CRISPR interference: RNA-directed adaptive immunity in bacteria and archaea. Nat Rev Genet. 2010;11:181-190. [PMID: 20125085 DOI: 10.1038/nrg2749]

Trans-cleavage activity of Cas12a effectors can be unleashed by both double-stranded DNA and single-stranded RNA targeting in absence of PAM

CRISPR-Cas12a is a powerful tool in nucleic acid detection, but the relationship between its trans-cleavage activity and protospacer adjacent motif (PAM) sequences remains incompletely understood. In this study, we synthesized diverse PAM-sequence substrates and conducted systematic cis-cleavage and trans-cleavage experiments with three Cas12a orthologs. We found that double-stranded DNA (dsDNA) can activate Cas12a's trans-cleavage activity even without PAM and this activation occurring independently of cis-cleavage. Notably, our results also revealed that single-stranded RNA (ssRNA) can directly initiate the trans-cleavage activity of Cas12a.We also experimentally validated the feasibility of CRISPR-Cas12a in detecting target dsDNA lacking PAM sequences, including identifying mutated sites in clinical samples. Structural prediction using AlphaFold 3 revealed the potential mechanism of Cas12a's PAM-independent trans-cleavage. Our research expands the understanding of Cas12a's trans-cleavage mechanism and demonstrates its potential for nucleic acid detection beyond PAM-dependent targets. This discovery broadens the application scope of Cas12a, providing new opportunities for developing highly sensitive and versatile diagnostic platforms.

Deep Learning-Based Classification of CRISPR Loci Using Repeat Sequences

With the widespread application of the CRISPR-Cas system in gene editing and related fields, along with the increasing availability of metagenomic data, the demand for detecting and classifying CRISPR-Cas systems in metagenomic data sets has grown significantly. Traditional classification methods for CRISPR-Cas systems primarily rely on identifying cas genes near CRISPR arrays. However, in cases where cas gene information is absent, such as in metagenomes or fragmented genome assemblies, traditional methods may fail. Here, we present a deep learning-based method, CRISPRclassify-CNN-Att, which classifies CRISPR loci solely based on repeat sequences. CRISPRclassify-CNN-Att utilizes convolutional neural networks (CNNs) and self-attention mechanisms to extract features from repeat sequences. It employs a stacking strategy to address the imbalance of samples across different subtypes and uses transfer learning to improve classification accuracy for subtypes with fewer samples. CRISPRclassify-CNN-Att demonstrates outstanding performance in classifying multiple subtypes, particularly those with larger sample sizes. Although CRISPR loci classification traditionally depends on cas genes, CRISPRclassify-CNN-Att offers a novel approach that serves as a significant complement to cas-based methods, enabling the classification of orphan or distant CRISPR loci. The proposed tool is freely accessible via https://github.com/Xingyu-Liao/CRISPRclassify-CNN-Att.

CRISPR-Cas Systems: A Functional Perspective and Innovations

Adaptation is a fundamental tenet of evolutionary biology and is essential for the survival of all organisms, including prokaryotes. The evolution of clustered regularity exemplifies this principle of interspaced short palindromic repeats (CRISPR) and associated proteins (Cas), an adaptive immune system that confers resistance to viral infections. By integrating short segments of viral genomes into their own, bacteria and archaea develop a molecular memory that enables them to mount a rapid and targeted response upon subsequent viral challenges. The fortuitous discovery of this immune mechanism prompted many studies and introduced researchers to novel tools that could potentially be developed from CRISPR-Cas and become clinically relevant as biotechnology rapidly advances in this area. Thus, a deeper understanding of the underpinnings of CRISPR-Cas and its possible therapeutic applications is required. This review analyses the mechanism of action of the CRISPR-Cas systems in detail and summarises the advances in developing biotechnological tools based on CRISPR, opening the field for further research.

Emerging applications of gene editing technologies for the development of climate-resilient crops

Climate change threatens global crop yield and food security due to rising temperatures, erratic rainfall, and increased abiotic stresses like drought, heat, and salinity. Gene editing technologies, including CRISPR/Cas9, base editors, and prime editors, offer precise tools for enhancing crop resilience. This review explores the mechanisms of these technologies and their applications in developing climate-resilient crops to address future challenges. While CRISPR/enables targeted modifications of plant DNA, the base editors allow for direct base conversion without inducing double-stranded breaks, and the prime editors enable precise insertions, deletions, and substitutions. By understanding and manipulating key regulator genes involved in stress responses, such as DREB, HSP, SOS, ERECTA, HsfA1, and NHX; crop tolerance can be enhanced against drought, heat, and salt stress. Gene editing can improve traits related to root development, water use efficiency, stress response pathways, heat shock response, photosynthesis, membrane stability, ion homeostasis, osmotic adjustment, and oxidative stress response. Advancements in gene editing technologies, integration with genomics, phenomics, artificial intelligence (AI)/machine learning (ML) hold great promise. However, challenges such as off-target effects, delivery methods, and regulatory barriers must be addressed. This review highlights the potential of gene editing to develop climate-resilient crops, contributing to food security and sustainable agriculture.

CRISPR: fundamental principles and implications for anaesthesia

Clustered regularly interspaced short palindromic repeats (CRISPR)-based medical therapies are increasingly gaining regulatory approval worldwide. Consequently, patients receiving CRISPR therapy will come under the care of anaesthesiologists. An understanding of CRISPR, its technological implementations, and the characteristics of patients likely to receive this therapy will be essential to caring for this patient population. However, the role of CRISPR in anaesthesiology extends beyond simply caring for patients with prior CRISPR therapy. CRISPR has multiple direct potential applications in anaesthesia, particularly for managing chronic pain and critical illness. Additionally, given the unique skills anaesthesiologists possess, CRISPR potentially allows new roles for anaesthesiologists in the field of oncology. Consequently, CRISPR technology could enable new domains of anaesthetic practice. This review provides a primer on CRISPR for anaesthesiologists and an overview on how the technology could impact the field.

Overcoming Bacteriophage Contamination in Bioprocessing: Strategies and Applications

Bacteriophage contamination has a devastating impact on the viability of bacterial hosts and can significantly reduce the productivity of bioprocesses in biotechnological industries. The consequences range from widespread fermentation failure to substantial economic losses, highlighting the urgent need for effective countermeasures. Conventional prevention methods, which focus primarily on the physical removal of bacteriophages from equipment, bioprocess units, and the environment, have proven ineffective in preventing phage entry and contamination. The coevolutionary dynamics between phages and their bacterial hosts have spurred the development of a diverse repertoire of antiviral defense mechanisms within microbial communities. These naturally occurring defense strategies can be harnessed through genetic engineering to convert phage-sensitive hosts into robust, phage-resistant cell factories, providing a strategic approach to mitigate the threats posed by bacteriophages to industrial bacterial processes. In this review, an overview of the various defense strategies and immune systems that curb the propagation of bacteriophages and highlight their applications in fermentation bioprocesses to combat phage contamination is provided. Additionally, the tactics employed by phages to circumvent these defense strategies are also discussed, as preventing the emergence of phage escape mutants is a key component of effective contamination management.

