Search bioRxiv⌕ Search

Biology subjects

Gjorevski, N.

Publications and source records attributed to Gjorevski, N..

9 recordsLinked to original sources

Organoid-based colorectal tumor microenvironment model for immuno-oncology research

The development of cancer immunotherapies is hindered by the lack of human-relevant models that accurately translate to patient outcomes. We combine patient-derived colorectal tumor organoids (PDOs) and cancer-associated fibroblasts (CAFs) into floating extracellular matrix drops to form miniature colorectal tumors. These SHaking Organoid CO-cultures (SHOCOs) reproducibly capture key features of the tumor microenvironment (TME), including physiologically relevant ECM, hypoxic regions, and a diversified stromal compartment that captures primary CAF states. Compared with traditional PDO-based co-culture models, SHOCOs maintain immune cells in numbers, states and functional interactions that more closely reflect the physiological tumor microenvironment. The modularity of the system allowed controlled simulation of diverse patient tumor archetypes, and defining how TME components shape therapy response. Immune-rich SHOCOs treated with T-cell bispecific antibodies exhibited robust anti-tumor responses that were stronger and more rapid than their PDO-based counterparts. Stroma-rich tumors, on the other hand, diminished therapy responses by physically hindering both immune cell recruitment and limiting antibody penetration. Thus, SHOCOs enable the construction of modular tumor microenvironments, providing a versatile platform to dissect immune and stromal tumor biology and to catalyze the discovery of novel therapeutic approaches.

cancer biology↗

Vascularized tumor organoids enable immunotherapy testing in tumor-remodeled stroma

Accurately predicting whether a new molecule will be safe and effective in humans remains a fundamental challenge in biomedical research, requiring models that can reliably inform clinical outcomes. In oncology, drug attrition rates remain disproportionately high compared to other therapeutic areas, largely due to the poor translatability of conventional preclinical models that fail to capture the complexity of human immune-tumor-stroma interactions (1, 2). Here, we describe human vascularized organoids (VascO), formed through self-assembly of an immune cell perfused capillary network and stromal compartment, interfacing with patient-derived colorectal cancer organoids that enable the combined safety and efficacy assessment of tumor-targeted immunotherapies. VascO generates functional and integrated vascular networks within tumor organoids that sustain organoid growth and recapitulate the morphology and functionality of tumor vasculature. Single-cell transcriptomics reveals that the tumor organoids-educated VascO niche reprograms otherwise healthy fibroblasts into canonical cancer-associated fibroblast states, adopting my-ofibroblastic or inflammatory signatures, and faithfully mirroring donor-specific tumor cues. In parallel, VascO tumor vessels display an expanded tip-cell program, aberrant morphology, and VEGF/ANG2-driven permeability, recapitulating defining hallmarks of tumor vasculature. Immune perfusion with a tumor-targeted T cell bispecific antibody induces dynamic immune trafficking, infiltration and engagement of effector cells with the tumor tissue, leading to its effective killing. A protease-activated variant restricts T cell activation to the tumor microenvironment, retaining potent tumoricidal activity while sparing donor-matched healthy colon organoids, and thereby improving the therapeutic index. VascO thus models a patient-specific, tumor-educated microenvironment that is amenable to assessing the combined safety and efficacy of new drug candidates and provides a scalable platform to improve the preclinical assessment of innovative cancer immunotherapies.

bioengineering↗

A bioengineered human urothelial organoid model reveals the urine-urothelium interplay in tissue resilience and UPEC recurrence in urinary tract infections

Urine is a dynamic and highly variable biofluid. Urine-urothelium interactions are a critical yet underexplored factor in bladder homeostasis and urinary tract infections (UTIs). Here, we report on a human mini-bladder model that exposes a stratified urothelium to urine of defined composition, and incorporates micturition. Prolonged exposure to high-solute concentration urine weakens tight junctions, dysregulates immune responses, and reduces bladder tissue resilience. This increases susceptibility to colonization of the bladder by uropathogenic E. coli (UPEC) which reduces efficacy of antibiotic therapy. In high-solute concentration urine, Fosfomycin monotherapy - prescribed for uncomplicated UTIs, induces the formation of cell wall-deficient (CWD) UPEC in the urine (as observed in patients with recurrent UTIs) but also within deeper urothelial layers. Tissue-associated CWD UPEC directly contributed to recurrence. Our findings expand the conceptual role for CWD UPEC in UTIs, and demonstrate the power of the mini-bladder platform to capture urine-urothelial microenvironment dynamics that actively shape UTI pathogenesis and antibiotic tolerance.

