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Holzinger, S.

Publications and source records attributed to Holzinger, S..

3 recordsLinked to original sources

Timed STING Inhibition Mitigates Gastrointestinal GvHD While Preserving Graft-versus-Leukemia Activity After Allo-HSCT

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is curative for hematological malignancies but limited by graft-versus-host disease (GvHD), in which donor T cells damage host tissues. Current prophylaxis broadly suppresses donor immunity, often compromising the beneficial graft-versus-leukemia (GvL) response, highlighting the need for strategies that uncouple GvHD from GvL. The cGAS-STING pathway can be strongly activated during conditioning-induced tissue damage and represents a potential therapeutic target. However, its context-dependent roles in inflammation and homeostasis have constrained its clinical translation. Here, we show that "timed" administration of the covalent STING inhibitor H151 before conditioning reduced GvHD-associated mortality without impairing GvL in murine allo-BMT models. Donor T cell activation and effector function were preserved, indicating that the protective effect operates at the level of GvHD target tissues rather than through systemic immunosuppression. Timed STING inhibition protected the intestinal epithelium by limiting apoptosis, preserving intestinal stem cell function, and sustaining metabolic fitness during conditioning-induced injury, independently of type I interferon (IFN-I) signaling. In allo-HSCT patients, low intestinal STING expression is associated with reduced transplant-related mortality. Together, these findings identify timed STING inhibition as a tissue-protective prophylactic strategy that could be incorporated into existing conditioning regimens to enhance efficacy while minimizing toxicity.

immunology↗

Deciphering chromatin architecture and dynamics in Plasmodium falciparum using the nucDetective pipeline

High-resolution analysis of cellular chromatin structure is crucial for uncovering developmental and cell-type-specific regulatory networks. We developed the nucDetective pipeline to provide a comprehensive evaluation of chromatin organisation. This involves assessing nucleosome positioning, occupancy, fuzziness, and array regularity. The pipeline was benchmarked by analysing the chromatin structure of the malaria-causing parasite Plasmodium falciparum (Pf) during its erythrocytic development cycle. Pf is characterised by a unique chromatin landscape, exhibiting unstable nucleosomes and a genomic AT-content exceeding 80%, which presents challenges for standard MNase-seq analysis of chromatin. The nucDetective pipeline provides specific, high-resolution nucleosome profiles for the different asexual stages of Pf, monitoring the dynamics of individual nucleosomes. In contrast to the current view, suggesting an irregular chromatin structure and lack of nucleosomal DNA, we demonstrate that the transcription start sites exhibit typical eukaryotic features, including +1 nucleosomes, nucleosome-free regions upstream, and phased nucleosome arrays downstream of the TSSs. The global mean nucleosome repeat length varies from 176 bp to 185 bp depending on the developmental stage. Stage specific changes in nucleosome positioning occur locally in intergenic regulatory regions, which are characterized by specific histone modifications and variants. Dynamic nucleosomes correlate with DNA accessibility, gene expression and determine the access to transcription factor binding sites in Pf. The highly regular chromatin structure, with stage-specific structural alterations, emphasises the important role of epigenetic mechanisms in regulating the complex life cycles of Pf.

bioinformatics↗

Adenovirus maturation establishes the transcription competent packaging of its genome

Adenoviruses are human pathogens that, more recently have gathered interest as tools for human gene therapy and vaccination. During their replication, adenoviruses undergo a critical maturation step culminating in the infectious particle. While the structural changes in the adenovirus protein shell during maturation have been subject to previous research, the maturation of the viral genome with associated proteins (core) remains largely unexplored. Here, we show that the adenovirus core maturation is guided by features embedded in the viral DNA sequence, which primes the genome for transcription. Using DMS-seq to compare the accessibility of the nucleoprotein core structure before and after maturation (using the maturation deficient ts1 mutant), we identified five genomic regions that become specifically decompacted during maturation. These regions are characterized by low GC-content and are evolutionarily conserved across different adenovirus species, independent of protein-coding constraints. We show that adenoviral DNA packaging is guided by a distinct 6.1-bp dinucleotide periodicity pattern that helps position viral chromatin proteins. Core processing during maturation serves a dual purpose: (i) it contributes to capsid uncoating by increasing internal pressure while (ii) simultaneously preparing the chromatin structure of the genome for rapid transcription upon nuclear entry. These findings reveal how sequence-encoded structural information guides adenoviral genome organization and suggest new approaches for optimizing adenoviral vectors used in gene therapy and vaccination.

molecular biology↗