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1.
Mol Cell ; 81(22): 4747-4756.e7, 2021 11 18.
Artículo en Inglés | MEDLINE | ID: mdl-34648747

RESUMEN

The CRISPR-Cas12a system shows unique features compared with widely used Cas9, making it an attractive and potentially more precise alternative. However, the adoption of this system has been hindered by its relatively low editing efficiency. Guided by physical chemical principles, we covalently conjugated 5' terminal modified CRISPR RNA (crRNA) to a site-specifically modified Cas12a through biorthogonal chemical reaction. The genome editing efficiency of the resulting conjugated Cas12a complex (cCas12a) was substantially higher than that of the wild-type complex. We also demonstrated that cCas12a could be used for precise gene knockin and multiplex gene editing in a chimeric antigen receptor T cell preparation with efficiency much higher than that of the wild-type system. Overall, our findings indicate that covalently linking Cas nuclease and crRNA is an effective approach to improve the Cas12a-based genome editing system and could potentially provide an insight into engineering other Cas family members with low efficiency as well.


Asunto(s)
Proteínas Bacterianas/genética , Proteínas Asociadas a CRISPR/genética , Sistemas CRISPR-Cas , Endodesoxirribonucleasas/genética , Edición Génica , Receptores Quiméricos de Antígenos/metabolismo , Acidaminococcus , Animales , ADN/química , ADN/metabolismo , Endonucleasas/metabolismo , Escherichia coli/metabolismo , Técnicas de Sustitución del Gen , Técnicas Genéticas , Proteínas Fluorescentes Verdes/metabolismo , Células HEK293 , Humanos , Técnicas In Vitro , Células K562 , Ratones , Mutagénesis , ARN/metabolismo , Espectrometría de Masas en Tándem
2.
Proc Natl Acad Sci U S A ; 120(48): e2308224120, 2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-37983496

RESUMEN

The TnpB proteins are transposon-associated RNA-guided nucleases that are among the most abundant proteins encoded in bacterial and archaeal genomes, but whose functions in the transposon life cycle remain unknown. TnpB appears to be the evolutionary ancestor of Cas12, the effector nuclease of type V CRISPR-Cas systems. We performed a comprehensive census of TnpBs in archaeal and bacterial genomes and constructed a phylogenetic tree on which we mapped various features of these proteins. In multiple branches of the tree, the catalytic site of the TnpB nuclease is rearranged, demonstrating structural and probably biochemical malleability of this enzyme. We identified numerous cases of apparent recruitment of TnpB for other functions of which the most common is the evolution of type V CRISPR-Cas effectors on about 50 independent occasions. In many other cases of more radical exaptation, the catalytic site of the TnpB nuclease is apparently inactivated, suggesting a regulatory function, whereas in others, the activity appears to be retained, indicating that the recruited TnpB functions as a nuclease, for example, as a toxin. These findings demonstrate remarkable evolutionary malleability of the TnpB scaffold and provide extensive opportunities for further exploration of RNA-guided biological systems as well as multiple applications.


Asunto(s)
Bacterias , Ribonucleasas , Ribonucleasas/metabolismo , Filogenia , Bacterias/metabolismo , Archaea/metabolismo , Endonucleasas/metabolismo , Sistemas CRISPR-Cas , ARN
3.
Mol Ther ; 32(1): 32-43, 2024 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-37952084

RESUMEN

In 2012, it was discovered that precise gene editing could be induced in target DNA using the reprogrammable characteristics of the CRISPR system. Since then, several studies have investigated the potential of the CRISPR system to edit various biological organisms. For the typical CRISPR system obtained from bacteria and archaea, many application studies have been conducted and have spread to various fields. To date, orthologs with various characteristics other than CRISPR-Cas9 have been discovered and are being intensively studied in the field of gene editing. CRISPR-Cas12 and its varied orthologs are representative examples of genome editing tools and have superior properties in terms of in vivo target gene editing compared with Cas9. Recently, TnpB and Fanzor of the OMEGA (obligate mobile element guided activity) system were identified to be the ancestor of CRISPR-Cas12 on the basis of phylogenetic analysis. Notably, the compact sizes of Cas12 and OMEGA endonucleases allow adeno-associated virus (AAV) delivery; hence, they are set to challenge Cas9 for in vivo gene therapy. This review is focused on these RNA-guided reprogrammable endonucleases: their structure, biochemistry, off-target effects, and applications in therapeutic gene editing.


