Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The CRISPR-Cas9 system has been used for genome editing of various organisms. We reported inhibition of the human immunodeficiency virus (HIV) in cell culture infections with a single guide RNA (gRNA) and subsequent viral escape, but complete inactivation of infectious HIV with certain combinations of two gRNAs. The new RNA-guided endonuclease system CRISPR-Cas12a (formerly Cpf1) may provide a more promising tool for genome engineering with increased activity and specificity. We compared Cas12a to the original Cas9 system for inactivation of the integrated HIV DNA genome. Superior antiviral activity is reported for Cas12a, which can achieve full HIV inactivation with only a single gRNA (called crRNA). We propose that the different architecture of Cas9 versus Cas12a endonuclease explains this effect. We also disclose that DNA cleavage by the Cas12a endonuclease and subsequent DNA repair causes mutations with a sequence profile that is distinct from that of Cas9. Both CRISPR systems can induce the typical small deletions around the site of DNA cleavage and subsequent repair, but Cas12a does not induce the pure DNA insertions that are routinely observed for Cas9. Although these typical signatures are apparent in many literature studies, this is the first report that documents these striking differences.
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PMID:Extinction of all infectious HIV in cell culture by the CRISPR-Cas12a system with only a single crRNA. 3228 99

Various antiretroviral drugs do not kill or cure the human immunodeficiency virus (HIV) but do prevent the replication of the virus. The combination of antiretroviral drugs is known as highly active antiretroviral therapy (HAART). Current drug therapies effectively suppress HIV-1 replication but do not inactivate the provirus that persists in latent reservoirs. Guide RNA (gRNA)-directed CRISPR/Cas9 system can be used for sequence-specific attacks on this proviral DNA. The biggest achievement might be the complete elimination of HIV from infected cells. A study revealed that the tail injection, in transgenic mice and rats having HIV-1 genome, of an adenoassociated virus (AAV) vector expressing a short version of the Cas9 endonuclease (saCas9) and the gRNAs resulted in the cleavage of integrated HIV-1 DNA and excision of a DNA fragment spanning between the LTR and Gag gene in the spleen, liver, heart, kidney, and circulating lymphocytes. HIV-1 has capacity to escape the attack on its genome from most of inhibitors. Thus, to achieve successful antiretroviral treatment, combinations of several antiviral therapies have been applied that are based on two important facts. The first is that multiple drugs lead to synergistic or additive inhibition, and the second is that the combinational therapy increases chances of drug resistance. The success that has been achieved with the help of the genetically engineered tool CRISPR is that dCas9 protein alone can efficiently silence viral gene expression in bacteria with sgRNA. All the reported investigations have indicated that CRISPR/Cas9 can be used as immune machinery into human cells in the form of novel antivirus tools.
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PMID:CRISPR-CAS Replacing Antiviral Drugs against HIV: An Update. 3242 86


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