Epigenetic scarring of terminally dysfunctional (TDysf) CD8+ T cells hinders long-term protection and response to immune checkpoint blockade during chronic infections and cancer. We developed a faithful in vitro model for CD8+ T cell terminal dysfunction as a platform to advance T cell immunotherapy. Using TCR-transgenic CD8+ T cells, we found that 1-week peptide stimulation, mimicking conditions in previous models, failed to induce a stable exhaustion program. In contrast, prolonged stimulation for 2–3 weeks induced T cell dysfunction but triggered activation-induced cell death, precluding long-term investigation of exhaustion programs. To better mimic in vivo exhaustion, we provided post-effector, chronic TGF-β1 signals, enabling survival of chronically stimulated CD8+ T cells for over 3 weeks. These conditions induced a state of terminal dysfunction, marked by a stable loss of effector, cytotoxicity, and memory programs, along with mitochondrial stress and impaired protein translation. Importantly, transcriptomic and epigenetic analyses verified the development of terminal exhaustion-specific signatures in TDysf cells. Adoptive transfer of TDysf cells revealed their inability to recall effector functions or proliferate after acute lymphocytic choriomeningitis virus rechallenge. This tractable model system enables investigation of molecular pathways driving T cell terminal dysfunction and discovery of therapeutic targets for cancer or chronic infections.
Amir Yousif, Abbey A. Saadey, Ava Lowin, Asmaa M. Yousif, Ankita Saini, Madeline R. Allison, Kelley Ptak, Eugene M. Oltz, Hazem E. Ghoneim
BACKGROUND. Cardiotoxicity is a major complication of anti-cancer therapy (CTx); yet, the impact of CTx on the human microcirculation is not well defined. This study evaluated the impact of CTx on microvascular function in breast cancer patients. METHODS. Endothelial function and angiogenic potential were assessed in arterioles and adipose biopsies obtained from breast cancer patients before, during, and after CTx (longitudinal and cross-sectional) and in healthy arterioles exposed to doxorubicin (Dox), trastuzumab (TZM), or paclitaxel (PTX) ex vivo. Conditioned media containing VEGF-B protein was used to test feasibility of a targeted intervention. RESULTS. Patients treated with Dox and/or TZM in vivo developed profound microvascular endothelial dysfunction that persisted for ≥9 months after treatment cessation. Angiogenic potential was reduced during CTx and recovered within one month after cessation. Gene expression related to angiogenesis and inflammation changed over the course of clinical treatment. Isolated adipose arterioles from healthy donors developed endothelial dysfunction when exposed to Dox or TZM ex vivo. In contrast, paclitaxel (PTX), which poses minimal cardiovascular risk, had no impact on vasomotor function. Ex vivo exposure to Dox or PTX suppressed angiogenic potential, whereas TZM had no effect. Treatment with VEGF-B protein preserved endothelial function in healthy arterioles exposed to Dox or TZM ex vivo. CONCLUSION. Breast cancer patients undergoing treatment with Dox and/or TZM develop prolonged microvascular endothelial dysfunction that is recapitulated in healthy arterioles exposed to Dox or TZM ex vivo. Targeted intervention with VEGF-B protects against direct Dox- or TZM-induced vascular toxicity in human arterioles ex vivo. FUNDING. National Institutes of Health grant R01 HL133029, HL173549 (AMB). National Institutes of Health grant T32 HL134643 (JDT, STH). American Heart Association grant SFRN847970 (AMB, DDG). We Care Foundation Grant (AMB, ALK). Medical College of Wisconsin Cardiovascular Center Pre-PPG Grant (AMB). Advancing a Healthier Wisconsin – Redox Biology Grant (AMB). Jenny and Antti Wihuri Foundation (RMK).
