搜索结果: 'gmp t cell activator'

The high mobility group (HMG) transcription factor TCF-1 is essential for early T cell development. Although in vitro biochemical assays suggest that HMG proteins can serve as architectural elements in the assembly of higher-order nuclear organization,the contribution of TCF-1 on the control of three-dimensional (3D) genome structures during T cell development remains unknown. Here,we investigated the role of TCF-1 in 3D genome reconfiguration. Using gain- and loss-of-function experiments,we discovered that the co-occupancy of TCF-1 and the architectural protein CTCF altered the structure of topologically associating domains in T cell progenitors,leading to interactions between previously insulated regulatory elements and target genes at late stages of T cell development. The TCF-1-dependent gain in long-range interactions was linked to deposition of active enhancer mark H3K27ac and recruitment of the cohesin-loading factor NIPBL at active enhancers. These data indicate that TCF-1 has a role in controlling global genome organization during T cell development. View Publication

Epitope-specific CD4+ T cells can be labeled in complex cell mixtures from secondary lymphoid organs with fluorophore-labeled peptide:major histocompatibility complex class II (p:MHCII) tetramers and then detected by flow cytometry. Magnetic enrichment of tetramer-bound cells before flow cytometry increases the sensitivity of detection to the point where epitope-specific cells can be studied even when very rare at early and late times after the host has been exposed to the epitope. This method is very useful for studying polyclonal epitope-specific CD4+ T cells under physiological conditions. {\textcopyright} 2019 by John Wiley {\&} Sons,Inc. View Publication

In recent years,Raman spectroscopy has garnered growing interest in the field of biomedical research. It offers a non-invasive and label-free approach to defining the molecular fingerprint of immune cells. We utilized Raman spectroscopy on optically trapped immune cells to investigate their molecular compositions. While numerous immune cell types have been studied in the past,the characterization of living human CD3/CD28-stimulated T cell subsets remains incomplete. In this study,we demonstrate the capability of Raman spectroscopy to readily distinguish between naïve and stimulated CD4 and CD8 cells. Additionally,we compared these cells with monocytes and discovered remarkable similarities between stimulated T cells and monocytes. This paper contributes to expanding our knowledge of Raman spectroscopy of immune cells and serves as a launching point for future clinical applications. View Publication

The progressive decline of CD8 T cell effector function—also known as terminal exhaustion—is a major contributor to immune evasion in cancer. Yet,the molecular mechanisms that drive CD8 T cell dysfunction remain poorly understood. Here,we report that the Kelch-like ECH-associated protein 1 (KEAP1)-Nuclear factor erythroid 2-related factor 2 (NRF2) signaling axis,which mediates cellular adaptations to oxidative stress,directly regulates CD8 T cell exhaustion. Transcriptional profiling of dysfunctional CD8 T cells from chronic infection and cancer reveals enrichment of NRF2 activity in terminally exhausted (Texterm) CD8 T cells. Increasing NRF2 activity in CD8 T cells (via conditional deletion of KEAP1) promotes increased glutathione production and antioxidant defense yet accelerates the development of terminally exhausted (PD-1+TIM-3+) CD8 T cells in response to chronic infection or tumor challenge. Mechanistically,we identify PTGIR,a receptor for the circulating eicosanoid prostacyclin,as an NRF2-regulated protein that promotes CD8 T cell dysfunction. Silencing PTGIR expression restores the anti-tumor function of KEAP1-deficient T cells. Moreover,lowering PTGIR expression in CD8 T cells both reduces terminal exhaustion and enhances T cell effector responses (i.e. IFN-γ and granzyme production) to chronic infection and cancer. Together,these results establish the KEAP1-NRF2 axis as a metabolic sensor linking oxidative stress to CD8 T cell dysfunction and identify the prostacyclin receptor PTGIR as an NRF2-regulated immune checkpoint that regulates CD8 T cell fate decisions between effector and exhausted states. One Sentence Summary:The KEAP1-NRF2 pathway is hyperactivated in terminally exhausted CD8 T cells and drives T cell dysfunction via transcriptional regulation of the prostacyclin receptor,Ptgir. View Publication

T cell therapies,such as chimeric antigen receptor (CAR) T cells and T cell receptor (TCR) T cells,are a growing class of anti-cancer treatments. However,expansion to novel indications and beyond last-line treatment requires engineering cells' dynamic population behaviors. Here we develop the tools for cellular behavior analysis of T cells from live-cell imaging,a common and inexpensive experimental setup used to evaluate engineered T cells. We first develop a state-of-the-art segmentation and tracking pipeline,Caliban,based on human-in-the-loop deep learning. We then build the Occident pipeline to collect a catalog of phenotypes that characterize cell populations,morphology,movement,and interactions in co-cultures of modified T cells and antigen-presenting tumor cells. We use Caliban and Occident to interrogate how interactions between T cells and cancer cells differ when beneficial knock-outs of RASA2 and CUL5 are introduced into TCR T cells. We apply spatiotemporal models to quantify T cell recruitment and proliferation after interactions with cancer cells. We discover that,compared to a safe harbor knockout control,RASA2 knockout T cells have longer interaction times with cancer cells leading to greater T cell activation and killing efficacy,while CUL5 knockout T cells have increased proliferation rates leading to greater numbers of T cells for hunting. Together,segmentation and tracking from Caliban and phenotype quantification from Occident enable cellular behavior analysis to better engineer T cell therapies for improved cancer treatment. View Publication

