PubMed HealthSearch

SEARCH · PubMed Health

Results for “Life cycle”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

"Not flying solo": phylogenetic identification and life-cycle insights of larval cestodes in the European flying squid Todarodes sagittatus (Cephalopoda: Ommastrephidae).

The European flying squid Todarodes sagittatus Lamarck is a widely distributed ommastrephid cephalopod in the Northeast Atlantic and Mediterranean Sea, yet its parasite fauna remains poorly documented in the Mediterranean Sea. In this study, two cestode larvae species infecting T. sagittatus from the Algerian coast (Western Mediterranean) were investigated using an integrative approach combining morphological observations and molecular analyses. A total of 63 squids were examined for parasitic infection. Cestodes in plerocercoid stage were detected in 31 individuals (prevalence of 46%), primarily located within the gastrointestinal tract, including the stomach, intestine, and caecum. Morphological features of the larvae were consistent with members of the order Phyllobothriidea but did not allow identification to the species level. Molecular analysis of the D1-D3 region of the 28S rDNA revealed two distinct larval lineages belonging to the genus Crossobothrium Linton, 1889. One lineage showed 100% sequence identity with the adult cestode Crossobothrium dohrnii (Oerley, 1885), a parasite of hexanchid sharks, confirming the identity of these larvae as plerocercoids of C. dohrnii. The second lineage clustered within the Crossobothrium clade but could not be assigned to a known species and is therefore referred to as Crossobothrium sp. The occurrence of these larvae in T. sagittatus, together with ecological data on squid diet and predator-prey relationships, suggests that this cephalopod acts as an intermediate or paratenic host in the life cycle of hexanchid cestodes. Infection likely occurs through predation on crustaceans acting as first intermediate hosts, while transmission to definitive hosts occurs when infected squids are consumed by sharks. These findings provide the first molecular identification of cestode larvae from T. sagittatus in the Mediterranean and highlight the important role of ommastrephid squids in the trophic transmission of elasmobranch parasites in pelagic ecosystems.

Crossobothrium

Insights into the Life Cycle and Therapeutic Agents for Monkeypox Virus Infection.

Since the first confirmed case in 1970, the monkeypox virus (MPXV) has emerged as a significant threat to global public health. The World Health Organization (WHO) has declared it a Public Health Emergency of International Concern (PHEIC) on two occasions. Despite decades of research, only tecovirimat has been approved by the European Medicines Agency (EMA) for the treatment of MPXV infection. The genome and structure are similar between MPXV and other orthopoxviruses (OPXVs), suggesting that the strategies used for other OPXVs may be applicable to MPXV. This review systematically summarizes the genome, structure, and critical stages in the life cycle of OPXVs, especially MPXV. A variety of antiviral agents against MPXV and other OPXVs are discussed according to their distinct mechanisms of action: 1) blocking viral entry and fusion, 2) inhibiting DNA replication and processing, 3) disrupting transcription and mRNA processing, 4) preventing virion assembly, maturation and release, 5) modulating immune responses, and 6) mechanism unknown. Overall, this article provides a systematic review of current research progress on potential therapeutic targets and agent for MPXV, aiming to offer innovative insights and strategies for the development of effective therapeutic agents against mpox.

Animals

RNA structures regulate norovirus life cycle and enable rational attenuation in vivo.

Viral genomes encode regulatory RNA structures that orchestrate key steps of viral replication and gene expression. Although these structures are increasingly recognized as critical regulators of viral function, their systematic characterization in an infection context and roles in regulating viral fitness and immune recognition in vivo remain limited. Here, we systematically map and functionally interrogate structured RNA elements across the murine norovirus genome using orthogonal in-cell chemical probing, revealing conserved motifs that regulate viral function. Targeted disruption of specific structural elements reduces viral replication in cell culture, modulates translation in cis, and decreases viral RNA levels in animal infection models. These findings enabled the rational design of a genetically stable, attenuated virus that elicits protective immunity and limits viral replication upon secondary challenge. Together, this work uncovers essential roles for RNA structure in norovirus biology and establishes a generalizable framework for RNA structure-guided design of antiviral vaccines and therapeutics.

RNA structure

Versatile, marker-free platform for life cycle-wide imaging of Plasmodium falciparum by integrating an exogenous gene cassette into a conserved intergenic locus.