Asunto(s)
Sistemas CRISPR-Cas , Edición Génica , Filogenia , Bacterias/genética , Endonucleasas/metabolismo
4.
Proc Natl Acad Sci U S A ; 119(26): e2202034119, 2022 06 28.
Artículo en Inglés | MEDLINE | ID: mdl-35727982

RESUMEN

CRISPR diagnostics based on nucleic acid amplification faces barriers to its commercial use, such as contamination risks and insufficient sensitivity. Here, we propose a robust solution involving optochemical control of CRISPR RNA (crRNA) activation in CRISPR detection. Based on this strategy, recombinase polymerase amplification (RPA) and CRISPR-Cas12a detection systems can be integrated into a completely closed test tube. crRNA can be designed to be temporarily inactivated so that RPA is not affected by Cas12a cleavage. After the RPA reaction is completed, the CRISPR-Cas12a detection system is activated under rapid light irradiation. This photocontrolled, fully closed CRISPR diagnostic system avoids contamination risks and exhibits a more than two orders of magnitude improvement in sensitivity compared with the conventional one-pot assay. This photocontrolled CRISPR method was applied to the clinical detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA, achieving detection sensitivity and specificity comparable to those of PCR. Furthermore, a compact and automatic photocontrolled CRISPR detection device was constructed.


Asunto(s)
Proteínas Bacterianas , Proteínas Asociadas a CRISPR , Sistemas CRISPR-Cas , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Endodesoxirribonucleasas , Juego de Reactivos para Diagnóstico , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , COVID-19/diagnóstico , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas/efectos de la radiación , Humanos , ARN/efectos de la radiación , Recombinasas/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , SARS-CoV-2/aislamiento & purificación , Sensibilidad y Especificidad
5.
J Biol Chem ; 299(5): 104700, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37059184

RESUMEN

Ribonucleoproteins (RNPs) comprise one or more RNA and protein molecules that interact to form a stable complex, which commonly involves conformational changes in the more flexible RNA components. Here, we propose that Cas12a RNP assembly with its cognate CRISPR RNA (crRNA) guide instead proceeds primarily through Cas12a conformational changes during binding to more stable, prefolded crRNA 5' pseudoknot handles. Phylogenetic reconstructions and sequence and structure alignments revealed that the Cas12a proteins are divergent in sequence and structure while the crRNA 5' repeat region, which folds into a pseudoknot and anchors binding to Cas12a, is highly conserved. Molecular dynamics simulations of three Cas12a proteins and their cognate guides revealed substantial flexibility for unbound apo-Cas12a. In contrast, crRNA 5' pseudoknots were predicted to be stable and independently folded. Limited trypsin hydrolysis, differential scanning fluorimetry, thermal denaturation, and CD analyses supported conformational changes of Cas12a during RNP assembly and an independently folded crRNA 5' pseudoknot. This RNP assembly mechanism may be rationalized by evolutionary pressure to conserve CRISPR loci repeat sequence, and therefore guide RNA structure, to maintain function across all phases of the CRISPR defense mechanism.


Asunto(s)
Sistemas CRISPR-Cas , ARN Guía de Sistemas CRISPR-Cas , ARN , Ribonucleoproteínas , Edición Génica , Filogenia , Ribonucleoproteínas/genética , ARN Guía de Sistemas CRISPR-Cas/genética , Pliegue de Proteína
6.
Plant J ; 116(5): 1370-1384, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37616189