bioengineering↗

Colorectal cancer heterogeneity co-evolves with tumor architecture to determine disease outcome

Intratumoral heterogeneity, originating from genetic, epigenetic, and phenotypic cellular diversity, is pervasive in cancer. As these heterogeneous states employ diverse mechanisms to promote tumor progression, metastasis, and therapy resistance, emergence of cancer heterogeneity is one of the most significant barriers to curative treatment. Here we leverage deep learning approaches to develop a high-throughput image-analysis paradigm with subcellular resolution that quantifies and predicts colorectal cancer (CRC) patient outcome based on tissue architecture and nuclear morphology. We further combine this approach with spatial transcriptomics, multiplex immunohistochemistry, and patient-derived organoids to uncover a dynamic, co-evolutionary relationship between tumor architecture and cell states. We identify clinically relevant architectural interfaces in CRC tissue that diversify cellular identities by favoring distinct cancer stem cell states and thus promote evolution of tumor heterogeneity. Specifically, tissue fragmentation and associated compressive forces promote loss of classic stem cell signature and acquisition of fetal/regenerative stem cell states, which initially emerges as a hybrid state with features of epithelial-to-mesenchyme (EMT) transition. Additional tumor stroma communication then diversifies these states into distinct stem cell and EMT states at the invasive margins of tumors. Reciprocally, Wnt signaling state of tumor cells tunes their responsiveness to tissue architecture. Collectively, this work uncovers a feedback loop between cell states and tissue architecture that drives cancer heterogeneity and cell state diversification. Machine learning-based analyses harness this co-dependency, independently of mutational status or cancer stage, to predict patient outcome.

cancer biology↗

Modeling host-microbe interactions in immunocompetent engineered human gut tissues

The intestinal mucosal barrier contains microbial organisms within the lumen while preserving the ability to absorb nutrients. Dietary, microbial, and other exposures shaped human barrier evolution and continue to impact disease susceptibility. Here, we established engineered barrier models of the human small intestine and colon composed of a multilineage epithelium, mucus layer, accessible microbial compartment and autologous tissue-resident immune cells. The epithelium has crypt- and villus-like topological domains, with stem cells differentiating into absorptive and secretory lineages with region-specific identities. Secreted mucins accumulate apically, forming a dense mucus layer separating the epithelium from colonizing commensal and pathogenic bacteria. Intestinal memory T cells integrate into and interact with the epithelium. We use the engineered intestinal tissues to identify an epithelial gene regulatory network underlying response to Salmonella Typhimurium infection, and uncover epithelial-immune-pathogen crosstalk coordinating cytokine release and epithelial damage. Overall, this work allows for the modular integration of epithelial, microbial, and immune compartments providing a versatile system for studying human intestinal physiology and pathologies.

bioengineering↗

High-throughput histopathology for complex in vitro models

Human complex in vitro models (CIVMs) have demonstrated remarkable potential to study tissue development, physiology and disease at high-throughput. To effectively employ these miniaturized systems in translational preclinical research, their in-depth benchmarking is pivotal. Histology has been the core of tissue characterization for centuries and the foundation of spatial phenotyping. However, standard histology workflows are inherently low-throughput and centered on large tissue pieces. This does not match the high sample volumes and small sample sizes in CIVM research. Here, we introduce a holistic histo-workflow, utilizing 3D-printed histomolds that facilitate co-planar embedding of CIVMs at high-throughput, resulting in up to 48 samples in one section. We developed a variety of model-specific histomold designs that enable spatially controlled histological sectioning and downstream analyses. We describe these workflows, including mold generation, highplex staining and image analysis, and exemplify their application to histological analyses of various CIVMs. Altogether, the histomolds introduced here afford opportunities for CIVM processing and analysis, while significantly reducing labor and reagent resources, thereby democratizing high-throughput CIVM in histopathology.

pathology↗

Human Lung Alveolar Model with an Autologous Innate and Adaptive Immune Compartment