Janée D. Terwoord, Laura E. Norwood Toro, Shelby N. Hader, Stephen T. Hammond, Joseph C. Hockenberry, Jasmine Linn, Ibrahim Y. Vazirabad, Amanda L. Kong, Alison J. Kriegel, Ziqing Liu, Riikka M. Kivelä, Gillian Murtagh, David D. Gutterman, Andreas M. Beyer
Glioblastoma IDH-wildtype is the most common and aggressive primary brain tumor in adults, with poor prognosis despite current therapies. To identify new therapeutic vulnerabilities, we investigated the role of CDK12, a transcription-associated cyclin-dependent kinase, in glioblastoma. Genetic or pharmacologic inactivation of CDK12 impaired tumor growth in patientderived xenograft (PDX) models and enhanced the efficacy of temozolomide. Metabolic profiling using extracellular flux analysis and stable isotope tracing with U-¹³C-glucose and U-¹³Cglutamine showed that CDK12 inhibition disrupted mitochondrial respiration, resulting in energy depletion and apoptotic cell death characterized by caspase activation and Noxa induction. Mechanistically, we identified a direct interaction between CDK12 and GSK3β. CDK12 inhibition activated GSK3β, leading to downregulation of PPARD, a transcriptional regulator of oxidative metabolism. This CDK12–GSK3β–PPARD axis was required for glioblastoma cell proliferation and metabolic homeostasis. In vivo, CDK12 inhibition significantly extended survival without overt toxicity and induced complete tumor regression in a subset of animals. Strikingly, combined CDK12 inhibition and temozolomide treatment led to complete tumor eradication in all animals tested. These findings establish CDK12 as a key regulator of glioblastoma metabolism and survival, and provide strong preclinical rationale for its therapeutic targeting in combination with standard-of-care treatments.
Jeong-Yeon Mun, Chang Shu, Qiuqiang Gao, Zhe Zhu, Hasan O. Akman, Mike-Andrew Westhoff, Georg Karpel-Massler, Markus D. Siegelin
Tumor suppressor NF1 is recurrently mutated in glioblastoma, leading to aberrant activation of Ras/rapidly accelerated fibrosarcoma (RAF)/MEK signaling. However, how tumor heterogeneity shapes the molecular landscape and efficacy of targeted therapies remains unclear. Here, we combined bulk and single-cell genomics of human somatic NF1-mutant, isocitrate dehydrogenase (IDH) wild-type glioblastomas with functional studies in cell lines and mouse intracranial tumor models to identify mechanisms of tumor heterogeneity underlying clinical outcome and MEK inhibitor response. Targeted DNA sequencing identified CDKN2A/B homozygous deletion as a poor prognostic marker in somatic NF1-mutant, but not NF1 wild-type, glioblastoma. Single-nucleus RNA sequencing of human patient NF1-mutant glioblastomas demonstrated that mesenchymal-like (MES-like) tumor cells were enriched for MEK activation signatures. Single-cell RNA-sequencing of mouse intracranial glioblastomas treated with the MEK inhibitor selumetinib identified distinct responses among tumor subpopulations. MEK inhibition selectively depleted MES-like cells, and selumetinib-resistant MES-like cells upregulated Ras signaling while resistant non-MES cells expressed markers of glial differentiation. Finally, genome-wide CRISPR interference screens validated Ras/RAF/MEK signaling as a key mediator of selumetinib response. Repression of the RAF regulator SHOC2 sensitized glioblastomas to selumetinib in vitro and in vivo, suggesting a synergistic treatment strategy. Taken together, these results highlighted the heterogeneity of NF1-mutant glioblastomas and informed future combination therapies.