RESUMEN

The genomic integrity of every organism is endangered by various intrinsic and extrinsic stresses. To maintain genomic integrity, a sophisticated DNA damage response (DDR) network is activated rapidly after DNA damage. Notably, the fundamental DDR mechanisms are conserved in eukaryotes. However, knowledge about many regulatory aspects of the plant DDR is still limited. Important, yet little understood, regulatory factors of the DDR are the long non-coding RNAs (lncRNAs). In humans, 13 lncRNAs functioning in DDR have been characterized to date, whereas no such lncRNAs have been characterized in plants yet. By meta-analysis, we identified the putative long intergenic non-coding RNA induced by DNA damage (LINDA) that responds strongly to various DNA double-strand break-inducing treatments, but not to replication stress induced by mitomycin C. After DNA damage, LINDA is rapidly induced in an ATM- and SOG1-dependent manner. Intriguingly, the transcriptional response of LINDA to DNA damage is similar to that of its flanking hypothetical protein-encoding gene. Phylogenetic analysis of putative Brassicales and Malvales LINDA homologs indicates that LINDA lncRNAs originate from duplication of a flanking small protein-encoding gene followed by pseudogenization. We demonstrate that LINDA is not only needed for the regulation of this flanking gene but also fine-tuning of the DDR after the occurrence of DNA double-strand breaks. Moreover, Δlinda mutant root stem cells are unable to recover from DNA damage, most likely due to hyper-induced cell death.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , ARN Largo no Codificante , Humanos , Arabidopsis/genética , Arabidopsis/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Filogenia , Daño del ADN/genética , ADN/metabolismo , Reparación del ADN , Factores de Transcripción/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo
7.
Small ; 20(28): e2310212, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38342699

RESUMEN

The free-to-total prostate-specific antigen (f/t-PSA) ratio is of great significance in the accurate diagnosis of prostate cancer. Herein, a smartphone-based detection system is reported using a colorimetric reaction integrated with proximity-induced bio-barcode and the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a assay for f/t-PSA ratio detection. DNA/antibody recognition probes are designed to bind f-PSA or t-PSA and induce the release of the DNA bio-barcode. The CRISPR/Cas12a system is activated by the DNA bio-barcode to release Ag+ from the C-Ag+-C structure of the hairpin DNA. The released Ag+ is used to affect the tetramethylbenzidine (TMB)-H2O2-based colorimetric reaction catalyzed by Pt nanoparticles (NPs), as the peroxidase-like activity of the Pt NPs can be efficiently inhibited by Ag+. A smartphone with a self-developed app is used as an image reader and analyzer to analyze the colorimetric reaction and provide the results. A limit of detection of 0.06 and 0.04 ng mL-1 is achieved for t-PSA and f-PSA, respectively. The smartphone-based method showed a linear response between 0.1 and 100 ng mL-1 of t-PSA or f-PSA. In tests with clinical samples, the smartphone-based method successfully diagnosed prostate cancer patients from benign prostatic hyperplasia patients and healthy cases with high sensitivity and specificity.


Asunto(s)
Sistemas CRISPR-Cas , Colorimetría , Nanopartículas del Metal , Antígeno Prostático Específico , Teléfono Inteligente , Colorimetría/métodos , Humanos , Masculino , Nanopartículas del Metal/química , Neoplasias de la Próstata/diagnóstico , Bencidinas/química , Plata/química , Peróxido de Hidrógeno/química , Platino (Metal)/química , Técnicas Biosensibles/métodos
8.
Plant Biotechnol J ; 22(2): 379-385, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37822083

RESUMEN

The CRISPR/Cas type V-I is a family of programmable nuclease systems that prefers a T-rich protospacer adjacent motif (PAM) and is guided by a short crRNA. In this study, the genome-editing application of Cas12i3, a type V-I family endonuclease, was characterized in rice. We developed a CRIPSR/Cas12i3-based Multiplex direct repeats (DR)-spacer Array Genome Editing (iMAGE) system that was efficient in editing various genes in rice. Interestingly, iMAGE produced chromosomal structural variations with a higher frequency than CRISPR/Cas9. In addition, we developed base editors using deactivated Cas12i3 and generated herbicide-resistant rice plants using the base editors. These CRIPSR/Cas12i3-based genome editing systems will facilitate precision molecular breeding in plants.


