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Willis, C.

Publications and source records attributed to Willis, C..

8 recordsLinked to original sources

TMEM33 deletion potentiates anti-tumor CD8+ T cell immunity

Improving responses to cancer immunotherapies requires deeper insight into the cellular mechanisms governing T cell-mediated anti-tumor immunity. TMEM33 is an endoplasmic reticulum-resident transmembrane protein enriched across multiple tumor types, with reported functions in anti-viral immunity as well as calcium and lipid homeostasis, yet its role in tumor immunosurveillance remains unknown. Using murine genetic models, we demonstrate that host TMEM33 constrains anti-tumor CD8+ T cell responses. Constitutive Tmem33-/- mice exhibited delayed melanoma tumor growth and increased CD8+ T cell infiltration. Antigen-specific CD8+ compartments in tumors of Tmem33-/- mice showed TCF-1+PD-1+ progenitor-exhausted cell (Tpex) enrichment, elevated effector function and reduced exhaustion, alongside improved effector memory expansion and T-bet expression in draining lymph nodes. We highlight that TMEM33 functions intrinsically within the T cell compartment, as TMEM33 deletion (1) enhanced polyclonal activation of naive CD8+ T cells ex vivo, (2) promoted preferential Tpex accumulation among adoptively transferred naive OT-I cells in B16F10-OVA tumors and draining lymph nodes, and (3) improved the potency of ex vivo-expanded OT-I cells in controlling tumor growth during adoptive cell therapy. Finally, in a large, prospectively recruited metastatic melanoma cohort, lower TMEM33 expression in patient CD8+ T cells significantly correlated with improved survival and elevated TCF-7 (encoding TCF-1). Collectively, our findings define TMEM33 as a formerly unrecognized intrinsic determinant of tumor-directed CD8+ T cell fate that limits Tpex maintenance, and restrains cell therapy responses, suggesting that its modulation may strengthen immunotherapeutic efficacy. One sentence summaryTMEM33 intrinsically limits progenitor exhausted CD8+ T cells, scales anti-tumor responses and predicts melanoma patient survival.

immunology↗

Chronic alcohol intake elicits distinct multi-omic profiles in the liver versus skeletal muscle of mice

Alcohol-related liver disease and alcohol-related myopathy are widespread consequences of chronic alcohol use. However, understanding of the associated molecular mechanisms and effective treatments remains limited. To address this, we employed multi-omics to uncover molecular blueprints of liver versus skeletal muscle responses to chronic alcohol exposure, using a pre-clinical mouse model showing signs of alcohol-related liver dysregulation (diminished liver phosphatidylcholine-to-phosphatidylethanolamine lipid ratio) and alcohol-related myopathy (reduced muscle mass and strength). We found that the liver was more sensitive to chronic alcohol than muscle across the transcriptome, proteome and metabolome levels, but both tissues were equally sensitive at the lipidome level. The liver displayed an extensive and multi-layered metabolic molecular profile, while muscle was associated with upregulated inflammatory and matrisome responses and impaired mitochondrial energetics. Lipidome analyses also revealed a novel potential role for altered phospholipid remodelling in the aetiology of alcohol-related myopathy. Finally, computational drug repurposing identified several compounds for therapeutic targeting of alcohol-induced liver (e.g., saracatinib, GSK126) and muscle (e.g., metformin, trichostatin A) pathophysiology, perhaps working partly to counter metabolic dysregulation. Overall, our study provides a tractable list of therapeutic targets and treatments to help expedite the understanding of and countermeasures against alcohol-related liver disease and alcohol-related myopathy in humans.

bioinformatics↗

Dark Microglia Are Abundant in Normal Postnatal Development, where they Remodel Synapses via Phagocytosis and Trogocytosis, and Are Dependent on TREM2

This study examined dark microglia--a state linked to central nervous system pathology and neurodegeneration--during postnatal development in the mouse ventral hippocampus, finding that dark microglia interact with blood vessels and synapses and perform trogocytosis of pre-synaptic axon terminals. Furthermore, we found that dark microglia in development notably expressed C-type lectin domain family 7 member A (CLEC7a), lipoprotein lipase (LPL) and triggering receptor expressed on myeloid cells 2 (TREM2) and required TREM2, differently from other microglia, suggesting a link between their role in remodeling during development and central nervous system pathology. Together, these results point towards a previously under-appreciated role for dark microglia in synaptic pruning and plasticity during normal postnatal development.