Redirecting Ag specificity by transfer of TCR genes into PBLs is an attractive method to generate large numbers of cytotoxic T cells for immunotherapy of cancer and viral diseases. However,transferred TCR chains can pair with endogenous TCR chains,resulting in the formation of mispaired TCR dimers and decreased or unspecific reactivity. TCR gene transfer into hematopoietic stem cells (HSCs) is an alternative to create T cells with desired Ag specificity,because in this case expression of endogenous TCR chains is then less likely owing to allelic exclusion. We generated TCR-transduced T cells from peripheral T cells using the lymphocytic choriomeningitis virus-specific P14 TCR. After transfer of the P14 TCR genes into HSCs and subsequent reconstitution of irradiated mice,TCR-engineered HSC-derived T cells were produced. We then compared the Ag-specific T cell populations with P14 TCR-transgenic T cells for their therapeutic efficiency in three in vivo models. In this study,we demonstrate that TCR-transduced T cells and TCR-engineered HSC-derived T cells are comparable in controlling lymphocytic choriomeningitis virus infection in mice and suppress growth of B16 tumor cells expressing the cognate Ag in a comparable manner. View Publication

CD8(+) T cells develop increased sensitivity following Ag experience,and differences in sensitivity exist between T cell memory subsets. How differential TCR signaling between memory subsets contributes to sensitivity differences is unclear. We show in mouse effector memory T cells (TEM) that textgreater50% of lymphocyte-specific protein tyrosine kinase (Lck) exists in a constitutively active conformation,compared with textless20% in central memory T cells (TCM). Immediately proximal to Lck signaling,we observed enhanced Zap-70 phosphorylation in TEM following TCR ligation compared with TCM Furthermore,we observed superior cytotoxic effector function in TEM compared with TCM,and we provide evidence that this results from a lower probability of TCM reaching threshold signaling owing to the decreased magnitude of TCR-proximal signaling. We provide evidence that the differences in Lck constitutive activity between CD8(+) TCM and TEM are due to differential regulation by SH2 domain-containing phosphatase-1 (Shp-1) and C-terminal Src kinase,and we use modeling of early TCR signaling to reveal the significance of these differences. We show that inhibition of Shp-1 results in increased constitutive Lck activity in TCM to levels similar to TEM,as well as increased cytotoxic effector function in TCM Collectively,this work demonstrates a role for constitutive Lck activity in controlling Ag sensitivity,and it suggests that differential activities of TCR-proximal signaling components may contribute to establishing the divergent effector properties of TCM and TEM. This work also identifies Shp-1 as a potential target to improve the cytotoxic effector functions of TCM for adoptive cell therapy applications. View Publication

CD4(+)Vβ5(+) peripheral T cells in C57BL/6 mice respond to encounter with a peripherally expressed endogenous superantigen by undergoing either deletion or TCR revision. In this latter process,cells lose surface Vβ5 expression and undergo RAG-dependent rearrangement of endogenous TCRβ genes,driving surface expression of novel TCRs. Although postrevision CD4(+)Vβ5(-)TCRβ(+) T cells accumulate with age in Vβ5 transgenic mice and bear a diverse TCR Vβ repertoire,it is unknown whether they respond to homeostatic and antigenic stimuli and thus may benefit the host. We demonstrate in this study that postrevision cells are functional. These cells have a high rate of steady-state homeostatic proliferation in situ,and they undergo extensive MHC class II-dependent lymphopenia-induced proliferation. Importantly,postrevision cells do not proliferate in response to the tolerizing superantigen,implicating TCR revision as a mechanism of tolerance induction and demonstrating that TCR-dependent activation of postrevision cells is not driven by the transgene-encoded receptor. Postrevision cells proliferate extensively to commensal bacterial Ags and can generate I-A(b)-restricted responses to Ag by producing IFN-γ following Listeria monocytogenes challenge. These data show that rescued postrevision T cells are responsive to homeostatic signals and recognize self- and foreign peptides in the context of self-MHC and are thus useful to the host. View Publication