From Origin to the Present: Establishment, Mechanism, Evolutions and Biomedical Applications of the CRISPR/Cas-Based Macromolecular System in Brief

Advancements in biological and medical science are intricately linked to the biological central dogma. In recent years, gene editing techniques, especially CRISPR/Cas systems, have emerged as powerful tools for modifying genetic information, supplementing the central dogma and holding significant promise for disease diagnosis and treatment. Extensive research has been conducted on the continuously evolving CRISPR/Cas systems, particularly in relation to challenging diseases, such as cancer and HIV infection. Consequently, the integration of CRISPR/Cas-based techniques with contemporary medical approaches and therapies is anticipated to greatly enhance healthcare outcomes for humans. This review begins with a brief overview of the discovery of the CRISPR/Cas system. Subsequently, using CRISPR/Cas9 as an example, a clear description of the classical molecular mechanism underlying the CRISPR/Cas system was given. Additionally, the development of the CRISPR/Cas system and its applications in gene therapy and high-sensitivity disease diagnosis were discussed. Furthermore, we address the prospects for clinical applications of CRISPR/Cas-based gene therapy, highlighting the ethical considerations associated with altering genetic information. This brief review aims to enhance understanding of the CRISPR/Cas macromolecular system and provide insight into the potential of genetic macromolecular drugs for therapeutic purposes.

SspA is a transcriptional regulator of CRISPR adaptation in E. coli

The CRISPR integrases Cas1-Cas2 create immunological memories of viral infection by storing phage-derived DNA in CRISPR arrays, a process known as CRISPR adaptation. A number of host factors have been shown to influence adaptation, but the full pathway from infection to a fully integrated, phage-derived sequences in the array remains incomplete. Here, we deploy a new CRISPRi-based screen to identify putative host factors that participate in CRISPR adaptation in the Escherichia coli Type I-E system. Our screen and subsequent mechanistic characterization reveal that SspA, through its role as a global transcriptional regulator of cellular stress, is required for functional CRISPR adaptation. One target of SspA is H-NS, a known repressor of CRISPR interference proteins, but we find that the role of SspA on adaptation is not H-NS-dependent. We propose a new model of CRISPR-Cas defense that includes independent cellular control of adaptation and interference by SspA.

Genetic advancements in breast cancer treatment: a review

Breast cancer (BC) remains a leading cause of cancer-related deaths among women globally, highlighting the urgent need for more effective and targeted therapies. Traditional treatments, including surgery, chemotherapy, and radiation, face limitations such as drug resistance, metastasis, and severe side effects. Recent advancements in gene therapy, particularly CRISPR/Cas9 technology and Oncolytic Virotherapy (OVT), are transforming the BC treatment landscape. CRISPR/Cas9 enables precise gene editing to correct mutations in oncogenes like HER2 and MYC, directly addressing tumor growth and immune evasion. Simultaneously, OVT leverages genetically engineered viruses to selectively destroy cancer cells and stimulate robust antitumor immune responses. Despite their potential, gene therapies face challenges, including off-target effects, delivery issues, and ethical concerns. Innovations in delivery systems, combination strategies, and integrating gene therapy with existing treatments offer promising solutions to overcome these barriers. Personalized medicine, guided by genomic profiling, further enhances treatment precision by identifying patient-specific mutations, such as BRCA1 and BRCA2, allowing for more tailored and effective interventions. As research progresses, the constructive interaction between gene therapy, immunotherapy, and traditional approaches is paving the way for groundbreaking advancements in BC care. Continued collaboration between researchers and clinicians is essential to translate these innovations into clinical practice, ultimately improving BC patients' survival rates and quality of life.

Using CRISPR for viral nucleic acid detection

Pathogenic microorganisms, such as viruses, have threatened human health and will continue to contribute to future epidemics and pandemics, highlighting the importance of developing effective diagnostics. To contain viral outbreaks within populations, fast and early diagnosis of infected individuals is essential. Although current standard methods are highly sensitive and specific, like RT-qPCR, some can have slow turnaround times, which can hinder the prevention of viral transmission. The discovery of CRISPR-Cas systems in bacteria and archaea initially revolutionized the world of genome editing. Intriguingly, CRISPR-Cas enzymes also have the ability to detect nucleic acids with high sensitivity and specificity, which sparked the interest of researchers to also explore their potential in diagnosis of viral pathogens. In particular, the CRISPR-Cas13 system has been used as a tool for detecting viral nucleic acids. Cas13's capability to detect both target RNA and non-specific RNAs has led to the development of detection methods that leverage these characteristics through designing specific detection read-outs. Optimization of viral sample collection, amplification steps and the detection process within the Cas13 detection workflow has resulted in assays with high sensitivity, rapid turnaround times and the capacity for large-scale implementation. This review focuses on the significant innovations of various CRISPR-Cas13-based viral nucleic acid detection methods, comparing their strengths and weaknesses while highlighting Cas13's great potential as a tool for viral diagnostics.

Engineering of CRISPR-Cas PAM recognition using deep learning of vast evolutionary data

CRISPR-Cas enzymes must recognize a protospacer-adjacent motif (PAM) to edit a genomic site, significantly limiting the range of targetable sequences in a genome. Machine learning-based protein engineering provides a powerful solution to efficiently generate Cas protein variants tailored to recognize specific PAMs. Here, we present Protein2PAM, an evolution-informed deep learning model trained on a dataset of over 45,000 CRISPR-Cas PAMs. Protein2PAM rapidly and accurately predicts PAM specificity directly from Cas proteins across Type I, II, and V CRISPR-Cas systems. Using in silico deep mutational scanning, we demonstrate that the model can identify residues critical for PAM recognition in Cas9 without utilizing structural information. As a proof of concept for protein engineering, we employ Protein2PAM to computationally evolve Nme1Cas9, generating variants with broadened PAM recognition and up to a 50-fold increase in PAM cleavage rates compared to the wild-type under in vitro conditions. This work represents the first successful application of machine learning to achieve customization of Cas enzymes for alternate PAM recognition, paving the way for personalized genome editing.

Structural and biochemical insights into the mechanism of the anti-CRISPR protein AcrIE3

Anti-CRISPR (Acr) proteins are natural inhibitors of CRISPR-Cas systems, found in bacteriophages and other genetic elements. AcrIE3, identified in a Pseudomonas phage, inactivates the type I-E CRISPR-Cas system in Pseudomonas aeruginosa by engaging with the Cascade complex. However, its precise inhibition mechanism has remained elusive. In this study, we present a comprehensive structural and biochemical analysis of AcrIE3, providing mechanistic insight into its anti-CRISPR function. Our results reveal that AcrIE3 selectively binds to the Cas8e subunit of the Cascade complex. The crystal structure of AcrIE3 exhibits an all-helical fold with a negatively charged surface. Through extensive mutational analyses, we show that AcrIE3 interacts with the protospacer adjacent motif (PAM) recognition site in Cas8e through its negatively charged surface residues. These findings enhance our understanding of the structure and function of type I-E Acr proteins, suggesting PAM interaction sites as primary targets for divergent Acr inhibitors.

Biological warfare between two bacterial viruses in a defense archipelago sheds light on the spread of CRISPR-Cas systems

CRISPR-Cas systems are adaptive immunity systems of bacteria and archaea that prevent infection by viruses and other external mobile genetic elements. It is currently known that these defense systems can be co-opted by the same viruses. We have found one of these viruses in the opportunistic pathogen Acinetobacter baumannii, and the same system has been also found in an integration hotspot of the bacterial genome that harbors other multiple defense systems. The CRISPR-Cas system appears to especially target another virus that could compete with the system itself for the same integration site. This virus is prevalent in strains of the species belonging to the so-called Global Clone 2, which causes the most frequent outbreaks worldwide. Knowledge of this viral warfare involving antiviral systems could be useful in the fight against infections caused by bacteria, and it would also shed light on how CRISPR-Cas systems expand in bacteria.