The creation of transgenic Plasmodium falciparum lines with robust fluorescence across the entire life cycle is essential for advancing our understanding of parasite biology, which in turn informs the development of new drugs and vaccines. In this study, we utilized Plasmodium-optimized genome editing to integrate an mCherry expression cassette into a selected intergenic locus without gene disruption. The resulting marker-free line, NF54-mCh, exhibited intense fluorescence throughout all developmental stages, including asexual and sexual blood stages, as well as mosquito (ookinete, oocyst, and sporozoite) and liver stages. NF54-mCh showed normal proliferation, gametocytogenesis, and efficient transmission to mosquitoes. The ultra-high brightness in salivary gland sporozoites allowed for the non-invasive identification of infected mosquitoes. Sporozoites remained highly infectious to humanized mouse livers, thus enabling the completion of the full life cycle. NF54-mCh serves as a parental line for performing additional genetic modifications, because the CRISPR/Cas9-based genome editing method is free of introduced drug resistance markers. The broader applicability of this strategy was validated by generating similar reporter lines in Plasmodium species utilized in rodent malaria models. In summary, NF54-mCh represents a unique, versatile platform that will accelerate fundamental research and support the future development of malaria control strategies, including new vaccines and drugs.

Animals

Single-cell RNA sequencing defines developmental progression and reproductive transitions of Pneumocystis carinii.

UNLABELLED: Pneumocystis species are host-obligate fungal pathogens that cause severe pneumonia in immunocompromised individuals. Despite their clinical importance, their life cycle remains poorly understood, in part because Pneumocystis depends on the host environment for most nutrients and requires sexual reproduction for survival, which occurs exclusively in vivo. This study presents the first single-cell RNA sequencing (scRNA-seq) atlas of Pneumocystis carinii, generated from isolated organisms recovered from the bronchoalveolar lavage fluid of infected rats to map the life cycle of P. carinii. Transcriptomes from 87,716 cells were analyzed using the 10× Genomics platform, revealing 13 transcriptionally distinct clusters representing key developmental stages, including biosynthetically active trophic forms, mating-competent intermediates, and asci undergoing sporulation. These states were characterized by expression of MAPK signaling components, β-glucan-modifying enzymes, and spore-associated genes, respectively. The scRNA-seq data support previous evidence that these host-obligate fungi undergo sexual reproduction and provide new insights into the gene expression patterns associated with different life cycle phases. Biomarkers associated with ascus formation identified by scRNA-seq were validated by RT-qPCR, showing decreased expression levels in ascus-depleted populations treated with anidulafungin, a drug that halts ascus formation. More broadly, this approach provides a strategy for studying the full life cycles of fungal pathogens that cannot be continuously cultured. IMPORTANCE: Pneumocystis species (spp.) are clinically significant fungal pathogens that cannot be sustainably cultured in vitro due to their host-obligate nature. This longstanding limitation has impeded progress in understanding their life cycle and identifying therapeutic vulnerabilities. Here, we apply scRNA-seq to P. carinii isolated directly from infected rat lungs, generating the first transcriptional map of its developmental progression. Our results define discrete gene expression states associated with trophic growth, mating activation, and ascus formation and provide transcriptional evidence for a structured life cycle, clarifying key developmental transitions and identifying potential regulatory targets for therapeutic intervention. Importantly, this study demonstrates that scRNA-seq can resolve the developmental biology of host-restricted fungal pathogens that cannot be cultured in vitro. This approach offers a generalizable framework for investigating other unculturable or obligate microbial pathogens directly within their native host environments, where traditional experimental tools are limited.

Pneumocystis carinii

Chromatin assembly by the histone chaperone HIRA facilitates Human Papillomavirus replication.

The circular, double-stranded DNA genomes of Human papillomaviruses (HPV) exist in a nucleosomal state throughout the infectious cycle and rely on host histone epigenetic modifications and chromatin assembly processes to promote various phases of the viral life cycle. Here, we show that the histone H3.3 chaperone HIRA and its associated complex members are recruited to HPV replication factories during the late phase of the HPV life cycle. HIRA is also recruited to HPV replication factories generated by amplification of a replicon with a minimal origin and expression of the viral replication proteins E1 and E2, demonstrating that the E1 and E2 proteins are sufficient for HIRA recruitment. Downregulation of HIRA expression reduces HPV31 DNA amplification and viral transcription in differentiated keratinocytes. Histone H3.3 that is highly phosphorylated on serine residue 31 is also enriched at sites of HPV replication and this modification links the DNA damage response to chromatin that supports rapid gene activation. We propose that deposition of histone H3.3 generates viral minichromosomes that are highly primed to support the late stages of the HPV life cycle.

