Virus AND gene edit

Human induced pluripotent stem cells (iPSCs) hold enormous promise for regenerative medicine. The major safety concern is the tumorigenicity of transplanted cells derived from iPSCs. A potential solution would be to introduce a suicide gene into iPSCs as a safety switch. The herpes simplex virus type 1 thymidine kinase ( HSV-TK ) gene, in combination with ganciclovir, is the most widely used enzyme/prodrug suicide system from basic research to clinical applications. In the present study, we attempted to establish human iPSCs that stably expressed HSV-TK with either lentiviral vectors or CRISPR/Cas9-mediated genome editing...

Differential editing of transcripts from the Newcastle disease virus (NDV) phosphoprotein gene results in mRNAs capable of encoding the phosphoprotein (P), the V protein, and the W protein which share a common N-terminus but specify different C-termini. Whereas the expression and viral incorporation of the P - and V proteins by NDV has been documented, evidence for the existence of a W protein was lacking. To analyze expression of the NDV W protein, two peptides encompassing predicted antigenic sites of the unique C-terminal W protein amino acid sequence of NDV Clone 30 were used for the generation of W-specific rabbit antisera...

Measles virus (MeV) is dual-tropic: it replicates first in lymphatic tissues and then in epithelial cells. This switch in tropism raises the question of whether, and how, intra-host evolution occurs. Towards addressing this question, we adapted MeV either to lymphocytic (Granta-519) or epithelial (H358) cells. We also passaged it consecutively in both human cell lines. Since passaged MeV had different replication kinetics, we sought to investigate the underlying genetic mechanisms of growth differences by performing deep-sequencing analyses...

The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) system discovered using bacteria has been repurposed for genome editing in human cells. Transient expression of the editor proteins (e.g. Cas9 protein) is desirable to reduce the risk of mutagenesis from off-target activity. Using the specific interaction between bacteriophage RNA-binding proteins and their RNA aptamers, we developed a system able to package up to 100 copies of Staphylococcus aureus Cas9 (SaCas9) mRNA in each lentivirus-like bionanoparticle (LVLP)...

Secretion of interleukin-1β (IL-1β) represents a fundamental innate immune response to microbial infection that, at the molecular level, occurs following activation of proteolytic caspases that cleave the immature protein into a secretable form. Human cytomegalovirus (HCMV) is the archetypal betaherpesvirus that is invariably capable of lifelong infection through the activity of numerous virally encoded immune evasion phenotypes. Innate immune pathways responsive to cytoplasmic double-stranded DNA (dsDNA) are known to be activated in response to contact between HCMV and host cells...

Porcine reproductive and respiratory syndrome (PRRS) is a highly contagious disease and the most economically important disease of the swine industry worldwide. Highly pathogenic-PRRS virus (HP-PRRSV) is a variant of PRRSV, which caused high morbidity and mortality. Scavenger receptor CD163, which contains nine scavenger receptor cysteine-rich (SRCR) domains, is a key entry mediator for PRRSV. A previous study demonstrated that SRCR domain 5 (SRCR5), encoded by exon 7, was essential for PRRSV infection in vitro ...

Adeno-associated virus (AAV) vectors are the leading platform for gene delivery for the treatment of a variety of human diseases. Recent advances in developing clinically desirable AAV capsids, optimizing genome designs and harnessing revolutionary biotechnologies have contributed substantially to the growth of the gene therapy field. Preclinical and clinical successes in AAV-mediated gene replacement, gene silencing and gene editing have helped AAV gain popularity as the ideal therapeutic vector, with two AAV-based therapeutics gaining regulatory approval in Europe or the United States...

Phages are the most abundant entities in the biosphere and profoundly impact the bacterial populations within and around us. They attach to a specific host, inject their DNA, hijack the host's cellular processes, and replicate exponentially while destroying the host. Historically, phages have been exploited as powerful antimicrobials, and phage-derived proteins have constituted the basis for numerous biotechnological applications. Only in recent years have metagenomic studies revealed that phage genomes harbor a rich reservoir of genetic diversity, which might afford further therapeutic and/or biotechnological value...

High-risk human papillomavirus (HPV) is a common cause of cervical cancer. HPV E6 oncoprotein promotes the degradation of host tumor suppressor gene p53 , leading to the development of tumors. Therapeutic strategies that specifically target E6, which is constitutively expressed in tumors and is not present in normal tissues, may be highly effective and safe. CRISPR-CRISPR associated protein 9 (Cas9) is one of the genome editing technologies that has recently garnered attention, and is used to knockout target gene expression...

Herpesvirus of turkeys (HVT) is an ideal viral vector for the generation of recombinant vaccines against a number of avian diseases, such as avian influenza (AI), Newcastle disease (ND), and infectious bursal disease (IBD), using bacterial artificial chromosome (BAC) mutagenesis or conventional recombination methods. The clustered regularly interspaced palindromic repeats (CRISPR)/Cas9 system has been successfully used in many settings for gene editing, including the manipulation of several large DNA virus genomes...