CRISPR-powered RNA sensing in vivo

RNA sensing in vivo evaluates past or ongoing endogenous RNA disturbances, which is crucial for identifying cell types and states and diagnosing diseases. Recently, the CRISPR-driven genetic circuits have offered promising solutions to burgeoning challenges in RNA sensing. This review delves into the cutting-edge developments of CRISPR-powered RNA sensors in vivo, reclassifying these RNA sensors into four categories based on their working mechanisms, including programmable reassembly of split single-guide RNA (sgRNA), RNA-triggered RNA processing and protein cleavage, miRNA-triggered RNA interference (RNAi), and strand displacement reactions. Then, we discuss the advantages and challenges of existing methodologies in diverse application scenarios and anticipate and analyze obstacles and opportunities in forthcoming practical implementations.

Exosomes for CRISPR-Cas9 Delivery: The Cutting Edge in Genome Editing

Gene mutation correction was challenging until the discovery of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein (Cas). CRISPR is a new era for genome modification, and this technology has bypassed the limitations of previous methods such as zinc-finger nuclease and transcription activator-like effector nuclease. Currently, this method is becoming the method of choice for gene-editing purposes, especially therapeutic gene editing in diseases such as cardiovascular, neurological, renal, genetic, optical, and stem cell, as well as blood disorders and muscular degeneration. However, finding the optimum delivery system capable of carrying this large complex persists as the main challenge of this technology. Therefore, it would be ideal if the delivery vehicle could direct the introduction of editing functions to specific cells in a multicellular organism. Exosomes are membrane-bound vesicles with high biocompatibility and low immunogenicity; they offer the best and most reliable way to fill the CRISPR/Cas9 system delivery gap. This review presents the current evidence on the molecular mechanisms and challenges of CRISPR/Cas9-mediated genome modification. Also, the role of CRISPR/Cas9 in the development of treatment and diagnosis of numerous disorders, from malignancies to viral infections, has been discussed. Lastly, the focus is on new advances in exosome-delivery technologies that may play a role in CRISPR/Cas9 delivery for future clinical settings.

Evolution of Repetitive Elements, Their Roles in Homeostasis and Human Disease, and Potential Therapeutic Applications

Repeating sequences of DNA, or repetitive elements (REs), are common features across both prokaryotic and eukaryotic genomes. Unlike many of their protein-coding counterparts, the functions of REs in host cells remained largely unknown and have often been overlooked. While there is still more to learn about their functions, REs are now recognized to play significant roles in both beneficial and pathological processes in their hosts at the cellular and organismal levels. Therefore, in this review, we discuss the various types of REs and review what is known about their evolution. In addition, we aim to classify general mechanisms by which REs promote processes that are variously beneficial and harmful to host cells/organisms. Finally, we address the emerging role of REs in cancer, aging, and neurological disorders and provide insights into how RE modulation could provide new therapeutic benefits for these specific conditions.

Structural basis of Cas3 activation in type I-C CRISPR-Cas system

CRISPR-Cas systems function as adaptive immune mechanisms in bacteria and archaea and offer protection against phages and other mobile genetic elements. Among many types of CRISPR-Cas systems, Type I CRISPR-Cas systems are most abundant, with target interference depending on a multi-subunit, RNA-guided complex known as Cascade that recruits a transacting helicase nuclease, Cas3, to degrade the target. While structural studies on several other types of Cas3 have been conducted long ago, it was only recently that the structural study of Type I-C Cas3 in complex with Cascade was revealed, shedding light on how Cas3 achieve its activity in the Cascade complex. In the present study, we elucidated the first structure of standalone Type I-C Cas3 from Neisseria lactamica (NlaCas3). Structural analysis revealed that the histidine-aspartate (HD) nuclease active site of NlaCas3 was bound to two Fe2+ ions that inhibited its activity. Moreover, NlaCas3 could cleave both single-stranded and double-stranded DNA in the presence of Ni2+ or Co2+, showing the highest activity in the presence of both Ni2+ and Mg2+ ions. By comparing the structural studies of various Cas3 proteins, we determined that our NlaCas3 stays in an inactive conformation, allowing us to understand the structural changes associated with its activation and their implication.

Reporter Mice for Gene Editing: A Key Tool for Advancing Gene Therapy of Rare Diseases

Most rare diseases are caused by mutations and can have devastating consequences. Precise gene editing by CRISPR/Cas is an exciting possibility for helping these patients, if no irreversible developmental defects have occurred. To optimize gene editing therapy, reporter mice for gene editing have been generated which, by expression of reporter genes, indicate the efficiency of precise and imprecise gene editing. These mice are important tools for testing and comparing novel gene editing methodologies. This review provides a comprehensive overview of reporter mice for gene editing which all have been used for monitoring CRISPR/Cas-mediated gene editing involving DNA double-strand breaks (DSBs). Furthermore, we discuss how reporter mice can be used for quickly checking genetic alterations by base editing (BE) or prime editing (PE).

Novel approaches for HTLV-1 therapy: innovative applications of CRISPR-Cas9

The human T-cell lymphotropic virus type 1 (HTLV-1) is a single-stranded positive-sense RNA virus that belongs to the Retroviridae family, genus Deltaretro, and infects approximately five to 10 million people worldwide. Although a significant number of individuals living with HTLV-1 remain asymptomatic throughout their lives, some develop one or more severe clinical conditions, such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), a progressive and debilitating disease, and/or a subtype of non-Hodgkin's lymphoma with a more threatening course known as adult T-cell leukemia/lymphoma (ATLL). Moreover, current therapeutic options are limited and focus primarily on treating symptoms and controlling viral latency. CRISPR-Cas9 gene editing is proposed as a promising tool to address the intricate links associated with HTLV-1. By targeting or silencing key genes during initial infection and dysregulating immune signaling pathways, CRISPR-Cas9 offers potential intervention opportunities. In this review, we address the therapeutic potential of CRISPR-Cas9 gene editing, as well as examine the primary mechanisms involved in editing potential target genes and discuss the existing evidence in the current scientific literature.

A LAMP-CRISPR/Cas12b rapid detection platform for canine parvovirus detection

Canine parvovirus (CPV) is one of the main pathogens causing toxic diarrhea in Chinese dogs, is the cause of large-scale epidemic of dogs, and poses a great threat to the dog industry in China. Rapid, sensitive, and specific CPV testing facilitates the timely diagnosis and treatment of sick dogs. The aim of this study was to build a LAMP-CRISPR/Cas12b platform for CPV detection. The loop mediated isothermal amplification (LAMP) technique was combined with CRISPR-Cas12b analysis to establish a "two-step" and "one-tube" CRISPR/Cas12b rapid CPV method, respectively. The detection system was constructed with specific LAMP primers and single guide RNA (sgRNA) for the highly conserved short fragment of the CPV gene, which could be detected within 1 h without cross-reaction with the other viruses causing canine diarrhea. The detection limits of both "two-step" and "one-tube" CRISPR/Cas12b reactions were 10-1 copies per μL, which was 100 times more sensitive than qPCR and LAMP. In order to achieve point-of-care testing (POCT) of CPV, a one-tube LAMP-CRISPR/Cas12b nucleic acid extraction and detection platform based on magnetic nanoparticle enrichment technology was established to achieve "sample in-result out". The results of this method for simulated samples were compared with those of quantitative real-time PCR; the results showed 100% consistency, and the time was shorter, which could be used to detect the diseased dogs earlier and provide a basis for clinical diagnosis. The LAMP-CRISPR/Cas12b method established in this study provides a sensitive and specific method for rapid detection of CPV, and provides technical support for rapid diagnosis of CPV.

