Biology subjects

Krausz, M.

Publications and source records attributed to Krausz, M..

3 recordsLinked to original sources

bioRxiv2026

Longitudinal Gut Microbiome Dynamics in Human CTLA-4 pathway Deficiencies: A One-Year Interventional Metagenomic Study

BackgroundCTLA-4 haploinsufficiency (CHAI) and LRBA deficiency cause severe immune dysregulation including enteropathy. Abatacept, a CTLA-4-immunoglobulin fusion protein, targets the underlying pathway defect, but its impact on the gut microbiome remains undefined. MethodsWe performed longitudinal shotgun metagenomics (MetaPhlAn4/HUMAnN3) on stool samples from patients enrolled in the ABACHAI clinical trial, collected at pre-treatment baseline and months 3, 6, and 12. Healthy individuals from the same household served as controls. Compositional and functional microbiome changes were analyzed using linear mixed-effects models and MaAsLin3, and correlated with organ-specific CHAI Morbidity Scores. ResultsAt baseline, patients showed significantly reduced alpha diversity (Shannon index, p=0.0029) and distinct community composition (PERMANOVA p=0.0001) compared to healthy controls, characterised by enrichment of oral-associated taxa (Veillonella, Streptococcus, Lacrimispora) and depletion of butyrate-producing commensals (Ruminococcus, Oscillibacter, Dysosmobacter). Functionally, the baseline metagenome exhibited broad reductions in amino acid and SCFA biosynthesis alongside enrichment of purine salvage and folate pathways. During treatment, beta diversity shifted significantly with treatment duration (Aitchison PERMANOVA R2=0.103, p=0.015), with within-patient community turnover peaking at month 6 ({Delta}=0.216, p=0.006). Longitudinal analyses demonstrated progressive decreases in disease-enriched taxa (Veillonella, Lacrimispora) and recovery of commensals (Collinsella, Adlercreutzia). FDR-significant reductions in microbial folate and purine biosynthesis pathways were observed over the treatment course. Gut CHAI domain severity correlated inversely with butyrate-producer abundance and positively with oral taxon enrichment. ConclusionIn CTLA-4 pathway insufficiency patients, abatacept therapy is associated with an improvement of enteropathy and a progressive, measurable gut microbiome restructuring, positioning microbiome dynamics as a candidate biomarker of treatment response in this monogenic immune dysregulation disorder.

immunology↗

bioRxiv2020

ADA2 is a lysosomal DNase regulating the type-I interferon response

Deficiency of adenosine deaminase 2 (DADA2) is a severe, congenital syndrome, which manifests with hematologic, immunologic and inflammatory pathologies. DADA2 is caused by biallelic mutations in ADA2, but the function of ADA2, and the mechanistic link between ADA2 deficiency and the severe inflammatory phenotype remains unclear. Here, we show that monocyte-derived proteomes from DADA2 patients are highly enriched in interferon response proteins. Using immunohistochemistry and detailed glycan analysis we demonstrate that ADA2 is post-translationally modified for sorting to the lysosomes. At acidic, lysosomal pH, ADA2 acts as a novel DNase that degrades cGAS/Sting-activating ligands. Furthermore, we define a clear structure-function relationship for this acidic DNase activity. Deletion of ADA2 increased the production of cGAMP and type I interferons upon exposure to dsDNA, which was reverted by ADA2 overexpression or deletion of STING. Our results identify a new level of control in the nucleic acid sensing machinery and provide a mechanistic explanation for the pathophysiology of autoinflammation in DADA2. One Sentence SummaryADA2 is a lysosomal nuclease controlling nucleic acid sensing and type I interferon production.

immunology↗

bioRxiv2018

Whole blood and hypertonic saline resuscitation improve the outcomes of controlled hemorrhagic shock combined with penetrating brain injury in rat

One of the most frequent injury patterns leading to early death of polytraumatized patients is hemorrhagic shock combined with traumatic brain injury. Currently, there is no agreement on the best treatment protocol of such injury. This study was aimed to compare the outcomes of resuscitation with various volumes of hypertonic saline (HTS), whole blood (WB) and fresh frozen plasma (FFP) in a rat model of penetrating brain injury combined with controlled hemorrhagic shock in order to look for optimal treatment. Anesthetized rats were intubated and ventilated. 30% of circulating blood volume was withdrawn following open brain injury, and intravenous resuscitation with various volumes of HTS, WB and FFP (3, 9, and 18 ml/kg) was administered. Blood samples were collected during the experiment for measurements of lactate and base excess levels, and before sacrifice for neutrophil counts. Twenty four and 48 hours after the injury, rats neurological status was examined. Rats were, then, sacrificed and pathological studies of brain and lung sections were performed. Regardless of fluid type, resuscitation improved the mean arterial pressure and lactate levels in accordance to fluids volume. However, base excess was improved only when rats were treated with WB and FFP. Improvement in behavioral performance of the rats was observed when treated with 3 and 9 ml/kg HTS or with 18 ml/kg WB or FFP. Blood and lung neutrophils were reduced in rats treated with 9 or 18 ml/kg WB. Mortality rates were reduced in rats administered with 9 and 18 ml/kg of HTS or WB. Taken together, resuscitation with WB at 9-18ml/kg or HTS at 9ml/kg is optimal for treatment of combined injury.

physiology↗