Adenovirus-based vectors are playing an important role as efficacious genetic vaccines to fight the current COVID-19 pandemic. Furthermore, they have an enormous potential as oncolytic vectors for virotherapy and as vectors for classic gene therapy. However, numerous vector–host interactions on a cellular and noncellular level, including specific components of the immune system, must be modulated in order to generate safe and efficacious vectors for virotherapy or classic gene therapy. Importantly, the current widespread use of Ad vectors as vaccines against COVID-19 will induce antivector immunity in many humans. This requires the development of strategies and techniques to enable Ad-based vectors to evade pre-existing immunity. In this review article, we discuss the current status of genetic and chemical capsid modifications as means to modulate the vector–host interactions of Ad-based vectors.

Only two decades after discovering miRNAs, our understanding of the functional effects of deregulated miRNAs in the development of diseases, particularly cancer, has been rapidly evolving. These observations and functional studies provide the basis for developing miRNA-based diagnostic markers or new therapeutic strategies. Adenoviral (Ad) vectors belong to the most frequently used vector types in gene therapy and are suitable for strong short-term transgene expression in a variety of cells. Here, we report the set-up and functionality of an Ad-based miRNA vector platform that can be employed to deliver and express a high level of miRNAs efficiently. This vector platform allows fast and efficient vector production to high titers and the expression of pri-miRNA precursors under the control of a polymerase II promoter. In contrast to non-viral miRNA delivery systems, this Ad-based miRNA vector platform allows accurate dosing of the delivered miRNAs. Using a two-vector model, we showed that Ad-driven miRNA expression was sufficient in down-regulating the expression of an overexpressed and highly stable protein. Additional data corroborated the downregulation of multiple endogenous target RNAs using the system presented here. Additionally, we report some unanticipated synergistic effects on the transduction efficiencies in vitro when cells were consecutively transduced with two different Ad-vectors. This effect might be taken into consideration for protocols using two or more different Ad vectors simultaneously.

The adenoviral vector based AstraZeneca and Janssen COVID vaccines have been associated with rare cases of thrombosis, a condition which depends on adenovirus binding to the blood protein Platelet Factor 4 (PF4). In order to identify adenoviruses with low or absent affinity for PF4, we screened dozens of types from various adenovirus species, and Adenovirus type 5 (Ad5) derived vectors carrying genetic or chemical modifications of different hexon hyper-variable regions (HVR). For this purpose, we established an armamentarium of techniques including ELISA-qPCR and Aggregate Pull-Down (APD), which enabled fast and sensitive assessments of virus-protein interactions. Unlike most tested serotypes, Ad34 did not bind to PF4. Likewise, the deletion or shielding of the HVR1 loop of Ad5 seemingly ablated its PF4 binding. Therefore, we showed that PF4 binds to adenovirus hexon through interactions dependent on HVR1, and identified vectors that may avoid or decrease the risk of thrombosis and represent safer candidates for vaccine or gene therapy vector development.

/Herdecke University Hospital. Contrary to his brother the boy presented dystrophic at birth (1.715 g birth weight; 150 g below 3rd percentile) and developed adverse gastrointestinal conditions within the first 2 months of life. These included chronic mucosal inflammation and oedematous lamina propria in the intestine, which contributed to intractable diarrhoea. At an age of 7 months the infant eventually died of enteral haemorrhages and liver failure. Further anamnesis revealed several similar fatalities in the familial clan with reportedly frequent parental consanguinity. Intractable chronic diarrhoea in infancy are heterogeneous disorders challenging for diagnostics and therapy. Despite extensive diagnostic approaches the etiology of many cases remains elusive. Investigating putatively underlying genetic disorders might clarify many cases. ResultsTo contribute to the diagnosis we performed whole exome sequencing of the affected infant as well as his twin brother and parents. We identified a suspicious nonsynonymous single nucleotide polymorphism (SNP) in the integrin beta-6 gene (ITGB6G1312A) entailing a V438M substitution. This SNP is very rare in the G1000 cohort and predicted being potentially harmful. The allelic distribution in the genotyped family members fit well with an autosomal recessive inheritance scheme. We performed computational biological and molecular biological analyses on the α V β6 integrin receptor function suggesting that the integrin α V β6 dimerization could be impaired, potentially causing a loss of α V β6 function in wound healing and epithelial tissue integrity. Conclusions Our study provides a starting point for elucidating integrin α V β6 function and for understanding a pathomechanistical relevance of ITGB6V438M. Consent for publicationThe authors have written informed consent from the patients' guardian/parent. Metabolic treatment according to current guideline recommendations has significantly improved neurological outcome. However, cognitive functions have not yet been studied in detail. Methods In a cross-sectional design, 30 patients detected by newborn screening (n = 13), high-risk screening (n = 3) or targeted metabolic testing (n = 14) were studied for simple reaction time (SRT), continuous performance (CP), visual working memory (VWM), visual-motor coordination (Tracking) and visual search (VS). Dystonia (n = 13 patients) was categorized using the Barry-Albright-Dystonia Scale (BADS). Patients were compared with 196 healthy controls. Developmental functions of cognitive performances were analysed using a negative exponential function model. Results BADS scores correlated with speed tests but not with tests measuring stability or higher cognitive functions without time constraints. Developmental functions of GA-I patients significantly differed from controls for SRT and VS but not for VWM and showed obvious trends for CP and Tracking. Dystonic patients were slower in SRT and CP but reached their asymptote of performance similar to asymptomatic patients and controls in all...