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Cell Reports Mar 2024Adeno-associated virus (AAV) is a member of the genus Dependoparvovirus, which infects a wide range of vertebrate species. Here, we observe that, unlike most primate AAV...
Adeno-associated virus (AAV) is a member of the genus Dependoparvovirus, which infects a wide range of vertebrate species. Here, we observe that, unlike most primate AAV isolates, avian AAV is transcriptionally silenced in human cells. By swapping the VP1 N terminus from primate AAVs (e.g., AAV8) onto non-mammalian isolates (e.g., avian AAV), we identify a minimal component of the AAV capsid that controls viral transcription and unlocks robust transduction in both human cells and mouse tissue. This effect is accompanied by increased AAV genome chromatin accessibility and altered histone methylation. Proximity ligation analysis reveals that host factors are selectively recruited by the VP1 N terminus of AAV8 but not avian AAV. Notably, these include AAV essential factors implicated in the nuclear factor κB pathway, chromatin condensation, and histone methylation. We postulate that the AAV capsid has evolved mechanisms to recruit host factors to its genome, allowing transcriptional activation in a species-specific manner.
Topics: Humans; Animals; Mice; Capsid; Dependovirus; Histones; Viral Transcription; Genetic Vectors; Capsid Proteins; Primates; Host Specificity; Chromatin
PubMed: 38431840
DOI: 10.1016/j.celrep.2024.113902 -
Molecular Therapy : the Journal of the... May 2024Maintaining functional adipose innervation is critical for metabolic health. We found that subcutaneous white adipose tissue (scWAT) undergoes peripheral neuropathy (PN)...
Maintaining functional adipose innervation is critical for metabolic health. We found that subcutaneous white adipose tissue (scWAT) undergoes peripheral neuropathy (PN) with obesity, diabetes, and aging (reduced small-fiber innervation and nerve/synaptic/growth-cone/vesicle markers, altered nerve activity). Unlike with nerve injuries, peripheral nerves do not regenerate with PN, and therefore new therapies are needed for treatment of this condition affecting 20-30 million Americans. Here, we validated a gene therapy approach using an adipocyte-tropic adeno-associated virus (AAV; serotype Rec2) to deliver neurotrophic factors (brain-derived neurotrophic factor [BDNF] and nerve growth factor [NGF]) directly to scWAT to improve tissue-specific PN as a proof-of-concept approach. AAVRec2-BDNF intra-adipose delivery improved tissue innervation in obese/diabetic mice with PN, but after longer periods of dietary obesity there was reduced efficacy, revealing a key time window for therapies. AAVRec2-NGF also increased scWAT innervation in obese mice and was more effective than BDNF, likely because Rec2 targeted adipocytes, the tissue's endogenous NGF source. AAVRec2-NGF also worked well even after 25 weeks of dietary obesity, unlike BDNF, which likely needs a vector that targets its physiological cellular source (stromal vascular fraction cells). Given the differing effects of AAVs carrying NGF versus BDNF, a combined therapy may be ideal for PN.
Topics: Animals; Dependovirus; Obesity; Mice; Genetic Therapy; Adipocytes; Genetic Vectors; Subcutaneous Fat; Brain-Derived Neurotrophic Factor; Disease Models, Animal; Nerve Growth Factor; Nerve Growth Factors; Gene Transfer Techniques; Humans; Male; Peripheral Nervous System Diseases; Transduction, Genetic
PubMed: 38429927
DOI: 10.1016/j.ymthe.2024.02.035 -
PloS One 2024Adeno-associated viral transduction allows the introduction of nucleic fragments into cells and is widely used to modulate gene expressions in vitro and in vivo. It...
Adeno-associated viral transduction allows the introduction of nucleic fragments into cells and is widely used to modulate gene expressions in vitro and in vivo. It enables the study of genetic functions and disease mechanisms and, more recently, serves as a tool for gene repair. To achieve optimal transduction performance for a given cell type, selecting an appropriate serotype and the number of virus particles per cell, also known as the multiplicity of infection, is critical. Fluorescent proteins are one of the common reporter genes to visualize successfully transduced cells and assess transduction efficiencies. Traditional methods of measuring fluorescence-positive cells are endpoint analysis by flow cytometry or manual counting with a fluorescence microscope. However, the flow cytometry analysis does not allow further measurement in a test run, and manual counting by microscopy is time-consuming. Here, we present a method that repeatedly evaluates transduction efficiencies by adding the DNA-stain Hoechst 33342 during the transduction process combined with a microscope or live-cell imager and microplate image analysis software. The method achieves fast, high-throughput, reproducible, and real-time post-transduction analysis and allows for optimizing transduction parameters and screening for a proper approach.