Systems and Methods for Continuous Evolution of Enzymes

Directed evolution generates novel biomolecules with desired functions by iteratively diversifying the genetic sequence of wildtype biomolecules, relaying the genetic information to the molecule with function, and selecting the variants that progresses towards the properties of interest. While traditional directed evolution consumes significant labor and time for each step, continuous evolution seeks to automate all steps so directed evolution can proceed with minimum human intervention and dramatically shortened time. A major application of continuous evolution is the generation of novel enzymes, which catalyze reactions under conditions that are not favorable to their wildtype counterparts, or on altered substrates. The challenge to continuously evolve enzymes lies in automating sufficient, unbiased gene diversification, providing selection for a wide array of reaction types, and linking the genetic information to the phenotypic function. Over years of development, continuous evolution has accumulated versatile strategies to address these challenges, enabling its use as a general tool for enzyme engineering. As the capability of continuous evolution continues to expand, its impact will increase across various industries. In this review, we summarize the working mechanisms of recently developed continuous evolution strategies, discuss examples of their applications focusing on enzyme evolution, and point out their limitations and future directions.

A rapid simultaneous detection of duck hepatitis A virus 3 and novel duck reovirus based on RPA CRISPR Cas12a/Cas13a

The mixed infection of duck hepatitis A virus 3 (DHAV-3) and novel duck reovirus (NDRV) has caused significant losses to the global duck farming industry. On-site point-of-care testing of viruses plays a crucial role in the early diagnosis, prevention, and disease control. Here, we proposed an RPA-CRISPR Cas12a/Cas13a one-pot strategy (DRCFS) for rapid and simultaneous detection of DHAV-3 and NDRV. This method integrated the reaction of RPA and CRISPR Cas12a/Cas13a in a single tube, eliminating the need to open the lid during the intermediate processes and thereby avoiding aerosol contamination. On this basis, we proposed a dual RPA-CRISPR strategy coupled with a lateral flow analysis platform (DRC-LFA). This circumvented the necessity for complex instruments, enabling direct visual interpretation of results, making the test more accessible and user-friendly. Our findings demonstrated that the DRCFS method could detect DHAV-3 and NDRV at concentrations as low as 100 copy/μL, while DRC-LFA achieved limit of 101 copies/μL within 35 min. Furthermore, when DRCFS, DRC-LFA, and qPCR were employed collectively for clinical samples analysis, all three methods yielded consistent results. The specificity, sensitivity, and user-friendly of these methods rendered them invaluable for on-site virus detection.

CRISPR-Cpf1 system and its applications in animal genome editing

The clustered regularly interspaced short palindromic repeats (CRISPR) and their associated protein (Cas) system is a gene editing technology guided by RNA endonuclease. The CRISPR-Cas12a (also known as CRISPR-Cpf1) system is extensively utilized in genome editing research due to its accuracy and high efficiency. In this paper, we primarily focus on the application of CRISPR-Cpf1 technology in the construction of disease models and gene therapy. Firstly, the structure and mechanism of the CRISPR-Cas system are introduced. Secondly, the similarities and differences between CRISPR-Cpf1 and CRISPR-Cas9 technologies are compared. Thirdly, the main focus is on the application of the CRISPR-Cpf1 system in cell and animal genome editing. Finally, the challenges faced by CRISPR-Cpf1 technology and corresponding strategies are analyzed. Although CRISPR-Cpf1 technology has certain off-target effects, it can effectively and accurately edit cell and animal genomes, and has significant advantages in the preclinical research.

Developing small Cas9 hybrids using molecular modeling

The contraction of CAG/CTG repeats is an attractive approach to correct the mutation that causes at least 15 neuromuscular and neurodegenerative diseases, including Huntington's disease and Myotonic Dystrophy type 1. Contractions can be achieved in vivo using the Cas9 D10A nickase from Streptococcus pyogenes (SpCas9) using a single guide RNA (sgRNA) against the repeat tract. One hurdle on the path to the clinic is that SpCas9 is too large to be packaged together with its sgRNA into a single adeno-associated virus. Here we aimed to circumvent this problem using the smaller Cas9 orthologue, SlugCas9, and the Cas9 ancestor OgeuIscB. We found them to be ineffective in inducing contractions, despite their advertised PAM sequences being compatible with CAG/CTG repeats. Thus, we further developed smaller Cas9 hybrids, made of the PAM interacting domain of S. pyogenes and the catalytic domains of the smaller Cas9 orthologues. We also designed the cognate sgRNA hybrids using molecular dynamic simulations and binding energy calculations. We found that the four Cas9/sgRNA hybrid pairs tested in human cells failed to edit their target sequences. We conclude that in silico approaches can identify functional changes caused by point mutations but are not sufficient for designing larger scale complexes of Cas9/sgRNA hybrids.

Current application and future perspective of CRISPR/cas9 gene editing system mediated immune checkpoint for liver cancer treatment

Liver cancer, which is well-known to us as one of human most prevalent malignancies across the globe, poses a significant risk to live condition and life safety of individuals in every region of the planet. It has been shown that immune checkpoint treatment may enhance survival benefits and make a significant contribution to patient prognosis, which makes it a promising and popular therapeutic option for treating liver cancer at the current time. However, there are only a very few numbers of patients who can benefit from the treatment and there also exist adverse events such as toxic effects and so on, which is still required further research and discussion. Fortunately, the clustered regularly interspaced short palindromic repeat/CRISPR-associated nuclease 9 (CRISPR/Cas9) provides a potential strategy for immunotherapy and immune checkpoint therapy of liver cancer. In this review, we focus on elucidating the fundamentals of the recently developed CRISPR/Cas9 technology as well as the present-day landscape of immune checkpoint treatment which pertains to liver cancer. What's more, we aim to explore the molecular mechanism of immune checkpoint treatment in liver cancer based on CRISPR/Cas9 technology. At last, its encouraging and powerful potential in the future application of the clinic is discussed, along with the issues that already exist and the difficulties that must be overcome. To sum up, our ultimate goal is to create a fresh knowledge that we can utilize this new CRISPR/Cas9 technology for the current popular immune checkpoint therapy to overcome the treatment issues of liver cancer.

Emerging Medical Technologies and Their Use in Bionic Repair and Human Augmentation

As both the proportion of older people and the length of life increases globally, a rise in age-related degenerative diseases, disability, and prolonged dependency is projected. However, more sophisticated biomedical materials, as well as an improved understanding of human disease, is forecast to revolutionize the diagnosis and treatment of conditions ranging from osteoarthritis to Alzheimer's disease as well as impact disease prevention. Another, albeit quieter, revolution is also taking place within society: human augmentation. In this context, humans seek to improve themselves, metamorphosing through self-discipline or more recently, through use of emerging medical technologies, with the goal of transcending aging and mortality. In this review, and in the pursuit of improved medical care following aging, disease, disability, or injury, we first highlight cutting-edge and emerging materials-based neuroprosthetic technologies designed to restore limb or organ function. We highlight the potential for these technologies to be utilized to augment human performance beyond the range of natural performance. We discuss and explore the growing social movement of human augmentation and the idea that it is possible and desirable to use emerging technologies to push the boundaries of what it means to be a healthy human into the realm of superhuman performance and intelligence. This potential future capability is contrasted with limitations in the right-to-repair legislation, which may create challenges for patients. Now is the time for continued discussion of the ethical strategies for research, implementation, and long-term device sustainability or repair.