H3.3 phosphorylation

Comparative and systems analyses of Leishmania spp. non-coding RNAs through developmental stages.

Leishmania spp. is the etiological agent of leishmaniases, neglected diseases that seek to be eradicated in the coming years. The life cycle of these parasites involves different host and stress environments. In recent years, many studies have shown that several protein-coding genes are directly involved with the development and host interactions. However, little is still known about the role of non-coding RNAs (ncRNAs) in life cycle progression. In this study, we aimed to identify the genomic structure and function of ncRNAs from Leishmania spp. and to get insights into the repertoire of ncRNAs (RNAome) of this protozoan genus. We studied 26 strains corresponding to 16 different species of Leishmania. Our RNAome analysis revealed the presence of several ncRNAs that are shared among different species, allowing us to differentiate between subgenera as well as between species that are canonically related to visceral leishmaniasis. We also studied co-expression relationships between coding genes and ncRNAs which in the amastigote developmental stage for Leishmania braziliensis and Leishmania donovani revealed the presence of miRNA-like transcripts co-expressed with several coding genes involved in starvation, survival and histone modification. This work represents the first effort to characterize the Leishmania ssp. RNAome, supporting further approaches to better understand the role of ncRNAs in gene regulation, infective process, and host-parasite interaction.

RNA, Untranslated

Trade-Offs Associated with Virulence of Soybean Cyst Nematode on the Broad-Spectrum Resistance Source PI 437654.

The soybean cyst nematode (SCN; Heterodera glycines) poses a major challenge to soybean production, intensified by the declining effectiveness of natural resistance against this pathogen. Although the use of resistant soybean varieties can be effective, their widespread and repeated use ultimately results in the emergence of virulent nematode populations that can successfully attack these resistant hosts. To assess for potential trade-offs between virulence and fitness, we investigated the hatch response, penetration rate, and reproductive potential of SCN adapted to overcome the broad-spectrum resistance source PI 437654. The hatching process is a critical phase in the life cycle of the SCN, influencing its ability to infect hosts and complete its life cycle. Our results indicated that SCN populations exhibit preferential and heightened hatch responses to their adapted host compared to alternative hosts, regardless of their virulence profile. Additionally, we found that SCN populations adapted to overcome broad-spectrum resistance showed reduced reproductive success on susceptible hosts compared to unadapted populations. This reduction in reproductive success was not attributed to differences in hatch response or penetration rates. The results from our study highlight the potential trade-offs associated with SCN virulence adaptation and emphasize the importance of considering these evolutionary dynamics in developing sustainable management strategies.

Disease Control and Pest Management

Degradation of ribosomal RNA during Plasmodium falciparum gametocytogenesis.

The life cycle of Plasmodium falciparum is characterized by complex regulatory changes that allow adaptation of the parasites to different environmental conditions, which are especially pronounced during transmission between the mammalian host and the insect vector. Previous studies have shown that P. falciparum uses three types of ribosomal RNAs (rRNA A, S1, and S2 types) at different stages of its life cycle. We used Oxford Nanopore Technologies direct RNA sequencing to investigate the dynamics of rRNA usage throughout the parasite's intraerythrocytic development, as well as in salivary gland sporozoites. Our study revealed a preponderance of A-type rRNAs during the intraerythrocytic cycle and gametocytogenesis, while S-type rRNAs slowly increase in abundance in mosquito stages starting 3 days post-infection. Salivary gland sporozoites showed an even proportion of all rRNA types. By examining the length distributions of rRNA molecules, we detected an extensive and specific degradation of rRNAs during gametocytogenesis, starting in stage II gametocytes and continuing until the final stages of gametocyte development. We hypothesize that rRNA degradation may be linked to the global translational repression and metabolic quiescence described in stage V gametocytes, similar to mechanisms observed in bacterial and eukaryotic stress responses.IMPORTANCEOur study uses Oxford Nanopore direct RNA sequencing of tightly synchronized blood-stage Plasmodium falciparum parasites to investigate the expression of ribosomal RNAs during asexual and sexual development. P. falciparum utilizes distinct types of rRNA during its development. However, due to the challenges of differentiating these highly similar molecules, their regulation and the mechanism underlying the switch between rRNA types remain unclear. We observe significant rRNA degradation in mature gametocytes, leading us to propose that this potentially leads to a reduced number of functional ribosomes when parasites become quiescent and translation is repressed.

Plasmodium falciparum

Multi-Omics insights into OsZFP252-OsGA20ox5 mediated drought tolerance in rice through stomatal and vascular regulation.

