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27 result(s) for "Erwin, Megan M."
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Hallmarks of CD8+ T cell dysfunction are established within hours of tumor antigen encounter before cell division
Tumor-specific CD8+ T cells (TST) in patients with cancer are dysfunctional and unable to halt cancer progression. TST dysfunction, also known as exhaustion, is thought to be driven by chronic T cell antigen receptor (TCR) stimulation over days to weeks. However, we know little about the interplay between CD8 + T cell function, cell division and epigenetic remodeling within hours of activation. Here, we assessed early CD8 + T cell differentiation, cell division, chromatin accessibility and transcription in tumor-bearing mice and acutely infected mice. Surprisingly, despite robust activation and proliferation, TST had near complete effector function impairment even before undergoing cell division and had acquired hallmark chromatin accessibility features previously associated with later dysfunction/exhaustion. Moreover, continued tumor/antigen exposure drove progressive epigenetic remodeling, ‘imprinting’ the dysfunctional state. Our study reveals the rapid divergence of T cell fate choice before cell division in the context of tumors versus infection. Rudloff et al. examine the kinetics of CD8 + T cell dysfunction/exhaustion. Tumor-specific CD8 + T cells in the tumor environment exhibit epigenetic modifications within hours, before cell division. The findings suggest a temporal relationship between tumor antigen exposure, chromatin remodeling and dysfunction ‘imprinting’.
Vaccination generates functional progenitor tumor-specific CD8 T cells and long-term tumor control
BackgroundImmune checkpoint blockade (ICB) therapies are an important treatment for patients with advanced cancers; however, only a subset of patients with certain types of cancer achieve durable remission. Cancer vaccines are an attractive strategy to boost patient immune responses, but less is known about whether and how immunization can induce long-term tumor immune reprogramming and arrest cancer progression. We developed a clinically relevant genetic cancer mouse model in which hepatocytes sporadically undergo oncogenic transformation. We compared how tumor-specific CD8 T cells (TST) differentiated in mice with early sporadic lesions as compared with late lesions and tested how immunotherapeutic strategies, including vaccination and ICB, impact TST function and liver cancer progression.MethodsMice with a germline floxed allele of the SV40 large T antigen (TAG) undergo spontaneous recombination and activation of the TAG oncogene, leading to rare early cancerous TAG-expressing lesions that inevitably progress to established liver cancer. We assessed the immunophenotype (CD44, PD1, TCF1, and TOX expression) and function (TNFα and IFNγ cytokine production) of tumor/TAG-specific CD8 T cells in mice with early and late liver lesions by flow cytometry. We vaccinated mice, either alone or in combination with ICB, to test whether these immunotherapeutic interventions could stop liver cancer progression and improve survival.ResultsIn mice with early lesions, a subset of TST were PD1+ TCF1+ TOX− and could produce IFNγ while TST present in mice with late liver cancers were PD1+ TCF1lo/− TOX+ and unable to make effector cytokines. Strikingly, vaccination with attenuated TAG epitope-expressing Listeria monocytogenes (LMTAG) blocked liver cancer development and led to a population of TST that were PD1-heterogeneous, TCF1+ TOX− and polyfunctional cytokine producers. Vaccine-elicited TCF1+TST could self-renew and differentiate, establishing them as progenitor TST. In contrast, ICB administration did not slow cancer progression or improve LMTAG vaccine efficacy.ConclusionVaccination, but not ICB, generated a population of functional progenitor TST and halted cancer progression in a clinically relevant model of sporadic liver cancer. In patients with early cancers or at high risk of cancer recurrence, immunization may be the most effective strategy.
