RESUMEN
Neurons of the mammalian central nervous system fail to regenerate. Substantial progress has been made toward identifying the cellular and molecular mechanisms that underlie regenerative failure and how altering those pathways can promote cell survival and/or axon regeneration. Here, we summarize those findings while comparing the regenerative process in the central versus the peripheral nervous system. We also highlight studies that advance our understanding of the mechanisms underlying neural degeneration in response to injury, as many of these mechanisms represent primary targets for restoring functional neural circuits.
Asunto(s)
Axones/metabolismo , Sistema Nervioso Central/metabolismo , Regeneración Nerviosa/fisiología , Neuronas/metabolismo , Transducción de Señal/fisiología , Animales , Humanos , Sistema Nervioso Periférico/metabolismoRESUMEN
We have known for decades that long noncoding RNAs (lncRNAs) can play essential functions across most forms of life. The maintenance of chromosome length requires an lncRNA (e.g., hTERC) and two lncRNAs in the ribosome that are required for protein synthesis. Thus, lncRNAs can represent powerful RNA machines. More recently, it has become clear that mammalian genomes encode thousands more lncRNAs. Thus, we raise the question: Which, if any, of these lncRNAs could also represent RNA-based machines? Here we synthesize studies that are beginning to address this question by investigating fundamental properties of lncRNA genes, revealing new insights into the RNA structure-function relationship, determining cis- and trans-acting lncRNAs in vivo, and generating new developments in high-throughput screening used to identify functional lncRNAs. Overall, these findings provide a context toward understanding the molecular grammar underlying lncRNA biology.
Asunto(s)
Genoma , Biosíntesis de Proteínas , ARN Largo no Codificante/genética , ARN Mensajero/genética , ARN/genética , Telomerasa/genética , Animales , Núcleo Celular/genética , Núcleo Celular/metabolismo , Células Eucariotas/citología , Células Eucariotas/metabolismo , Humanos , Conformación de Ácido Nucleico , Regiones Promotoras Genéticas , ARN/metabolismo , ARN Largo no Codificante/química , ARN Largo no Codificante/metabolismo , ARN Mensajero/química , ARN Mensajero/metabolismo , Relación Estructura-Actividad , Telomerasa/metabolismo , Homeostasis del Telómero , Transcripción GenéticaRESUMEN
Genes specifying long non-coding RNAs (lncRNAs) occupy a large fraction of the genomes of complex organisms. The term 'lncRNAs' encompasses RNA polymerase I (Pol I), Pol II and Pol III transcribed RNAs, and RNAs from processed introns. The various functions of lncRNAs and their many isoforms and interleaved relationships with other genes make lncRNA classification and annotation difficult. Most lncRNAs evolve more rapidly than protein-coding sequences, are cell type specific and regulate many aspects of cell differentiation and development and other physiological processes. Many lncRNAs associate with chromatin-modifying complexes, are transcribed from enhancers and nucleate phase separation of nuclear condensates and domains, indicating an intimate link between lncRNA expression and the spatial control of gene expression during development. lncRNAs also have important roles in the cytoplasm and beyond, including in the regulation of translation, metabolism and signalling. lncRNAs often have a modular structure and are rich in repeats, which are increasingly being shown to be relevant to their function. In this Consensus Statement, we address the definition and nomenclature of lncRNAs and their conservation, expression, phenotypic visibility, structure and functions. We also discuss research challenges and provide recommendations to advance the understanding of the roles of lncRNAs in development, cell biology and disease.
Asunto(s)
ARN Largo no Codificante , ARN Largo no Codificante/genética , Núcleo Celular/genética , Cromatina/genética , Secuencias Reguladoras de Ácidos Nucleicos , ARN Polimerasa II/genéticaRESUMEN
Pathogenic clostridial species secrete potent toxins that induce severe host tissue damage. Paeniclostridium sordellii lethal toxin (TcsL) causes an almost invariably lethal toxic shock syndrome associated with gynecological infections. TcsL is 87% similar to C. difficile TcdB, which enters host cells via Frizzled receptors in colon epithelium. However, P. sordellii infections target vascular endothelium, suggesting that TcsL exploits another receptor. Here, using CRISPR/Cas9 screening, we establish semaphorins SEMA6A and SEMA6B as TcsL receptors. We demonstrate that recombinant SEMA6A can protect mice from TcsL-induced edema. A 3.3 Å cryo-EM structure shows that TcsL binds SEMA6A with the same region that in TcdB binds structurally unrelated Frizzled. Remarkably, 15 mutations in this evolutionarily divergent surface are sufficient to switch binding specificity of TcsL to that of TcdB. Our findings establish semaphorins as physiologically relevant receptors for TcsL and reveal the molecular basis for the difference in tissue targeting and disease pathogenesis between highly related toxins.
