Biology subjects

Basi, A.

Publications and source records attributed to Basi, A..

3 recordsLinked to original sources

bioRxiv2026

Niche-level immune evasion in TP53 mutant AML residual disease revealed by spatial proteomics

Measurable (or minimal) residual disease (MRD) predicts relapse in patients with acute myeloid leukemia (AML). However, the biological and spatial characteristics of the AML bone marrow (BM) microenvironment (BMME) in which MRD cells survive remain largely unexplored; in particular, little is known of the BMME in TP53 mutant (TP53mut) AML. Here, we applied sequential immunofluorescence to whole BM biopsy specimens obtained from patients with TP53 wild-type (TP53WT) AML and TP53mut AML at diagnosis and in morphological complete remission (CR) to generate a comprehensive spatial map of the hematopoietic and BMME components. We identified TP53mut leukemia cells based on high p53 expression and delineated their spatial organization relative to stromal and immune niches. Biopsy-based cell composition analysis revealed marked B-cell depletion and an increased abundance of regulatory T-cells (Tregs) in TP53mut BM at CR. Unlike TP53WT BM, TP53mut BM at CR exhibited persistent TP53mut erythroid and immature leukemia cell clusters, spatially segregated from T-cell clusters, in perisinusoidal niches, suggesting niche-level immune evasion. Spatial profiling further revealed that Tregs characterized by FOXP3 upregulation were enriched near TP53mut MRD cells, indicating a locally enhanced immunosuppressive activity. Single-cell RNA sequencing-based cell-cell communication analysis identified erythroid-T-cell interactions mediated by the GDF15-CD48 axis as a potential mechanism of T-cell suppression, suggesting that the erythroid differentiation of TP53mut AML cells enhances local immunosuppression. Collectively, our results show a spatially organized immunosuppressive BMME in TP53mut AML and highlight the potential of spatial proteomics to identify actionable MRD niches in leukemias. Key pointsO_LITP53 mutant erythroid and immature leukemia cells form spatial clusters segregated from T-cells in complete remission. C_LIO_LIAn erythroblast-centered immunosuppressive niche characterizes TP53 mutant leukemia cells. C_LI

cancer biology↗

bioRxiv2025

Macrophage-Dendritic Cell-T-Cell Tetrads Orchestrate Antitumor Immunity and Response to Checkpoint Blockade

Immune checkpoint inhibitors (ICIs) elicit durable responses in only a subset of patients with solid tumors, underscoring the need to define the cellular architectures that govern effective antitumor immunity. Here we identify a spatially organized multicellular immune unit comprising macrophages, cDC1s, CD4 T-cells, and CD8 T-cells that emerges in response to anti-CTLA-4 or dual checkpoint blockade. We term these structures tetrads. Using multiplexed imaging and spatial transcriptomics in mouse and human tumors, we show that tetrads assemble early during immune priming, depend on the ICOS-ICOSL pathway, and are enriched for ICOS Th1-like CD4 T cells and ICOSLhigh cDC1s. CD8 T-cells within tetrads exhibit an activated, non-terminally differentiated state, while tetrad-associated macrophages display an interferon-{gamma}-responsive program that sustains CD8 T-cell function and prevents dysfunction. Functionally, ICOSL cDC1s are required for tumor eradication in vivo. In patients with bladder cancer treated with neoadjuvant dual checkpoint blockade, tetrad, but not triad or dyad formation correlates with clinical response. These findings establish tetrads as a fundamental cellular unit coordinating antitumor immunity and responsiveness to ICIs.

immunology↗

bioRxiv2025

Integrated single cell spatial multi-omics landscape of WHO grades 2-4 diffuse gliomas identifies locoregional metabolomic regulators of glioma growth

Diffuse infiltrating gliomas are aggressive tumors of the central nervous system driven by intra-tumoral heterogeneity and aberrant normal-tumor cell-cell interactions. Grade specific and locoregional metabolic dependencies driving aberrant cell-states linked to treatment resistance, seizures and infiltration of gliomas remain elusive. Here, we applied spatial transcriptomics (stRNAseq), imaging mass cytometry (IMC) and mass spectrometry imaging (MSI; metabolites, peptides and glycans) to the core and edge tumor tissue from patients with World Health Organization (WHO) grades 2-4 diffuse infiltrating gliomas including isocitrate dehydrogenase (IDH) mutant oligodendrogliomas (WHO Grades 2 and 3) and IDH wildtype astrocytomas including anaplastic astrocytoma (prior 2016 WHO histological grade 3) and glioblastoma (GBM, WHO grade 4) stRNAseq identified regions-specific differentially expressed genes with significant overall survival implications particularly in IDH wildtype GBM. Integration of stRNA seq and MSI-derived metabolite expression demonstrated enrichment of L-glutamine in SOX4+ Neural progenitor-like (NPC-like) cells and DL-dopamine in GPNMB+ Mesenchymal-like (MES-like) GBM cells at the tumor edge relative to the core. Our results uncover clinically relevant and locoregional cell state-specific metabolites that may contribute to GBM proliferation, infiltration and seizures. This comprehensive pan-diffuse infiltrating glioma multi-omics study could serve as a resource for uncovering region-specific metabolic vulnerabilities encompassing metabolites, glycans and peptides within transcriptionally defined cell states across WHO 2-4 diffuse glioma.

cancer biology↗