Biology subjects

Bartoszek, E.

Publications and source records attributed to Bartoszek, E..

5 recordsLinked to original sources

bioRxiv2026

CD117 epitope-shielded hematopoietic stem cell transplantation with toxin-free conditioning and in vivo selection ameliorates β-thalassemia model

Clinical evidence demonstrates that ex vivo gene therapy and genome engineering of hematopoietic stem and progenitor cells (HSPCs) could represent one-time cures. However, while genome editing itself has become increasingly efficient and precise, the toxic conditioning required for hematopoietic stem cell transplantation remains a major barrier to broad clinical implementation of these otherwise curative therapies. In particular, the use of busulfan for myeloablative conditioning constitutes a major safety concern. While preclinical studies established CD117 as a promising target for antigen-specific therapy, clinical translation faced setbacks balancing efficacy and safety. To overcome current limitations, we generated a new CD117-blocking monoclonal antibody (CIM058) and demonstrate its potency to block wild-type HSPCs. To enable long-term blockade of host HSPCs even after transplantation, we used prime editing to engineer CIM058-resistant human CD34+ HSPCs. When combined, CIM058 and the epitope engineered CD34+ HSPCs ameliorated disease phenotype in a {beta}-thalassemia model. Our results suggest that this approach may overcome the reliance on busulfan or other myeloablative conditioning regimens with their associated morbidities, and by enabling toxin-free conditioning and in vivo selection of edited cells, may facilitate clinical implementation of these highly valuable genetic therapies.

bioengineering↗

bioRxiv2026

Persistent Staphylococcus aureus in human musculoskeletal tissues despite targeted antibiotic therapy

Staphylococcus aureus is a leading cause of musculoskeletal infection with frequent recurrence despite surgery and antibiotic therapy. Its persistence in human tissues under antibiotic pressure remains unclear. We performed longitudinal in situ analyses of matched tissue samples before and during therapy from patients undergoing repeated surgery using advanced imaging and tissue-based metagenomics. S. aureus remained detectable in all samples--including culture-negative specimens--and whole-genome sequencing confirmed persistence of the infecting strain. Antibiotic initiation reduced bacterial burden by 1.0Slog10 bacteria/mm3 but residual loads stabilized thereafter. Quantitative imaging identified a culture detection threshold ([~]103bacteria/mm3), indicating that culture negativity reflects diagnostic sensitivity limits rather than true bacterial clearance. Persistence under antibiotic therapy was associated with high baseline burden and intracellular sequestration, whereas long-term persistence was characterized by predominantly extracellular bacteria capable of driving relapse. These findings reveal sustained tissue persistence despite apparent microbiological clearance and guide precision strategies to target resilient bacterial reservoirs.

microbiology↗

bioRxiv2025

HIF-1α+ CD4 T cells coordinate a tissue resident immune cell network in the lung

A deeper understanding of how tissue localized immune cells arise and function is critical for developing mucosal vaccines. Currently, there are no murine models that specifically target tissue T cells while leaving their lymphoid counterparts untouched. Here we leverage the observation that during influenza infection, HIF-1 regulatory activity is higher in the lung compared to lymph node CD4 T cells. Inducible deletion of Hif1a in CD4 T cells, at the onset of its activity in the lung, reduces the tissue resident T cell compartment with minimal impact on peripheral immunity. HIF-1-active CD4 T cells occupy the border of tertiary lymphoid structures, where they coordinate an IL-21-dependent network of spatially co-localized immune cells including macrophages, NK cells and IgA+ B cells. A similar HIF-1-dependent network is engaged in a lung adenocarcinoma model, highlighting a broader role for HIF-1+ CD4 T cells in integrating protective immunity during infection and cancer.

immunology↗

bioRxiv2022

Immunotherapy of glioblastoma explants induces interferon-γ responses and immune cell rearrangements in tumor center, but not periphery

Recent therapeutic strategies for glioblastoma (GBM) aim at targeting immune tumor microenvironment (iTME) components to induce antitumoral immunity. A patient-tailored, ex vivo drug testing and response analysis platform for GBM would facilitate personalized therapy planning, provide insights into treatment-induced immune mechanisms in the iTME, and enable the discovery of biomarkers of therapy response and resistance. We cultured 47 GBM explants from tumor center and periphery from 7 patients in perfusion bioreactors to assess iTME responses to immunotherapy. Explants were exposed to antibodies blocking the immune checkpoints CD47, PD-1 or or their combination, and were analyzed by highly multiplexed microscopy (CODEX, co-detection by indexing) using an immune-focused 55-marker panel. Culture media were examined for changes of soluble factors including cytokines, chemokines and metabolites. CODEX enabled the spatially resolved identification and quantification of >850,000 single cells in explants, which were classified into 10 cell types by clustering. Explants from center and periphery differed significantly in their cell type composition, their levels of soluble factors, and their responses to immunotherapy. In a subset of explants, culture media displayed increased interferon-{gamma} levels, which correlated with shifts in immune cell composition within specific tissue compartments, including the enrichment of CD4+ and CD8+ T cells within an adaptive immune compartment. Furthermore, significant differences in the expression levels of functional molecules in innate and adaptive immune cell types were found between explants responding or not to immunotherapy. In non-responder explants, T cells showed higher expression of PD-1, LAG-3, TIM-3 and VISTA, whereas in responders, macrophages and microglia showed higher cathepsin D levels. Our study demonstrates that ex vivo immunotherapy of GBM explants enables an active antitumoral immune response within the tumor center in a subset of patients, and provides a framework for multidimensional personalized assessment of tumor response to immunotherapy.

cancer biology↗

bioRxiv2021

Successful IL-12 cancer immunotherapy requires NK cell-derived CCL5 for anti-tumor DC-T cell crosstalk

T cell-directed cancer immunotherapy often fails to generate lasting tumor control. Harnessing additional effectors of the immune response against tumors may strengthen the clinical benefit of immunotherapies. Here, we demonstrate that therapeutic targeting of the IFN{gamma}-IL-12 pathway relies on the ability of a population of tissue-resident NK (trNK) cells to orchestrate an anti-tumor microenvironment. Particularly, utilizing an engineered adenoviral platform, we show that paracrine IL-12 enhances functional DC-CD8 T cell interactions to generate adaptive anti-tumor immunity. This effect depends on the abundance of trNK cells and specifically their capacity to produce the cDC1-chemoattractant CCL5. Failure to respond to IL-12 and other IFN{gamma}-inducing therapies such as immune checkpoint blockade in tumors with low trNK cell infiltration could be overcome by intra-tumoral delivery of CCL5. Our findings reveal a novel barrier for T cell-focused therapies and offer mechanistic insights into how T cell-NK cell-DC crosstalk can be enhanced to promote anti-tumor immunity and overcome resistance. SignificanceWe identified the lack of CCL5-producing, tissue-resident NK (trNK) cells as a barrier to T cell-focused therapies. While IL-12 induces anti-tumoral DC-T cell crosstalk in trNK cellrich tumors, resistance to IL-12 or anti-PD-1 in trNK cellpoor tumors can be overcome by the additional delivery of CCL5.

immunology↗