Biology subjects

Zandvliet, M.

Publications and source records attributed to Zandvliet, M..

3 recordsLinked to original sources

bioRxiv2026

A 16-colour spectral flow cytometry panel to characterise T cell immunophenotypes in canine oral melanoma

Advances in immunophenotyping of tumour-infiltrating lymphocytes (TILs) have improved our understanding of prognostic biomarkers and immune targets in human melanoma. However, whether the tumour-immune landscape in canine oral malignant melanoma (COMM) is concordant with that of human melanoma has not been properly defined. To address this gap, we developed a 16-colour spectral flow cytometry panel to characterise TIL phenotypic and functional profiles in COMM. Validation using mitogen-stimulated peripheral blood mononuclear cells from healthy dogs (n = 5) demonstrated robust identification of major T cell lineages, including regulatory T cells (Tregs) and memory subsets, and reliable evaluation of their activation and exhaustion status. COMM patients (n = 8) displayed a distinct protumour microenvironment, characterised by an increased proportion of Tregs, enrichment of tumour-specific exhausted-like T cells co-expressing programmed cell death protein 1 (PD-1) and tumour necrosis factor receptor 2 (TNFR2), and a reduction in cytotoxic CD8 and natural killer T (NKT) cell populations compared with tissue-resident (n = 4) and circulating (n = 8) lymphocytes. Analysis of additional solid tumours, including a mast cell tumour, nerve sheath tumour and adrenal cortical carcinoma, further supported the capability of the panel to identify similar patterns of immune dysregulation across diverse canine tumour landscapes. Collectively, this work describes the first detailed evaluation of canine TIL immunophenotyping using spectral flow cytometry and provides insights into the immunosuppressive mechanisms shaping the tumour microenvironment in COMM. These findings not only increase our understanding of canine tumour immunology but also identify potential immune targets and support ongoing comparative immuno-oncology efforts.

immunology↗

bioRxiv2024

Tuft cells act as regenerative stem cells in the human intestine

In mice, intestinal tuft cells have been described as a long-lived, post-mitotic cell type of which two distinct subsets have been identified, named tuft-1 and tuft-21. By combining analysis of primary human intestinal resection material and intestinal organoids, we identify four distinct human tuft cell states, two of which overlap with their murine counterparts. We show that tuft cell development depends on the presence of Wnt ligands, and that tuft cell numbers rapidly increase upon interleukin (IL)-4 and IL-13 exposure, as reported previously in mouse2-4. This occurs through proliferation of pre-existing tuft cells, rather than through increased de novo generation from stem cells. Indeed, proliferative tuft cells occur in vivo both in fetal and in adult human intestine. Single mature proliferating tuft cells can form organoids that contain all intestinal epithelial cell types. Unlike stem- and progenitor cells, human tuft cells survive irradiation damage and retain the ability to generate all other epithelial cell types. Accordingly, organoids engineered to lack tuft cells fail to recover from radiation-induced damage. Thus, tuft cells represent a damage-induced reserve intestinal stem cell pool in humans.

cell biology↗

bioRxiv2023

Pre-existing Subclones Determine Radioresistance in Rectal Cancer Organoids

More than half of all cancer patients receive radiation therapy, but resistance is commonly observed. Currently, it is unknown whether resistance to radiation therapy is acquired or inherently present. Here, we employed organoids derived from rectal cancer and single-cell whole genome sequencing to investigate the long-term evolution of subclones in response to radiation. Comparing single-cell whole genome karyotypes between unirradiated and irradiated organoids revealed three patterns of subclonal evolution: (i) subclonal persistence, (ii) subclonal extinction, and (iii) subclonal expansion. Only organoids in which subclonal shifts occurred (i.e., expansion or extinction) became more resistant to radiation. Although radioresistant subclones did not share recurrent copy number alterations that could explain their radioresistance, resistance was associated with reduced chromosomal instability; an association that was also observed in 529 human cancer cell lines. These data suggest resistance to radiation is inherently present and associated with reduced chromosomal instability.

cancer biology↗