Biology subjects

Blandin, J.

Publications and source records attributed to Blandin, J..

3 recordsLinked to original sources

bioRxiv2025

Haruka Resolves Perturbation Response Heterogeneity in Spatial Cell Niches

Understanding how tissues remodel in response to perturbations requires computational tools that can untangle condition-specific changes from the conserved tissue architecture. We present Haruka, a spatially aware contrastive learning framework that identifies salient (condition-specific) and background (shared) spatial domains across tissue slices and experimental conditions. Haruka integrates contrastive variational inference with an auxiliary microenvironment reconstruction task, enabling the model to learn spatial-context-informed embeddings that capture both perturbation effects and local neighborhood context. Benchmarking on simulated and real datasets demonstrates superior detection of spatially heterogeneous perturbation responses compared to existing methods. Applied to diverse spatial omics platforms, Haruka distinguished immunotherapy responders in melanoma, traced fibrosis progression in human lung tissue, and mapped treatment-resistant microenvironments in KRASG12D-mutated lung cancer. Extended to spatially resolved multiomics data co-profiling transcriptomics and chromatin accessibility from an LPC-induced neuroinflammation mouse model, using a modality-parallel design that independently models each omics layer before integration, Haruka resolved condition-specific regulatory programs encoded across chromatin and transcriptome layers, linking spatial domain identity to transcription factor network architecture and human psychiatric disease genetics. Thus, Haruka provides a generalizable framework for spatial contrastive analysis, enabling systematic dissection of tissue organization, cellular plasticity, and microenvironmental remodeling across disease contexts and therapeutic perturbations.

bioinformatics↗

bioRxiv2024

CD47 predominates over CD24 as a macrophage immune checkpoint in cancer.

Macrophages hold tremendous promise as effectors of cancer immunotherapy, but the best strategies to provoke these cells to attack tumors remain unknown. Here, we evaluated the therapeutic potential of targeting two distinct macrophage immune checkpoints: CD47 and CD24. We found that antibodies targeting these antigens could elicit maximal levels of phagocytosis when combined together in vitro. However, to our surprise, via unbiased genome-wide CRISPR screens, we found that CD24 primarily acts as a target of opsonization rather than an immune checkpoint. In a series of in vitro and in vivo genetic validation studies, we found that CD24 was neither necessary nor sufficient to protect cancer cells from macrophage phagocytosis in most mouse and human tumor models. Instead, anti-CD24 antibodies exhibit robust Fc-dependent activity, and as a consequence, they cause significant on-target hematologic toxicity in mice. To overcome these challenges and leverage our findings for therapeutic purposes, we engineered a collection of 77 novel bispecific antibodies that bind to a tumor antigen with one arm and engage macrophages with the second arm. We discovered multiple novel bispecifics that maximally activate macrophage-mediated cytotoxicity and reduce binding to healthy blood cells, including bispecifics targeting macrophage immune checkpoint molecules in combination with EGFR, TROP2, and CD71. Overall, our findings indicate that CD47 predominates over CD24 as a macrophage immune checkpoint in cancer, and that the novel bispecifics we created may be optimal immunotherapies to direct myeloid cells to eradicate solid tumors.

cancer biology↗

bioRxiv2024

Unbiased discovery of antibody therapies that stimulate macrophage-mediated destruction of B-cell lymphoma

Macrophages are critical effectors of antibody therapies for lymphoma, but the best targets for this purpose remain unknown. Here, we sought to define a comprehensive repertoire of cell surface antigens that can be targeted to stimulate macrophage-mediated destruction of B-cell lymphoma. We developed a high-throughput assay to screen hundreds of antibodies for their ability to provoke macrophages to attack B-cell lymphoma cells. Across both mouse and human systems, we identified multiple unappreciated targets of opsonization as well as putative immune checkpoints. We used this information to engineer a compendium of 156 bispecific antibodies, and we identified dozens of bispecifics that dramatically stimulate macrophage-mediated cytotoxicity of lymphoma cells. Among these, a bispecific comprising a SIRP decoy domain and a CD38-targeting arm (WTa2d1xCD38) exhibited maximal efficacy while minimizing the risk of hematologic toxicity. This bispecific stimulated robust anti-tumor responses in multiple xenograft models of aggressive B-cell lymphoma. Our approach can be directly applied to other cancers to rapidly discover bispecific antibodies that leverage anti-tumor responses by macrophages or other innate immune cells.

immunology↗