Asunto(s)
Edición Génica , Oryza , Edición Génica/métodos , Sistemas CRISPR-Cas/genética , Oryza/genética , Plantas/genética , Endonucleasas/genética
9.
J Med Virol ; 96(4): e29624, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38647075

RESUMEN

Respiratory infections pose a serious threat to global public health, underscoring the urgent need for rapid, accurate, and large-scale diagnostic tools. In recent years, the CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated) system, combined with isothermal amplification methods, has seen widespread application in nucleic acid testing (NAT). However, achieving a single-tube reaction system containing all necessary components is challenging due to the competitive effects between recombinase polymerase amplification (RPA) and CRISPR/Cas reagents. Furthermore, to enable precision medicine, distinguishing between bacterial and viral infections is essential. Here, we have developed a novel NAT method, termed one-pot-RPA-CRISPR/Cas12a, which combines RPA with CRISPR molecular diagnostic technology, enabling simultaneous detection of 12 common respiratory pathogens, including six bacteria and six viruses. RPA and CRISPR/Cas12a reactions are separated by paraffin, providing an independent platform for RPA reactions to generate sufficient target products before being mixed with the CRISPR/Cas12a system. Results can be visually observed under LED blue light. The sensitivity of the one-pot-RPA-CRISPR/Cas12a method is 2.5 × 100 copies/µL plasmids, with no cross-reaction with other bacteria or viruses. Additionally, the clinical utility was evaluated by testing clinical isolates of bacteria and virus throat swab samples, demonstrating favorable performance. Thus, our one-pot-RPA-CRISPR/Cas12a method shows immense potential for accurate and large-scale detection of 12 common respiratory pathogens in point-of-care testing.


Asunto(s)
Bacterias , Sistemas CRISPR-Cas , Técnicas de Diagnóstico Molecular , Infecciones del Sistema Respiratorio , Virus , Bacterias/genética , Bacterias/aislamiento & purificación , Infecciones Bacterianas/diagnóstico , Infecciones Bacterianas/microbiología , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , Recombinasas/genética , Recombinasas/metabolismo , Infecciones del Sistema Respiratorio/diagnóstico , Infecciones del Sistema Respiratorio/virología , Infecciones del Sistema Respiratorio/microbiología , Sensibilidad y Especificidad , Virosis/diagnóstico , Virus/genética , Virus/aislamiento & purificación
10.
Anal Biochem ; 693: 115592, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38871161

RESUMEN

In numerous malignancies, miRNA-155 is overexpressed and has oncogenic activity because it is one of the most efficient microRNAs for inhibiting apoptosis in human cancer cells. As a result, the highest sensitive detection of the miRNA-155 gene is a technological instrument that can enable early cancer screening. In this study, a miRNA-155 biosensor was created to create a hairpin probe that can bind to the miRNA-155 gene using lambda nucleic acid exonuclease, which can cut the 5' phosphorylated double strand, and by the DNA probe is recognized by the Cas12a enzyme, which then activates Cas12a to catalyze trans-cutting produces strong fluorescence. Research finding, the target concentration's logarithm and corresponding fluorescence intensity have a strong linear connection, and the limit of detection (LOD) of the sensing system was determined to be 8.3 pM. In addition, the biosensor displayed exceptional specificity, low false-positive signal, and high sensitivity in detecting the miRNA-155 gene in serum samples. This study's creation of a biosensor that has high sensitivity, good selectivity, and is simple to operate provides promising opportunities for research into biosensor design and early cancer detection.


Asunto(s)
Técnicas Biosensibles , Sistemas CRISPR-Cas , MicroARNs , MicroARNs/genética , MicroARNs/sangre , MicroARNs/análisis , Humanos , Técnicas Biosensibles/métodos , Sistemas CRISPR-Cas/genética , Proteínas Asociadas a CRISPR/metabolismo , Proteínas Asociadas a CRISPR/genética , Técnicas de Amplificación de Ácido Nucleico/métodos , Límite de Detección , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Bacteriófago lambda/genética , Endodesoxirribonucleasas
11.
Anal Biochem ; 691: 115526, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38621604

RESUMEN

The imperative for the point-of-care testing of methamphetamine and cocaine in drug abuse prevention necessitates innovative solutions. To address this need, we have introduced a multi-channel wearable sensor harnessing CRISPR/Cas12a system. A CRISPR/Cas12a based system, integrated with aptamers specific to methamphetamine and cocaine, has been engineered. These aptamers function as signal-mediated intermediaries, converting methamphetamine and cocaine into nucleic acid signals, subsequently generating single-stranded DNA to activate the Cas12 protein. Additionally, we have integrated a microfluidic system and magnetic separation technology into the CRISPR system, enabling rapid and precise detection of cocaine and methamphetamine. The proposed sensing platform demonstrated exceptional sensitivity, achieving a detection limit as low as 0.1 ng/mL. This sensor is expected to be used for on-site drug detection in the future.