Topics: Cell Nucleus; Coloring Agents; Dependovirus; Microscopy, Fluorescence; Benzimidazoles
PubMed: 38427668
DOI: 10.1371/journal.pone.0298173 -
Nature Apr 2024The eye, an anatomical extension of the central nervous system (CNS), exhibits many molecular and cellular parallels to the brain. Emerging research demonstrates that...
The eye, an anatomical extension of the central nervous system (CNS), exhibits many molecular and cellular parallels to the brain. Emerging research demonstrates that changes in the brain are often reflected in the eye, particularly in the retina. Still, the possibility of an immunological nexus between the posterior eye and the rest of the CNS tissues remains unexplored. Here, studying immune responses to herpes simplex virus in the brain, we observed that intravitreal immunization protects mice against intracranial viral challenge. This protection extended to bacteria and even tumours, allowing therapeutic immune responses against glioblastoma through intravitreal immunization. We further show that the anterior and posterior compartments of the eye have distinct lymphatic drainage systems, with the latter draining to the deep cervical lymph nodes through lymphatic vasculature in the optic nerve sheath. This posterior lymphatic drainage, like that of meningeal lymphatics, could be modulated by the lymphatic stimulator VEGFC. Conversely, we show that inhibition of lymphatic signalling on the optic nerve could overcome a major limitation in gene therapy by diminishing the immune response to adeno-associated virus and ensuring continued efficacy after multiple doses. These results reveal a shared lymphatic circuit able to mount a unified immune response between the posterior eye and the brain, highlighting an understudied immunological feature of the eye and opening up the potential for new therapeutic strategies in ocular and CNS diseases.
Topics: Animals; Female; Humans; Male; Mice; Rabbits; Bacteria; Brain; Dependovirus; Eye; Glioblastoma; Herpesvirus 2, Human; Intravitreal Injections; Lymphatic System; Lymphatic Vessels; Macaca mulatta; Meninges; Optic Nerve; Swine; Zebrafish; Vascular Endothelial Growth Factor C
PubMed: 38418880
DOI: 10.1038/s41586-024-07130-8 -
World Journal of Gastroenterology Feb 2024Primary sclerosing cholangitis (PSC) is characterized by chronic inflammation and it predisposes to cholangiocarcinoma due to lack of effective treatment options....
BACKGROUND
Primary sclerosing cholangitis (PSC) is characterized by chronic inflammation and it predisposes to cholangiocarcinoma due to lack of effective treatment options. Recombinant adeno-associated virus (rAAV) provides a promising platform for gene therapy on such kinds of diseases. A microRNA (miRNA) let-7a has been reported to be associated with the progress of PSC but the potential therapeutic implication of inhibition of let-7a on PSC has not been evaluated.
AIM
To investigate the therapeutic effects of inhibition of a miRNA let-7a transferred by recombinant adeno-associated virus 8 (rAAV8) on a xenobiotic-induced mouse model of sclerosing cholangitis.
METHODS
A xenobiotic-induced mouse model of sclerosing cholangitis was induced by 0.1% 3,5-Diethoxycarbonyl-1,4-Dihydrocollidine (DDC) feeding for 2 wk or 6 wk. A single dose of rAAV8-mediated anti-let-7a-5p sponges or scramble control was injected into mice onset of DDC feeding. Upon sacrifice, the liver and the serum were collected from each mouse. The hepatobiliary injuries, hepatic inflammation and fibrosis were evaluated. The targets of let-7a-5p and downstream molecule NF-κB were detected using Western blot.
RESULTS
rAAV8-mediated anti-let-7a-5p sponges can depress the expression of let-7a-5p in mice after DDC feeding for 2 wk or 6 wk. The reduced expression of let-7a-5p can alleviate hepato-biliary injuries indicated by serum markers, and prevent the proliferation of cholangiocytes and biliary fibrosis. Furthermore, inhibition of let-7a mediated by rAAV8 can increase the expression of potential target molecules such as suppressor of cytokine signaling 1 and Dectin1, which consequently inhibit of NF-κB-mediated hepatic inflammation.
CONCLUSION
Our study demonstrates that a rAAV8 vector designed for liver-specific inhibition of let-7a-5p can potently ameliorate symptoms in a xenobiotic-induced mouse model of sclerosing cholangitis, which provides a possible clinical translation of PSC of human.
