Biology subjects

Greer, P. A.

Publications and source records attributed to Greer, P. A..

4 recordsLinked to original sources

bioRxiv2026

Failure of Bacillus Calmette-Guerin Therapy in Patients with Bladder Cancer is Characterized by Immune Dysfunction Associated with Activator Protein 1

The standard-of-care for patients with higher-risk non-muscle invasive bladder cancer (NMIBC) after tumour resection is intravesical administration of Bacillus Calmette-Guerin (BCG). While this form of adjuvant immunotherapy has improved recurrence-free and progression-free survival, a large proportion of patients experience recurrences within a year of diagnosis. The reasons for this high rate of early recurrence following BCG therapy remain unclear; however, inadequate activation of systemic immunity may be a contributing factor. To address this, we analysed the transcriptomic and chromatin accessibility profiles of peripheral blood mononuclear cells obtained from patients with NMIBC at single-cell resolution before BCG immunotherapy and after five induction doses of BCG. Monocytes from patients who experienced disease recurrence within a year of initiation of BCG therapy (BCG non-responders) exhibited a pro-inflammatory phenotype consistent with age-related immunosenescence prior to BCG immunotherapy. Moreover, inflammation-associated pathways that were active before initiation of BCG therapy in the BCG non-responders were down-regulated after five instillations of BCG. In contrast, these pathways were quiescent before BCG therapy in patients who remained disease-free for at least a year but were markedly up-regulated after five doses of BCG. Genomic regions with accessible chromatin were enriched in activator protein 1 (AP-1) binding sequences in monocytes from BCG-non-responders prior to BCG therapy. AP-1 is a central regulator of the inflammatory phenotype associated with immunosenescence. Our findings indicate that a pre-existing state of innate immunosenescence underlies early disease recurrence following BCG. Patients unlikely to benefit from BCG may be offered alternative therapies early in their disease journey. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=176 SRC="FIGDIR/small/723215v1_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@55b065org.highwire.dtl.DTLVardef@1afcea6org.highwire.dtl.DTLVardef@12833baorg.highwire.dtl.DTLVardef@5c22fc_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2026

Differential effects of BCG-Russia and BCG-TICE on trained immunity: potential implications for bladder cancer immunotherapy

In recent years, immunotherapy of patients with higher-risk non-muscle invasive bladder cancer (NMIBC) in North America has relied on the use of the TICE strain of BCG. However, limitations in the supply chain have warranted investigation of the therapeutic benefit of other strains of BCG, such as BCG-Russia. Trained immunity, a form of innate immune memory, is now widely believed to be an important component of the therapeutic benefit of BCG. Therefore, in the present study we compared the effects of BCG-TICE and BCG-Russia on the acquisition of trained immunity and related secondary immune responses. C57BL/6 mice received a single intravenous injection of BCG-Russia or BCG-TICE. Four weeks later, bone marrow was collected for flow cytometric analysis of hematopoietic stem and progenitor cell (HSPC) populations, generation of bone marrow-derived macrophages, functional assessment of trained immunity, and transcriptomic profiling. Compared with BCG-Russia, BCG-TICE elicited stronger levels of trained immunity, characterized by higher production of several proinflammatory cytokines upon secondary activation. BCG promoted the expansion of HSPCs independent of strain. BCG-TICE was linked to upregulation of key inflammation-related genes and enrichment of functionally relevant pathways. The results of this study reveal strain-dependent differences in the ability of BCG to induce innate immune memory and inflammatory pathways that could ultimately determine efficacy of immunotherapy of patients with NMIBC.

immunology↗

bioRxiv2024

Fes-deficient macrophages enhance CD8+ T cell priming and tumour control through increased proinflammatory cytokine production and presentation