Rice growth is highly dependent on water availability, and drought stress significantly impacts its entire life cycle. However, previous studies lack systematic investigations into drought-responsive candidate genes across the full life cycle of rice. This study integrates transcriptomic and phenotypic data from two rice lines, IR64 (drought-sensitive) and DK151 (drought-tolerant), under varied environmental conditions at distinct growth stages. Using k-means clustering, 13 369 genes were categorized into 17 distinct expression patterns, revealing drought-responsive genes specifically upregulated or downregulated under drought stress. Weighted co-expression network analysis (WGCNA) further identified four gene modules strongly correlated with drought-related phenotypes, co-localizing 2859 drought-responsive genes through both approaches. Proteomics and metabolomics were supplemented at the booting stage, where phenotypic and transcriptomic differences under drought were most pronounced. Integrated omics results demonstrate gibberellin (GA) and abscisic acid (ABA) pathways play a key role during drought tolerance in rice, and 79 high-confidence drought-resistant candidate genes were prioritized from the 2859 drought-responsive genes. Among these, Gibberellin 20-oxidase 5 (OsGA20ox5) was identified as a key negative regulator of drought tolerance. Furthermore, the transcription factor zinc finger protein 252 (OsZFP252) directly binds to the OsGA20ox5 promoter, repressing its expression and enhancing ABA biosynthesis, thereby improving drought tolerance by increasing stomatal closure and expanding vascular bundle water transport capacity. Notably, the drought-tolerant haplotype 2-4 (Hap2-4) of OsGA20ox5 provides valuable insights for drought-resistant breeding.

Oryza

REVIEW: CAUSES AND CONSEQUENCES OF DOING IT WITH ONESELF-SYNTHESIS AND META-ANALYSIS OF NEODERMATAN HERMAPHRODITIC MATING SYSTEMS.

Hermaphroditic mating systems profoundly influence evolution, yet in parasitic flatworms (Neodermata) they remain strikingly understudied. For decades, sweeping claims have oscillated between pervasive selfing and near-universal outcrossing, reflecting a lack of comprehensive synthesis. This review, the first in more than 40 yr, integrates nearly a century of research, from early observational studies to modern genetic analyses, to reveal a far more nuanced picture. Our meta-analysis of population-genetic data shows a sharp departure from the bimodal selfing patterns typical of plants and other hermaphroditic animals: neodermatan parasites are strongly skewed toward outcrossing. We link variation in mating systems to parasite demography and life-history traits, especially in species exhibiting mixed mating or elevated selfing. Current evidence suggests outcrossing is common, but taxonomic and life-history gaps preclude definitive conclusions. Beyond patterns and causes, we explore evolutionary consequences ranging from fitness costs such as inbreeding depression to trait evolution, including delayed selfing, sex allocation, and complex life cycles. Evidence for inbreeding depression is mixed and limited, yet emerging approaches using selfing-rate comparisons offer promising avenues for future research. Notably, demographic constraints, such as infection intensity and life-cycle architecture, often explain mixed mating without invoking selection, challenging classical models. Similarly limited in number, studies on sex allocation indicate that hermaphroditic mating systems can shape reproductive investment, with patterns consistent with local sperm competition in some taxa. By consolidating historical observations with modern genetic insights, this review provides the most comprehensive synthesis of hermaphroditic mating systems in the Neodermata to date. We highlight critical gaps in taxonomic coverage and experimental data and point to future opportunities for integrating genomic approaches with ecological and demographic frameworks. Such integration will be essential to illuminate how mating systems shape parasite evolution and to resolve long-standing questions about the persistence of mixed mating despite theoretical expectations.

Animals

Rab10 coordinates SADS-CoV non-lytic egress through the ERGIC-TGN-lysosome trafficking pathway.