Topics: Humans; Mice; Animals; Cholangitis, Sclerosing; MicroRNAs; Dependovirus; Liver Cirrhosis; NF-kappa B; Xenobiotics; Fibrosis; Disease Models, Animal; Inflammation
PubMed: 38414587
DOI: 10.3748/wjg.v30.i5.471 -
Molecular Therapy : the Journal of the... May 2024Osteoarthritis (OA) is an age-related or post-traumatic degenerative whole joint disease characterized by the rupture of articular cartilage homeostasis, the regulatory...
Osteoarthritis (OA) is an age-related or post-traumatic degenerative whole joint disease characterized by the rupture of articular cartilage homeostasis, the regulatory mechanisms of which remain elusive. This study identifies the essential role of heterogeneous nuclear ribonucleoprotein K (hnRNPK) in maintaining articular cartilage homeostasis. Hnrnpk expression is markedly downregulated in human and mice OA cartilage. The deletion of Hnrnpk effectively accelerates the development of post-traumatic and age-dependent OA in mice. Mechanistically, the KH1 and KH2 domain of Hnrnpk bind and degrade the mRNA of WWC1. Hnrnpk deletion increases WWC1 expression, which in turn leads to the activation of Hippo signaling and ultimately aggravates OA. In particular, intra-articular injection of LPA and adeno-associated virus serotype 5 expressing WWC1 RNA interference ameliorates cartilage degeneration induced by Hnrnpk deletion, and intra-articular injection of adeno-associated virus serotype 5 expressing Hnrnpk protects against OA. Collectively, this study reveals the critical roles of Hnrnpk in inhibiting OA development through WWC1-dependent downregulation of Hippo signaling in chondrocytes and defines a potential target for the prevention and treatment of OA.
Topics: Animals; Humans; Male; Mice; Cartilage, Articular; Chondrocytes; Dependovirus; Disease Models, Animal; Gene Expression Regulation; Heterogeneous-Nuclear Ribonucleoprotein K; Hippo Signaling Pathway; Intracellular Signaling Peptides and Proteins; Osteoarthritis; Protein Serine-Threonine Kinases; RNA, Messenger; Signal Transduction
PubMed: 38414246
DOI: 10.1016/j.ymthe.2024.02.027 -
Advanced Science (Weinheim,... May 2024CRISPR-based gene therapies are making remarkable strides toward the clinic. But the large size of most widely used Cas endonucleases including Cas9 and Cas12a restricts...
CRISPR-based gene therapies are making remarkable strides toward the clinic. But the large size of most widely used Cas endonucleases including Cas9 and Cas12a restricts their efficient delivery by the adeno-associated virus (AAV) for in vivo gene editing. Being exceptionally small, the recently engineered type V-F CRISPR-Cas12f1 systems can overcome the cargo packaging bottleneck and present as strong candidates for therapeutic applications. In this study, the pairwise editing efficiencies of different engineered Cas12f1/sgRNA scaffold combinations are systemically screened and optimized, and the CasMINI_v3.1/ge4.1 system is identified as being able to significantly boost the gene editing activity. Moreover, packaged into single AAV vectors and delivered via subretinal injection, CasMINI_v3.1/ge4.1 achieves remarkably high in vivo editing efficiencies, over 70% in transduced retinal cells. Further, the efficacy of this Cas12f1 system-based gene therapy to treat retinitis pigmentosa in Rho mice is demonstrated by the therapeutic benefits achieved including rescued visual function and structural preservation. And minimal bystander editing activity is detected. This work advances and expands the therapeutic potential of the miniature Cas12f1 system to support efficient and accurate in vivo gene therapy.
Topics: Dependovirus; Gene Editing; Animals; CRISPR-Cas Systems; Genetic Therapy; Mice; Genetic Vectors; Disease Models, Animal; Retinitis Pigmentosa; Humans
PubMed: 38408137
DOI: 10.1002/advs.202308095 -
Experimental Neurology May 2024Spinal cord injury (SCI) is a disorder of the central nervous system resulting from various factors such as trauma, inflammation, tumors, and other etiologies. This...