neuroscience↗

Integrative single-cell analysis of neural stem/progenitor cells reveals epigenetically dysregulated interferon response in progressive multiple sclerosis

Progressive multiple sclerosis (PMS) is characterized by a primary smouldering pathological disease process associated with a superimposed inflammatory activity. Cellular and molecular processes sustaining the pathobiology of PMS remain to be identified. We previously discovered senescence signatures in neural stem/progenitor cells (NSCs) from people with PMS. Applying direct reprogramming to generate directly induced NSCs (iNSCs) from somatic fibroblasts, we retain epigenetic information and observe hypomethylation of genes associated with lipid metabolic processes and IFN signalling only in PMS lines. Single-cell/nucleus transcriptomic and epigenetic profiling reveal an inflammatory, senescent-like, IFN-responsive radial glia (RG)-like cell subcluster mainly in PMS iNSCs that is driven by IFN-associated transcription factors. Lastly, we identify a population of senescent, IFN-responsive, disease-associated RG-like cells (DARGs) in the PMS brain that share pseudotime trajectories with iNSCs in vitro. We describe the existence of a non-neurogenic, dysfunctional DARG population that has the potential to fuel smouldering inflammation in PMS.

neuroscience↗

Rapid establishment of a tumor-retained state curtails the contribution of conventional NK cells to anti-tumor immunity in solid cancers

Immune cell dysfunction within the tumor microenvironment undermines the control of cancer progression. NK cells play critical roles in limiting early tumor growth and metastatic disease, however, established cancers contain a phenotypically distinct, tumor-specific NK cell compartment. The temporal dynamics, mechanistic underpinning and functional significance of this tumor NK pool remains incompletely understood. To address this, we exploited photo-labeling, combined with longitudinal transcriptomic and cellular analyses, to interrogate the fate of NK cells after tumor entry. In multiple murine cancer models we reveal that conventional NK cells are continuously recruited into tumors, but rapidly adopt a distinct phenotypic state with features associated with tissue-residency and complete loss of effector functions (including chemokine and cytokine production and cytotoxicity), within 48-72 hrs of entering the tumor. Depletion of NK cells from established tumors did not alter tumor growth, indicating that intratumoral NK cells cease to actively contribute to anti- tumor responses. Furthermore, comparable NK populations were identified in human colorectal cancers, confirming translational relevance and raising the possibility that interventions to reactivate NK cells within tissues may boost anti-tumor immunity in established cancers. Indeed, administration of IL-15:IL-15Ra complexes prevented the loss of NK cell function and improved tumor control, generating intratumoral NK cells with both enhanced tissue-residency characteristics and effector function. Collectively, our data reveals the fate of cNK cells after recruitment into tumors and provides insight into how intratumoral NK cell functions may be revived. SummaryConventional NK cells recruited from the circulation rapidly establish a tissue-resident phenotype defined by impaired cytotoxicity and chemokine production after tumor entry; administration of IL- 15:IL-15R complexes further promotes this tissue-residency programme but maintains core NK cell effector functions within the tumor.

immunology↗

Time-, tissue- and treatment-associated heterogeneity in tumour-residing migratory DCs

Tumour dendritic cells (DCs) internalise antigen and upregulate CCR7, which directs their migration to tumour-draining lymph nodes (dLN). CCR7 expression is coupled to a maturation programme enriched in regulatory molecule expression, including PD-L1, termed mRegDC. However, the spatio- temporal dynamics and role of mRegDCs in anti-tumour immune responses remain unclear. Using photoconvertible mice to precisely track DC migration, we found that mRegDCs were the dominant DC population arriving in the dLN, but a subset remained tumour-resident despite CCR7 expression. These tumour-retained mRegDCs were phenotypically and transcriptionally distinct from their dLN counterparts and were heterogeneous. Specifically, they demonstrated a progressive reduction in the expression of antigen presentation and pro-inflammatory transcripts with more prolonged tumour dwell-time. Tumour mRegDCs spatially co-localised with PD-1+CD8+ T cells in human and murine solid tumours. Following anti-PD-L1 treatment, tumour-residing mRegDCs adopted a state enriched in lymphocyte stimulatory molecules, including OX40L, which was capable of augmenting anti- tumour cytolytic activity. Altogether, these data uncover previously unappreciated heterogeneity in mRegDCs that may underpin a variable capacity to support intratumoural cytotoxic T cells, and provide insights into their role in cancer immunotherapy.

