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Cells Mar 2023Despite scientific discoveries in the field of gene and cell therapy, some diseases still have no effective treatment. Advances in genetic engineering methods have... (Review)
Review
Despite scientific discoveries in the field of gene and cell therapy, some diseases still have no effective treatment. Advances in genetic engineering methods have enabled the development of effective gene therapy methods for various diseases based on adeno-associated viruses (AAVs). Today, many AAV-based gene therapy medications are being investigated in preclinical and clinical trials, and new ones are appearing on the market. In this article, we present a review of AAV discovery, properties, different serotypes, and tropism, and a following detailed explanation of their uses in gene therapy for disease of different organs and systems.
Topics: Serogroup; Genetic Vectors; Genetic Therapy; Genetic Engineering; Tropism; Dependovirus
PubMed: 36899921
DOI: 10.3390/cells12050785 -
International Journal of Molecular... Aug 2020Many genetic diseases and undesirable traits are due to base-pair alterations in genomic DNA. Base-editing, the newest evolution of clustered regularly interspaced short... (Review)
Review
Many genetic diseases and undesirable traits are due to base-pair alterations in genomic DNA. Base-editing, the newest evolution of clustered regularly interspaced short palindromic repeats (CRISPR)-Cas-based technologies, can directly install point-mutations in cellular DNA without inducing a double-strand DNA break (DSB). Two classes of DNA base-editors have been described thus far, cytosine base-editors (CBEs) and adenine base-editors (ABEs). Recently, prime-editing (PE) has further expanded the CRISPR-base-edit toolkit to all twelve possible transition and transversion mutations, as well as small insertion or deletion mutations. Safe and efficient delivery of editing systems to target cells is one of the most paramount and challenging components for the therapeutic success of BEs. Due to its broad tropism, well-studied serotypes, and reduced immunogenicity, adeno-associated vector (AAV) has emerged as the leading platform for viral delivery of genome editing agents, including DNA-base-editors. In this review, we describe the development of various base-editors, assess their technical advantages and limitations, and discuss their therapeutic potential to treat debilitating human diseases.
Topics: CRISPR-Cas Systems; Dependovirus; Gene Editing; Genetic Predisposition to Disease; Humans; Point Mutation; RNA, Guide, CRISPR-Cas Systems; Tropism
PubMed: 32872311
DOI: 10.3390/ijms21176240 -
Annual Review of Neuroscience Jul 2022Recombinant adeno-associated viruses (AAVs) are commonly used gene delivery vehicles for neuroscience research. They have two engineerable features: the capsid (outer... (Review)
Review
Recombinant adeno-associated viruses (AAVs) are commonly used gene delivery vehicles for neuroscience research. They have two engineerable features: the capsid (outer protein shell) and cargo (encapsulated genome). These features can be modified to enhance cell type or tissue tropism and control transgene expression, respectively. Several engineered AAV capsids with unique tropisms have been identified, including variants with enhanced central nervous system transduction, cell type specificity, and retrograde transport in neurons. Pairing these AAVs with modern gene regulatory elements and state-of-the-art reporter, sensor, and effector cargo enables highly specific transgene expression for anatomical and functional analyses of brain cells and circuits. Here, we discuss recent advances that provide a comprehensive (capsid and cargo) AAV toolkit for genetic access to molecularly defined brain cell types.
Topics: Brain; Capsid; Dependovirus; Gene Transfer Techniques; Genetic Vectors
PubMed: 35440143
DOI: 10.1146/annurev-neuro-111020-100834 -
Nature Microbiology Jun 2019Interferon (IFN)-mediated antiviral responses are central to host defence against viral infection. Despite the existence of at least 20 IFNs, there are only three known... (Review)
Review
Interferon (IFN)-mediated antiviral responses are central to host defence against viral infection. Despite the existence of at least 20 IFNs, there are only three known cell surface receptors. IFN signalling and viral evasion mechanisms form an immensely complex network that differs across species. In this Review, we begin by highlighting some of the advances that have been made towards understanding the complexity of differential IFN signalling inputs and outputs that contribute to antiviral defences. Next, we explore some of the ways viruses can interfere with, or circumvent, these defences. Lastly, we address the largely under-reviewed impact of IFN signalling on host tropism, and we offer perspectives on the future of research into IFN signalling complexity and viral evasion across species.