Sixuan Pan, Kanish Mirchia, Emily Payne, S. John Liu, Nadeem Al-Adli, Zain Peeran, Poojan Shukla, Jacob S. Young, Rohit Gupta, Jasper Wu, Joanna Pak, Tomoko Ozawa, Brian Na, Alyssa T. Reddy, Steve E. Braunstein, Joanna J. Phillips, Susan Chang, David A. Solomon, Arie Perry, David R. Raleigh, Mitchel S. Berger, Adam R. Abate, Harish N. Vasudevan
Immune checkpoint therapy has changed cancer treatment, including non-small cell lung cancer (NSCLC). The unresponsiveness of PD-L1lo/– tumors to anti–PD-1/PD-L1 immunotherapy is attributed to alternative immune evasion mechanisms that remain elusive. We previously reported that farnesoid X receptor (FXR) was increased in PD-L1lo/– NSCLC. Herein, we found that immune checkpoint HVEM was positively correlated with FXR but inversely correlated with PD-L1 in NSCLC. HVEM was highly expressed in FXRhiPD-L1lo NSCLC. Consistently, clinically relevant FXR antagonist dose-dependently inhibited HVEM expression in NSCLC. FXR inhibited cytokine production and cytotoxicity of cocultured CD8+ T cells in vitro, and it shaped an immunosuppressive tumor microenvironment (TME) in mouse tumors in vivo through the HVEM/BTLA pathway. Clinical investigations show that the FXR/HVEM axis was associated with immunoevasive TME and inferior survival outcomes in patients with NSCLC. Mechanistically, FXR upregulated HVEM via transcriptional activation, intracellular Akt, Erk1/2 and STAT3 signals, and G1/S cycle progression in NSCLC cells. In vivo treatment experiments demonstrated that anti-BTLA immunotherapy reinvigorated antitumor immunity in TME, resulting in enhanced tumor inhibition and survival improvement in FXRhiPD-L1lo mouse Lewis lung carcinomas. In summary, our findings establish the FXR/HVEM axis as an immune evasion mechanism in PD-L1lo/– NSCLC, providing translational implications for future immunotherapy in this subgroup of patients.
Xiaolong Xu, Bin Shang, Hancheng Wu, Xiuye Jin, Junren Wang, Jing Li, Daowei Li, Bin Liang, Xingguang Wang, Lili Su, Wenjie You, Shujuan Jiang
Jayanta Mondal, Patrick Nylund, Prit Benny Malgulwar, William E. Johnson, Jason T. Huse
We conceived of a type of antitumor mechanism of action by which a soluble target in the tumor microenvironment, such as a tumor-driving growth factor, can be phagocytized along with cancer cells via antibody-dependent cellular phagocytosis (ADCP) using an antibody bispecific for the soluble target and a solid target overexpressed on the cancer cell surface. We explored this concept through engineering bispecific antibodies (BsAbs) co-targeting human epidermal growth factor receptor-2 (HER2) and vascular endothelial growth factor A (VEGFA) in an scFv-IgG format (VHS). We showed that the HER2-VEGFA BsAbs but not the parental antibodies alone or in combination induced co-phagocytosis of VEGFA and HER2-overexpressing cancer cells by tumor-associated macrophages via ADCP. In both immunocompromised and immunocompetent mice with aggressive tumors, the BsAbs demonstrated greater anti-metastasis activity and produced a greater survival benefit than the parental antibodies alone or in combination, in a manner dependent on Fcγ receptors on the macrophages. Our results provide proof of the concept that HER2-VEGFA BsAbs achieve enhanced antitumor activity by leveraging HER2 overexpressed on the cancer cell surface to induce co-phagocytosis of VEGFA. Our findings warrant clinical testing of the strategy to treat metastasis and recurrence of HER2-overexpressing solid tumors that respond to anti-VEGFA therapy.
