Biology subjects

Yilgor, C.

Publications and source records attributed to Yilgor, C..

3 recordsLinked to original sources

bioRxiv2025

Modeling Immunosenescence on-a-chip: a platform for cancer vaccine efficacy assessment

Immunosenescence dramatically reduces cancer vaccine efficacy in elderly patients, who represent the majority of cancer cases. Despite this clinical reality, age-related immune decline is rarely considered in preclinical testing. Therefore, novel in vitro models to test cancer vaccine efficacy, considering immunosenescence, are needed. Our novel lymph node paracortex on-a-chip (LNPoC) platform addresses this gap by recapitulating age-dependent immune responses against cancer vaccines, specifically antigen presentation, antigen-specific T cell activation, and antitumoral responses. Using this platform, we demonstrated that bone marrow-derived antigen-presenting cells (APCs) from young mice (6-7 weeks) displayed significantly enhanced ovalbumin (OVA) peptide presentation compared to APCs from older mice (35-36 weeks). This age-dependent difference translated to significantly greater OVA-specific CD8+ T cell activation and increased cytotoxicity against B16-OVA cancer cells. These age-dependent differences are unique to our LNPoC and undetectable in traditional 2D cultures, confirming that our LNPoC was more effective than 2D cultures at recapitulating immunosenescence-mediated immune responses against cancer vaccines in vitro. The in vivo validation confirms these findings, as young mice demonstrated higher OVA-specific CD8+ T cell responses and smaller tumors than older mice. Our LNPoC is a valuable tool for assessing immunosenescences impact on cancer vaccines, potentially guiding more effective therapies for older adults.

bioengineering↗

bioRxiv2024

Microphysiological system modeling pericyte-induced temozolomide resistance in glioblastoma

Glioblastoma (GBM) is a malignancy with poor survival and high rates of chemoresistance. Temozolomide (TMZ), the standard-of-care chemotherapy for GBM patients, but GBM cells can be resistant to TMZ, resulting in limited clinical efficacy. Elucidating the complex mechanisms of TMZ chemoresistance in GBM requires novel in vitro models replicating the complex tumor microenvironment (TME). We present an multicellular 3D GBM model recapitulating the biomechanical characteristics of brain tissues and pericyte-mediated TMZ resistance. The composite hydrogel used to encapsulate GBM spheroids (U87, LN229, and PDM140), pericytes, or GBM spheroids with pericytes, mimics the rheological properties of brain tissues (G[~]800Pa and G"[~]100Pa). When untreated, the GBM models remain viable and proliferative for 14 days. PDM140 spheroids were most sensitive to TMZ (IC50=73M), followed by LN229 (IC50=278M) and U87 (IC50=446M). With pericytes, the viability of TMZ-treated GBM spheroids significantly increases by 22.7% for PDM140, 32.5% for LN229, and 22.1% for U87, confirming pericyte-induced GBM chemoresistance responses. The upregulation (380-fold) of C-C motif chemokine ligand 5 (CCL5) in pericytes upon TMZ treatment could explain the chemoresistance responses. This innovative brain-mimicking 3D GBM model represents a novel in vitro platform for testing the efficacy of TMZ and novel drugs targeting CCL5-mediated chemoresistance pathways in GBM.

bioengineering↗

bioRxiv2024

Human Organoid Tumor Transplantation Identifies Functional Glioblastoma - Microenvironmental Communication Mediated by PTPRZ1

Glioblastoma, the most aggressive and deadly form of primary brain cancer, is driven by both intrinsic cellular properties and external factors from the tumor microenvironment. Here, we leverage our novel human organoid tumor transplantation (HOTT) system to explore how extrinsic cues modulate glioblastoma cell type specification, heterogeneity, and migration. We show that HOTT recapitulates the core features of major patient tumor cell types and key aspects of peritumor cell types, while providing a human microenvironment that uniquely enables perturbations in both the patient tumor and its microenvironment. Our exploration of patient tumor - microenvironmental interactions in HOTT highlighted PTPRZ1, a receptor tyrosine phosphatase implicated in tumor migration, as a key player in intercellular communication. We observed that tumor knockdown of PTPRZ1 recapitulated previously described roles in migration and maintaining progenitor identity. Unexpectedly, environmental PTPRZ1 knockdown drove opposite migration and cell fate changes in the tumor, even when the tumor was not manipulated. This previously undiscovered mode of tumor-microenvironmental communication highlights the need to study human glioblastoma in the context of a human microenvironment such as HOTT.

cancer biology↗