Bone marrow (BM) failure syndrome encompasses a group of disorders characterized by BM stem cell dysfunction,resulting in varying degrees of hypoplasia and blood pancytopenia,and in many patients is autoimmune and inflammatory in nature. The important role of T helper 1 (Th1) polarized CD4+ T cells in driving BM failure has been clearly established in several models. However,animal model data demonstrating a functional role for CD8+ T cells in BM dysfunction is largely lacking and our objective was to test the hypothesis that CD8+ T cells play a non-redundant role in driving BM failure. Clinical evidence implicates a detrimental role for CD8+ T cells in BM failure and a beneficial role for Foxp3+ regulatory T cells (Tregs) in maintaining immune tolerance in the BM. We demonstrate that IL-2-deficient mice,which have a deficit in functional Tregs,develop spontaneous BM failure. Furthermore,we demonstrate a critical role for CD8+ T cells in the development of BM failure,which is dependent on the cytokine,IFNgamma$. CD8+ T cells promote hematopoietic stem cell dysfunction and depletion of myeloid lineage progenitor cells,resulting in anemia. Adoptive transfer experiments demonstrate that CD8+ T cells dramatically expedite disease progression and promote CD4+ T cell accumulation in the BM. Thus,BM dysregulation in IL-2-deficient mice is mediated by a Th1 and IFNgamma$-producing CD8+ T cell (Tc1) response. View Publication

Mesenchymal stromal cells (MSCs) may be derived from a variety of tissues,with human umbilical cord (UC) providing an abundant and noninvasive source. Human UC-MSCs share similar in vitro immunosuppressive properties as MSCs obtained from bone marrow and cord blood. However,the mechanisms and cellular interactions used by MSCs to control immune responses remain to be fully elucidated. In this paper,we report that suppression of mitogen-induced T cell proliferation by human UC-,bone marrow-,and cord blood-MSCs required monocytes. Removal of monocytes but not B cells from human adult PBMCs (PBMNCs) reduced the immunosuppressive effects of MSCs on T cell proliferation. There was rapid modulation of a number of cell surface molecules on monocytes when PBMCs or alloantigen-activated PBMNCs were cultured with UC-MSCs. Indomethacin treatment significantly inhibited the ability of UC-MSCs to suppress T cell proliferation,indicating an important role for PGE(2). Monocytes purified from UC-MSC coculture had significantly reduced accessory cell and allostimulatory function when tested in subsequent T cell proliferation assays,an effect mediated in part by UC-MSC PGE(2) production and enhanced by PBMNC alloactivation. Therefore,we identify monocytes as an essential intermediary through which UC-MSCs mediate their suppressive effects on T cell proliferation. View Publication

SummarySepsis survivors are at high risk for infection-related rehospitalization and mortality for years following the resolution of the acute septic event. These infection-causing microorganisms generally do not cause disease in immunocompetent hosts,suggesting that the post-septic immune response is compromised. Given the importance of CD4 T cells in the development of long-lasting protective immunity,we analyzed their post-septic function. Here we showed that sepsis induced chronic increased and non-specific production of IL-17 by CD4 T cells,resulting in the inability to mount an effective immune response to a secondary pneumonia challenge. Altered cell function was associated with metabolic reprogramming,characterized by mitochondrial dysfunction and increased glycolysis. This metabolic reprogramming began during the acute septic event and persisted long after sepsis had resolved. Our findings reveal cell metabolism as a potential therapeutic target. Given the critical role of cell metabolism in the physiological and pathophysiological processes of immune cells,these findings reveal a potential new therapeutic target to help mitigate sepsis survivors’ susceptibility to secondary infections. Graphical abstract Highlights•Sepsis survivors demonstrate dysfunctional CD4 T cell immunity•Sepsis induces persistent mitochondrial dysfunction in CD4 T cells•Post-septic CD4 T cells are highly glycolytic and exhibit a Th17 phenotype•Sepsis impairs the CD4 T cell recall response Physiology; Molecular biology; Immunology; Components of the immune system View Publication

The differentiation of effector CD8(+) T cells is a dynamically regulated process that varies during different infections and is influenced by the inflammatory milieu of the host. In this study,we define three signals regulating CD8(+) T cell responses during tuberculosis by focusing on cytokines known to affect disease outcome: IL-12,type I IFN,and IL-27. Using mixed bone marrow chimeras,we compared wild-type and cytokine receptor knockout CD8(+) T cells within the same mouse following aerosol infection with Mycobacterium tuberculosis. Four weeks postinfection,IL-12,type 1 IFN,and IL-27 were all required for efficient CD8(+) T cell expansion in the lungs. We next determined if these cytokines directly promote CD8(+) T cell priming or are required only for expansion in the lungs. Using retrogenic CD8(+) T cells specific for the M. tuberculosis Ag TB10.4 (EsxH),we observed that IL-12 is the dominant cytokine driving both CD8(+) T cell priming in the lymph node and expansion in the lungs; however,type I IFN and IL-27 have nonredundant roles supporting pulmonary CD8(+) T cell expansion. Thus,IL-12 is a major signal promoting priming in the lymph node,but a multitude of inflammatory signals converge in the lung to promote continued expansion. Furthermore,these cytokines regulate the differentiation and function of CD8(+) T cells during tuberculosis. These data demonstrate distinct and overlapping roles for each of the cytokines examined and underscore the complexity of CD8(+) T cell regulation during tuberculosis. View Publication