AcrIIA28 is a metalloprotein that specifically inhibits targeted-DNA loading to SpyCas9 by binding to the REC3 domain

CRISPR-Cas systems serve as adaptive immune systems in bacteria and archaea, protecting against phages and other mobile genetic elements. However, phages and archaeal viruses have developed countermeasures, employing anti-CRISPR (Acr) proteins to counteract CRISPR-Cas systems. Despite the revolutionary impact of CRISPR-Cas systems on genome editing, concerns persist regarding potential off-target effects. Therefore, understanding the structural and molecular intricacies of diverse Acrs is crucial for elucidating the fundamental mechanisms governing CRISPR-Cas regulation. In this study, we present the structure of AcrIIA28 from Streptococcus phage Javan 128 and analyze its structural and functional features to comprehend the mechanisms involved in its inhibition of Cas9. Our current study reveals that AcrIIA28 is a metalloprotein that contains Zn2+ and abolishes the cleavage activity of Cas9 only from Streptococcus pyrogen (SpyCas9) by directly interacting with the REC3 domain of SpyCas9. Furthermore, we demonstrate that the AcrIIA28 interaction prevents the target DNA from being loaded onto Cas9. These findings indicate the molecular mechanisms underlying AcrIIA28-mediated Cas9 inhibition and provide valuable insights into the ongoing evolutionary battle between bacteria and phages.

Epigenetic contribution to cancer

Epigenetics has transformed our understanding of cancer by revealing how changes in gene activity, which do not alter the DNA itself, can initiate and progress the disease. These changes include adjustments in DNA methylation, histone configuration, and non-coding RNA activity. For instance, DNA methylation can inactivate genes that typically protect against cancer, leading to broader genomic instability. Histone modifications can alter how tightly DNA is wound, influencing which genes are active or silenced; while non-coding RNAs can interfere with the messages that direct protein production, impacting cancer-related processes. Unlike genetic mutations, which are permanent and irreversible, epigenetic changes provide a malleable target for therapeutic intervention, allowing potentially reversible adjustments to gene expression patterns. This flexibility is essential in the complex landscape of cancer where static genetic solutions may be insufficient. Additionally, epigenetics bridges the gap between genetic predispositions and environmental influences on cancer, offering a comprehensive framework for understanding how lifestyle factors and external exposures impact cancer risk and progression. The integration of epigenetics into cancer research not only enhances our understanding of the disease but also opens innovative avenues for intervention that were previously unexplored in traditional genetic-focused studies. Technologies like advanced sequencing and precise epigenetic modification are paving the way for early cancer detection and more personalized treatment approaches, highlighting the critical role of epigenetics in modern cancer care.

Structures, mechanisms and applications of RNA-centric CRISPR-Cas13

Prokaryotes are equipped with a variety of resistance strategies to survive frequent viral attacks or invading mobile genetic elements. Among these, CRISPR-Cas surveillance systems are abundant and have been studied extensively. This Review focuses on CRISPR-Cas type VI Cas13 systems that use single-subunit RNA-guided Cas endonucleases for targeting and subsequent degradation of foreign RNA, thereby providing adaptive immunity. Notably, distinct from single-subunit DNA-cleaving Cas9 and Cas12 systems, Cas13 exhibits target RNA-activated substrate RNase activity. This Review outlines structural, biochemical and cell biological studies toward elucidation of the unique structural and mechanistic principles underlying surveillance effector complex formation, precursor CRISPR RNA (pre-crRNA) processing, self-discrimination and RNA degradation in Cas13 systems as well as insights into suppression by bacteriophage-encoded anti-CRISPR proteins and regulation by endogenous accessory proteins. Owing to its programmable ability for RNA recognition and cleavage, Cas13 provides powerful RNA targeting, editing, detection and imaging platforms with emerging biotechnological and therapeutic applications.

Clustered Regularly Interspaced Short Palindromic Repeat-1 (CRISPR-1) Locus as a Tool for Tracing the Zoonotic History of Salmonella enterica Strains

Background Salmonella enterica is a significant foodborne pathogen that causes considerable illness and death in humans and animals. The clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated protein (Cas) system in bacteria acts as an adaptive immune defense against invasive genetic elements by incorporating short intergenic spacers (IGSs) into CRISPR loci. These loci serve as molecular records of past interactions with phages and plasmids, providing insights into the transmission and evolution of bacterial strains across different hosts. Aim This study aimed to investigate the diversity of IGSs in the CRISPR-1 locus of S. enterica isolates from humans and camels. The objective was to assess the potential of IGSs to distinguish strains, track sources, and understand patterns of zoonotic transmission. Materials and methods Genomic DNA was extracted from multiple strains of S. enterica, and the CRISPR-1 locus was polymerase chain reaction (PCR) amplified and sequenced. The sequences were compared to identify distinct patterns of IGSs and potential host-specific characteristics. Sanger sequencing and bioinformatics tools were used to classify the IGSs and determine their similarity to known sequences in the National Center for Biotechnology Information (NCBI) database. Results Sequence analysis revealed five distinct CRISPR-1 types among S. enterica isolates from humans and three among camel isolates. The presence of shared IGSs between human and camel S. enterica isolates suggested zoonotic or reverse-zoonotic transmission events. Additionally, host-specific unknown IGSs (UIGS) were identified. Importantly, camel isolates initially identified as S. enterica subspecies enterica serovar Enteritidis based on rrnH gene sequencing were reclassified as S. enterica serovar Enteritidis based on CRISPR-1 profiling, demonstrating the higher resolution of CRISPR-based genotyping. Conclusion The diversity of IGSs in the CRISPR-1 locus effectively differentiated S. enterica strains and provided insights into their evolutionary origins and transmission dynamics. CRISPR-based genotyping proves to be a promising tool to complement traditional serotyping methods, enhancing the molecular epidemiology of salmonellosis and potentially leading to better management and control strategies for this pathogen.

Unity among the diverse RNA-guided CRISPR-Cas interference mechanisms

CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated) systems are adaptive immune systems that protect bacteria and archaea from invading mobile genetic elements (MGEs). The Cas protein-CRISPR RNA (crRNA) complex uses complementarity of the crRNA "guide" region to specifically recognize the invader genome. CRISPR effectors that perform targeted destruction of the foreign genome have emerged independently as multi-subunit protein complexes (Class 1 systems) and as single multi-domain proteins (Class 2). These different CRISPR-Cas systems can cleave RNA, DNA, and protein in an RNA-guided manner to eliminate the invader, and in some cases, they initiate programmed cell death/dormancy. The versatile mechanisms of the different CRISPR-Cas systems to target and destroy nucleic acids have been adapted to develop various programmable-RNA-guided tools and have revolutionized the development of fast, accurate, and accessible genomic applications. In this review, we present the structure and interference mechanisms of different CRISPR-Cas systems and an analysis of their unified features. The three types of Class 1 systems (I, III, and IV) have a conserved right-handed helical filamentous structure that provides a backbone for sequence-specific targeting while using unique proteins with distinct mechanisms to destroy the invader. Similarly, all three Class 2 types (II, V, and VI) have a bilobed architecture that binds the RNA-DNA/RNA hybrid and uses different nuclease domains to cleave invading MGEs. Additionally, we highlight the mechanistic similarities of CRISPR-Cas enzymes with other RNA-cleaving enzymes and briefly present the evolutionary routes of the different CRISPR-Cas systems.