BACKGROUND: The apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3 (APOBEC3) genes A3D, A3F, A3G and A3H have all been implicated in the restriction of human immunodeficiency virus type 1 (HIV-1) replication. Polymorphisms in these genes are likely to impact viral replication and fitness, contributing to viral diversity. Currently, only a few studies indicate that polymorphisms in the A3 genes may be correlated with infection risk and disease progression. METHODS: To characterize polymorphisms in the coding regions of these APOBEC3 genes in an HIV-1 infected population from the Limpopo Province of South Africa, APOBEC3 gene fragments were amplified from genomic DNA of 192 HIV-1 infected subjects and sequenced on an Illumina MiSeq platform...

Orf virus (ORFV) infects sheep and goats and is also an important zoonotic pathogen. The viral protein OV20.0 has been shown to suppress innate immunity by targeting the double-stranded RNA (dsRNA)-activated protein kinase (PKR) by multiple mechanisms. These mechanisms include a direct interaction with PKR and binding with two PKR activators, dsRNA and the cellular PKR activator (PACT), which ultimately leads to the inhibition of PKR activation. In the present study, we identified a novel association between OV20...

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of Kaposi's sarcoma (KS), an AIDS defining cancer in HIV-1 infected individuals or immune suppressed transplant patients. The prevalence for both KSHV and KS are highest in sub-Saharan Africa where HIV-1 infection is also epidemic. There is no effective treatment for advanced KS; therefore, the survival rate is low. Similar to other herpesviruses, KSHV's ability to establish latent infection in the host presents a major challenge to KS treatment or prevention...

CRISPR editing is being considered as a potential gene repair therapy to treat Duchenne muscular dystrophy (DMD), a dystrophin-deficient lethal muscle disease affecting all muscles in the body. A recent preliminary study from the Olson laboratory (Amoasii et al. 2018 Science 362:89-91) showed robust dystrophin restoration in a canine DMD model following intramuscular or intravenous delivery of the CRISPR editing machinery by adeno-associated virus serotype-9 (AAV9). Despite the limitation of the small sample size, short study duration and the lack of muscle function data, the Olson lab findings have provided important proof-of-principle for scaling up the CRISPR therapy from rodents to large mammals...

H9N2 avian influenza viruses (AIVs) were prevailing in chickens, causing great economic losses and public health threats. In this study, turkey herpesviruses (HVT) was cloned as an infectious bacterial artificial chromosomes (BAC). Recombinant HVT (rHVT-H9) containing hemagglutinin (HA) gene from H9N2 virus were constructed via galactokinase (galK) selection and clustered regularly interspaced short palindromic repeats/associated 9 (CRISPR/Cas9) gene editing system. The recombinant rHVT-H9 showed no difference with parent HVT in plague morphology and virus replication kinetics...

The Chinese tree shrew holds a great potential as a viable animal model in biomedical research, especially for infectious diseases and neuropsychiatric disorders. A thorough understanding of the innate immunity, which represents the first line that defends the host against viral infection, of the Chinese tree shrew, is needed. However, the progress is hindered by the lack of a proper cell line for research usage. In this study, we established a cell line that is applicable to the study of tree shrew innate immune responses against viral infections...

We recently developed adeno-associated virus (AAV) capsids to facilitate efficient and noninvasive gene transfer to the central and peripheral nervous systems. However, a detailed protocol for generating and systemically delivering novel AAV variants was not previously available. In this protocol, we describe how to produce and intravenously administer AAVs to adult mice to specifically label and/or genetically manipulate cells in the nervous system and organs, including the heart. The procedure comprises three separate stages: AAV production, intravenous delivery, and evaluation of transgene expression...

CRISPR/Cas9-mediated gene editing of stem cells and primary cell types has several limitations for clinical applications. The direct delivery of ribonucleoprotein (RNP) complexes consisting of Cas9 nuclease and guide RNA (gRNA) has improved DNA- and virus-free gene modifications, but it does not enable the essential enrichment of the gene-edited cells. Here, we established a protocol for the fluorescent labeling and delivery of CRISPR/Cas9-gRNA RNP in primary human hematopoietic stem and progenitor cells (HSPCs) and induced pluripotent stem cells (iPSCs)...

A lack of effective drugs and technical means to eradicate hepatitis B virus (HBV) is a bottleneck that limits the ability to fully cure HBV infection. Recently, genome-editing technology based on clustered regularly interspaced short palindromic repeats -associated protein 9 is an emerging technique for editing specific gene loci, which can specifically target HBV covalently closed circular DNA, effectively inhibits HBV DNA replication and regulates HBV functional protein expression, and is expected to become a powerful gene therapy tool for the complete eradication of HBV...

The rapid developments of science and technology in China over recent decades, particularly in biomedical research, have brought forward serious challenges regarding ethical governance. Recently, Jian-kui HE, a Chinese scientist, claimed to have "created" the first gene-edited babies, designed to be naturally immune to the human immunodeficiency virus (HIV). The news immediately triggered widespread criticism, denouncement, and debate over the scientific and ethical legitimacy of HE's genetic experiments...