Biology subjects

Olson, J. M.

Publications and source records attributed to Olson, J. M..

11 recordsLinked to original sources

bioRxiv2026

Intratumoral B7H3:CD3 Bispecific T-cell Engager Drives Localized T-cell Accumulation in Canine Sarcoma Patients

BackgroundBispecific T-cell Engagers (TCEs) targeting B7H3 (CD276) show promise for solid tumors but are limited by systemic toxicities and poor tumor penetration. Intratumoral (IT) delivery is proposed as a solution, but the safety and spatial pharmacodynamics (PD) remain poorly defined in these malignancies. Spontaneous canine tumors serve as a highly translatable model for human therapeutic development due to its clinical, genetic, and immunological similarities to human patients. This study evaluates the feasibility of an IT-delivered B7H3:CD3 TCE in a trial that enrolls companion dogs with solid tumors. MethodsWe engineered a canine B7H3:CD3 TCE and validated its ability to induce T-cell activation and T-cell mediated cytotoxicity in vitro on several B7H3-expressing canine tumor cell lines. Two STS canine patients received intratumoral columnar injections of the TCE and saline (internal control) at fixed distance of 1.5cm using a custom-engineered multi-needle assembly. Safety was evaluated by physical examinations and hematological and biochemical changes in peripheral blood. PD response was analyzed by H&E and immunohistochemistry. ResultsIn vitro assays validated the cytotoxicity of the B7H3:CD3 TCE on B7H3+ canine tumor cell lines. TCE IT administration (7.83 g / 148.2 pmol) was well tolerated with no adverse events greater than Grade 1 and no evidence of systemic cytokine release or organ toxicity. Immunohistochemistry of tumors collected 7 days after TCE administration revealed a significant five-fold increase in CD3+ T-cell density at the TCE injection site (within 0.5 cm radius) compared to internal saline controls. ConclusionsThis study demonstrated the feasibility of evaluating pharmacodynamic response to IT delivery of B7H3:CD3 TCE, namely local T-cell accumulation. T-cell localization around the TCE injection site supports our hypothesis that effective IT immunotherapy might require enhanced volumetric coverage using multi-needle injections and/or co-stimulatory strategies to convert T-cell localization into a robust, sustained anti-tumor response.

immunology↗

bioRxiv2025

Autocrine TGFβ2 enforces a transcriptionally hybrid cell state in Ewing sarcoma

Sub-populations of cancer-associated fibroblast (CAF)-like tumor cells deposit extracellular matrix (ECM) proteins that support Ewing sarcoma (EwS) progression and metastasis. We previously showed a hallmark of CAF-like EwS cells is their hybrid transcriptional state wherein the driver fusion oncogene, EWS::FLI1, maintains activation of proliferative programs but loses capacity to repress mesenchymal genes. Here, we studied primary patient tumors and cell line models to identify molecular drivers of this hybrid state. Our data reveal that hybrid EwS cells are induced and maintained by a TGF{beta} signaling positive feedback loop. Hybrid cells de-repress TGFBR2 and upregulate expression and secretion of TGF{beta}2 to sustain pathway activation and ECM deposition. While TGF{beta} ligands can potently induce growth arrest in cells of epithelial origin, we show that TGF{beta}1 and TGF{beta}2 promote cell invasion of EwS cells without affecting proliferation. Thus, stroma and tumor-derived TGF{beta} ligands induce and maintain hybrid EwS cells to promote pro-metastatic cell phenotypes.

cancer biology↗

bioRxiv2025

Efficacy of DNA Methyltransferase Inhibitor Immune Priming Therapy in Combination with PD-1 Inhibitors to Treat High-Risk Pediatric Brain Tumors