Asunto(s)
Toxinas Bacterianas/metabolismo , Clostridium sordellii/metabolismo , Semaforinas/metabolismo , Animales , Toxinas Bacterianas/química , Toxinas Bacterianas/toxicidad , Sitios de Unión , Sistemas CRISPR-Cas/genética , Línea Celular , Microscopía por Crioelectrón , Edema/patología , Edema/prevención & control , Femenino , Humanos , Pulmón/efectos de los fármacos , Pulmón/patología , Ratones , Ratones Endogámicos C57BL , Simulación de Dinámica Molecular , Mutagénesis Sitio-Dirigida , Unión Proteica , Estructura Terciaria de Proteína , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/uso terapéutico , Semaforinas/química , Semaforinas/genéticaRESUMEN
To discover regulatory elements driving the specificity of gene expression in different cell types and regions of the developing human brain, we generated an atlas of open chromatin from nine dissected regions of the mid-gestation human telencephalon, as well as microdissected upper and deep layers of the prefrontal cortex. We identified a subset of open chromatin regions (OCRs), termed predicted regulatory elements (pREs), that are likely to function as developmental brain enhancers. pREs showed temporal, regional, and laminar differences in chromatin accessibility and were correlated with gene expression differences across regions and gestational ages. We identified two functional de novo variants in a pRE for autism risk gene SLC6A1, and using CRISPRa, demonstrated that this pRE regulates SCL6A1. Additionally, mouse transgenic experiments validated enhancer activity for pREs proximal to FEZF2 and BCL11A. Thus, this atlas serves as a resource for decoding neurodevelopmental gene regulation in health and disease.
Asunto(s)
Cromatina/genética , Cromatina/metabolismo , Elementos de Facilitación Genéticos , Regulación del Desarrollo de la Expresión Génica/genética , Corteza Prefrontal/embriología , Telencéfalo/embriología , Animales , Trastorno Autístico/genética , Línea Celular , Secuenciación de Inmunoprecipitación de Cromatina , Eucromatina/genética , Proteínas Transportadoras de GABA en la Membrana Plasmática/genética , Ontología de Genes , Predisposición Genética a la Enfermedad , Edad Gestacional , Humanos , Ratones , Ratones Transgénicos , Motivos de Nucleótidos , Mutación Puntual , Corteza Prefrontal/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Análisis Espacio-Temporal , Telencéfalo/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Ebola virus (EBOV) causes epidemics with high mortality yet remains understudied due to the challenge of experimentation in high-containment and outbreak settings. Here, we used single-cell transcriptomics and CyTOF-based single-cell protein quantification to characterize peripheral immune cells during EBOV infection in rhesus monkeys. We obtained 100,000 transcriptomes and 15,000,000 protein profiles, finding that immature, proliferative monocyte-lineage cells with reduced antigen-presentation capacity replace conventional monocyte subsets, while lymphocytes upregulate apoptosis genes and decline in abundance. By quantifying intracellular viral RNA, we identify molecular determinants of tropism among circulating immune cells and examine temporal dynamics in viral and host gene expression. Within infected cells, EBOV downregulates STAT1 mRNA and interferon signaling, and it upregulates putative pro-viral genes (e.g., DYNLL1 and HSPA5), nominating pathways the virus manipulates for its replication. This study sheds light on EBOV tropism, replication dynamics, and elicited immune response and provides a framework for characterizing host-virus interactions under maximum containment.