TCF1 lo CD8 T cells proliferate and persist autonomously in tumors
Cancers develop in humans over months to years, and tumor-specific CD8 T cells (TST) can interact with cancer cells throughout tumorigenesis. Nevertheless, the long-term population dynamics of TST, especially within progressing tumors, are not well understood. A paradigm first established in chronic viral infection and applied to tumors describes a population hierarchy among exhausted T cells. Progenitor/stem-like exhausted T cells, which express the transcription factor T cell factor 1 (TCF1), maintain the population through self-renewal and by giving rise to terminally differentiated TCF1 progeny. This has led to a focus on TCF1 T cells, and though TCF1 CD8 T cells are the predominant tumor-infiltrating/tumor-reactive subtype in patients, they have been largely overlooked. We leveraged our autochthonous liver cancer model to analyze TST differentiation and proliferation throughout tumorigenesis. Dual EdU/BrdU labeling studies revealed that throughout tumorigenesis, a subset of TCF1 TST in the liver stochastically entered and exited cell cycle, and at later time points there was no evidence of a TCF1 progenitor-like population. Moreover, TCF1-knockout TST proliferated and persisted robustly in tumors. Using liver cancer and melanoma models, we showed that tumor-resident TCF1 TST proliferate and persist autonomously, even when new TST influx into tumors is inhibited. The prevailing notion is that only TCF1 TST self-renew but we now demonstrate, using a clinically relevant mouse cancer model, that TCF1 TST stochastically proliferate to achieve long-term population maintenance. Future studies to understand and harness this mechanism to improve T cell persistence in tumors could lead to novel immunotherapies for patients with cancer.
Hallmarks of CD8 T cell dysfunction are established within hours of tumor antigen encounter prior to cell division
Tumor-specific CD8 T cells (TST) in patients with cancer are dysfunctional and unable to halt cancer progression. TST dysfunction, also known as exhaustion, is thought to be driven by chronic antigen/T cell receptor (TCR) stimulation over days to weeks. However, we know little about the interplay between CD8 T cell function, cell division, and epigenetic remodeling within hours of activation. Here, we assessed early CD8 T cell differentiation, cell division, chromatin accessibility, and transcription in tumor-bearing mice and acutely-infected mice. Surprisingly, despite robust activation and proliferation, TST had near complete effector function impairment even prior to undergoing cell division, and had acquired hallmark chromatin accessibility features previously associated with later dysfunction/exhaustion. Moreover, continued tumor/antigen exposure drove progressive epigenetic remodeling, “imprinting” the dysfunctional state. Our study reveals the rapid divergence of T cell fate choice prior to cell division in the context of tumors versus infection.
MDR1 promotes CD8 T cell persistence in tumors and protects against cytotoxic chemotherapy
Multidrug transporters, including multidrug resistance-1 (MDR1), are recognized chiefly for effluxing chemotherapeutic drugs out of tumor cells. However, they are also expressed in many normal cells and tissues, including lymphocytes, but their physiological role is less well-understood. Here, we investigated the role of MDR1 in tumor-specific CD8 T cells (TST), which are critical in antitumor immunity and key targets of immunotherapies. Using a clinically-relevant genetic liver cancer mouse model, we investigated the efflux dynamics of TST as they underwent activation, proliferation, and differentiation to dysfunctional states in tumor-bearing hosts. Surprisingly, we found that late-stage/terminally dysfunctional TST had the highest efflux capacity in both murine and human liver tumors. TST upregulated transcription of , encoding MDR1. We used CRISPR/Cas9 to generate MDR1-deficient TST, which persisted poorly in tumor-bearing mice as compared to MDR1-sufficient TST. MDR1 expression improved TST viability and reduced reactive oxygen species accumulation. Loss of MDR1 made T cells more susceptible to cytotoxic chemotherapy-induced cell death. Our findings demonstrate a role for MDR1 in regulating TST persistence and oxidative stress, with implications for antitumor T cell therapies in patients and immune regulation following cytotoxic chemotherapy.
Pre-division TCF1 drop determines long-term CD8 T cell fates
T Cell Factor 1 (TCF1) is a master transcription factor controlling T cell development and peripheral T cell differentiation during infection, cancer, and autoimmunity. TCF1 is highly expressed in naive CD8 T cells but must be downregulated as T cells proliferate to become effectors. If and how TCF1 plays a role during T cell priming prior to cell cycle entry is unknown. Surprisingly, we found that TCF1 expression is rapidly downregulated within hours after antigen encounter in both murine and human CD8 T cells, even before T cells enter cell cycle. TCF1 then rebounds to high levels upon cell cycle entry, ultimately declining again with proliferation and effector differentiation. This rapid pre-division drop and rebound occurs in diverse settings, including infection and cancer. The magnitude of the pre-division TCF1 drop is modulated by TCR signal strength and inflammatory cytokines and strikingly, regulates long-term effector and memory fates. Paired transcriptomic and epigenetic analyses revealed that TCF1-regulated chromatin regions were remodeled within hours following antigen encounter, activating effector and inflammatory cytokine signaling modules and poising T cells for effector differentiation. Remarkably, transient siRNA-mediated TCF1 downmodulation during the pre-division priming phase was sufficient to induce long-term population effector skewing. We have uncovered a novel mechanism whereby pre-division dynamic TCF1 regulation determines long-term CD8 T cell fate commitment, potentially serving as a critical checkpoint regulating T cell responses in infection, cancer, and autoimmunity.
