T cells selectively filter oscillatory signals on the minutes timescale.
02 Mar 2021-Proceedings of the National Academy of Sciences of the United States of America (Proceedings of the National Academy of Sciences)-Vol. 118, Iss: 9
TL;DR: The engineered T cells obtained from healthy human donors were engineered to respond to light as a stimulus by building an optogenetically controlled chimeric antigen receptor (optoCAR) and it was discovered that T cells respond to minute-scale oscillations of activation signal by stimulating optoCAR T cells with tunable pulse trains of light.
Abstract: T cells experience complex temporal patterns of stimulus via receptor-ligand-binding interactions with surrounding cells. From these temporal patterns, T cells are able to pick out antigenic signals while establishing self-tolerance. Although features such as duration of antigen binding have been examined, our understanding of how T cells interpret signals with different frequencies or temporal stimulation patterns is relatively unexplored. We engineered T cells to respond to light as a stimulus by building an optogenetically controlled chimeric antigen receptor (optoCAR). We discovered that T cells respond to minute-scale oscillations of activation signal by stimulating optoCAR T cells with tunable pulse trains of light. Systematically scanning signal oscillation period from 1 to 150 min revealed that expression of CD69, a T cell activation marker, reached a local minimum at a period of ∼25 min (corresponding to 5 to 15 min pulse widths). A combination of inhibitors and genetic knockouts suggest that this frequency filtering mechanism lies downstream of the Erk signaling branch of the T cell response network and may involve a negative feedback loop that diminishes Erk activity. The timescale of CD69 filtering corresponds with the duration of T cell encounters with self-peptide-presenting APCs observed via intravital imaging in mice, indicating a potential functional role for temporal filtering in vivo. This study illustrates that the T cell signaling machinery is tuned to temporally filter and interpret time-variant input signals in discriminatory ways.
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TL;DR: Optogenetics combines light and genetics to enable precise control of living cells, tissues, and organisms with tailored functions as mentioned in this paper , which has the advantages of noninvasiveness, rapid responsiveness, tunable reversibility, and superior spatiotemporal resolution.
Abstract: Optogenetics combines light and genetics to enable precise control of living cells, tissues, and organisms with tailored functions. Optogenetics has the advantages of noninvasiveness, rapid responsiveness, tunable reversibility, and superior spatiotemporal resolution. Following the initial discovery of microbial opsins as light-actuated ion channels, a plethora of naturally occurring or engineered photoreceptors or photosensitive domains that respond to light at varying wavelengths has ushered in the next chapter of optogenetics. Through protein engineering and synthetic biology approaches, genetically encoded photoswitches can be modularly engineered into protein scaffolds or host cells to control a myriad of biological processes, as well as to enable behavioral control and disease intervention in vivo. Here, we summarize these optogenetic tools on the basis of their fundamental photochemical properties to better inform the chemical basis and design principles. We also highlight exemplary applications of opsin-free optogenetics in dissecting cellular physiology (designated "optophysiology") and describe the current progress, as well as future trends, in wireless optogenetics, which enables remote interrogation of physiological processes with minimal invasiveness. This review is anticipated to spark novel thoughts on engineering next-generation optogenetic tools and devices that promise to accelerate both basic and translational studies.
31 citations
TL;DR: In this article, the authors review experimental strategies aimed at revealing quantitative and dynamic properties of T-cell development and how they have been implemented in mathematical modeling strategies that were reported to help understand the flexible dynamics of the highly dividing and dying thymic cell populations.
Abstract: The thymus hosts the development of a specific type of adaptive immune cells called T cells. T cells orchestrate the adaptive immune response through recognition of antigen by the highly variable T-cell receptor (TCR). T-cell development is a tightly coordinated process comprising lineage commitment, somatic recombination of Tcr gene loci and selection for functional, but non-self-reactive TCRs, all interspersed with massive proliferation and cell death. Thus, the thymus produces a pool of T cells throughout life capable of responding to virtually any exogenous attack while preserving the body through self-tolerance. The thymus has been of considerable interest to both immunologists and theoretical biologists due to its multi-scale quantitative properties, bridging molecular binding, population dynamics and polyclonal repertoire specificity. Here, we review experimental strategies aimed at revealing quantitative and dynamic properties of T-cell development and how they have been implemented in mathematical modeling strategies that were reported to help understand the flexible dynamics of the highly dividing and dying thymic cell populations. Furthermore, we summarize the current challenges to estimating in vivo cellular dynamics and to reaching a next-generation multi-scale picture of T-cell development.