Swine acute diarrhea syndrome coronavirus (SADS-CoV) is a bat-originated alphacoronavirus that causes devastating enteric disease in neonatal piglets and possesses significant potential for cross-species transmission. While the early stages of the coronavirus life cycle have been extensively characterized, the host factors indispensable for virion assembly and subsequent export remain largely enigmatic. Here, by performing a genome-wide CRISPR-Cas9 knockout screen using a recombinant icSADS-CoV-GFP reporter virus, we identified the small GTPase Rab10 as a critical host dependency factor for SADS-CoV infection. Viral life cycle analysis revealed that Rab10 is not required for viral attachment, entry, or initial genome replication, but is essential for the virion transport and non-lytic egress. Rab10 deficiency markedly reduced the extracellular release of viral RNA, viral proteins, and infectious progeny, as well as the secretion of SADS-CoV virus-like particles. Confocal imaging showed that Rab10 and viral protein-positive intracellular structures were associated with LMAN1, TGN46, and LAMP1 positive compartments. These findings support a model in which Rab10 coordinates a virus-containing vesicles trafficking pathway associated with ERGIC-TGN-lysosome compartments. Mechanistically, Rab10 facilitates the loading of the viral envelope (E) protein into transport vesicles derived from the ERGIC. Rab10 associates with the SADS-CoV E protein, and mapping analyses implicated the C-terminal PDZ-binding motif, particularly residue V75, in efficient Rab10 association and viral release. Collectively, our findings identify Rab10 as a host regulator of SADS-CoV non-lytic egress and highlight the E-Rab10 interaction and the vesicular trafficking machinery as a potential target for developing antiviral strategies.

Animals

Bergamottin, a bioactive component of bergamot: dual inhibition of Japanese encephalitis virus internalization and genome replication.

Japanese encephalitis virus (JEV) is associated with high mortality and severe neurological sequelae, and existing prevention and control strategies remain insufficient. Therefore, the development of novel antiviral agents is of critical public health importance. This study systematically evaluated the antiviral activity and underlying mechanism of bergamottin, a natural product. Bergamottin exhibited significant dose-dependent inhibitory effects against JEV in multiple cell lines, including BHK-21, HuH-7, and Vero cells, demonstrating potent antiviral efficacy. Mechanistic investigations revealed that bergamottin primarily targeted the internalization and replication stages of the JEV life cycle, thereby effectively suppressing viral proliferation. Additionally, adaptive mutation screening indicated that the D389G mutation in envelope protein E confers drug resistance by potentially changing E protein conformation or reducing endocytic efficiency. In vivo experiment, bergamottin significantly reduced viral loads in mouse brain tissue and effectively improved the survival rate of infected mice. Our findings indicated that bergamottin exerted antiviral activity by dual targeting of key steps in the viral life cycle, making it a highly promising candidate for anti-JEV therapy. Further exploration of the antiviral properties of bergamottin is expected to facilitate its clinical development as a treatment for JEV infection.

Animals

Antiviral Activity of the MEK1/2 Inhibitor Trametinib Against Lymphocytic Choriomeningitis Virus.

The lymphocytic choriomeningitis virus (LCMV) is a widespread pathogen that causes mild-to-severe infections to severe outcomes. In this study, we explored the potential of trametinib, a mitogen-activated protein kinase (MAPK) inhibitor, as an antiviral agent against LCMV. Trametinib demonstrated significant antiviral activity against two distinct LCMV strains, Armstrong and Cl13, with promising half-maximal inhibitory concentrations (IC50) and selectivity indices (SI) indicating its potency and safety profile. Mechanistic investigations revealed that trametinib interfered with multiple stages of the LCMV life cycle, including membrane fusion and genomic replication, leading to the robust inhibition of viral proliferation. Furthermore, trametinib disrupted the MEK/ERK signaling pathway, which is crucial for LCMV infection. In both in vitro and in vivo experiments, trametinib effectively reduced viral loads and mitigated pathological damage to the spleen and liver tissues. Overall, our findings suggest that trametinib is a promising novel therapeutic option for combating LCMV infection by targeting key stages of the viral life cycle and disrupting host cellular signaling pathways. Further exploration of the antiviral properties of trametinib is likely to pave the way for its clinical development as a treatment for LCMV infections.

Pyridones

Resolving a century-old enigma: potato 'Bolters' originate from instability of the StCDF1.3 allele.

Potato bolters are caused by excision of a transposon from the StCDF1.3 allele, resulting in a somatic mutant with late maturity. Somatic mutations during vegetative propagation can lead to novel genotypes, known as sports. In cultivated potato (Solanum tuberosum), a recurring sport type, called 'Bolters', is characterized by vigorous haulms and prolonged flowering. Bolters emerge spontaneously during potato cultivation. While deviating phenotypes are typically rogued during clonal propagation, certain bolters have been selected as sub-clonal strains. Their delayed maturity results in a longer growing season and higher yield, in particular when cultivated under short daylengths. Despite their prevalence and agronomical benefits, the genetic basis of bolters has remained unresolved 160 years after their first description in the literature. We investigated whether allelic variation at the StCDF1 locus, a central regulator of potato life cycle, underlies the bolter phenotype. We describe 34 bolters from eight cultivars. Bolters are isogenic with their parent varieties and carried new StCDF1 alleles. These arose from excision events of the Class II TIR transposon disrupting the StCDF1.3 allele conferring early maturity. Among the newly formed alleles, we predominantly identified StCDF1.2 variants, characterized by a 7-nucleotide insertion and associated with a mild effect on early maturity. We also found novel variants, including StCDF1.7, with a 6-nucleotide in-frame insertion, which appears to confer an even milder shortening of the life cycle. Based on this knowledge, we propose that selecting bolters represents a promising breeding strategy to expand the cultivation range of elite varieties and to enhance allelic diversity at a key regulatory locus.

