected phage antibody display libraries on live mesothelioma cells and tissues following counterselection on normal cells and identified a panel of human antibodies that bind all subtypes of mesothelioma, but not normal mesothelium. One of the antibodies, M25, showed high specificity against an antigen we identify here as ALPPL2. IHC on normal human tissues found that ALPPL2 is expressed only on placental trophoblasts, but not on any other normal tissues. This significant tissue specificity and broad tumor type coverage suggest that ALPPL2 could be an excellent cell surface target for therapeutic development against mesothelioma. To evaluate therapeutic potential of ALPPL2 targeting, an ALPPL2-targeted antibody-drug conjugate was developed and demonstrated potent and specific tumor killing and against both epithelioid and sarcomatoid mesothelioma. Thus, ALPPL2 belongs to a rare class of cell surface antigens classified as truly tumor specific and is well suited for therapy development against ALPPL2-expressing tumors. SIGNIFICANCE: These findings identify ALPP2 as a true tumor-specific cell surface antigen whose tissue specificity enables the development of novel therapies.
Topics: Alkaline Phosphatase; Animals; Antigens, Surface; Antineoplastic Agents, Immunological; CHO Cells; Cell Line, Tumor; Cricetulus; Epitopes; Female; GPI-Linked Proteins; Humans; Immunoconjugates; Immunoglobulin G; Male; Mesothelioma, Malignant; Mice, Inbred NOD; Molecular Targeted Therapy; Xenograft Model Antitumor Assays
PubMed: 32868383
DOI: 10.1158/0008-5472.CAN-20-1418 -
Pathobiology : Journal of... 2022Trophoblast cell surface antigen 2 (TROP2) is the target of sacituzumab govitecan, an antibody-drug conjugate approved for treatment of triple negative breast cancer and...
INTRODUCTION
Trophoblast cell surface antigen 2 (TROP2) is the target of sacituzumab govitecan, an antibody-drug conjugate approved for treatment of triple negative breast cancer and urothelial carcinoma.
METHODS
A tissue microarray containing 18,563 samples from 150 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by TROP2 immunohistochemistry.
RESULTS
TROP2 positivity was found in 109 tumor categories, including squamous cell carcinomas of various origins, urothelial, breast, prostate, pancreatic, and ovarian cancers (>95% positive). High TROP2 expression was linked to advanced stage (p = 0.0069) and nodal metastasis (p < 0.0001) in colorectal cancer as well as to nodal metastasis in gastric adenocarcinoma (p = 0.0246) and papillary thyroid cancer (p = 0.0013). Low TROP2 expression was linked to advanced stage in urothelial carcinoma (p < 0.0001), high pT (p = 0.0024), and high grade (p < 0.0001) in breast cancer, as well as with high Fuhrmann grade (p < 0.0001) and pT stage (p = 0.0009) in papillary renal cell carcinomas.
CONCLUSION
TROP2 is expressed in many epithelial neoplasms. TROP2 deregulation can be associated with cancer progression in a tumor-type dependent manner. Since anti-TROP2 cancer drugs have demonstrated efficiency, they may be applicable to a broad range of tumor entities in the future.
Topics: Adenocarcinoma; Antigens, Neoplasm; Carcinoma, Transitional Cell; Cell Adhesion Molecules; Female; Humans; Male; Trophoblasts; Urinary Bladder Neoplasms
PubMed: 35477165
DOI: 10.1159/000522206 -
Nature Sep 2023Certain bacterial strains from the microbiome induce a potent, antigen-specific T cell response. However, the specificity of microbiome-induced T cells has not been...