14 citations
TL;DR: Optogenetic tools are based on genetically encoded light-sensing proteins facilitating the precise spatiotemporal control of signal transduction pathways and cell fate decisions in the absence of natural ligands as discussed by the authors.
Abstract: Biological signals are sensed by their respective receptors and are transduced and processed by a sophisticated intracellular signaling network leading to a signal-specific cellular response. Thereby, the response to the signal depends on the strength, the frequency, and the duration of the stimulus as well as on the subcellular signal progression. Optogenetic tools are based on genetically encoded light-sensing proteins facilitating the precise spatiotemporal control of signal transduction pathways and cell fate decisions in the absence of natural ligands. In this review, we provide an overview of optogenetic approaches connecting light-regulated protein-protein interaction or caging/uncaging events with steering the function of signaling proteins. We briefly discuss the most common optogenetic switches and their mode of action. The main part deals with the engineering and application of optogenetic tools for the control of transmembrane receptors including receptor tyrosine kinases, the T cell receptor and integrins, and their effector proteins. We also address the hallmarks of optogenetics, the spatial and temporal control of signaling events.
12 citations
TL;DR: Optogenetics combines genetics and biophotonics to enable non-invasive control of biological processes with high spatio-temporal precision as discussed by the authors , where multiple genetically encoded non-opsin photosensory modules have been harnessed to modulate gene transcription, DNA or RNA modifications, DNA recombination, and genome engineering by utilizing photons emitting in the wide range of 200-1000 nm.
9 citations
TL;DR: Recent improvements on the CAR and other non-CAR molecules aimed to enhance CAR T cell efficacy and safety are discussed and the development of different types of inducible CAR T cells that can be controlled by environmental cues and/or external stimuli are highlighted.
Abstract: Despite its success in treating hematologic malignancies, chimeric antigen receptor (CAR) T cell therapy faces two major challenges which hinder its broader applications: the limited effectiveness against solid tumors and the nonspecific toxicities. To address these concerns, researchers have used synthetic biology approaches to develop optimization strategies. In this review, we discuss recent improvements on the CAR and other non-CAR molecules aimed to enhance CAR T cell efficacy and safety. We also highlight the development of different types of inducible CAR T cells that can be controlled by environmental cues and/or external stimuli. These advancements are bringing CAR T therapy one step closer to safer and wider applications, especially for solid tumors.
6 citations
References
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TL;DR: Understanding of the complex signaling networks downstream from RTKs and how alterations in these networks are translated into cellular responses provides an important context for therapeutically countering the effects of pathogenic RTK mutations in cancer and other diseases.
7,056 citations
"T cells selectively filter oscillat..." refers background in this paper
...R interactions on the surface of eukaryotic cells initiate reversible signaling and transcriptional cascades that ultimately culminate in long-lasting or irreversible changes in gene expression and functional activation (1, 2)....
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TL;DR: The emergence of tumor cells that no longer express the target indicates a need to target other molecules in addition to CD19 in some patients with ALL.
Abstract: Chimeric antigen receptor-modified T cells with specificity for CD19 have shown promise in the treatment of chronic lymphocytic leukemia (CLL). It remains to be established whether chimeric antigen receptor T cells have clinical activity in acute lymphoblastic leukemia (ALL). Two children with relapsed and refractory pre-B-cell ALL received infusions of T cells transduced with anti-CD19 antibody and a T-cell signaling molecule (CTL019 chimeric antigen receptor T cells), at a dose of 1.4×10(6) to 1.2×10(7) CTL019 cells per kilogram of body weight. In both patients, CTL019 T cells expanded to a level that was more than 1000 times as high as the initial engraftment level, and the cells were identified in bone marrow. In addition, the chimeric antigen receptor T cells were observed in the cerebrospinal fluid (CSF), where they persisted at high levels for at least 6 months. Eight grade 3 or 4 adverse events were noted. The cytokine-release syndrome and B-cell aplasia developed in both patients. In one child, the cytokine-release syndrome was severe; cytokine blockade with etanercept and tocilizumab was effective in reversing the syndrome and did not prevent expansion of chimeric antigen receptor T cells or reduce antileukemic efficacy. Complete remission was observed in both patients and is ongoing in one patient at 11 months after treatment. The other patient had a relapse, with blast cells that no longer expressed CD19, approximately 2 months after treatment. Chimeric antigen receptor-modified T cells are capable of killing even aggressive, treatment-refractory acute leukemia cells in vivo. The emergence of tumor cells that no longer express the target indicates a need to target other molecules in addition to CD19 in some patients with ALL.