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Ebolavirus/fisiología , Fiebre Hemorrágica Ebola/genética , Fiebre Hemorrágica Ebola/virología , Interacciones Huésped-Patógeno/genética , Análisis de la Célula Individual , Animales , Antígenos CD/metabolismo , Biomarcadores/metabolismo , Efecto Espectador , Diferenciación Celular , Proliferación Celular , Citocinas/metabolismo , Ebolavirus/genética , Chaperón BiP del Retículo Endoplásmico , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Regulación Viral de la Expresión Génica , Fiebre Hemorrágica Ebola/inmunología , Fiebre Hemorrágica Ebola/patología , Antígenos de Histocompatibilidad Clase II/metabolismo , Interferones/genética , Interferones/metabolismo , Macaca mulatta , Macrófagos/metabolismo , Monocitos/metabolismo , Mielopoyesis , ARN Mensajero/genética , ARN Mensajero/metabolismo , Factores de Tiempo , Transcriptoma/genéticaRESUMEN
Exhausted CD8 T cells (TEX) are a distinct state of T cell differentiation associated with failure to clear chronic viruses and cancer. Immunotherapies such as PD-1 blockade can reinvigorate TEX cells, but reinvigoration is not durable. A major unanswered question is whether TEX cells differentiate into functional durable memory T cells (TMEM) upon antigen clearance. Here, using a mouse model, we found that upon eliminating chronic antigenic stimulation, TEX cells partially (re)acquire phenotypic and transcriptional features of TMEM cells. These 'recovering' TEX cells originated from the T cell factor (TCF-1+) TEX progenitor subset. Nevertheless, the recall capacity of these recovering TEX cells remained compromised as compared to TMEM cells. Chromatin-accessibility profiling revealed a failure to recover core memory epigenetic circuits and maintenance of a largely exhausted open chromatin landscape. Thus, despite some phenotypic and transcriptional recovery upon antigen clearance, exhaustion leaves durable epigenetic scars constraining future immune responses. These results support epigenetic remodeling interventions for TEX cell-targeted immunotherapies.
Asunto(s)
Antígenos Virales/inmunología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/patología , Memoria Inmunológica/inmunología , Coriomeningitis Linfocítica/inmunología , Animales , Linfocitos T CD8-positivos/citología , Diferenciación Celular/inmunología , Línea Celular , Chlorocebus aethiops , Cricetinae , Epigénesis Genética/genética , Femenino , Factor Nuclear 1-alfa del Hepatocito/metabolismo , Virus de la Coriomeningitis Linfocítica/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Transcripción Genética/genética , Células VeroRESUMEN
Resistance to chemotherapy plays a significant role in cancer mortality. To identify genetic units affecting sensitivity to cytarabine, the mainstay of treatment for acute myeloid leukemia (AML), we developed a comprehensive and integrated genome-wide platform based on a dual protein-coding and non-coding integrated CRISPRa screening (DICaS). Putative resistance genes were initially identified using pharmacogenetic data from 760 human pan-cancer cell lines. Subsequently, genome scale functional characterization of both coding and long non-coding RNA (lncRNA) genes by CRISPR activation was performed. For lncRNA functional assessment, we developed a CRISPR activation of lncRNA (CaLR) strategy, targeting 14,701 lncRNA genes. Computational and functional analysis identified novel cell-cycle, survival/apoptosis, and cancer signaling genes. Furthermore, transcriptional activation of the GAS6-AS2 lncRNA, identified in our analysis, leads to hyperactivation of the GAS6/TAM pathway, a resistance mechanism in multiple cancers including AML. Thus, DICaS represents a novel and powerful approach to identify integrated coding and non-coding pathways of therapeutic relevance.
Asunto(s)
Sistemas CRISPR-Cas , Resistencia a Antineoplásicos , Genoma Humano , ARN Largo no Codificante/genética , Animales , Citarabina/farmacología , Femenino , Perfilación de la Expresión Génica , Redes Reguladoras de Genes , Células HEK293 , Células HL-60 , Humanos , Células K562 , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Masculino , Ratones , Farmacogenética , Proteínas/genética , ARN/análisis , ARN Mensajero/genética , Transducción de SeñalRESUMEN
Non-coding "ultraconserved" regions containing hundreds of consecutive bases of perfect sequence conservation across mammalian genomes can function as distant-acting enhancers. However, initial deletion studies in mice revealed that loss of such extraordinarily constrained sequences had no immediate impact on viability. Here, we show that ultraconserved enhancers are required for normal development. Focusing on some of the longest ultraconserved sites genome wide, located near the essential neuronal transcription factor Arx, we used genome editing to create an expanded series of knockout mice lacking individual or combinations of ultraconserved enhancers. Mice with single or pairwise deletions of ultraconserved enhancers were viable and fertile but in nearly all cases showed neurological or growth abnormalities, including substantial alterations of neuron populations and structural brain defects. Our results demonstrate the functional importance of ultraconserved enhancers and indicate that remarkably strong sequence conservation likely results from fitness deficits that appear subtle in a laboratory setting.