BackgroundDespite intensive therapies, outcomes for high-risk pediatric brain tumors (PBTs) remain dismal, prompting the search for novel treatments. DNA methyltransferase inhibitors (DNMTi) have been shown to prime tumors to improve response to checkpoint inhibition. The aim of this study was to investigate the potential of decitabine (DAC), in combination with a PD-1 inhibitor, to improve survival in pediatric high-risk brain tumor models. MethodsAnalysis of human PBT datasets was performed to determine gene expression levels of immune cell associated markers. Tumor response to DAC, with or without a PD-1 inhibitor, was tested in murine models representing H3-wildtype diffuse intrinsic pontine glioma (DIPG), H3K27-mutant diffuse midline glioma (DMG), atypical teratoid rhabdoid tumor (ATRT), and medulloblastoma (MB). CyTOF analysis of allograft tumors was performed to characterize changes within the tumor microenvironment. ResultsAnalysis of PBT subtypes revealed heterogeneous expression of immune cell markers, checkpoint receptors, and MHC molecules. DAC treatment decreased DNA methylation and increased neoantigen expression in human and mouse tumor cells. DAC alone or in combination with a PD-1 inhibitor resulted in prolonged survival in syngeneic mouse models of DIPG and ATRT but not DMG and MB models. CyTOF analysis of mouse tumors revealed changes in local immune cell infiltration upon combination treatment. ConclusionsDAC in combination with a PD-1 inhibitor can alter the immune microenvironment in mouse tumor models. Changes were observed in H3-wildtype DIPG and ATRT models, suggesting that certain tumor subtypes may respond to checkpoint blockade after immune augmentation with DNMTi. Key PointsO_LIPBTs show heterogenous expression of immune cell infiltrates C_LIO_LIDAC or DAC plus a PD-1 inhibitor shows extension of survival in H3-wildtype DIPG and ATRT mouse models C_LIO_LIMyeloid-derived suppressor cell abundance could be a major contributing factor to treatment response C_LI Importance of the StudyChildren with high-risk PBTs face dismal outcomes. Immune checkpoint inhibitor (ICI) successes have been demonstrated in a variety of adult malignancies; however, such beneficial outcomes have not been realized in PBTs. Here we investigate single and combination treatment of DNMTi and PD-1 checkpoint inhibition in syngeneic mouse models of high-risk PBTs. Our results suggest that some H3-wildtype DIPG and ATRT tumor types may be responsive to checkpoint therapy post immunomodulation and warrant further investigation.

immunology↗

bioRxiv2024

CYpHER: Catalytic extracellular targeted protein degradation with high potency and durable effect

Many disease-causing proteins have multiple pathogenic mechanisms, and conventional inhibitors struggle to reliably disrupt more than one. Targeted protein degradation (TPD) can eliminate the protein, and thus all its functions, by directing a cells protein turnover machinery towards it. Two established strategies either engage catalytic E3 ligases or drive uptake towards the endolysosomal pathway. Here we describe CYpHER (CatalYtic pH-dependent Endolysosomal delivery with Recycling) technology with potency and durability from a novel catalytic mechanism that shares the specificity and straightforward modular design of endolysosomal uptake. By bestowing pH-dependent release on the target engager and using the rapid-cycling transferrin receptor as the uptake receptor, CYpHER induces endolysosomal target delivery while re-using drug, potentially yielding increased potency and reduced off-target tissue exposure risks. The TfR-based approach allows targeting to tumors that overexpress this receptor and offers the potential for transport to the CNS. CYpHER function was demonstrated in vitro with EGFR and PD-L1, and in vivo with EGFR in a model of EGFR-driven non-small cell lung cancer.

bioengineering↗

bioRxiv2023

Versatile Tissue-Injectable Hydrogels with Extended Hydrolytic Release of Bioactive Protein Therapeutics