immunology↗

Radioactive Contamination in Feral Dogs in the Chernobyl Exclusion Zone: Population Body-Burden Survey and Implications for Human Radiation Exposure

This report describes a two-year effort to survey the internal 137Cs and external {beta}-emitter contamination present in the feral dog population near the Chernobyl nuclear power plant (ChNPP) site, and to quantify the potential for human radiation exposure from this contamination. This work was performed as an integral part of the radiation safety and control procedures of an animal welfare oriented trap-neuter-release (TNR) program. The measurement program employed handheld {beta}-sensitive probes, and a simple whole-body counter to measure internal 137Cs burden during post-surgical observation and recovery. External {beta} contamination surveys performed during intake showed that 21/288 animals had significant, removable external contamination. Measurements with the whole-body counter indicated internal 137Cs body burdens ranging from undetectable (minimum detection level [~]100 Bq/kg in 2017, [~] 30 Bq/kg in 2018) to approximately 30,000 Bq/kg. A total of 33 animals had 137Cs body-burdens above 1 kBq/kg. We observe that internal contamination levels are positively correlated with capture locations within ChNPP boundaries. The large variation in the 137Cs concentration in these animals is not well-understood, could be due to prey selection, access to human food scraps, or extended residence in highly contaminated areas. These internally-contaminated animals are unlikely to pose an exposure hazard despite their large body-burdens due to their limited exposure to humans. However, the small minority of animals with external contamination may pose a contamination hazard to workers, tourists, and others interacting with the dogs, as evidenced by total quantity of removable activity and incidents of transfer to materials used in animal capture.

zoology↗

Landscape and Selection of Vaccine Epitopes in SARS-CoV-2

There is an urgent need for a vaccine with efficacy against SARS-CoV-2. We hypothesize that peptide vaccines containing epitope regions optimized for concurrent B cell, CD4+ T cell, and CD8+ T cell stimulation would drive both humoral and cellular immunity with high specificity, potentially avoiding undesired effects such as antibody-dependent enhancement (ADE). Additionally, such vaccines can be rapidly manufactured in a distributed manner. In this study, we combine computational prediction of T cell epitopes, recently published B cell epitope mapping studies, and epitope accessibility to select candidate peptide vaccines for SARS-CoV-2. We begin with an exploration of the space of possible T cell epitopes in SARS-CoV-2 with interrogation of predicted HLA-I and HLA-II ligands, overlap between predicted ligands, protein source, as well as concurrent human/murine coverage. Beyond MHC affinity, T cell vaccine candidates were further refined by predicted immunogenicity, viral source protein abundance, sequence conservation, coverage of high frequency HLA alleles and co-localization of CD4+ and CD8+ T cell epitopes. B cell epitope regions were chosen from linear epitope mapping studies of convalescent patient serum, followed by filtering to select regions with surface accessibility, high sequence conservation, spatial localization near functional domains of the spike glycoprotein, and avoidance of glycosylation sites. From 58 initial candidates, three B cell epitope regions were identified. By combining these B cell and T cell analyses, as well as a manufacturability heuristic, we propose a set of SARS-CoV-2 vaccine peptides for use in subsequent murine studies and clinical trials. O_FIG O_LINKSMALLFIG WIDTH=180 HEIGHT=200 SRC="FIGDIR/small/135004v1_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@1fc6599org.highwire.dtl.DTLVardef@1725a45org.highwire.dtl.DTLVardef@84a233org.highwire.dtl.DTLVardef@1b4c7aa_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