Asunto(s)
Cocaína , Metanfetamina , Pruebas en el Punto de Atención , Dispositivos Electrónicos Vestibles , Cocaína/análisis , Metanfetamina/análisis , Humanos , Técnicas Biosensibles/métodos , Aptámeros de Nucleótidos/química , Sistemas CRISPR-Cas , Detección de Abuso de Sustancias/métodos
12.
Crit Rev Food Sci Nutr ; : 1-16, 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38659323

RESUMEN

Global food safety stands out as a prominent public concern, affecting populations worldwide. The recurrent challenge of food safety incidents reveals the need for a robust inspection framework. In recent years, the integration of isothermal nucleic acid amplification with CRISPR-Cas12a techniques has emerged as a promising tool for molecular detection of food hazards, presenting next generation of biosensing for food safety detection. This paper provides a comprehensive review of the current state of research on the synergistic application of isothermal nucleic acid amplification and CRISPR-Cas12a technology in the field of food safety. This innovative combination not only enriches the analytical tools, but also improving assay performance such as sensitivity and specificity, addressing the limitations of traditional methods. The review summarized various detection methodologies by the integration of isothermal nucleic acid amplification and CRISPR-Cas12a technology for diverse food safety concerns, including pathogenic bacterium, viruses, mycotoxins, food adulteration, and genetically modified foods. Each section elucidates the specific strategies employed and highlights the advantages conferred. Furthermore, the paper discussed the challenges faced by this technology in the context of food safety, offering insightful discussions on potential solutions and future prospects.

13.
Microb Cell Fact ; 23(1): 6, 2024 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-38172811

RESUMEN

BACKGROUND: Clostridium sp. AWRP (AWRP) is a novel acetogenic bacterium isolated under high partial pressure of carbon monoxide (CO) and can be one of promising candidates for alcohol production from carbon oxides. Compared to model strains such as C. ljungdahlii and C. autoethanogenum, however, genetic manipulation of AWRP has not been established, preventing studies on its physiological characteristics and metabolic engineering. RESULTS: We were able to demonstrate the genetic domestication of AWRP, including transformation of shuttle plasmids, promoter characterization, and genome editing. From the conjugation experiment with E. coli S17-1, among the four replicons tested (pCB102, pAMß1, pIP404, and pIM13), three replicated in AWRP but pCB102 was the only one that could be transferred by electroporation. DNA methylation in E. coli significantly influenced transformation efficiencies in AWRP: the highest transformation efficiencies (102-103 CFU/µg) were achieved with unmethylated plasmid DNA. Determination of strengths of several clostridial promoters enabled the establishment of a CRISPR/Cas12a genome editing system based on Acidaminococcus sp. BV3L6 cas12a gene; interestingly, the commonly used CRISPR/Cas9 system did not work in AWRP, although it expressed the weakest promoter (C. acetobutylicum Pptb) tested. This system was successfully employed for the single gene deletion (xylB and pyrE) and double deletion of two prophage gene clusters. CONCLUSIONS: The presented genome editing system allowed us to achieve several genome manipulations, including double deletion of two large prophage groups. The genetic toolbox developed in this study will offer a chance for deeper studies on Clostridium sp. AWRP for syngas fermentation and carbon dioxide (CO2) sequestration.