A high-fidelity DNAzyme-assisted CRISPR/Cas13a system with single-nucleotide resolved specificity

A CRISPR/Cas system represents an innovative tool for developing a new-generation biosensing and diagnostic strategy. However, the off-target issue (i.e., mistaken cleavage of nucleic acid targets and reporters) remains a great challenge for its practical applications. We hypothesize that this issue can be overcome by taking advantage of the site-specific cleavage ability of RNA-cleaving DNAzymes. To test this idea, we propose a DNAzyme Operation Enhances the Specificity of CRISPR/Cas13a strategy (termed DOES-CRISPR) to overcome the problem of relatively poor specificity that is typical of the traditional CRISPR/Cas13a system. The key to the design is that the partial hybridization of the CRISPR RNA (crRNA) with the cleavage fragment of off-target RNA was not able to activate the collateral cleavage activity of Cas13a. We showed that DOES-CRISPR can significantly improve the specificity of traditional CRISPR/Cas13a-based molecular detection by up to ∼43-fold. The broad utility of the strategy is illustrated through engineering three different systems for the detection of microRNAs (miR-17 and let-7e), CYP2C19*17 gene, SARS-Cov-2 variants (Gamma, Delta, and Omicron) and Omicron subtypes (BQ.1 and XBB.1) with single-nucleotide resolved specificity. Finally, clinical evaluation of this assay using 10 patient blood samples demonstrated a clinical sensitivity of 100% and specificity of 100% for genotyping CYP2C19*17, and analyzing 20 throat swab samples provided a diagnostic sensitivity of 95% and specificity of 100% for Omicron detection, and a clinical sensitivity of 92% and specificity of 100% for XBB.1 detection.

The CRISPR-Cas13a Gemini System for noncontiguous target RNA activation

Simultaneous multi-target detection and multi-site gene editing are two key factors restricting the development of disease diagnostic and treatment technologies. Despite numerous explorations on the source, classification, functional features, crystal structure, applications and engineering of CRISPR-Cas13a, all reports use the contiguous target RNA activation paradigm that only enables single-target detection in vitro and one-site gene editing in vivo. Here we propose a noncontiguous target RNA activation paradigm of Cas13a and establish a CRISPR-Cas13a Gemini System composed of two Cas13a:crRNA binary complexes, which can provide rapid, simultaneous, highly specific and sensitive detection of two RNAs in a single readout, as well as parallel dual transgene knockdown. CRISPR-Cas13a Gemini System are demonstrated in the detection of two miRNAs (miR-155 and miR-375) for breast cancer diagnosis and two small RNAs (EBER-1 and EBER-2) for Epstein-Barr virus diagnosis using multiple diagnostic platforms, including fluorescence and colorimetric-based lateral flow systems. We also show that CRISPR-Cas13a Gemini System can knockdown two foreign genes (EGFP and mCherry transcripts) in mammalian cells simultaneously. These findings suggest the potential of highly effective and simultaneous detection of multiple biomarkers and gene editing of multiple sites.

CRISPR-Cas9 in basic and translational aspects of cancer therapy

Introduction

The discovery of gene editing techniques has opened a new era within the field of biology and enabled scientists to manipulate nucleic acid molecules. CRISPR-Cas9 genome engineering has revolutionized this achievement by successful targeting the DNA molecule and editing its sequence. Since genomic changes are the basis of the birth and growth of many tumors, CRISPR-Cas9 method has been successfully applied to identify and manipulate the genes which are involved in initiating and driving some neoplastic processes.

Methods

By review of the existing literature on application of CRISPR-Cas9 in cancer, different databases, such as PubMed and Google Scholar, we started data collection for "CRISPR-Cas9", "Genome Editing", "Cancer", "Solid tumors", "Hematologic malignancy" "Immunotherapy", "Diagnosis", "Drug resistance" phrases. Clinicaltrials.gov, a resource that provides access to information on clinical trials, was also searched in this review.

Results

We have defined the basics of this technology and then mentioned some clinical and preclinical studies using this technology in the treatment of a variety of solid tumors as well as hematologic neoplasms. Finally, we described the progress made by this technology in boosting immune-mediated cell therapy in oncology, such as CAR-T cells, CAR-NK cells, and CAR-M cells.

Conclusion

CRISPR-Cas9 system revolutionized the therapeutic strategies in some solid malignant tumors and leukemia through targeting the key genes involved in the pathogenesis of these cancers.

Advances and applications of CRISPR/Cas-mediated interference in Escherichia coli

The bacterium Escherichia coli (E. coli) is one of the most widely used chassis microbes employed for the biosynthesis of numerous valuable chemical compounds. In the past decade, the metabolic engineering of E. coli has undergone significant advances, although further productivity improvements will require extensive genome modification, multi-dimensional regulation, and multiple metabolic-pathway coordination. In this context, clustered regularly interspaced short palindromic repeats (CRISPR), along with CRISPR-associated protein (Cas) and its inactive variant (dCas), have emerged as notable recombination and transcriptional regulation tools that are particularly useful for multiplex metabolic engineering in E. coli. In this review, we briefly describe the CRISPR/Cas9 technology in E. coli, and then summarize the recent advances in CRISPR/dCas9 interference (CRISPRi) systems in E. coli, particularly the strategies designed to effectively regulate gene repression and overcome retroactivity during multiplexing. Moreover, we discuss recent applications of the CRISPRi system for enhancing metabolite production in E. coli, and finally highlight the major challenges and future perspectives of this technology.

Ultrasensitive Detection Strategy of Norovirus Based on a Dual Enhancement Strategy: CRISPR-Responsive Self-Assembled SNA and Isothermal Amplification

Spherical nucleic acids (SNAs) have been used to construct various nanobiosensors with gold nanoparticles (AuNPs) as nuclei. The SNAs play a critical role in biosensing due to their various physical and chemical properties, programmability, and specificity recognition ability. In this study, CRISPR-responsive self-assembled spherical nucleic acid (CRISPR-rsSNA) detection probes were constructed by conjugating fluorescein-labeled probes to the surface of AuNPs to improve the sensing performance. Also, the mechanism of ssDNA and the role of different fluorescent groups in the self-assembly process of CRISPR-rsSNA were explored. Then, CRISPR-rsSNA and reverse transcription-recombinase polymerase amplification (RT-RPA) were combined to develop an ultrasensitive fluorescence-detection strategy for norovirus. In the presence of the virus, the target RNA sequence of the virus was transformed and amplified by RT-RPA. The resulting dsDNA activated the trans-cleavage activity of CRISPR cas12a, resulting in disintegrating the outer nucleic acid structure of the CRISPR-rsSNA at a diffusible rate, which released reporter molecules. Norovirus was quantitated by fluorescence detection. This strategy facilitated the detection of the norovirus at the attomolar level. An RT-RPA kit for norovirus detected would be developed based on this method. The proposed method would be used for the detection of different viruses just by changing the target RNA and crRNA of the CRISPR cas12a system which provided a foundation for high-throughput detection of various substances.

Recent Research Trends in Stem Cells Using CRISPR/Cas-Based Genome Editing Methods

The clustered regularly interspaced short palindromic repeats (CRISPR) system, a rapidly advancing genome editing technology, allows DNA alterations into the genome of organisms. Gene editing using the CRISPR system enables more precise and diverse editing, such as single nucleotide conversion, precise knock-in of target sequences or genes, chromosomal rearrangement, or gene disruption by simple cutting. Moreover, CRISPR systems comprising transcriptional activators/repressors can be used for epigenetic regulation without DNA damage. Stem cell DNA engineering based on gene editing tools has enormous potential to provide clues regarding the pathogenesis of diseases and to study the mechanisms and treatments of incurable diseases. Here, we review the latest trends in stem cell research using various CRISPR/Cas technologies and discuss their future prospects in treating various diseases.

