Biology subjects

Hübner, J.

Publications and source records attributed to Hübner, J..

5 recordsLinked to original sources

bioRxiv2025

A novel CAR T cell blend targeting PDPN and GD2 to overcome glioblastoma heterogeneity

BackgroundWhile chimeric antigen receptor (CAR) T cells have achieved encouraging remission rates in hematological malignancies, they demonstrated limited success in treating Glioblastoma (GBM), particularly due to high intra- and intertumoral heterogeneity. In this study, we identified a relevant and preserved target antigen, Podoplanin (PDPN), and evaluated the potential of a PDPN- and GD2-CAR T cell blend to overcome GBM heterogeneity. MethodsTarget antigen screening included clinical samples, healthy tissues and cell lines, as well as publicly available RNA sequencing datasets. The anti-tumor function of CAR T cells were examined in co-culture experiments with GBM cell lines and patient-derived organoids (PDOs), and in vivo after locoregional delivery in orthotopic xenograft models. ResultsThe generated CAR T cells demonstrated strong anti-tumor activity against several cell lines and PDOs from multiple patients. PDPN and GD2 expression was detectable in all PDOs at varying densities and regardless of the antigenic profile, the CAR T cell blend induced significantly higher levels of apoptosis in organoids than single antigen targeting counterparts. In vivo, we observed efficient tumor regression after locoregional administration of monospecific CAR T cells. While heterogeneous orthotopic tumors eventually relapsed in these groups, blended therapy resulted in a significantly increased overall survival and even achieved cure in the majority of mice. ConclusionThis novel PDPN-/GD2-CAR T cell blend demonstrated strong efficacy in advanced preclinical models of glioblastoma. The results suggest that this approach can overcome GBM heterogeneity in clinical application and address previous limitations of single antigen CAR T cell therapies. KEYPOINTSO_LIPDPN is a relevant and consistent CAR T cell target antigen in primary and recurrent GBM C_LIO_LIPDPN- and GD2-CAR T cells display synergistic anti-tumor activity in patient-derived organoids C_LIO_LILocal delivery of our CAR T cell blend confers long-term survival and cure in GBM-bearing mice C_LI IMPORTANCE OF THE STUDYThe highly variable landscape of tumor antigens in GBM represents a serious obstacle to single antigen CAR T cell therapies. In this study, we identified Podoplanin (PDPN) and GD2 as the most preserved target antigens in a screening campaign, with an even increased density in recurrent GBM compared to primary GBM. We combined PDPN- and GD2-CAR T cells in a blended treatment approach to counter antigen heterogeneity, and achieved a substantial gain in efficacy against patient-derived organoids (PDOs). In an orthotopic xenograft model, locoregional administration of the PDPN- and GD2-CAR T cell blend conferred long-term complete remission and increased survival compared to single antigen targeting. This study provides a hierarchy of CAR target antigens for treating GBM and illustrates the therapeutic potential of combinatorial antigen targeting using a PDPN/GD2-CAR T cell blend. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=89 SRC="FIGDIR/small/636223v1_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@109a9aaorg.highwire.dtl.DTLVardef@16215faorg.highwire.dtl.DTLVardef@910623org.highwire.dtl.DTLVardef@129f79c_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGRAPHICAL ABSTRACT:C_FLOATNO C_FIG

immunology↗

bioRxiv2024

Image-Based Recognition of Parasitoid Wasps Using Advanced Neural Networks

Hymenoptera have some of the highest diversity and number of individuals among insects. Many of these species potentially play key roles as food sources, pest controllers, and pollinators. However, little is known about their diversity and biology, and about 80% of the species have not been described yet. Classical taxonomy based on morphology is a rather slow process, but DNA barcoding has already brought considerable progress in identification. Innovative methods such as image-based identification and automation can even further speed up the process. We present a proof of concept for image data recognition of a parasitic wasp family, the Diapriidae (Hymenoptera), obtained as part of the GBOL III project. These tiny (1.2 - 4.5 mm) wasps were photographed and identified using DNA barcoding to provide a solid ground truth for training a neural network. Subsequently, three different neural network architectures were trained, evaluated, and optimized. As a result, 11 different classes of diaprids and one class of "other Hymenoptera can be classified with an average accuracy of 96%. Additionally, the sex of the specimen can be classified automatically with an accuracy of > 96%.