Asunto(s)
Sistemas CRISPR-Cas , Escherichia coli , Escherichia coli/genética , Edición Génica , Clostridium/genética , Clostridium/metabolismo , Ingeniería Metabólica
14.
BMC Infect Dis ; 24(1): 458, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38689239

RESUMEN

BACKGROUND: Pseudomonas aeruginosa (P. aeruginosa) is a life-threatening bacterium known for its rapid development of antibiotic resistance, posing significant challenges in clinical treatment, biosecurity, food safety, and environmental monitoring. Early and accurate identification of P. aeruginosa is crucial for effective intervention. METHODS: The lasB gene of P. aeruginosa was selected as the target for the detection. RPA primers for recombinase polymerase amplification (RPA) and crRNA for CRISPR/Cas12a detection were meticulously designed to target specific regions within the lasB gene. The specificity of the RPA/CRISPR/Cas12a detection platform was assessed using 15 strains. The detection limit of RPA/CRISPR/Cas12a detection platform was determined by utilizing a pseudo-dilution series of the P. aeruginosa DNA. The practical applicability of the RPA/CRISPR/Cas12a detection platform was validated by comparing it with qPCR on 150 samples (35 processed meat product samples, 55 cold seasoned vegetable dishes, 60 bottled water samples). RESULTS: The RPA/CRISPR/Cas12a detection platform demonstrates high specificity, with no cross-reactivity with non-P. aeruginosa strains. This assay exhibits remarkable sensitivity, with a limit of detection (LOD) of 100 copies/µL for fluorescence assay and 101 copies/µL for the LFTS method. Furthermore, the performance of the RPA/CRISPR/Cas12a detection platform is comparable to that of the well-established qPCR method, while offering advantages such as shorter reaction time, simplified operation, and reduced equipment requirements. CONCLUSIONS: The RPA/CRISPR/Cas12a detection platform presents a straightforward, accurate, and sensitive approach for early P. aeruginosa detection and holds great promise for diverse applications requiring rapid and reliable identification.


Asunto(s)
Proteínas Bacterianas , Proteínas Asociadas a CRISPR , Sistemas CRISPR-Cas , Endodesoxirribonucleasas , Pseudomonas aeruginosa , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/aislamiento & purificación , Sensibilidad y Especificidad , Técnicas de Amplificación de Ácido Nucleico/métodos , Infecciones por Pseudomonas/microbiología , Infecciones por Pseudomonas/diagnóstico , Humanos , Límite de Detección , Recombinasas/metabolismo
15.
Anal Bioanal Chem ; 416(2): 363-372, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37935845

RESUMEN

A recent outbreak of porcine circovirus-like virus (PCLV), a virus that may be associated with porcine diarrhea, has been reported in swine herds in China. The virus is spreading rapidly, causing huge economic losses to the swine farming industry. To achieve the rapid, inexpensive, and sensitive detection of PCLV, we combined loop-mediated isothermal amplification (LAMP) and the CRISPR/Cas12a system, whose fluorescence intensity readout can detect PCLV ORF4 gene levels as low as 10 copies. To overcome the need for sophisticated equipment, lateral flow strip reading technology was introduced for the first time in a LAMP-Cas12a-based system to detect PCLV. The lateral flow strip (LFS) results were readout by the naked eye, and the method was highly sensitive with a detection limit of 10 copies, with a detection time of about 60 min. In addition, the method is highly specific and has no cross-reactivity with other related viruses. In conclusion, LAMP-CRISPR/Cas12a-based assays have the advantages of rapidity, accuracy, portability, low cost, and visualization of the results. They therefore have great potential, especially for areas where specialized equipment is lacking, and can expect to be an ideal method for early diagnosis and on-site detection of PCLV.


Asunto(s)
Circovirus , Enfermedades de los Porcinos , Virus , Porcinos , Animales , Circovirus/genética , Sistemas CRISPR-Cas , Enfermedades de los Porcinos/diagnóstico , Sensibilidad y Especificidad , Técnicas de Amplificación de Ácido Nucleico/métodos
16.
Anal Bioanal Chem ; 416(15): 3509-3518, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38647692