Topics: Animals; Antiviral Agents; Gene Expression Regulation; Host-Pathogen Interactions; Humans; Immune Evasion; Immunity, Innate; Interferon Type I; Interferons; Signal Transduction; Tropism; Virus Diseases; Viruses; Interferon Lambda
PubMed: 30936491
DOI: 10.1038/s41564-019-0421-x -
Viruses Mar 2023An influenza pandemic happens when a novel influenza A virus is able to infect and transmit efficiently to a new, distinct host species. Although the exact timing of... (Review)
Review
An influenza pandemic happens when a novel influenza A virus is able to infect and transmit efficiently to a new, distinct host species. Although the exact timing of pandemics is uncertain, it is known that both viral and host factors play a role in their emergence. Species-specific interactions between the virus and the host cell determine the virus tropism, including binding and entering cells, replicating the viral RNA genome within the host cell nucleus, assembling, maturing and releasing the virus to neighboring cells, tissues or organs before transmitting it between individuals. The influenza A virus has a vast and antigenically varied reservoir. In wild aquatic birds, the infection is typically asymptomatic. Avian influenza virus (AIV) can cross into new species, and occasionally it can acquire the ability to transmit from human to human. A pandemic might occur if a new influenza virus acquires enough adaptive mutations to maintain transmission between people. This review highlights the key determinants AIV must achieve to initiate a human pandemic and describes how AIV mutates to establish tropism and stable human adaptation. Understanding the tropism of AIV may be crucial in preventing virus transmission in humans and may help the design of vaccines, antivirals and therapeutic agents against the virus.
Topics: Animals; Humans; Influenza in Birds; Influenza A virus; Influenza, Human; Birds; Tropism
PubMed: 37112812
DOI: 10.3390/v15040833 -
Viruses Oct 2022The Epstein-Barr virus (EBV) is associated with a variety of human malignancies, including Burkitt's lymphoma, Hodgkin's disease, nasopharyngeal carcinoma and gastric... (Review)
Review
The Epstein-Barr virus (EBV) is associated with a variety of human malignancies, including Burkitt's lymphoma, Hodgkin's disease, nasopharyngeal carcinoma and gastric cancers. EBV infection is crucial for the oncogenesis of its host cells. The prerequisite for the establishment of infection is the virus entry. Interactions of viral membrane glycoproteins and host membrane receptors play important roles in the process of virus entry into host cells. Current studies have shown that the main tropism for EBV are B cells and epithelial cells and that EBV is also found in the tumor cells derived from NK/T cells and leiomyosarcoma. However, the process of EBV infecting B cells and epithelial cells significantly differs, relying on heterogenous glycoprotein-receptor interactions. This review focuses on the tropism and molecular mechanism of EBV infection. We systematically summarize the key molecular events that mediate EBV cell tropism and its entry into target cells and provide a comprehensive overview.
Topics: Humans; Herpesvirus 4, Human; Epstein-Barr Virus Infections; B-Lymphocytes; Hodgkin Disease; Glycoproteins; Tropism
PubMed: 36366470
DOI: 10.3390/v14112372 -
Developmental Cell Apr 2021The shoot apical meristem allows for reiterative formation of new aerial structures throughout the life cycle of a plant. We use single-cell RNA sequencing to define the...
The shoot apical meristem allows for reiterative formation of new aerial structures throughout the life cycle of a plant. We use single-cell RNA sequencing to define the cellular taxonomy of the Arabidopsis vegetative shoot apex at the transcriptome level. We find that the shoot apex is composed of highly heterogeneous cells, which can be partitioned into 7 broad populations with 23 transcriptionally distinct cell clusters. We delineate cell-cycle continuums and developmental trajectories of epidermal cells, vascular tissue, and leaf mesophyll cells and infer transcription factors and gene expression signatures associated with cell fate decisions. Integrative analysis of shoot and root apical cell populations further reveals common and distinct features of epidermal and vascular tissues. Our results, thus, offer a valuable resource for investigating the basic principles underlying cell division and differentiation in plants at single-cell resolution.
Topics: Arabidopsis; Cell Cycle; Cell Differentiation; Gravitropism; Phloem; Plant Epidermis; Plant Roots; Plant Shoots; Plant Stomata; RNA-Seq; Single-Cell Analysis; Xylem
PubMed: 33725481
DOI: 10.1016/j.devcel.2021.02.021 -
Nature Communications Aug 2023The delivery of genetic cargo remains one of the largest obstacles to the successful translation of experimental therapies, in large part due to the absence of...
