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Rudloff, M. W.

Publications and source records attributed to Rudloff, M. W..

3 recordsLinked to original sources

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. SYNOPSISWe show that tumor-specific T cells with little/no expression of TCF1, previously considered incapable of self-renewal, can proliferate stochastically and persist long-term. As TCF1lo CD8 T cells are often the predominant tumor-reactive T cells found in tumors, future studies should be aimed at reprogramming these proliferating T cells within tumors.

immunology↗

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.

immunology↗

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 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. 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 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. ResultsIn mice with early lesions, a subset of TST were PD1+ TCF1+ TOX- and could produce IFN{gamma}, 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 TCF1+ TOX- TST and polyfunctional cytokine producers. In contrast, ICB administration did not slow cancer progression or improve LMTAG vaccine efficacy. ConclusionVaccination, 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. What is already known on this topicImmunotherapy, including immune checkpoint blockade and cancer vaccines, fails to induce long-term remissions in most patients with cancer. What this study addsHosts 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. How this study might affect research, practice, or policyFor 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.

cancer biology↗