RESUMEN

Escherichia coli O157:H7 (E. coli O157:H7) is a foodborne pathogenic microorganism that is commonly found in the environment and poses a significant threat to human health, public safety, and economic stability worldwide. Thus, early detection is essential for E. coli O157:H7 control. In recent years, a series of E. coli O157:H7 detection methods have been developed, but the sensitivity and portability of the methods still need improvement. Therefore, in this study, a rapid and efficient testing platform based on the CRISPR/Cas12a cleavage reaction was constructed. Through the integration of recombinant polymerase amplification and lateral flow chromatography, we established a dual-interpretation-mode detection platform based on CRISPR/Cas12a-derived fluorescence and lateral flow chromatography for the detection of E. coli O157:H7. For the fluorescence detection method, the limits of detection (LODs) of genomic DNA and E. coli O157:H7 were 1.8 fg/µL and 2.4 CFU/mL, respectively, within 40 min. Conversely, for the lateral flow detection method, LODs of 1.8 fg/µL and 2.4 × 102 CFU/mL were achieved for genomic DNA and E. coli O157:H7, respectively, within 45 min. This detection strategy offered higher sensitivity and lower equipment requirements than industry standards. In conclusion, the established platform showed excellent specificity and strong universality. Modifying the target gene and its primers can broaden the platform's applicability to detect various other foodborne pathogens.


Asunto(s)
Sistemas CRISPR-Cas , Escherichia coli O157 , Límite de Detección , Escherichia coli O157/genética , Escherichia coli O157/aislamiento & purificación , ADN Bacteriano/análisis , ADN Bacteriano/genética , Microbiología de Alimentos/métodos , Proteínas Asociadas a CRISPR/genética , Humanos , Endodesoxirribonucleasas/genética
17.
BMC Vet Res ; 20(1): 258, 2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38877537

RESUMEN

BACKGROUND: Senecavirus A (SVA), identified in 2002, is known to cause porcine idiopathic vesicular disease (PIVD), which presents with symptoms resembling other vesicular diseases. This similarity complicates field diagnosis. Conventional molecular diagnostic techniques are limited by their cost, sensitivity, and requirement for complicated instrumentation. Therefore, developing an effective and accurate diagnostic method is crucial for timely identification and isolation of affected pigs, thereby preventing further disease spread. METHODS: In this study, we developed a highly-specific and ultra-sensitive SVA detection method powered by CRISPR/Cas12a. To enhance the availability in laboratories with varied equipment conditions, microplate reader and ultraviolet light transilluminator were introduced. Moreover, PCR amplification has also been incorporated into this method to improve sensitivity. The specificity and sensitivity of this method were determined following the preparation of the recombinant Cas12a protein and optimization of the CRISPR/Cas12a-based trans-cleavage system. RESULTS: The method demonstrated no cross-reactivity with ten kinds of viruses of swine. The minimum template concentration required to activate substantial trans-cleavage activity was determined to be 106 copies/µL of SVA templates. However, when PCR amplification was incorporated, the method achieved a detection limit of one copy of SVA templates per reaction. It also exhibited 100% accuracy in simulated sample testing. The complete testing process does not exceed three hours. CONCLUSIONS: Importantly, this method utilizes standard laboratory equipment, making it accessible for use in resource-limited settings and facilitating widespread and ultra-sensitive screening during epidemics. Overall, the development of this method not only broadens the array of tools available for detecting SVA but also holds significant promise for controlling the spread of PIVD.


Asunto(s)
Sistemas CRISPR-Cas , Picornaviridae , Sensibilidad y Especificidad , Enfermedades de los Porcinos , Animales , Porcinos , Picornaviridae/aislamiento & purificación , Picornaviridae/genética , Enfermedades de los Porcinos/virología , Enfermedades de los Porcinos/diagnóstico , Infecciones por Picornaviridae/veterinaria , Infecciones por Picornaviridae/diagnóstico , Infecciones por Picornaviridae/virología , Reacción en Cadena de la Polimerasa/veterinaria , Reacción en Cadena de la Polimerasa/métodos , Proteínas Asociadas a CRISPR/genética
18.
Phytopathology ; 114(2): 474-483, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37589413