Development of a CRISPR-Cas12a based assay for the detection of swine enteric coronaviruses in pig herds in China

Porcine epidemic diarrhea virus (PEDV), Transmissible gastroenteritis virus (TGEV), Porcine deltacoronavirus (PDCoV) and Swine acute diarrhea syndrome coronavirus (SADS-CoV) rank among the most frequently encountered swine enteric coronaviruses (SECoVs), leading to substantial economic losses to the swine industry. The availability of a rapid and highly sensitive detection method proves beneficial for the monitoring and surveillance of SECoVs. Based on the N genes of four distinct SECoVs, a novel detection method was developed in this study by combining recombinant enzyme polymerase isothermal amplification (RPA) with clustered regularly interspaced short palindromic repeats (CRISPR)-associated proteins (Cas) 12a. Results showed that the cut-off value of CRISPR-Cas12a assay for SADS-CoV, PEDV, PDCoV and TGEV was 2.19 × 104 Relative Fluorescence Units (RFU), 1.57 × 104 RFU, 3.07 × 104 RFU and 1.64 × 104 RFU, respectively. The coefficient of variation (CV) of within and between runs by CRISPR-Cas12a assay for 6 clinical diarrhea samples were both less than 10%. The CRISPR-Cas12a assay demonstrated high specificity for TGEV, PEDV, PDCoV, and SADS-CoV with no cross-reactivity to other common swine viruses. This method also exhibited a low limit of detection of 2 copies for each virus. Additionally, the results demonstrated a perfect agreement (100%) between the CRISPR-Cas12a assay and the RT-qPCR assay. Finally, a total of 494 pig samples from the field tested by CRISPR-Cas12a assay showed that positive rate for SADS-CoV, TGEV, PDCoV and PEDV was 0, 0, 1.2% and 48.6%, respectively. The results suggested the great potential of CRISPR-Cas12a assay to detect SECoVs in the field.

Recent progress on the CRISPR/Cas system in optical biosensors

Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) protein systems are adaptive immune systems unique to archaea and bacteria, with the characteristics of targeted recognition and gene editing to resist the invasion of foreign nucleic acids. Biosensors combined with the CRISPR/Cas system and optical detection technology have attracted much attention in medical diagnoses, food safety, agricultural progress, and environmental monitoring owing to their good sensitivity, high selectivity, and fast detection efficiency. In this review, we introduce the mechanism of CRISPR/Cas systems and developments in this area, followed by summarizing recent progress on CRISPR/Cas system-based optical biosensors combined with colorimetric, fluorescence, electrochemiluminescence and surface-enhanced Raman scattering optical techniques in various fields. Finally, we discuss the challenges and future perspectives of CRISPR/Cas systems in optical biosensors.

Distribution characteristics of the Legionella CRISPR-Cas system and its regulatory mechanism underpinning phenotypic function

Legionella is a common intracellular parasitic bacterium that infects humans via the respiratory tract, causing Legionnaires' disease, with fever and pneumonia as the main symptoms. The emergence of highly virulent and azithromycin-resistant Legionella pneumophila is a major challenge in clinical anti-infective therapy. The CRISPR-Cas acquired immune system provides immune defense against foreign nucleic acids and regulates strain biological functions. However, the distribution of the CRISPR-Cas system in Legionella and how it regulates gene expression in L. pneumophila remain unclear. Herein, we assessed 915 Legionella whole-genome sequences to determine the distribution characteristics of the CRISPR-Cas system and constructed gene deletion mutants to explore the regulation of the system based on growth ability in vitro, antibiotic sensitivity, and intracellular proliferation of L. pneumophila. The CRISPR-Cas system in Legionella was predominantly Type II-B and was mainly concentrated in the genome of L. pneumophila ST1 strains. The Type II-B CRISPR-Cas system showed no effect on the strain's growth ability in vitro but significantly reduced resistance to azithromycin and decreased proliferation ability due to regulation of the lpeAB efflux pump and the Dot/Icm type IV secretion system. Thus, the Type II-B CRISPR-Cas system plays a crucial role in regulating the virulence of L. pneumophila. This expands our understanding of drug resistance and pathogenicity in Legionella, provides a scientific basis for the prevention of Legionnaires' disease outbreaks and the rational use of clinical drugs, and facilitates effective treatment of Legionnaires' disease.

CRISPR-Cas9: A Potent Gene-editing Tool for the Treatment of Cancer

The prokaryotic adaptive immune system has clustered regularly interspaced short palindromic repeat. CRISPR-associated protein (CRISPR-Cas) genome editing systems have been harnessed. A robust programmed technique for efficient and accurate genome editing and gene targeting has been developed. Engineered cell therapy, in vivo gene therapy, animal modeling, and cancer diagnosis and treatment are all possible applications of this ground-breaking approach. Multiple genetic and epigenetic changes in cancer cells induce malignant cell growth and provide chemoresistance. The capacity to repair or ablate such mutations has enormous potential in the fight against cancer. The CRISPR-Cas9 genome editing method has recently become popular in cancer treatment research due to its excellent efficiency and accuracy. The preceding study has shown therapeutic potential in expanding our anticancer treatments by using CRISPR-Cas9 to directly target cancer cell genomic DNA in cellular and animal cancer models. In addition, CRISPR-Cas9 can combat oncogenic infections and test anticancer medicines. It may design immune cells and oncolytic viruses for cancer immunotherapeutic applications. In this review, these preclinical CRISPRCas9- based cancer therapeutic techniques are summarised, along with the hurdles and advancements in converting therapeutic CRISPR-Cas9 into clinical use. It will increase their applicability in cancer research.

Molecular insights and omics-based understanding of plant-microbe interactions under drought stress

The detrimental effects of adverse environmental conditions are always challenging and remain a major concern for plant development and production worldwide. Plants deal with such constraints by physiological, biochemical, and morphological adaptations as well as acquiring mutual support of beneficial microorganisms. As many stress-responsive traits of plants are influenced by microbial activities, plants have developed a sophisticated interaction with microbes to cope with adverse environmental conditions. The production of numerous bioactive metabolites by rhizospheric, endo-, or epiphytic microorganisms can directly or indirectly alter the root system architecture, foliage production, and defense responses. Although plant-microbe interactions have been shown to improve nutrient uptake and stress resilience in plants, the underlying mechanisms are not fully understood. "Multi-omics" application supported by genomics, transcriptomics, and metabolomics has been quite useful to investigate and understand the biochemical, physiological, and molecular aspects of plant-microbe interactions under drought stress conditions. The present review explores various microbe-mediated mechanisms for drought stress resilience in plants. In addition, plant adaptation to drought stress is discussed, and insights into the latest molecular techniques and approaches available to improve drought-stress resilience are provided.

CRISPR-Cas systems feature and targeting phages diversity in Lacticaseibacillus rhamnosus strains

One of the most important adaptive immune systems in bacteria against phages is clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (CAS) genes. In this investigation, an approach based on genome mining was employed to characterize the CRISPR-Cas systems of Lacticaseibacillus rhamnosus strains. The analysis involved retrieving complete genome sequences of L. rhamnosus strains, and assessing the diversity, prevalence, and evolution of their CRISPR-Cas systems. Following this, an analysis of homology in spacer sequences from identified CRISPR arrays was carried out to investigate and characterize the range of target phages. The findings revealed that 106 strains possessed valid CRISPR-Cas structures (comprising CRISPR loci and Cas genes), constituting 45% of the examined L. rhamnosus strains. The diversity observed in the CRISPR-Cas systems indicated that all identified systems belonged to subtype II-A. Analyzing the homology of spacer sequences with phage and prophage genomes discovered that strains possessing only CRISPR-Cas subtype II targeted a broader spectrum of foreign phages. In summary, this study suggests that while there is not significant diversity among the CRISPR-Cas systems identified in L. rhamnosus strains, there exists notable variation in subtype II-A systems between L. rhamnosus and other lactobacilli. The diverse nature of these CRISPR-Cas systems underscores their natural activity and importance in adaptive immunity.