Certain bacterial strains from the microbiome induce a potent, antigen-specific T cell response. However, the specificity of microbiome-induced T cells has not been explored at the strain level across the gut community. Here, we colonize germ-free mice with complex defined communities (roughly 100 bacterial strains) and profile T cell responses to each strain. The pattern of responses suggests that many T cells in the gut repertoire recognize several bacterial strains from the community. We constructed T cell hybridomas from 92 T cell receptor (TCR) clonotypes; by screening every strain in the community against each hybridoma, we find that nearly all the bacteria-specific TCRs show a one-to-many TCR-to-strain relationship, including 13 abundant TCR clonotypes that each recognize 18 Firmicutes. By screening three pooled bacterial genomic libraries, we discover that these 13 clonotypes share a single target: a conserved substrate-binding protein from an ATP-binding cassette transport system. Peripheral regulatory T cells and T helperĀ 17 cells specific for an epitope from this protein are abundant in community-colonized and specific pathogen-free mice. Our work reveals that T cell recognition of commensals is focused on widely conserved, highly expressed cell-surface antigens, opening the door to new therapeutic strategies in which colonist-specific immune responses are rationally altered or redirected.
Topics: Animals; Mice; Antigens, Surface; Bacteria; Firmicutes; Gastrointestinal Microbiome; T-Lymphocytes, Regulatory; Th17 Cells; T-Lymphocytes; Symbiosis; Germ-Free Life; Receptors, Antigen, T-Cell; Hybridomas; Cell Separation
PubMed: 37587342
DOI: 10.1038/s41586-023-06431-8 -
Cell Stem Cell Apr 2021Lack of cellular differentiation is a hallmark of many human cancers, including acute myeloid leukemia (AML). Strategies to overcome such a differentiation blockade are...
Lack of cellular differentiation is a hallmark of many human cancers, including acute myeloid leukemia (AML). Strategies to overcome such a differentiation blockade are an approach for treating AML. To identify targets for differentiation-based therapies, we applied an integrated cell surface-based CRISPR platform to assess genes involved in maintaining the undifferentiated state of leukemia cells. Here we identify the RNA-binding protein ZFP36L2 as a critical regulator of AML maintenance and differentiation. Mechanistically, ZFP36L2 interacts with the 3' untranslated region of key myeloid maturation genes, including the ZFP36 paralogs, to promote their mRNA degradation and suppress terminal myeloid cell differentiation. Genetic inhibition of ZFP36L2 restores the mRNA stability of these targeted transcripts and ultimately triggers myeloid differentiation in leukemia cells. Epigenome profiling of several individuals with primary AML revealed enhancer modules near ZFP36L2 that associated with distinct AML cell states, establishing a coordinated epigenetic and post-transcriptional mechanism that shapes leukemic differentiation.
Topics: Antigens, Surface; Cell Differentiation; Clustered Regularly Interspaced Short Palindromic Repeats; Hematopoiesis; Humans; Leukemia, Myeloid, Acute
PubMed: 33450187
DOI: 10.1016/j.stem.2020.12.005 -
Oncoimmunology 2022Chimeric antigen receptor (CAR) T cell therapies have resulted in profound clinical responses in the treatment of CD19-positive hematological malignancies, but a...
Chimeric antigen receptor (CAR) T cell therapies have resulted in profound clinical responses in the treatment of CD19-positive hematological malignancies, but a significant proportion of patients do not respond or relapse eventually. As an alternative to CAR T cells, T cells can be engineered to express a tumor-targeting T cell receptor (TCR). Due to HLA restriction of TCRs, CARs have emerged as a preferred treatment moiety when targeting surface antigens, despite the fact that functional differences between engineered TCR (eTCR) T and CAR T cells remain ill-defined. Here, we compared the activity of CAR T cells versus engineered TCR T cells in targeting the B cell malignancy-associated antigen CD20 as a function of antigen exposure. We found CAR T cells to be more potent effector cells, producing higher levels of cytokines and killing more efficiently than eTCR T cells in a short time frame. However, we revealed that the increase of antigen exposure significantly impaired CAR T cell expansion, a phenotype defined by high expression of coinhibitory molecules and effector differentiation. In contrast, eTCR T cells expanded better than CAR T cells under high antigenic pressure, with lower expression of coinhibitory molecules and maintenance of an early differentiation phenotype, and comparable clearance of tumor cells.
Topics: Antigens, CD20; Humans; Immunotherapy, Adoptive; Neoplasm Recurrence, Local; Receptors, Antigen, T-Cell; T-Lymphocytes
PubMed: 35127255
DOI: 10.1080/2162402X.2022.2033528