RESUMEN

Brassica yellows virus (BrYV) is an economically important virus on cruciferous species. In this study, a one-pot reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay coupled with the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a system was developed for the detection of BrYV. The limit of detection of this method reached 32.8 copies of the BrYV ORF5, which is 100-fold more sensitive than the RT-LAMP method. Moreover, there was no cross-reactivity with other rapeseed-infecting RNA viruses or poleroviruses. We dried the CRISPR/Cas12a reagent in a trehalose and pullulan mixture to retain its efficacy at the RT-LAMP temperature of 63°C in order to allow portable BrYV detection in a water bath. The entire process can be performed in about 1 h, and a positive result can be rapidly and conveniently detected using a handheld UV lamp. In the field, the RT-LAMP-CRISPR/Cas12a assay was accurate and had higher sensitivity than RT-LAMP and reverse transcription-polymerase chain reaction assays. The novel RT-LAMP-CRISPR/Cas12a assay allows convenient, portable, rapid, low-cost, highly sensitive, and specific detection of BrYV and has great potential for on-site monitoring of BrYV.


Asunto(s)
Brassica , Técnicas de Diagnóstico Molecular , Técnicas de Amplificación de Ácido Nucleico , Transcripción Reversa , Sistemas CRISPR-Cas , Enfermedades de las Plantas
19.
J Nanobiotechnology ; 22(1): 266, 2024 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-38762451

RESUMEN

The detection of carcinoembryonic antigen (CEA) holds significant importance in the early diagnosis of cancer. However, current methods are hindered by limited accessibility and specificity. This study proposes a rapid and convenient Cas12a-based assay for the direct detection of CEA in clinical serum samples, aiming to address these limitations. The protocol involves a rolling machine operation, followed by a 5-min Cas12a-mediated cleavage process. The assay demonstrates the capability to detect human serum with high anti-interference performance and a detection limit as low as 0.2 ng/mL. The entire testing procedure can be accomplished in 75 min without centrifugation steps, and successfully reduced the limit of detection of traditional DNA walking machine by 50 folds. Overall, the testing procedure can be easily implemented in clinical settings.


Asunto(s)
Técnicas Biosensibles , Sistemas CRISPR-Cas , Antígeno Carcinoembrionario , ADN , Límite de Detección , Antígeno Carcinoembrionario/sangre , Humanos , Técnicas Biosensibles/métodos , ADN/química , Endodesoxirribonucleasas , Técnicas de Amplificación de Ácido Nucleico/métodos , Proteínas Asociadas a CRISPR , Proteínas Bacterianas/genética
20.
Cell Mol Biol Lett ; 29(1): 34, 2024 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-38459454

RESUMEN

Persistent infection with high-risk human papillomavirus (HR-HPV) is the primary and initiating factor for cervical cancer. With over 200 identified HPV types, including 14 high-risk types that integrate into the host cervical epithelial cell DNA, early determination of HPV infection type is crucial for effective risk stratification and management. Presently, on-site immediate testing during the HPV screening stage, known as Point of Care Testing (POCT), remains immature, severely limiting the scope and scenarios of HPV screening. This study, guided by the genomic sequence patterns of HPV, established a multiplex recombinase polymerase amplification (RPA) technology based on the concept of "universal primers." This approach achieved the multiple amplification of RPA, coupled with the CRISPR/Cas12a system serving as a medium for signal amplification and conversion. The study successfully constructed a POCT combined detection system, denoted as H-MRC12a (HPV-Multiple RPA-CRISPR/Cas12a), and applied it to high-risk HPV typing detection. The system accomplished the typing detection of six high-risk HPV types (16, 18, 31, 33, 35, and 45) can be completed within 40 min, and the entire process, from sample loading to result interpretation, can be accomplished within 45 min, with a detection depth reaching 1 copy/µL for each high-risk type. Validation of the H-MRC12a detection system's reproducibility and specificity was further conducted through QPCR on 34 clinical samples. Additionally, this study explored and optimized the multiplex RPA amplification system and CRISPR system at the molecular mechanism level. Furthermore, the primer design strategy developed in this study offers the potential to enhance the throughput of H-MRC12a detection while ensuring sensitivity, providing a novel research avenue for high-throughput detection in Point-of-Care molecular pathogen studies.


Asunto(s)
Infecciones por Papillomavirus , Recombinasas , Humanos , Sistemas CRISPR-Cas/genética , Infecciones por Papillomavirus/diagnóstico , Reproducibilidad de los Resultados , Pruebas en el Punto de Atención , Virus del Papiloma Humano
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