Precise base editing without unintended indels in human cells and mouse primary myoblasts

Base editors are powerful tools for making precise single-nucleotide changes in the genome. However, they can lead to unintended insertions and deletions at the target sites, which is a significant limitation for clinical applications. In this study, we aimed to eliminate unwanted indels at the target sites caused by various evolved base editors. Accordingly, we applied dead Cas9 instead of nickase Cas9 in the base editors to induce accurate substitutions without indels. Additionally, we tested the use of chromatin-modulating peptides in the base editors to improve nucleotide conversion efficiency. We found that using both dead Cas9 and chromatin-modulating peptides in base editing improved the nucleotide substitution efficiency without unintended indel mutations at the desired target sites in human cell lines and mouse primary myoblasts. Furthermore, the proposed scheme had fewer off-target effects than conventional base editors at the DNA level. These results indicate that the suggested approach is promising for the development of more accurate and safer base editing techniques for use in clinical applications.

Engineering of the LAMP-CRISPR/Cas12b platform for Chlamydia psittaci detection

Introduction. Chlamydia psittaci (C. psittaci) is a zoonotic infection, that causes psittacosis (parrot fever) in humans, leading to severe clinical manifestations, including severe pneumonia, adult respiratory distress syndrome, and, in rare cases, death.Gap Statement. Rapid, sensitive and specific detection of C. psittaci facilitates timely diagnosis and treatment of patients.Aim. This study aimed to engineer the LAMP-CRISPR/Cas12b platform for C. psittaci detection.Methodology. The loop-mediated isothermal amplification (LAMP) technique and clustered regularly interspaced short palindromic repeats-CRISPR associated protein 12b (CRISPR-Cas12b) assay were combined to establish two-step and one-tube LAMP-CRISPR/Cas12b reaction systems, respectively, for rapidly detecting C. psittaci.Results. The two-step and one-tube LAMP-CRISPR/Cas12b assay could complete detection within 1 h. No cross-reactivity was observed from non-C. psittaci templates with specific LAMP amplification primers and single-guide RNA (sgRNA) targeting the highly conserved short fragment CPSIT_0429 gene of C. psittaci. The detection limits of the two-step and one-tube LAMP-CRISPR/Cas12b reaction were 102 aM and 103 aM, respectively. The results were consistent with qPCR for nucleic acid detection in 160 clinical samples, including 80 suspected C. psittaci samples, kept in the laboratory.Conclusions. The LAMP-CRISPR/Cas12b assay developed in this study provides a sensitive and specific method for rapidly detecting C. psittaci and offers technical support for its rapid diagnosis.

Presence of CRISPR CAS-Like Sequences as a Proposed Mechanism for Horizontal Genetic Exchanges between Trichomonas vaginalis and Its Associated Virus: A Comparative Genomic Analysis with the First Report of a Putative CRISPR CAS Structures in Eukaryotic Cells

Introduction

Trichomonas vaginalis genome is among the largest genome size and coding capacities. Combinations of gene duplications, transposon, repeated sequences, and lateral gene transfers (LGTs) have contributed to the unexpected large genomic size and diversity. This study is aimed at investigating genomic exchange and seeking for presence of the CRISPR CAS system as one of the possible mechanisms for some level of genetic exchange. Material and Methods. In this comparative analysis, 398 publicly available Trichomonas vaginalis complete genomes were investigated for the presence of CRISPR CAS. Spacer sequences were also analyzed for their origin using BLAST.

Results

We identified a CRISPR CAS (Cas3). CRISPR spacers are highly similar to transposable genetic elements such as viruses of protozoan parasites, especially megavirals, some transposons, and, interestingly, papillomavirus and HIV-1 in a few cases. Discussion. There is a striking similarity between the prokaryotes/Archaean CRISPR and what we find as eukaryotic CRISPR. About 5-10% of the 398 T. vaginalis possess a CRISPR structure.

Conclusion

According to sequences and their organization, we assume that these repeated sequences and spacer, along with their mentioned features, could be the eukaryotic homolog of prokaryotes and Archaean CRISPR systems and may involve in a process similar to the CRISPR function.

Epigenome editing in cancer: Advances and challenges for potential therapeutic options

Cancers are diseases caused by genetic and non-genetic environmental factors. Epigenetic alterations, some attributed to non-genetic factors, can lead to cancer development. Epigenetic changes can occur in tumor suppressors or oncogenes, or they may contribute to global cell state changes, making cells abnormal. Recent advances in gene editing technology show potential for cancer treatment. Herein, we will discuss our current knowledge of epigenetic alterations occurring in cancer and epigenetic editing technologies that can be applied to developing therapeutic options.

CRISPR-based Biosensors for Human Health: A Novel Strategy to Detect Emerging Infectious Diseases

Infectious diseases (such as sepsis, influenza, and malaria), caused by various pathogenic bacteria and viruses, are widespread across the world. Early and rapid detection of disease-related pathogens is necessary to reduce their spread in the world and prevent their potential global pandemics. The clustered regularly interspaced short palindromic repeats (CRISPR) technology, as the next-generation molecular diagnosis technique, holds immense promise in the detection of infectious diseases because of its remarkable advantages, including supreme flexibility, sensitivity, and specificity. While numerous CRISPR-based biosensors have been developed for application in environmental monitoring, food safety, and point-of-care diagnosis, there remains a critical need to summarize and explore their potential in human health. This review aims to address this gap by focusing on the latest advancements in CRISPR-based biosensors for infectious disease detection. We provide an overview of the current status, pre-amplification methods, the unique feature of each CRISPR system, and the design of CRISPR-based biosensing strategies to detect disease-associated nucleic acids. Last but not least, the review analyzes the current challenges and provides future perspectives, which will contribute to developing more effective CRISPR-based biosensors for human health.

Application of the endogenous CRISPR-Cas type I-D system for genetic engineering in the thermoacidophilic archaeon Sulfolobus acidocaldarius

CRISPR (clustered regularly interspaced short palindromic repeats)-Cas systems are widely distributed among bacteria and archaea. In this study, we demonstrate the successful utilization of the type I-D CRISPR-Cas system for genetic engineering in the thermoacidophilic archaeon Sulfolobus acidocaldarius. Given its extreme growth conditions characterized by a temperature of 75°C and pH 3, an uracil auxotrophic selection system was previously established, providing a basis for our investigations. We developed a novel plasmid specifically designed for genome editing, which incorporates a mini-CRISPR array that can be induced using xylose, resulting in targeted DNA cleavage. Additionally, we integrated a gene encoding the β-galactosidase of Saccharolobus solfataricus into the plasmid, enabling blue-white screening and facilitating the mutant screening process. Through the introduction of donor DNA containing genomic modifications into the plasmid, we successfully generated deletion mutants and point mutations in the genome of S. acidocaldarius. Exploiting the PAM (protospacer adjacent motif) dependence of type I systems, we experimentally confirmed the functionality of three different PAMs (CCA, GTA, and TCA) through a self-targeting assessment assay and the gene deletion of upsE. Our findings elucidate the application of the endogenous Type I-D CRISPR-Cas system for genetic engineering in S. acidocaldarius, thus expanding its genetic toolbox.