Hydrogels generally have broad utilization in healthcare due to their tunable structures, high water content, and inherent biocompatibility. FDA-approved applications of hydrogels include spinal cord regeneration, skin fillers, and local therapeutic delivery. Drawbacks exist in the clinical hydrogel space, largely pertaining to inconsistent therapeutic exposure, short-lived release windows, and difficulties inserting the polymer into tissue. In this study, we engineered injectable, biocompatible hydrogels that function as a local protein therapeutic depot with a high degree of user-customizability. We showcase a PEG-based hydrogel functionalized with bioorthogonal strain-promoted azide-alkyne cycloaddition (SPAAC) handles for its polymerization and functionalization with a variety of payloads. Small-molecule and protein cargos, including chemokines and antibodies, were site-specifically modified with hydrolysable "azidoesters" of varying hydrophobicity via direct chemical conjugation or sortase-mediated transpeptidation. These hydrolysable esters afforded extended release of payloads linked to our hydrogels beyond diffusion; with timescales spanning days to months dependent on ester hydrophobicity. Injected hydrogels polymerize in situ and remain in tissue over extended periods of time. Hydrogel-delivered protein payloads elicit biological activity after being modified with SPAAC-compatible linkers, as demonstrated by the successful recruitment of murine T-cells to a mouse melanoma model by hydrolytically released murine CXCL10. These results highlight a highly versatile, customizable hydrogel-based delivery system for local delivery of protein therapeutics with payload release profiles appropriate for a variety of clinical needs. Translational ImpactWe developed injectable hydrogels that provide loco-regional, controlled release of protein therapeutics. Local delivery is especially suitable for potent, protein-based drugs like chemokines and monoclonal antibodies whose systemic toxicities can be life threatening. Our hydrogel is equipped with slowly hydrolyzing linkers for transient payload coupling, prolonging its therapeutic window and minimizing the need for repeat surgeries in a clinical setting. A range of release profiles, spanning days to over a month, and a broad compatibility to therapeutically relevant, recombinant proteins provide clinicians with flexible therapeutic options to suit a variety of circumstances.

bioengineering↗

bioRxiv2023

Cadherin-mediated cell-cell adhesion regulates collective pediatric glioma cell migration

Pediatric high-grade gliomas are highly invasive and essentially incurable. Glioma cells migrate between neurons and glia, along axon tracts, and through extracellular matrix surrounding blood vessels and underlying the pia. Mechanisms that allow adaptation to such complex environments are poorly understood. N-cadherin is highly expressed in pediatric gliomas and associated with shorter survival. We found that inter-cellular homotypic N-cadherin interactions differentially regulate glioma migration according to the microenvironment, stimulating migration on cultured neurons or astrocytes but inhibiting invasion into reconstituted or astrocyte-deposited extracellular matrix. N-cadherin localizes to filamentous connections between migrating leader cells but to epithelial-like junctions between followers. Leader cells have more surface and recycling N-cadherin, increased YAP1/TAZ signaling, and increased proliferation relative to followers. YAP1/TAZ signaling is dynamically regulated as leaders and followers change position, leading to altered N-cadherin levels and organization. Together, the results suggest that pediatric glioma cells adapt to different microenvironments by regulating N-cadherin dynamics and cell-cell contacts. SummaryPediatric gliomas invade the brain by migrating between nerve cells or exploiting extracellular matrix along blood vessels. This research reveals cross-talk between YAP1/TAZ signaling and N-cadherin that regulates leader-follower cell phenotypes and migration efficiency in neural and extracellular matrix environments.

cancer biology↗

bioRxiv2021

Adaptable and Automated Rodent Behavior Maze System

Mazes are a fundamental and widespread tool in behavior and systems neuroscience research in rodents, especially in spatial navigation and spatial memory investigations in freely behaving animals. However, their form and inflexibility often restrict potential experimental paradigms that involve multiple or adaptive maze designs. Unique layouts often lead to elevated costs, whether financially or in terms of time investment from scientists. To alleviate these issues, we have developed an automated, modular maze system that is flexible and scalable. This open source Adapt-A-Maze (AAM) system will allow for experiments with multiple track configurations in rapid succession. Additionally, the flexibility can expedite prototyping of behavioral paradigms. Automation ensures less variability in experimental parameters and higher throughput. Finally, the standardized componentry enhances experimental repeatability within labs and replicability across labs. Our maze was successfully used across labs, in multiple experimental designs, with and without extracellular or optical recordings, in rats. The AAM system presents multiple advantages over current maze options and can facilitate novel behavior and systems neuroscience research. Significance statementWe have developed an open source, modular maze system (the Adapt-A-Maze, AAM) that enables any lab interested in rodent behavior and cognition to create standard and unique mazes for their research. The AAM uses modular track pieces that can be combined to create a wide array of maze types. The AAM system also included reward wells with lick detection and pneumatic barriers. All aspects of the maze can be controlled via TTL signals to automate tasks and improve repeatability of experiments. The AAM system is expected to help labs quickly and inexpensively set up recordable experiments to advance our understanding of the neurophysiology underlying behavior and cognition.