Vaccination generates functional progenitor tumor-specific CD8 T cells and long-term tumor control
Immune checkpoint blockade (ICB) therapies are an important treatment for patients with advanced cancers; however only a subset of patients with certain types of cancer achieves durable remissions. Cancer vaccines are an attractive strategy to boost patient immune responses, but less is known about whether and how immunization can induce long-term tumor immune reprogramming and arrest cancer progression. We developed a clinically-relevant genetic cancer mouse model in which hepatocytes sporadically undergo oncogenic transformation. We compared how tumor-specific CD8 T cells (TST) differentiate in mice with early sporadic lesions as compared to late lesions and tested how immunotherapeutic strategies, including vaccination and ICB, reprogram TST and impact liver cancer progression. Mice with a germline floxed allele of the SV40 large T antigen (TAG) undergo spontaneous recombination and activation of the TAG oncogene, leading to rare early pre-cancerous lesions that inevitably progress to established liver cancer. We assessed the immunophenotype and function of TAG-specific CD8 T cells in mice with early and late liver lesions. We vaccinated mice, either alone or in combination with ICB, to test whether these immunotherapeutic interventions could stop liver cancer progression. In mice with early lesions, a subset of TST were PD1 TCF1 TOX and could produce IFNγ, while TST present in mice with late liver cancers were PD1 TCF1 TOX and unable to make effector cytokines. Strikingly, vaccination with attenuated TAG epitope-expressing (LM ) blocked liver cancer development and led to a population of TST that were TCF1 TOX TST and polyfunctional cytokine producers. In contrast, ICB administration did not slow cancer progression or improve LM vaccine efficacy. Vaccination, but not ICB, generated a population of progenitor TST and halted cancer progression in a clinically relevant model of sporadic liver cancer. In patients with early cancers or at high-risk of cancer recurrence, immunization may be the most effective strategy. Immunotherapy, including immune checkpoint blockade and cancer vaccines, fails to induce long-term remissions in most patients with cancer. Hosts with early lesions but not hosts with advanced cancer retain a progenitor TCF1+ TST population. This population can be reprogrammed and therapeutically exploited by vaccination, but not ICB, to block tumor progression. For people at high-risk of cancer progression, vaccination administered when a responsive progenitor TST population is present may be the optimal immunotherapy to induce long-lasting progression-free survival.
TCF1lo CD8 T cells proliferate and persist autonomously in tumors
Cancers develop in humans over months to years, and tumor-specific CD8 T cells (TST) can interact with cancer cells throughout tumorigenesis. Nevertheless, the long-term population dynamics of TST, especially within progressing tumors, are not well understood. A paradigm first established in chronic viral infection and applied to tumors describes a population hierarchy among exhausted T cells. Progenitor/stem-like exhausted T cells, which express the transcription factor T cell factor 1 (TCF1), maintain the population through self-renewal and by giving rise to terminally differentiated TCF1lo progeny. This has led to a focus on TCF1hi T cells, and though TCF1lo CD8 T cells are the predominant tumor-infiltrating/tumor-reactive subtype in patients, they have been largely overlooked. We leveraged our autochthonous liver cancer model to analyze TST differentiation and proliferation throughout tumorigenesis. Dual EdU/BrdU labeling studies revealed that throughout tumorigenesis, a subset of TCF1lo TST in the liver stochastically entered and exited cell cycle, and at later time points there was no evidence of a TCF1hi progenitor-like population. Moreover, TCF1-knockout TST proliferated and persisted robustly in tumors. Using liver cancer and melanoma models, we showed that tumor-resident TCF1lo TST proliferate and persist autonomously, even when new TST influx into tumors is inhibited. The prevailing notion is that only TCF1hi TST self-renew but we now demonstrate, using a clinically relevant mouse cancer model, that TCF1lo TST stochastically proliferate to achieve long-term population maintenance. Future studies to understand and harness this mechanism to improve T cell persistence in tumors could lead to novel immunotherapies for patients with cancer.Competing Interest StatementThe authors have declared no competing interest.Funder Information DeclaredNational Institute of Arthritis and Musculoskeletal and Skin Diseases, T32AR059039National Institute of General Medical Sciences, https://ror.org/04q48ey07, T32GM008554, T32GM007347American Society of Hematology, https://ror.org/02nw48b86, ASH Medical Student Physician-Scientist AwardV Foundation, V Foundation Scholar AwardNational Institute of Diabetes and Digestive and Kidney Diseases, https://ror.org/00adh9b73, P30DK058404National Cancer Institute, T32CA009592, R37CA263614, P30CA068485