Lung-resident immune cells, spanning both innate and adaptive compartments, preserve the integrity of the respiratory barrier, but become pathogenic if dysregulated1. Current in vitro organoid models aim to replicate interactions between the alveolar epithelium and immune cells but have not yet incorporated lung-specific immune cells critical for tissue residency2. Here we address this shortcoming by describing human lung alveolar immuno-organoids (LIO) that contain an autologous tissue-resident lymphoid compartment, primarily composed of tissue-resident memory T cells (TRMs). Additionally, we introduce lung alveolar immuno-organoids with myeloid cells (LIOM), which include both TRMs and a macrophage-rich alveolar myeloid compartment. The resident immune cells formed a stable immune-epithelial system, frequently interacting with the epithelium and promoting a regenerative alveolar transcriptomic profile. To understand how dysregulated inflammation perturbed the respiratory barrier, we simulated T-cell-mediated inflammation in LIOs and LIOMs and used single-cell transcriptomic analyses to uncover the molecular mechanisms driving immune responses. The presence of innate cells induced a shift in T cell identity from cytotoxic to immunosuppressive, reducing epithelial cell killing and inflammation. Based on insights obtained with bulk RNA-seq data from the phase 3 IMpower150 trial, we tested whether LIOM cultures could model clinically-relevant but poorly understood pulmonary side effects caused by immunotherapies such as the checkpoint inhibitor atezolizumab3. We observed a decrease in immunosuppressive T cells and identified gene signatures that matched the transcriptomic profile of patients with drug-induced pneumonitis. Given its effectiveness in capturing outcomes and mechanisms associated with a prevalent pulmonary disease, this system unlocks opportunities for studying a wide range of immune-related pathologies in the lung.

cell biology↗

Human intestinal organoids with an autologoustissue-resident immune compartment

The intimate relationship between the epithelium and the immune system is crucial for maintaining tissue homeostasis, with perturbations in epithelial-immune interactions linked to autoimmune disease and cancer. Whereas stem cell-derived organoids are powerful models of tissue-specific epithelial function, these structures lack tissue-resident immune cells that are essential for capturing organ-level processes. We describe human intestinal immuno-organoids (IIOs), formed through self-organization of epithelial organoids and autologous tissue-resident lymphocytes (TRMs), a portion of which integrate within the IIO epithelium and survey the barrier. IIO formation was driven by TRM migration and interaction with epithelial cells, as orchestrated by TRM-enriched transcriptomic programs governing cell motility and epithelial inspection. We combined IIOs and single-cell transcriptomics to investigate intestinal inflammation triggered by cancer-targeting biologics in patients, and found that the system recapitulates clinical outcomes and the underlying cellular mechanisms. Inflammation was associated with the emergence of an activated population of CD8+ T cells, which progressively acquired intraepithelial and cytotoxic features. The appearance of this effector population was preceded and likely mediated by a Th1-like CD4+ population, which initially displayed a cytokine-producing character and subsequently became cytotoxic itself. A system amenable to direct perturbation and interrogation, IIOs allowed us to identify the Rho pathway as a novel target for mitigating immunotherapy-associated intestinal inflammation. Given that they recapitulate both the phenotypic outcomes and the underlying inter-lineage immune interactions, IIOs can be used to broadly study tissue-resident immune responses in the context of tumorigenesis, infectious and autoimmune diseases.

immunology↗

Human immunocompetent Organs-on-Chips platforms allow safety profiling of tumor-targeted T-cell bispecific antibodies

AbstractTraditional drug safety assessment often fails to predict complications in humans, especially when the drug targets the immune system. Here, we show the unprecedented capability of two Organs-on-Chips to evaluate the safety profile of T-cell bispecific antibodies (TCBs) targeting tumor antigens. Although promising for cancer immunotherapy, TCBs are associated with an on-target, off-tumor risk due to low levels of expression of tumor antigens in healthy tissues. We leveraged in vivo target expression and toxicity data of TCBs targeting folate receptor 1 (FOLR1) or carcinoembryonic antigen (CEA) to design and validate human immunocompetent Organs-on-Chips safety platforms. We discovered that the Lung-Chip and Intestine-Chip could reproduce and predict target-dependent TCB safety liabilities, based on sensitivity to key determinants thereof, such as target expression and antibody affinity. These novel tools broaden the research options available for mechanistic understandings of engineered therapeutic antibodies and assessing safety in tissues susceptible to adverse events.

cancer biology↗