The delivery of genetic cargo remains one of the largest obstacles to the successful translation of experimental therapies, in large part due to the absence of targetable delivery vectors. Enveloped delivery modalities use viral envelope proteins, which determine tropism and induce membrane fusion. Here we develop DIRECTED (Delivery to Intended REcipient Cells Through Envelope Design), a modular platform that consists of separate fusion and targeting components. To achieve high modularity and programmable cell type specificity, we develop multiple strategies to recruit or immobilize antibodies on the viral envelope, including a chimeric antibody binding protein and a SNAP-tag enabling the use of antibodies or other proteins as targeting molecules. Moreover, we show that fusogens from multiple viral families are compatible with DIRECTED and that DIRECTED components can target multiple delivery chassis (e.g., lentivirus and MMLV gag) to specific cell types, including primary human T cells in PBMCs and whole blood.
Topics: Humans; Antibodies; Lentivirus; Membrane Fusion; Tropism; Viral Envelope Proteins
PubMed: 37612276
DOI: 10.1038/s41467-023-40788-8 -
Molecular Therapy. Methods & Clinical... Mar 2021Therapeutic payload delivery to the central nervous system (CNS) remains a major challenge in gene therapy. Recent studies using function-driven evolution of...
Therapeutic payload delivery to the central nervous system (CNS) remains a major challenge in gene therapy. Recent studies using function-driven evolution of adeno-associated virus (AAV) vectors have successfully identified engineered capsids with improved blood-brain barrier (BBB) penetration and CNS tropism in mouse. However, these strategies require transgenic animals and thus are limited to rodents. To address this issue, we developed a directed evolution approach based on recovery of capsid library RNA transcribed from CNS-restricted promoters. This RNA-driven screen platform, termed TRACER (Tropism Redirection of AAV by Cell-type-specific Expression of RNA), was tested in the mouse with AAV9 peptide display libraries and showed rapid emergence of dominant sequences. Ten individual variants were characterized and showed up to 400-fold higher brain transduction over AAV9 following systemic administration. Our results demonstrate that the TRACER platform allows rapid selection of AAV capsids with robust BBB penetration and CNS tropism in non-transgenic animals.
PubMed: 33553485
DOI: 10.1016/j.omtm.2020.12.006 -
MBio Apr 2022In the 21st century, several human and swine coronaviruses (CoVs) have emerged suddenly and caused great damage to people's lives and property. The porcine epidemic...
In the 21st century, several human and swine coronaviruses (CoVs) have emerged suddenly and caused great damage to people's lives and property. The porcine epidemic diarrhea virus (PEDV), leading to enormous economic losses to the pork industry and remains a large challenge. PEDV showed extensive cell tropism, and we cannot ignore the potential risk of cross-species transmission. However, the mechanism of adaptation and cell tropism of PEDV remains largely unknown and isolation of PEDV remains a huge challenge, which seriously impedes the development of vaccines. In this study, we confirmed that the spike (S) protein determines the adaptability of PEDV to monkey Vero cells and LLC-PK1 porcine cells, and isolated exchange of S1 and S2 subunits of adaptive strains did not make PEDV adapt to cells. Further, we found that the cellular adaptability of rCH/SX/2016-S depends on S1 and the first half of S2 (S3), and the 803L and 976H of the S2 subunit are critical for rCH/SX/2016-S1+S3 adaptation to Vero cells. These findings highlight the decisive role of PEDV S protein in cell tropism and the potential role of coronaviruses S protein in cross-species transmissibility. Besides, our work also provides some different insight into finding PEDV receptors and developing PEDV and other coronaviruses vaccines. CoVs can spill from an animal reservoir into a naive host to cause diseases in humans or domestic animals. PEDV results in high mortality in piglets, which has caused immense economic losses in the pork industry. Virus isolation is the first step in studying viral pathogenesis and developing effective vaccines. However, the molecular mechanism of PEDV cell tropism is largely unknown, and isolation of endemic PEDV strains remains a major challenge. This study confirmed that the S gene is the decisive gene of PEDV adaptability to monkey Vero cells and porcine LLC-PK1 cells by the PEDV reverse genetics system. Isolated exchange of S1 and S2 of adaptive strains did not make PEDV adapt to cells, and the 803L and 976H of S2 subunit are critical for rCH/SX/2016-S1+S3 adaptation to Vero cells. These results illustrate the decisive role of PEDV S protein in cell tropism and highlight the potential role of coronaviruses S protein in cross-species transmissibility. Besides, our finding also provides some unique insight into identifying PEDV functional receptors and has guiding significance for developing PEDV and other coronavirus vaccines.
Topics: Animals; Chlorocebus aethiops; Coronavirus Infections; Humans; Porcine epidemic diarrhea virus; Swine; Swine Diseases; Tropism; Vero Cells
PubMed: 35285698
DOI: 10.1128/mbio.03739-21