Spinal cord injury (SCI) is a disorder of the central nervous system resulting from various factors such as trauma, inflammation, tumors, and other etiologies. This condition leads to impairment in motor, sensory, and autonomic functions below the level of injury. Limitations of current therapeutic approaches prompt an investigation into therapeutic angiogenesis through persistent local expression of proangiogenic factors. Here, we investigated whether overexpression of adeno-associated virus (AAV)-mediated vascular endothelial growth factor A (VEGFA) in mouse SCI promoted locomotor function recovery, and whether the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway was mechanistically involved. Three weeks before SCI, AAV-VEGFA was injected at the T10 level to induce VEGFA overexpression. Neurofunctional, histological, and biochemical assessments were done to determine tissue damage and/or recovery of neuromuscular and behavioral impairments. Daily injections of the PI3K/Akt pathway inhibitor LY294002 were made to assess a possible mechanism. AAV-VEGFA overexpression dramatically improved locomotor function and ameliorated pathological injury caused by SCI. Improved motor-evoked potentials in hindlimbs and more spinal CD31-positive microvessels were observed in AAV-VEGFA-overexpressing mice. LY294002 reduced PI3K and Akt phosphorylation levels and attenuated AAV-VEGFA-related improvements. In conclusion, sustained local AAV-mediated VEGFA overexpression in spinal cord can significantly promote angiogenesis and ameliorate locomotor impairment after SCI in a contusion mouse model through activation of the PI3K/Akt signaling pathway.
Topics: Mice; Animals; Proto-Oncogene Proteins c-akt; Phosphatidylinositol 3-Kinases; Vascular Endothelial Growth Factor A; Dependovirus; Phosphatidylinositol 3-Kinase; Angiogenesis; Signal Transduction; Spinal Cord Injuries; Spinal Cord; Recovery of Function
PubMed: 38401852
DOI: 10.1016/j.expneurol.2024.114739 -
Gene Therapy May 2024Manufacturing of recombinant adeno-associated virus (AAV) vectors produces three types of capsids: full, intermediate, and empty. While there are different opinions...
Manufacturing of recombinant adeno-associated virus (AAV) vectors produces three types of capsids: full, intermediate, and empty. While there are different opinions about the impact of intermediate and empty capsids on safety and efficacy of AAV products, they are generally considered impurities because they are not the intended fully intact vector product. The presence of these impurities could impact product efficacy due to potential competition with fully packaged AAVs for cellular transduction, as well as have potential implications to patient safety due to increased capsid load during dosing. To determine the impact of intermediate capsids on potency, an AAV preparation was separated into fractions enriched for full, intermediate, or empty capsids. Using a matrix of in vitro (infectivity, gene expression, biological activity) and in vivo potency assays to determine potency as a function of capsid content, our results indicate that while intermediate capsids contribute to the vector genome titer of the product and are equally as infectious as full capsids, they do not contribute to the potency of the AAV product. This study confirms the criticality of reducing and controlling the level of intermediate capsids to ensure a more efficacious AAV product.
Topics: Dependovirus; Capsid; Genetic Vectors; Humans; Animals; Mice; Transduction, Genetic; HEK293 Cells; Genetic Therapy
PubMed: 38374348
DOI: 10.1038/s41434-024-00444-2 -
Sheng Wu Gong Cheng Xue Bao = Chinese... Feb 2024Adeno-associated virus (AAV) is one of the most frequently used viral vectors in the field of gene therapy. However, the industrial production of AAV is facing key...
Adeno-associated virus (AAV) is one of the most frequently used viral vectors in the field of gene therapy. However, the industrial production of AAV is facing key bottlenecks such as low yield and high-cost. The aim of this study was to establish a technology system for production of AAV in the double virus infected insects by using multiple-gene deleted baculovirus. First, a multiple gene deleted baculovirus for AAV production was constructed, and the baculovirus titer and its effect on infected cells was examined. Subsequently, the insect cells were co-infected with the double baculovirus and the infection conditions were optimized. At the final stage, we performed AAV production based on optimized conditions, and evaluated relevant parameters including production titer and quality. The results showed that the titer of AAV produced in the multiple gene deleted baculovirus was not different from that of the wild type, but the rate of cell death was significantly slower upon infection. Using the double virus route for optimized production of AAV, the genome titers were 1.63×10 VG/mL for Bac4.0-1 and 1.02×10 VG/mL for Bac5.0-2, which were elevated 240% and 110%, respectively, compared with that of the wild-type. Electron microscopy observations revealed that all three groups exhibited normal AAV viral morphology and they showed similar transduction activity. Taken together, we developed an AAV production system based on the infection of insect cells using multiple-gene deleted baculovirus, which significantly improved the virus yield and showed application potential.
Topics: Animals; Dependovirus; Baculoviridae; Cell Line; Genetic Vectors; Insecta
PubMed: 38369834
DOI: 10.13345/j.cjb.230325