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Secuencia Conservada , Desarrollo Embrionario/genética , Elementos de Facilitación Genéticos , Animales , Encéfalo/anomalías , Encéfalo/embriología , Encéfalo/metabolismo , Femenino , Eliminación de Gen , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Masculino , Ratones , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Microbial rhodopsins are a family of photoactive retinylidene proteins widespread throughout the microbial world. They are notable for their diversity of function, using variations of a shared seven-transmembrane helix design and similar photochemical reactions to carry out distinctly different light-driven energy and sensory transduction processes. Their study has contributed to our understanding of how evolution modifies protein scaffolds to create new protein chemistry, and their use as tools to control membrane potential with light is fundamental to optogenetics for research and clinical applications. We review the currently known functions and present more in-depth assessment of three functionally and structurally distinct types discovered over the past two years: (a) anion channelrhodopsins (ACRs) from cryptophyte algae, which enable efficient optogenetic neural suppression; (b) cryptophyte cation channelrhodopsins (CCRs), structurally distinct from the green algae CCRs used extensively for neural activation and from cryptophyte ACRs; and
Asunto(s)
Optogenética/métodos , Proteínas de Plantas/química , Retinoides/química , Rodopsinas Microbianas/química , Rodopsinas Sensoriales/química , Chlorophyta/clasificación , Chlorophyta/genética , Chlorophyta/metabolismo , Evolución Molecular , Expresión Génica , Luz , Fototransducción , Potenciales de la Membrana/fisiología , Modelos Moleculares , Procesos Fotoquímicos , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Conformación Proteica en Hélice alfa , Conformación Proteica en Lámina beta , Dominios Proteicos , Retinoides/metabolismo , Rodopsinas Microbianas/genética , Rodopsinas Microbianas/metabolismo , Rodopsinas Sensoriales/genética , Rodopsinas Sensoriales/metabolismoRESUMEN
A wide spectrum of clinical manifestations has become a hallmark of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) COVID-19 pandemic, although the immunological underpinnings of diverse disease outcomes remain to be defined. We performed detailed characterization of B cell responses through high-dimensional flow cytometry to reveal substantial heterogeneity in both effector and immature populations. More notably, critically ill patients displayed hallmarks of extrafollicular B cell activation and shared B cell repertoire features previously described in autoimmune settings. Extrafollicular activation correlated strongly with large antibody-secreting cell expansion and early production of high concentrations of SARS-CoV-2-specific neutralizing antibodies. Yet, these patients had severe disease with elevated inflammatory biomarkers, multiorgan failure and death. Overall, these findings strongly suggest a pathogenic role for immune activation in subsets of patients with COVID-19. Our study provides further evidence that targeted immunomodulatory therapy may be beneficial in specific patient subpopulations and can be informed by careful immune profiling.
Asunto(s)
Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Linfocitos B/inmunología , COVID-19/inmunología , SARS-CoV-2/inmunología , Humanos , InmunofenotipificaciónRESUMEN
In this issue of Cell, Hite and MacKinnon (2017) report the open conformation structure of Slo2.2, a neuronal Na+-activated K+ channel. More importantly, 3D classification of electron cryomicroscopy (cryo-EM) images allows visualization of the structural transition that occurs as the open probability of individual channels increases with added sodium.
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Microscopía por Crioelectrón , Canales Iónicos , SodioRESUMEN
The evolution of land flora transformed the terrestrial environment. Land plants evolved from an ancestral charophycean alga from which they inherited developmental, biochemical, and cell biological attributes. Additional biochemical and physiological adaptations to land, and a life cycle with an alternation between multicellular haploid and diploid generations that facilitated efficient dispersal of desiccation tolerant spores, evolved in the ancestral land plant. We analyzed the genome of the liverwort Marchantia polymorpha, a member of a basal land plant lineage. Relative to charophycean algae, land plant genomes are characterized by genes encoding novel biochemical pathways, new phytohormone signaling pathways (notably auxin), expanded repertoires of signaling pathways, and increased diversity in some transcription factor families. Compared with other sequenced land plants, M. polymorpha exhibits low genetic redundancy in most regulatory pathways, with this portion of its genome resembling that predicted for the ancestral land plant. PAPERCLIP.
