Biology subjects

Wolf, M. M.

Publications and source records attributed to Wolf, M. M..

9 recordsLinked to original sources

bioRxiv2025

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↗

bioRxiv2025

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 Abcb1a, 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.

immunology↗

bioRxiv2025

Impaired oxidative phosphorylation drives primary tumor escape and metastasis

Metastasis causes most cancer deaths and reflects transitions from primary tumor escape to seeding and growth at metastatic sites. Epithelial-to-mesenchymal transition (EMT) is important early in metastasis to enable cancer cells to detach from neighboring cells, become migratory, and escape the primary tumor. While different phases of metastasis expose cells to variable nutrient environments and demands, the metabolic requirements and plasticity of each step are uncertain. Here we show that EMT and primary tumor escape are stimulated by disrupted oxidative metabolism. Using Renal Cell Carcinoma (RCC) patient samples, we identified the mitochondrial electron transport inhibitor NDUFA4L2 as upregulated in cells undergoing EMT. Deletion of NDUFA4L2 enhanced oxidative metabolism and prevented EMT and metastasis while NDUFA4L2 overexpression enhanced these processes. Mechanistically, NDUFA4L2 suppressed oxidative phosphorylation and caused citric acid cycle intermediates to accumulate, which modified chromatin accessibility of EMT-related loci to drive primary tumor escape. The effect of impaired mitochondrial metabolism to drive EMT appeared general, as renal cell carcinoma patient tumors driven by fumarate hydratase mutations with disrupted oxidative phosphorylation were highly metastatic and also had robust EMT. These findings highlight the importance of dynamic shifts in metabolism for cell migration and metastasis, with mitochondrial impairment driving early phases of this process. Understanding mitochondrial dynamics may have important implications in both basic and translational efforts to prevent cancer deaths.

cancer biology↗

bioRxiv2023

Tissue-Specific Dependence of Th1 Cells on the Amino Acid Transporter SLC38A1 in Inflammation

Amino acid (AA) uptake is essential for T cell metabolism and function, but how tissue sites and inflammation affect CD4+ T cell subset requirements for specific AA remains uncertain. Here we tested CD4+ T cell AA demands with in vitro and multiple in vivo CRISPR screens and identify subset- and tissue-specific dependencies on the AA transporter SLC38A1 (SNAT1). While dispensable for T cell persistence and expansion over time in vitro and in vivo lung inflammation, SLC38A1 was critical for Th1 but not Th17 cell-driven Experimental Autoimmune Encephalomyelitis (EAE) and contributed to Th1 cell-driven inflammatory bowel disease. SLC38A1 deficiency reduced mTORC1 signaling and glycolytic activity in Th1 cells, in part by reducing intracellular glutamine and disrupting hexosamine biosynthesis and redox regulation. Similarly, pharmacological inhibition of SLC38 transporters delayed EAE but did not affect lung inflammation. Subset- and tissue-specific dependencies of CD4+ T cells on AA transporters may guide selective immunotherapies. HIGHLIGHTSO_LIT cells dynamically regulate glutamine amino acid transporters when activated C_LIO_LISLC38A1 supports Th1 cell mTORC1 and proliferation by redox and hexosamine pathways C_LIO_LITargeting SLC38A1 does not affect lung inflammation but delays IBD and EAE C_LIO_LINutrient transporter needs of T cell subsets vary based on disease and tissue site C_LI

immunology↗

bioRxiv2023

Androgen Signaling Restricts Glutaminolysis to Drive Sex-Specific Th17 Metabolism

Females have increased prevalence of many Th17-mediated diseases. While androgen signaling decreases Th17-mediated inflammation, the mechanisms are not fully understood. Th17 cells rely on glutaminolysis; however, it remains unclear whether androgen receptor (AR) signaling in males modifies glutamine metabolism to suppress Th17-mediated inflammation. We show that Th17 cells from male humans and mice had decreased glutaminolysis compared to females, and AR signaling attenuated Th17 cell mitochondrial respiration and glutaminolysis. Using allergen-induced airway inflammation models, we determined females, but not males, had a critical reliance upon glutaminolysis for Th17-mediated airway inflammation, and AR signaling attenuated glutamine uptake by reducing expression of glutamine transporters. These findings were confirmed in circulating human Th17 cells with minimal reliance on glutamine uptake in male compared to female Th17 cells. We found that AR signaling attenuates glutaminolysis, demonstrating sex-specific metabolic regulation of Th17 cells with implications for design and implementation of Th17 or glutaminolysis targeted therapeutics. HighlightsO_LIHuman male CD4+ T cells have decreased expression of metabolic enzymes and decreased reliance on glutaminolysis compared to female CD4+ T cells. C_LIO_LIAndrogen signaling decreased mitochondrial metabolism in Th17 cells and decreased airway inflammation. C_LIO_LIAndrogen signaling decreased glutamine uptake and utilization in Th17 cells. C_LI

immunology↗

bioRxiv2022

PD-1 is induced on tumor-associated macrophages in obesity to directly restrain anti-tumor immunity