Solanum tuberosum

One mother for two species via obligate cross-species cloning in ants.

Living organisms are assumed to produce same-species offspring1,2. Here, we report a shift from this norm in Messor ibericus, an ant that lays individuals from two distinct species. In this life cycle, females must clone males of another species because they require their sperm to produce the worker caste. As a result, males from the same mother exhibit distinct genomes and morphologies, as they belong to species that diverged over 5 million years ago. The evolutionary history of this system appears as sexual parasitism3 that evolved into a natural case of cross-species cloning4,5, resulting in the maintenance of a male-only lineage cloned through distinct species' ova. We term females exhibiting this reproductive mode as xenoparous, meaning they give birth to other species as part of their life cycle.

Animals

Emerging trends in the study of spiralian larvae.

Many animals undergo indirect development, where their embryogenesis produces an intermediate life stage, or larva, that is often free-living and later metamorphoses into an adult. As their adult counterparts, larvae can have unique and diverse morphologies and occupy various ecological niches. Given their broad phylogenetic distribution, larvae have been central to hypotheses about animal evolution. However, the evolution of these intermediate forms and the developmental mechanisms diversifying animal life cycles are still debated. This review focuses on Spiralia, a large and diverse clade of bilaterally symmetrical animals with a fascinating array of larval forms, most notably the archetypical trochophore larva. We explore how classic research and modern advances have improved our understanding of spiralian larvae, their development, and evolution. Specifically, we examine three morphological features of spiralian larvae: the anterior neural system, the ciliary bands, and the posterior hyposphere. The combination of molecular and developmental evidence with modern high-throughput techniques, such as comparative genomics, single-cell transcriptomics, and epigenomics, is a promising strategy that will lead to new testable hypotheses about the mechanisms behind the evolution of larvae and life cycles in Spiralia and animals in general. We predict that the increasing number of available genomes for Spiralia and the optimization of genome-wide and single-cell approaches will unlock the study of many emerging spiralian taxa, transforming our views of the evolution of this animal group and their larvae.

Animals

Differentiation-independent activation of HPV genome replication by the lncRNA DINO.

Human papillomaviruses (HPVs) rely on multiple host cell factors to replicate the viral genome, yet the contribution of host long non-coding RNAs (lncRNAs) to viral genome maintenance and amplification in the productive life cycle remains poorly understood. In this study, we show that the lncRNA damage-induced long non-coding RNA (DINO) is a driver of HPV DNA replication. DINO levels increase during keratinocyte differentiation, and ectopic expression of DINO promotes both HPV genome replication and the formation of replication foci, and this is independent of keratinocyte differentiation signals. Ectopic DINO expression increases select early viral transcript levels, including E1^E4, E1, and E2. Notably, DINO's subcellular localization is also context-dependent: during DNA damage, DINO is predominantly cytoplasmic, but during keratinocyte differentiation, nuclear retention is observed. This differential localization suggests that DINO has distinct functional roles in keratinocyte differentiation and HPV biology. Our findings highlight DINO as a lncRNA that promotes HPV genome replication and suggest that lncRNAs may play underappreciated roles in host-virus interactions. This work provides a foundation for further exploration of lncRNAs as potential therapeutic targets in HPV-associated diseases.IMPORTANCEHuman papillomaviruses (HPVs) are the causative agents of many anogenital tract and oral cancers, yet the host factors that trigger and support viral genome replication during the productive life cycle are incompletely understood. This study identifies the long non-coding RNA DINO as a host regulator that promotes HPV DNA replication, replication focus formation, and early viral gene expression independently of keratinocyte differentiation. We further show that DINO exhibits context-dependent subcellular localization, suggesting distinct functional roles in cellular stress responses and HPV biology. These findings reveal an underappreciated role for host lncRNAs in virus-host interactions and provide new insight into cellular pathways that support HPV genome replication.

Virus Replication