neuroscience↗

bioRxiv2021

Complementary Maps for Location and Environmental Structure in CA1 and Subiculum

The dorsal subiculum lies among a network of interconnected brain regions that collectively map multiple spatial and orientational relationships between an organism and the boundaries and pathways composing its environment. A unique role of the subiculum in spatial information processing has yet to be defined despite reports of small neuron subpopulations that encode relationships to specific boundaries, axes of travel, or locations. We examined the activity patterns among populations of subiculum neurons during performance of a spatial working memory task performed within a complex network of interconnected pathways. Compared to neurons in hippocampal sub-region CA1, a major source of its afferents, subiculum neurons were far more likely to exhibit multiple firing fields at locations that were analogous with respect to path structure and function. Subiculum neuron populations were also found to exhibit a greater dynamic range in scale of spatial representation and for persistent patterns of spiking activity to be aligned to transitions between maze segments. Together, the findings indicate that the subiculum plays a unique role in spatial mapping, one that complements the location-specific firing of CA1 neurons with the encoding of emergent and recurring structural features of a complex path network.

neuroscience↗

bioRxiv2020

Histone deposition pathways determine the chromatin landscapes of H3.1 and H3.3 K27M oncohistones

Lysine 27-to-methionine (K27M) mutations in the H3.1 or H3.3 histone genes are characteristic of pediatric diffuse midline gliomas (DMGs). These oncohistone mutations dominantly inhibit histone H3K27 trimethylation and silencing, but it is unknown how oncohistone type affects gliomagenesis. We show that the genomic distributions of H3.1 and H3.3 oncohistones in human patient-derived DMG cells are consistent with the DNA replication-coupled deposition of histone H3.1 and the predominant replication-independent deposition of histone H3.3. Although H3K27 trimethylation is reduced for both oncohistone types, H3.3K27M-bearing cells retain some domains, and only H3.1K27M-bearing cells lack H3K27 trimethylation. Neither oncohistone interferes with PRC2 binding. Using Drosophila as a model, we demonstrate that inhibition of H3K27 trimethylation occurs only when H3K27M oncohistones are deposited into chromatin and only when expressed in cycling cells. We propose that oncohistones inhibit the H3K27 methyltransferase as chromatin patterns are being duplicated in proliferating cells, predisposing them to tumorigenesis.

molecular biology↗

bioRxiv2019

Secondary Motor Cortex Transforms Spatial Information into Planned Action During Navigation

Fluid navigation requires constant updating of planned movements to adapt to evolving obstacles and goals. A neural substrate for navigation demands spatial and environmental information and the ability to effect actions through efferents. Secondary motor cortex is a prime candidate for this role given its interconnectivity with association cortices that encode spatial relationships and its projection to primary motor cortex. Here we report that secondary motor cortex neurons robustly encode both planned and current left/right turning actions across multiple turn locations in a multi-route navigational task. Comparisons within a common statistical framework reveal that secondary motor cortex neurons differentiate contextual factors including environmental position, route, action sequence, orientation, and choice availability. Despite significant modulation by context, action planning and execution are the dominant output signals of secondary motor cortex neurons. These results identify secondary motor cortex as a structure integrating environmental context toward the updating of planned movements.

neuroscience↗

bioRxiv2018

Automated in situ profiling of chromatin modifications resolves cell types and gene regulatory programs

Our understanding of eukaryotic gene regulation is limited by the complexity of protein-DNA interactions that comprise the chromatin landscape and by inefficient methods for characterizing these interactions. We recently introduced CUT&RUN, an antibody-targeted nuclease-cleavage method that profiles DNA-binding proteins, histones and chromatin modifying proteins in situ with exceptional sensitivity and resolution. Here we describe an automated CUT&RUN platform and apply it to characterize the chromatin landscapes of human cell lines. We find that CUT&RUN profiles of histone modifications crisply demarcate active and repressed chromatin regions, and we develop a continuous metric to identify cell-type specific promoter and enhancer activities. We test the ability of automated CUT&RUN to profile frozen tumor samples, and find that our method readily distinguishes two diffuse midline gliomas by their subtype-specific gene expression programs. The easy, cost-effective workflow makes automated CUT&RUN an attractive tool for high-throughput characterization of cell types and patient samples.

genomics↗