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Mussolino, C.

Publications and source records attributed to Mussolino, C..

4 recordsLinked to original sources

Castling, a novel therapeutic concept for rewiring pathological gene-expression networks, enabled by the TRIPLE technology

Pathological conditions often arise from dysregulation of complex gene networks, with microRNAs (miRNAs) acting as central modulators. Disease progression is frequently characterized by upregulation of "disease-promoting" miRNA, suppressing beneficial pathways, and concomitant downregulation of "protective/therapeutic" miRNAs, normally restraining pathological programs. Since individual miRNAs coordinately regulate multiple genes, their manipulation represents powerful therapeutic intervention, yet synthetic or ectopically overexpressed miRNA mimics or inhibitors may perturb physiological miRNA processing and/or cause off-target effects. We hypothesized that pathological gene regulatory imbalances could instead be corrected by rewiring endogenous miRNA regulation. Specifically, by placing downregulated "protective/therapeutic" miRNAs under the control of promoters activated in pathology, and driving overexpression of "disease-promoting" miRNAs, thereby disabling the pathogenic program while inducing the therapeutic one in a single editing event. We termed this concept castling, after the chess move. For effective implementation of castling, we developed TRIPLE (Targeted Replacement Induced by Persistent Locus Editing), a novel genome-editing procedure enhancing homology-directed repair through sequential cleavage. As proof of concept, we castled miRNAs inversely regulated during onset of CAR T cell dysfunction in a model of chronic antigen stimulation. Castled CAR T cells exhibited a delayed dysfunction enabled by up- and downregulation of relevant gene subsets.

molecular biology↗

Multimodal HLA-I genotype regulation by human cytomegalovirus US10 and resulting surface patterning

To control human cytomegalovirus (HCMV) infection, NK cells and CD8+ T-cells are crucial. HLA class I (HLA-I) molecules play a central role for both NK and T-cell responses and are targets of multifaceted HCMV-encoded immunoevasins. A so far insufficiently studied HLA-I immunoevasin is the glycoprotein US10. It was shown that US10 targets HLA-G, but it is unknown whether US10 contributes also to escape from classical HLA-I antigen presentation. Our biochemical analysis revealed that early during maturation, all investigated HLA-I (HLA-A/B/C/E/G) heavy chains are recognized and bound by US10. Remarkably, the consequences of this initial binding strongly depended on both the HLA-I geno- and allotypes: i) HLA-A molecules escaped down-regulation by US10, ii) tapasin-dependent HLA-B molecules exhibited impaired recruitment to the peptide loading complex and maturation, iii) HLA-C and HLA-G, but not HLA-A/B/E, strongly bound US10 also in their {beta}2m-assembled form. Thus, US10 senses geno- and allotypic differences in a so far unparalleled and multimodal manner, suggestive of adaptation to HLA-I genotype differences. At a further level of complexity, in HCMV-infected fibroblasts inhibition of overlapping US10 and US11 transcription revealed an additional HLA-I specificity, suggesting targeting of HLA-I in a synergistically arranged manner. Our study unveils the exceptional HLA-I selectivity of HCMV-encoded US10 and underlines its contribution to immune escape.

microbiology↗

Efficient in vivo genome editing mediated by stem cells-derived extracellular vesicles carrying designer nucleases

Precise genome editing using designer nucleases (DNs), such as zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and the clustered regularly interspaced short palindromic repeat/Cas9 (CRISPR/Cas9) system, has become a method of choice in a variety of biological and biomedical applications in recent years. Notably, efficacy of these systems is currently under scrutiny in about 50 clinical trials. Although high DNs activity in various cell types in vitro has already been achieved, efficient in vivo genome editing remains a challenge. To solve this problem, we employed stem cells-derived extracellular vesicles (EVs) as carriers of DNs. We used umbilical cord-derived mesenchymal stem cells (UC-MSCs) and induced pluripotent stem cells (iPSCs) as EV-producer cells, since they are both applied in regenerative medicine. In our proof-of-concept studies, we achieved up to 50% of EGFP marker gene knockout in vivo using EVs carrying either ZFN, TALEN or the CRISPR/Cas9 system, particularly in the liver. Importantly, we obtained almost 50% of modified alleles in the liver of the experimental animals, when targeting the Pcsk9 gene, whose overexpression is implicated in hypercholesterolemia. Taken together, our data provide strong evidence that stem cells-derived EVs constitute a robust tool in delivering DNs in vivo, which may be harnessed to clinical practice in the future.

bioengineering↗

Therapeutic gene editing in hematopoietic progenitor cells from a mouse model of Fanconi anemia

The promising ability to genetically modify hematopoietic stem and progenitor cells (HSPCs) by precise gene editing remains challenging due to their sensitivity and poor permissiveness. This represents the first evidence of implementing a gene editing strategy in a murine safe harbor locus that phenotypically corrects primary cells derived from a mouse model of Fanconi anemia (FA).\n\nBy co-delivering TALENs and a donor therapeutic FANCA cassette template to the Mbs85 locus (ortholog of the hAAVS1 safe harbor locus), we achieved efficient gene targeting (23%) in FA mouse embryonic fibroblasts (MEFs). This resulted in the phenotypic correction of these cells, as revealed by the improvement of their hypersensitivity to mitomycinC. Moreover, robust evidence of targeted integration was observed in murine WT and FA-A hematopoietic progenitor cells (HPC) reaching mean targeted integration values of 20.98% and 16.33% respectively, with phenotypic correction of FA HPCs. Overall, our results demonstrate the feasibility of implementing a therapeutic targeted integration strategy in a murine safe harbor locus, such as the Mbs85 gene, of MEFs and murine HPC from a FA mouse model.

molecular biology↗