Asunto(s)
Evolución Biológica , Embryophyta/genética , Genoma de Planta , Marchantia/genética , Adaptación Biológica , Embryophyta/fisiología , Regulación de la Expresión Génica de las Plantas , Marchantia/fisiología , Anotación de Secuencia Molecular , Transducción de Señal , Transcripción GenéticaRESUMEN
Nucleosomes, the basic structural units of chromatin, hinder recruitment and activity of various DNA repair proteins, necessitating modifications that enhance DNA accessibility. Poly(ADP-ribosyl)ation (PARylation) of proteins near damage sites is an essential initiation step in several DNA-repair pathways; however, its effects on nucleosome structural dynamics and organization are unclear. Using NMR, cryoelectron microscopy (cryo-EM), and biochemical assays, we show that PARylation enhances motions of the histone H3 tail and DNA, leaving the configuration of the core intact while also stimulating nuclease digestion and ligation of nicked nucleosomal DNA by LIG3. PARylation disrupted interactions between nucleosomes, preventing self-association. Addition of LIG3 and XRCC1 to PARylated nucleosomes generated condensates that selectively partition DNA repair-associated proteins in a PAR- and phosphorylation-dependent manner in vitro. Our results establish that PARylation influences nucleosomes across different length scales, extending from the atom-level motions of histone tails to the mesoscale formation of condensates with selective compositions.
Asunto(s)
Nucleosomas , Poli ADP Ribosilación , Nucleosomas/genética , Poli ADP Ribosilación/genética , Poli(ADP-Ribosa) Polimerasas/metabolismo , Microscopía por Crioelectrón , Condensados Biomoleculares , Reparación del ADN , Histonas/genética , Histonas/metabolismo , ADN/genética , ADN/metabolismo , Daño del ADN , Poli(ADP-Ribosa) Polimerasa-1/metabolismoRESUMEN
Defects in organellar acidification indicate compromised or infected compartments. Recruitment of the autophagy-related ATG16L1 complex to pathologically neutralized organelles targets ubiquitin-like ATG8 molecules to perturbed membranes. How this process is coupled to proton gradient disruption is unclear. Here, we reveal that the V1H subunit of the vacuolar ATPase (V-ATPase) proton pump binds directly to ATG16L1. The V1H/ATG16L1 interaction only occurs within fully assembled V-ATPases, allowing ATG16L1 recruitment to be coupled to increased V-ATPase assembly following organelle neutralization. Cells lacking V1H fail to target ATG8s during influenza infection or after activation of the immune receptor stimulator of interferon genes (STING). We identify a loop within V1H that mediates ATG16L1 binding. A neuronal V1H isoform lacks this loop and is associated with attenuated ATG8 targeting in response to ionophores in primary murine and human iPSC-derived neurons. Thus, V1H controls ATG16L1 recruitment following proton gradient dissipation, suggesting that the V-ATPase acts as a cell-intrinsic damage sensor.
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Proteínas Relacionadas con la Autofagia , ATPasas de Translocación de Protón Vacuolares , ATPasas de Translocación de Protón Vacuolares/metabolismo , ATPasas de Translocación de Protón Vacuolares/genética , Humanos , Proteínas Relacionadas con la Autofagia/metabolismo , Proteínas Relacionadas con la Autofagia/genética , Animales , Ratones , Unión Proteica , Neuronas/metabolismo , Familia de las Proteínas 8 Relacionadas con la Autofagia/metabolismo , Familia de las Proteínas 8 Relacionadas con la Autofagia/genética , Autofagia , Células HEK293 , Células Madre Pluripotentes Inducidas/metabolismo , Gripe Humana/virología , Gripe Humana/metabolismo , Gripe Humana/genética , Ratones Endogámicos C57BL , Transducción de Señal , Proteínas Portadoras/metabolismo , Proteínas Portadoras/genética , Ratones NoqueadosRESUMEN
In the past 25 years, genetic and biochemical analyses of ribosome assembly in yeast have identified most of the factors that participate in this complex pathway and have generated models for the mechanisms driving the assembly. More recently, the publication of numerous cryo-electron microscopy structures of yeast ribosome assembly intermediates has provided near-atomic resolution snapshots of ribosome precursor particles. Satisfyingly, these structural data support the genetic and biochemical models and provide additional mechanistic insight into ribosome assembly. In this Review, we discuss the mechanisms of assembly of the yeast small ribosomal subunit and large ribosomal subunit in the nucleolus, nucleus and cytoplasm. Particular emphasis is placed on concepts such as the mechanisms of RNA compaction, the functions of molecular switches and molecular mimicry, the irreversibility of assembly checkpoints and the roles of structural and functional proofreading of pre-ribosomal particles.