zoology↗

bioRxiv2023

Hydrophobic Clusters Direct Folding of a Synthetic Chimeric Protein

Extant proteins frequently share sub-domain sized fragments, suggesting that among other mechanisms, proteins evolved new structure and functions via recombination of existing fragments. While the role of protein fragments as evolutionary units is well-established, their biophysical features necessary for generating a well-folded and stable protein are not clearly understood. In order to probe how fragments determine foldability and stability of recombined proteins, we investigated the stability, folding and dynamics of a synthetic chimera created by fusion of fragments of the chemotactic response regulator protein CheY that belongs to the flavodoxin-like fold and imidazole glycerol phosphate synthase from histidine biosynthesis (HisF) which harbors the TIM-barrel fold. The chimera unfolds via an equilibrium intermediate. Mutation of a glycine residue present at the interface of the CheY and HisF fragments to a valine abrogates the equilibrium intermediate while mutation to isoleucine dramatically increases the native state kinetic stability without any significant change in the folding rate. Parts of the fragment interface in the chimera are found to be conformationally dynamic while hydrophobic mutations globally increase its conformational rigidity. We hypothesize that the hydrophobic mutation improves sidechain packing in a large cluster of isoleucine, leucine and valine (ILV) residues that spans the fragment interface. We also extrapolate that inheritance of large ILV clusters from parent proteins could be a key determinant of successful fragment recombination.

biophysics↗

bioRxiv2022

Nutritional and host environments determine community ecology and keystone species in a synthetic gut bacterial community

Microbe-microbe interactions are critical for gut microbiome function. A challenging task to understand health and disease-related microbiome signatures is to move beyond descriptive community-level profiling towards disentangling microbial interaction networks. Here, we aimed to determine members taking on a keystone role in shaping community ecology of a widely used synthetic bacterial community (OMM12). Using single-species dropout communities and metabolomic profiling, we identified Bacteroides caecimuris I48, Blautia coccoides YL58 and Enterococcus faecalis KB1 as major drivers of in vitro community assembly and elucidated underlying mechanisms of these keystone functions. Importantly, keystone species and bacterial strain relationships were found to strongly vary across different nutritional conditions, depending on the strains potential to modify the corresponding environment. Further, gnotobiotic mice transplanted with communities lacking B. caecimuris I48 and B. coccoides YL58 exhibited morphological anomalies and altered intestinal metabolomic profiles, exposing physiologically relevant functions of these keystone community members. In summary, the presented study experimentally confirms the strong interdependency between bacterial community ecology and the biotic and abiotic environment, underlining the context-dependency and conditionality of bacterial interaction networks.

ecology↗

bioRxiv2022

A conserved and tunable mechanism for the temperature-controlled condensation of the translation factor Ded1p

Heat shock promotes the assembly of translation factors into condensates to facilitate the production of stress-protective proteins. How translation factors detect heat and assemble into condensates is not well understood. Here, we investigate heat-induced condensate assembly by the translation factor Ded1p from five different fungi, including Ded1p from Saccharomyces cerevisiae. Using targeted mutagenesis and in vitro reconstitution biochemistry, we find that heat-induced Ded1p assembly is driven by a conformational rearrangement of the folded helicase domain. This rearrangement determines the assembly temperature and the assembly of Ded1p into nanometer-sized particles, while the flanking intrinsically disordered regions engage in intermolecular interactions to promote assembly into micron-sized condensates. Using protein engineering, we identify six amino acid substitutions that determine most of the thermostability of a thermophilic Ded1p ortholog, thereby providing a molecular understanding underlying the adaptation of the Ded1p assembly temperature to the specific growth temperature of the species. We conclude that heat-induced assembly of Ded1p into translation factor condensates is regulated by a complex interplay of the structured domain and intrinsically disordered regions which is subject to evolutionary tuning.

biochemistry↗