The Efficacy of Resiliency Training Programs: A Systematic Review and Meta-Analysis of Randomized Trials
Poor mental health places a burden on individuals and populations. Resilient persons are able to adapt to life's challenges and maintain high quality of life and function. Finding effective strategies to bolster resilience in individuals and populations is of interest to many stakeholders. To synthesize the evidence for resiliency training programs in improving mental health and capacity in 1) diverse adult populations and 2) persons with chronic diseases. Electronic databases, clinical trial registries, and bibliographies. We also contacted study authors and field experts. Randomized trials assessing the efficacy of any program intended to enhance resilience in adults and published after 1990. No restrictions were made based on outcome measured or comparator used. Reviewers worked independently and in duplicate to extract study characteristics and data. These were confirmed with authors. We conducted a random effects meta-analysis on available data and tested for interaction in planned subgroups. The standardized mean difference (SMD) effect of resiliency training programs on 1) resilience/hardiness, 2) quality of life/well-being, 3) self-efficacy/activation, 4) depression, 5) stress, and 6) anxiety. We found 25 small trials at moderate to high risk of bias. Interventions varied in format and theoretical approach. Random effects meta-analysis showed a moderate effect of generalized stress-directed programs on enhancing resilience [pooled SMD 0.37 (95% CI 0.18, 0.57) p = .0002; I2 = 41%] within 3 months of follow up. Improvement in other outcomes was favorable to the interventions and reached statistical significance after removing two studies at high risk of bias. Trauma-induced stress-directed programs significantly improved stress [-0.53 (-1.04, -0.03) p = .03; I2 = 73%] and depression [-0.51 (-0.92, -0.10) p = .04; I2 = 61%]. We found evidence warranting low confidence that resiliency training programs have a small to moderate effect at improving resilience and other mental health outcomes. Further study is needed to better define the resilience construct and to design interventions specific to it. PROSPERO #CRD42014007185.
Increased Use of Prophylactic Measures in Preventing Post-Endoscopic Retrograde Cholangiopancreatography Pancreatitis
BackgroundNonsteroidal anti-inflammatory drugs (NSAIDs), pancreatic duct stenting, and intensive intravenous hydration have been proven to prevent post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis. Trial participation and guideline changes demanded an assessment of the clinical practice of post-ERCP pancreatitis prophylaxis.AimsThe surveys aim to identify points of improvement to inform and educate ERCPists about current evidence-based practice.MethodsTwo anonymous surveys were conducted among Dutch gastroenterologists in 2013 (n = 408) and 2020 (n = 575) for longitudinal views and attitudes pertaining to post-ERCP pancreatitis prophylaxis and recognition of post-ERCP pancreatitis risk factors.ResultsIn 2013 and 2020, respectively, 121 and 109 ERCPists responded. In the 2013 survey, 98% of them utilized NSAID prophylaxis and 62% pancreatic duct stent prophylaxis in specific cases. In the 2020 survey, the use of NSAIDs (100%), pancreatic duct stents (78%), and intensive intravenous hydration (33%) increased among ERCPists. NSAID prophylaxis was the preferred prophylactic measure for all risk factors in the 2020 survey, except for ampullectomy, pancreatic duct contrast injection, and pancreatic duct cannulation, for which NSAID prophylaxis and pancreatic duct stent combined was equally favored or preferred.ConclusionRectal NSAIDs are the most applied post-ERCP pancreatitis prophylaxis in the Netherlands, followed by pancreatic duct stents and intensive intravenous hydration. Additionally, there is reason to believe that recent guideline updates and active research participation have led to increased prophylaxis implementation.