Obesity is a leading risk factor for progression and metastasis of many cancers1,2, yet can also promote improved survival for some cancers3-5 and enhance responses to some immune checkpoint blockade therapies6-8. The role of the immune system in the obesity-cancer connection and how obesity influences immunotherapy, however, remain unclear. While PD-1 expression by macrophages has been described9-12, we found that obesity selectively induced PD-1 on macrophages and that PD-1 directly impaired macrophage function. Single cell RNA sequencing of murine colorectal carcinoma tumors showed obesity remodeled myeloid and T cell populations, with fewer clonally expanded effector T cells and increased abundance of PD-1+ tumor-associated macrophages (TAM). Cytokines and molecules associated with obesity, including IL-6, leptin, and insulin, and the unsaturated fatty acid palmitate, induced PD-1 expression on macrophages in a glycolysis-dependent manner. PD-1+ TAMs had increased mitochondrial respiration and expression of genes regulating oxidative phosphorylation, lipid uptake and cell cycle while PD-1- TAMs showed greater signatures of phagocytosis and antigen presentation to T cells. These patterns were directly regulated by PD-1, as recombinant PD-L1 reduced macrophage glycolysis and phagocytic capacity, and this was reversed with blocking PD-1 antibody. Conversely, PD-1-deficient Pdcd1-/- TAMs had high rates of glycolysis, phagocytosis, and expression of MHC-II. Myeloid-specific PD-1 deficiency correlated with slower tumor growth, enhanced TAM antigen presentation capability, and increased CD8 T cell activation together with reduced markers of exhaustion. These findings show metabolic signaling in obesity induces PD-1-mediated suppression of TAM function and reveal a unique macrophage-specific mechanism to modulate immune tumor surveillance and checkpoint blockade. This may contribute to increased cancer risk yet improved response to PD-1 blockade in TAM-enriched tumors and obesity.

immunology↗

bioRxiv2022

ACSS2 Regulates HIF-2α Degradation through the E3-Ubiquitin Ligase MUL1 in Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC) is an aggressive kidney cancer driven by VHL loss and aberrant HIF-2 signaling. Acetate metabolism may contribute to this axis by ACSS2-dependent acetylation of HIF-2 and may provide opportunities to intervention. Here we tested the effects of pharmacological and genetic manipulation of ACSS2 on HIF-2, ccRCC cells, and tumors. ACSS2 inhibition led to HIF-2 degradation and suppressed ccRCC growth in vitro, in vivo, and in primary cell cultures of ccRCC patient tumors. This treatment resulted in reduced glucose and cholesterol metabolism, mitochondrial biogenesis and altered cristae deformation, that are consistent with loss of HIF-2. Mechanistically, HIF-2 protein levels are regulated through proteolytic degradation and we found, in parallel to VHL, HIF-2 stability was dependent on ACSS2 activity to prevent direct interaction with the E3 ligase MUL1. These findings highlight ACSS2 as a critical upstream regulator of HIF-2 that may be exploited to overcome resistance to HIF-2 inhibitor therapies. STATEMENT OF SIGNIFICANCEWe have unveiled ACSS2 as a critical upstream regulator of HIF-2 in ccRCC. Targeting ACSS2 potently promotes HIF-2 degradation via MUL1 to effectively deplete mitochondrial activity and block ccRCC primary tumor models and growth models resistant to HIF-2 inhibitor therapy.

cancer biology↗

bioRxiv2021

MTHFD2 is a Metabolic Checkpoint Controlling Effector and Regulatory T Cell Fate and Function

Antigenic stimulation promotes T cells metabolic reprogramming to meet increased biosynthetic, bioenergetic, and signaling demands. We show that the one-carbon (1C) metabolism enzyme Methylenetetrahydrofolate Dehydrogenase-2 (MTHFD2) is highly expressed in inflammatory diseases and induced in activated T cells to promote proliferation and produce inflammatory cytokines. In pathogenic Th17 cells, MTHFD2 also prevented aberrant upregulation of FoxP3 and suppressive capacity. Conversely, MTHFD2-deficiency enhanced lineage stability of regulatory T (Treg) cells. Mechanistically, MTHFD2 maintained cellular 10-formyltetrahydrofolate for de novo purine synthesis and MTHFD2 inhibition led to accumulation of the intermediate 5-aminoimidazole carboxamide ribonucleotide that was associated with decreased mTORC1 signaling. MTHFD2 was also required for proper histone de-methylation in Th17 cells. Importantly, inhibiting MTHFD2 in vivo reduced disease severity in Experimental Autoimmune Encephalomyelitis and Delayed-Type Hypersensitivity. MTHFD2 induction is thus a metabolic checkpoint for pathogenic effector cells that suppresses anti-inflammatory Treg cells and is a potential therapeutic target within 1C metabolism.

immunology↗

bioRxiv2020

Cell Programmed Nutrient Partitioning in the Tumor Microenvironment

The tumor microenvironment (TME) includes transformed cancer and infiltrating immune cells1,2. Cancer cells can consume large quantities of glucose through Warburg metabolism3,4 that can be visualized with positron emission tomography (PET). While infiltrating immune cells also rely on glucose, disruptions to metabolism can contribute to tumor immunological evasion5-9. How immune cell metabolism is programmed or restrained by competition with cancer cells for nutrients, remains uncertain. Here we used PET tracers to measure the accessibility of glucose and glutamine to cell subsets in the TME. Surprisingly, myeloid cells including macrophages were the greatest consumers of intra-tumoral glucose, followed by T cells and cancer cells. Cancer cells, in contrast, had the highest glutamine uptake. This distinct nutrient partitioning was programmed through selective mTORC1 signaling and glucose or glutamine-related gene expression. Inhibition of glutamine uptake enhanced glucose uptake across tumor resident cell types and shifted macrophage phenotype, demonstrating glucose is not limiting in the TME. Thus, cancer cells are not the only cells in tumors which exhibit high glucose uptake in vivo and instead preferentially utilize glutamine over other cell types. We observe that intrinsic cellular programs can play a major role in the use of some nutrients. Together, these data argue cell selective partitioning of glucose and glutamine can be exploited to develop therapies and imaging strategies to alter the metabolic programs of specific cell populations in the TME.

cancer biology↗