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Subunidades Ribosómicas/genética , Animales , Núcleo Celular/genética , Microscopía por Crioelectrón/métodos , Citoplasma/genética , Humanos , ARN/genéticaRESUMEN
For the past several decades, advances in plant development, physiology, cell biology, and genetics have relied heavily on the model (or reference) plant Arabidopsis thaliana. Arabidopsis resembles other plants, including crop plants, in many but by no means all respects. Study of Arabidopsis alone provides little information on the evolutionary history of plants, evolutionary differences between species, plants that survive in different environments, or plants that access nutrients and photosynthesize differently. Empowered by the availability of large-scale sequencing and new technologies for investigating gene function, many new plant models are being proposed and studied.
Asunto(s)
Modelos Biológicos , Plantas , Arabidopsis , Biodiversidad , Evolución Biológica , Chlorophyta , Desarrollo de la PlantaRESUMEN
The proteome of cells is synthesized by ribosomes, complex ribonucleoproteins that in eukaryotes contain 79-80 proteins and four ribosomal RNAs (rRNAs) more than 5,400 nucleotides long. How these molecules assemble together and how their assembly is regulated in concert with the growth and proliferation of cells remain important unanswered questions. Here, we review recently emerging principles to understand how eukaryotic ribosomal proteins drive ribosome assembly in vivo. Most ribosomal proteins assemble with rRNA cotranscriptionally; their association with nascent particles is strengthened as assembly proceeds. Each subunit is assembled hierarchically by sequential stabilization of their subdomains. The active sites of both subunits are constructed last, perhaps to prevent premature engagement of immature ribosomes with active subunits. Late-assembly intermediates undergo quality-control checks for proper function. Mutations in ribosomal proteins that affect mostly late steps lead to ribosomopathies, diseases that include a spectrum of cell type-specific disorders that often transition from hypoproliferative to hyperproliferative growth.
Asunto(s)
Células Eucariotas/metabolismo , Proteínas Ribosómicas/metabolismo , Ribosomas/química , Ribosomas/metabolismo , Animales , Células Eucariotas/química , Humanos , Modelos Moleculares , Proteínas Ribosómicas/químicaRESUMEN
Adjuvants are critical for improving the quality and magnitude of adaptive immune responses to vaccination. Lipid nanoparticle (LNP)-encapsulated nucleoside-modified mRNA vaccines have shown great efficacy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but the mechanism of action of this vaccine platform is not well-characterized. Using influenza virus and SARS-CoV-2 mRNA and protein subunit vaccines, we demonstrated that our LNP formulation has intrinsic adjuvant activity that promotes induction of strong T follicular helper cell, germinal center B cell, long-lived plasma cell, and memory B cell responses that are associated with durable and protective antibodies in mice. Comparative experiments demonstrated that this LNP formulation outperformed a widely used MF59-like adjuvant, AddaVax. The adjuvant activity of the LNP relies on the ionizable lipid component and on IL-6 cytokine induction but not on MyD88- or MAVS-dependent sensing of LNPs. Our study identified LNPs as a versatile adjuvant that enhances the efficacy of traditional and next-generation vaccine platforms.
Asunto(s)
Linfocitos B/inmunología , Vacunas contra la COVID-19/inmunología , COVID-19/inmunología , Centro Germinal/inmunología , SARS-CoV-2/fisiología , Linfocitos T Colaboradores-Inductores/inmunología , Vacunas de ARNm/inmunología , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Adyuvantes Inmunológicos , Animales , Células HEK293 , Humanos , Inmunidad Humoral , Interleucina-6/genética , Interleucina-6/metabolismo , Liposomas/administración & dosificación , Ratones , Ratones Endogámicos BALB C , Nanopartículas/administración & dosificación , Subunidades de Proteína/genética , Vacunas de ARNm/genéticaRESUMEN
Induced pluripotency is a promising avenue for disease modeling and therapy, but the molecular principles underlying this process, particularly in human cells, remain poorly understood due to donor-to-donor variability and intercellular heterogeneity. Here, we constructed and characterized a clonal, inducible human reprogramming system that provides a reliable source of cells at any stage of the process. This system enabled integrative transcriptional and epigenomic analysis across the human reprogramming timeline at high resolution. We observed distinct waves of gene network activation, including the ordered re-activation of broad developmental regulators followed by early embryonic patterning genes and culminating in the emergence of a signature reminiscent of pre-implantation stages. Moreover, complementary functional analyses allowed us to identify and validate novel regulators of the reprogramming process. Altogether, this study sheds light on the molecular underpinnings of induced pluripotency in human cells and provides a robust cell platform for further studies. PAPERCLIP.