Homeostatic immunoregulatory mechanisms that prevent adverse effects of immune overaction can serve as barriers to successful anti-cancer immunity, representing attractive targets to improve cancer immunotherapy. Here, we demonstrate a novel role of the Fes tyrosine kinase, abundantly expressed in immune cells, as an innate intracellular immune checkpoint. Host Fes-deficiency delays tumour onset in a gene dose-dependent manner and improves murine triple negative breast cancer and melanoma tumour control, survival, doxorubicin efficacy, and anti-PD-1 therapy sensitization. These effects were associated with a shift to an anti-tumourigenic tumour immune microenvironment. In vitro, we observed increased Toll-like receptor signaling, and proinflammatory cytokine production and presentation from antigen presenting cells, leading to increased T cell activation, cancer cell killing and tumour control. This study highlights Fes as a novel innate immune checkpoint with potential as a predictive biomarker for effective immune checkpoint blockade treatment, and a potential therapeutic target to improve anti-cancer immunotherapy.

immunology↗

bioRxiv2019

A NOVEL MECHANISM FOR NF-κB-ACTIVATION VIA IκB-AGGREGATION: IMPLICATIONS FOR HEPATIC MALLORY-DENK-BODY INDUCED INFLAMMATION

Background & AimsMallory-Denk-bodies (MDBs) are hepatic protein aggregates associated with inflammation both clinically and in MDB-inducing models. Similar protein aggregation in neurodegenerative diseases also triggers inflammation and NF-{kappa}B activation. However, the precise mechanism that links protein aggregation to NF{kappa}B-activation and inflammatory response remains unclear.\n\nMethodsHerein, we find that treating primary hepatocytes with MDB-inducing agents (N-methylprotoporphyrin, protoporphyrin IX (PPIX), or ZnPPIX) elicited an I{kappa}B-loss with consequent NF-{kappa}B activation. We characterized the underlying mechanism in detail using hepatocytes from various knockout mice and MEF cell lines and multiple approaches including immunoblotting, EMSA, RT-PCR, confocal immunofluorescence microscopy, affinity immunoprecipitation, and protein solubility assays. Additionally, we performed rigorous proteomic analyses to identify the proteins aggregating upon PPIX treatment and/or co-aggregating with I{kappa}B.\n\nResultsFour known mechanisms of I{kappa}B-loss were probed and excluded. Immunofluorescence analyses of ZnPPIX-treated cells coupled with 8 M urea/CHAPS-extraction revealed that this I{kappa}B-loss was due to its sequestration along with I{kappa}B{beta} into insoluble aggregates. Through proteomic analyses we identified 47 aggregation-prone proteins that co-aggregate with I{kappa}B through direct interaction or proximity. Of these ZnPPIX-aggregation targets, the nucleoporins Nup153 and Nup358/RanBP2 were identified through RNA-interference, as likely mediators of I{kappa}B-nuclear import.\n\nConclusionWe discovered a novel mechanism of inflammatory NF-{kappa}B activation through I{kappa}B-sequestration into insoluble aggregates along with interacting aggregation-prone proteins. This mechanism may account for the protein aggregate-induced inflammation observed in MDB-associated liver diseases, thereby identifying novel targets for therapeutic intervention. Because of inherent commonalities this MDB cell model is a bona fide protoporphyric model, making these findings equally relevant to the liver inflammation associated with clinical protoporphyria.\n\nLay SummaryMallory-Denk-bodies (MDBs) are hepatic protein aggregates commonly featured in many liver diseases. MDB-presence is associated with the induction of inflammatory responses both clinically and in all MDB-inducing models. Similar protein aggregation in neurodegenerative diseases is also known to trigger inflammation and NF{kappa}B pathway activation via an as yet to be characterized non-canonical mechanism. Herein using a MDB-inducing cell model, we uncovered a novel mechanism for NF{kappa}B activation via cytosolic I{kappa}B-sequestration into insoluble aggregates. Furthermore, using a proteomic approach, we identified 47 aggregation-prone proteins that interact and co-aggregate with I{kappa}B. This novel mechanism may account for the protein aggregate-induced inflammation observed in liver diseases, thereby identifying novel targets for therapeutic intervention.

cell biology↗