Yang Lu, Songbo Qiu, Zhen Fan
BACKGROUND. Emerging evidence indicates a reduced incidence of multiple cancers in users of Glucagon-like peptide-1 receptor agonists (GLP-1RAs), drugs widely used for glycemic control and weight reduction that modulate several key regulators of metabolism. We sought to examine their association with non-small cell lung cancer (NSCLC) outcomes in overweight and obese patients and gain mechanistic insights from mouse models. METHODS. Two clinical cohorts of overweight and obese NSCLC patients—one undergoing surgical resection (n=1,177, 71 GLP-1RA users) and another receiving immune checkpoint inhibitors (ICIs; n=300, 10 GLP-1RA users), were propensity score matched for relevant covariates and analyzed for clinical outcomes. RESULTS. GLP-1RA use was associated with increased recurrence-free survival in overweight and obese patients (HR=0.41 [95%CI=0.16-1.04], p=0.026) after lobectomy. GLP-1RA treatment reduced tumor burden in obese but not normal-weight mice and altered the frequency and phenotypes of leukocyte populations and gene expression patterns in obese tumors, crucial to cancer progression and anti-tumor immunity. Concurrent GLP-1RA and immunotherapy was associated with improved overall (0.41 [0.16-1.01], 0.027) and progression-free survival (HR=0.31, [0.10-0.94], 0.019) for patients with advanced NSCLC. CONCLUSIONS. In our cohort, GLP-1RAs enhanced lung cancer-specific clinical outcomes and augment immunotherapy efficacy. Preclinical evidence suggested this effect to be obesity-restricted and mediated by immune modulation of the tumor microenvironment. FUNDING. This work was supported by a generous donation from Mr. George Duke to SY; W81XWH-21-1-0377, (GM147497), and RSG-22-071-01-TBE to VRS; 1R01 CA255515-01A1 to SY and JB; and NIH/NCI Cancer Center Support Grants P30CA013696 and P30CA016056.
Akhil Goud Pachimatla, Bailey Fitzgerald, Joyce Ogidigo, Meera Bhatia, Randall J. Smith Jr., Kalyan Ratnakaram, Sukumar Kalvapudi, Yeshwanth Vedire, Deschana Washington, Robert Vethanayagam rr, Hua-Hsin Hsiao, Spencer Rosario, Viraj R. Sanghvi, Joseph Barbi, Sai Yendamuri
We assessed the therapeutic efficacy of a semiallogeneic dendritic cell (DC) vaccine in comparison to a syngeneic one for suppression of B16-F10 and TC-1 tumors. Syngeneic bone marrow–derived DCs (BMDCs) were generated from C57BL/6J mice and semiallogeneic BMDCs with a mutation in either MHC class I or II were generated from B6.C-H2-Kbm1/ByJ or B6(C)-H2-Ab1bm12/KhEgJ mice, respectively. We demonstrated in vivo and in vitro that the MHC class II semiallogeneic BMDC vaccine had superior efficacy over the syngeneic and the MHC class I semiallogeneic BMDC vaccine, providing allogeneic CD4+ T cell help to enhance the antitumor CD8+ T cell response through allogeneic stimulation by the mutant MHC class II molecules. We discovered that this help was induced only at an early stage of tumor growth and at a later stage of tumor growth; combining our BMDC vaccine with Treg depletion enhanced tumor suppression. We demonstrated the improved efficacy of a semiallogeneic BMDC vaccine that kept tumor-peptide presentation intact on syngeneic MHC class I molecules so that mutant MHC class II could provide allogeneic help. This strategy should enable promising new DC-based cancer immunotherapies, offering an alternative to autologous DC vaccines by incorporating allogenicity as an adjuvant.
Noriko Seishima, William Becker, Purevdorj B. Olkhanud, Hoyoung M. Maeng, Miguel A. Lopez-Lago, William V. Williams, Jay A. Berzofsky
While the accumulation of tumor-associated macrophages (TAMs) in glioblastoma (GBM) has been well documented, targeting TAMs has thus far yielded limited clinical success in slowing GBM progression due, in part, to an incomplete understanding of TAM function. Using an engineered 3D hydrogel–based model of the brain tumor microenvironment (TME), we show that M2-polarized macrophages stimulate transcriptional and phenotypic changes in GBM stem cells (GSCs) closely associated with the highly aggressive and invasive mesenchymal subtype. By combining proteomics with GBM patient single-cell transcriptomics, we identify multiple TAM-secreted proteins with putative proinvasive functions and validate TGF-β induced (TGFBI, also known as BIGH3) as a targetable TAM-secreted tumorigenic factor. Our work highlights the utility of coupling multiomics analyses with engineered TME models to investigate TAM–cancer cell crosstalk and offers insights into TAM function to guide TAM-targeting therapies.
Erin A. Akins, Dana Wilkins, Zaki Abou-Mrad, Kelsey Hopland, Robert C. Osorio, Kenny K.H. Yu, Manish K. Aghi, Sanjay Kumar
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