3,027 citations
"T cells selectively filter oscillat..." refers background in this paper
...Part one of the optoCAR receptor was built by fusing the α-CD19 scFv (53) or the Lag17 αGFP nanobody (36) to the human CD8α hinge and transmembrane domains and the iLID light-sensitive domain (39) (SI Appendix, Fig....
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TL;DR: Insight gained from studies of the signaling pathways downstream of TCR and BCR stimulation is likely to contribute significantly to future understanding of mechanisms responsible for lymphocyte differentiation and for the discrimination of self from nonself in developing and mature cells.
2,122 citations
"T cells selectively filter oscillat..." refers methods in this paper
...To construct light-responsive T cells, we engineered an optogenetically controlled chimeric antigen receptor (optoCAR) using a split receptor design similar to that of endogenous antigenic receptors, that is, the TCR/CD3 and B cell receptor (BCR) complexes, whose ligand-recognition and signaling domains are expressed as separate polypeptides (3)....
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TL;DR: The epidermal growth factor receptor (EGFR) is one member of the ERBB family of transmembrane gly-coprotein tyrosine receptor kinases (RTK) and stimulates intracellular signal transduction cascades that are involved in regulating cellular proliferation, differentiation, and survival.
Abstract: This is a free sample of content from Signaling by Receptor Tyrosine Kinases Click here for more information or to buy the book. This is a free sample of content from Signaling by Receptor Tyrosine Kinases Click here for more information or to buy the book. Front cover artwork: Stylized representations of the 20 different receptor tyrosine kinase (RTK) families found in humans—accounting for a total of 58 different receptors. The common intra-cellular tyrosine kinase domain (lower part of each receptor) is shown as a red rectangle. Domains in the extracellular region (upper part of each receptor) are much more variable across families and include immunoglobulin domains (blue), fibronectin type III domains (orange), and many others. The chapters in this volume describe mechanisms by which ligand binding to the extracellular region controls activity of the intracellular kinase domain, which vary substantially across the family and drive a variety of intracellular signaling pathways. All World Wide Web addresses are accurate to the best of our knowledge at the time of printing. Authorization to photocopy items for internal or personal use, or the internal or personal use of specific clients, is granted by Cold Spring Harbor Laboratory Press, provided that the appropriate fee is paid directly to the Copyright Clearance Center (CCC). Write or call CCC at 222 Rosewood Drive, Danvers, MA 01923 (978-750-8400) for information about fees and regulations. Prior to photocopying items for educational classroom use, contact CCC at the above address. Additional information on CCC can be obtained at CCC Online at www.copyright.com.
1,710 citations
TL;DR: T-cell priming by DCs occurs in three successive stages: transient serial encounters during the first activation phase are followed by a second phase of stable contacts culminating in cytokine production, which makes a transition into a third phase of high motility and rapid proliferation.
Abstract: Primary T-cell responses in lymph nodes (LNs) require contact-dependent information exchange between T cells and dendritic cells (DCs). Because lymphocytes continually enter and leave normal LNs, the resident lymphocyte pool is composed of non-synchronized cells with different dwell times that display heterogeneous behaviour in mouse LNs in vitro. Here we employ two-photon microscopy in vivo to study antigen-presenting DCs and naive T cells whose dwell time in LNs was synchronized. During the first 8 h after entering from the blood, T cells underwent multiple short encounters with DCs, progressively decreased their motility, and upregulated activation markers. During the subsequent 12 h T cells formed long-lasting stable conjugates with DCs and began to secrete interleukin-2 and interferon-gamma. On the second day, coinciding with the onset of proliferation, T cells resumed their rapid migration and short DC contacts. Thus, T-cell priming by DCs occurs in three successive stages: transient serial encounters during the first activation phase are followed by a second phase of stable contacts culminating in cytokine production, which makes a transition into a third phase of high motility and rapid proliferation.
1,659 citations