Biology subjects

Garcia, Z.

Publications and source records attributed to Garcia, Z..

5 recordsLinked to original sources

bioRxiv2026

T cell engagers convert acute tumor killing into endogenous vaccination

T cell engagers (TCEs) redirect T cells to kill tumors by cross-linking CD3{varepsilon} to a tumor antigen, independently of T cell receptor specificity. Some patients achieve remissions that persist long after drug clearance, but whether TCEs can couple acute cytotoxicity to the generation of lasting adaptive immunity remains unknown. Here, using an immunocompetent mouse model for clinical-grade human TCEs, we show that TCE-mediated killing initiates an endogenous vaccination cascade. Intravital two-photon imaging reveals a perforin-dependent cytotoxic wave that peaks within 24 hours, then subsides despite massive T cell accumulation. Single-cell transcriptomics and adoptive transfers demonstrate that memory CD8 T cells, the principal effector reservoir in mouse and human, transit through a progenitor-like state before differentiating into cytotoxic effectors with recall competence. Crucially, tumor lysis fuels cross-priming of tumor-specific CD8 T cells by XCR1 type 1 conventional dendritic cells, a cDC1-dependent step essential for durable tumor control and protective memory upon rechallenge.

immunology↗

bioRxiv2026

CAR-MACROPHAGES ACTIVATE ANTI TUMOR T CELLS IN THE ABSENCE OF PHAGOCYTOSIS

Macrophages are highly abundant within the tumor microenvironment and serve as an essential bridge between innate and adaptive immune responses. Thus, they have emerged as promising candidates for chimeric antigen receptor (CAR)-based therapeutic strategies. Previous studies demonstrated that adenovirally-transduced CAR-macrophages (CAR-M), used in clinical trials, can perform tumor cell phagocytosis, reshape the tumor microenvironment towards a proinflammatory state, and promote host T cell activation. However, how early interactions between CAR-M and tumor cells shape subsequent T cell effector functions remains poorly understood. Particularly, uncoupling the adenoviral-induced proinflammatory phenotype from CAR-M effector functions remains to be dissected. Here, using phagocytosis-optimized CAR-Ms, we demonstrated that T cells are crucial mediators of CAR-M therapeutic efficacy. Mechanistically, we identify that CAR-M-derived cytokines and chemokines are key drivers of T cell functions while antigen cross presentation appears largely dispensable. Dynamic imaging of CAR-M-tumor cell interactions revealed heterogenous phagocytic abilities, regardless of contact duration. Finally, we show that non-phagocytic interactions can instruct pro-inflammatory macrophage repolarization and subsequent T cell activation. Altogether, these findings define an alternative mode of CAR-M action in which CAR engagement alone, independently of target cell uptake, is sufficient to enhance T cell functions. Our study underscores the importance of non-phagocytic CAR signaling as an additional mechanism for CAR-M effector functions opening new avenues for the design of next generation CAR for macrophage-based therapies.

immunology↗

bioRxiv2025

Met-Vision stratifies single cell metabolism revealing coexisting energetic states in tissue macrophages redistributed by inflammation

The function of tissue-associated macrophages is tightly linked to their energy metabolism. Yet, the diversity of macrophage metabolic profiles coexisting in tissues at homeostasis or during immune challenges is incompletely understood. Here, we introduce Met-Vision, an imaging-based pipeline for single-cell functional profiling and classification of energy metabolism. Across multiple tissue contexts, we identified that macrophages do not adopt a uniform metabolic profile but typically co-exist in four discrete metabolic states with distinct dependence on OXPHOS and metabolic plasticity. Inflammation reconfigured the distribution of macrophage metabolic profiles that remained heterogeneous. Notably, inflammation-derived nitric oxide finely tuned the distribution of macrophage energetic states. These findings challenge the view of homogenous metabolic activation and reveal a layer of metabolic diversity in tissue at steady state and during inflammation. The ability to stratify macrophage energy metabolic profiles with Met-Vision should help guide the development of metabolism-targeted therapies for inflammatory diseases, cancer, and metabolic disorders. Significance statementThis study introduces Met-Vision and reveal that tissue macrophages occupy four distinct energetic states, challenging the notion of uniform metabolic activation and opening avenues for guiding metabolism-targeted therapies.

immunology↗

bioRxiv2020

Imaging the mechanisms of anti-CD20 therapy in vivo uncovers spatiotemporal bottlenecks in antibody-dependent phagocytosis

Anti-CD20 monoclonal antibody (mAb) represents an effective strategy for the treatment of B cell malignancies that may involve complement activity, antibody dependent cellular cytotoxicity (ADCC) and phagocytosis (ADP). While ADP mediated by Kupffer cells is essential to deplete circulating tumors, the relative contribution of each mechanism to the elimination of non-circulating targets has yet to be clarified. Using intravital imaging in a model of MYC-driven B cell lymphoma, we establish here the dominance and limitations of ADP in the bone marrow (BM). We found that tumor cells were stably residing in the BM with little evidence for recirculation. To quantify the contribution of different cytotoxic mechanisms in situ, we designed a dual fluorescent reporter to track phagocytosis and apoptosis in real-time. ADP by BM-associated macrophages was the primary mode of tumor elimination but was no longer active after one hour, resulting only in partial depletion. Moreover, macrophage density was strongly reduced in tumor-rich regions. Given their sessile phenotype, macrophages primarily targeted neighboring tumors, resulting in a substantial spatial constraint. Overcoming spatiotemporal bottlenecks in tumor-targeting Ab therapy represents a critical path towards the design of optimized therapies. Key pointsO_LIFunctional intravital imaging establishes antibody-dependent phagocytosis as the major mechanism acting at the tumor site during anti-CD20 therapy. C_LIO_LIA transient wave of phagocytosis and a limited macrophage density restrict the efficiency of anti-CD20 anti-tumor activity. C_LI

immunology↗

bioRxiv2019

CLASP2 lattice-binding near microtubule plus ends stabilizes kinetochore attachments

The fine regulation of kinetochore microtubule dynamics during mitosis ensures proper chromosome segregation by promoting error correction and spindle assembly checkpoint (SAC) satisfaction. CLASPs are widely conserved microtubule plus-end-tracking proteins that regulate microtubule dynamics throughout the cell cycle and independently localize to kinetochores during mitosis. Thus, CLASPs are ideally positioned to regulate kinetochore microtubule dynamics, but the underlying molecular mechanism remains unknown. Here we found that human CLASP2 can dimerize through its C-terminal kinetochore-targeting domain, but kinetochore localization was independent of dimerization. CLASP2 kinetochore localization, microtubule plus-end-tracking and microtubule lattice binding through TOG2 and TOG3 (but not TOG1) domains, independently sustained normal spindle length, timely SAC satisfaction, chromosome congression and faithful segregation. Measurements of kinetochore microtubule half-life in living cells expressing RNAi-resistant mutants revealed that CLASP2 kinetochore localization, microtubule plus-end-tracking and lattice binding cooperatively modulate kinetochore microtubule stability during mitosis. Thus, CLASP2 regulates kinetochore microtubule dynamics by integrating distinctive microtubule-binding properties at the kinetochore-microtubule interface to ensure chromosome segregation fidelity.

cell biology↗