RESUMEN
Pathogens produce diverse effector proteins to manipulate host cellular processes. However, how functional diversity is generated in an effector repertoire is poorly understood. Many effectors in the devastating plant pathogen Phytophthora contain tandem repeats of the "(L)WY" motif, which are structurally conserved but variable in sequences. Here, we discovered a functional module formed by a specific (L)WY-LWY combination in multiple Phytophthora effectors, which efficiently recruits the serine/threonine protein phosphatase 2A (PP2A) core enzyme in plant hosts. Crystal structure of an effector-PP2A complex shows that the (L)WY-LWY module enables hijacking of the host PP2A core enzyme to form functional holoenzymes. While sharing the PP2A-interacting module at the amino terminus, these effectors possess divergent C-terminal LWY units and regulate distinct sets of phosphoproteins in the host. Our results highlight the appropriation of an essential host phosphatase through molecular mimicry by pathogens and diversification promoted by protein modularity in an effector repertoire.
Asunto(s)
Monoéster Fosfórico Hidrolasas , Phytophthora , Monoéster Fosfórico Hidrolasas/metabolismo , Proteínas/metabolismo , Phytophthora/química , Phytophthora/metabolismo , Plantas/metabolismo , Procesamiento Proteico-Postraduccional , Proteína Fosfatasa 2/metabolismo , Enfermedades de las PlantasRESUMEN
Natural antibodies (Abs) can target host glycans on the surface of pathogens. We studied the evolution of glycan-reactive B cells of rhesus macaques and humans using glycosylated HIV-1 envelope (Env) as a model antigen. 2G12 is a broadly neutralizing Ab (bnAb) that targets a conserved glycan patch on Env of geographically diverse HIV-1 strains using a unique heavy-chain (VH) domain-swapped architecture that results in fragment antigen-binding (Fab) dimerization. Here, we describe HIV-1 Env Fab-dimerized glycan (FDG)-reactive bnAbs without VH-swapped domains from simian-human immunodeficiency virus (SHIV)-infected macaques. FDG Abs also recognized cell-surface glycans on diverse pathogens, including yeast and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike. FDG precursors were expanded by glycan-bearing immunogens in macaques and were abundant in HIV-1-naive humans. Moreover, FDG precursors were predominately mutated IgM+IgD+CD27+, thus suggesting that they originated from a pool of antigen-experienced IgM+ or marginal zone B cells.
Asunto(s)
Anticuerpos Neutralizantes/inmunología , VIH-1/inmunología , Fragmentos Fab de Inmunoglobulinas/inmunología , Polisacáridos/inmunología , SARS-CoV-2/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Animales , Linfocitos B/inmunología , Anticuerpos ampliamente neutralizantes/inmunología , COVID-19/inmunología , Dimerización , Epítopos/inmunología , Glicosilación , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , Humanos , Fragmentos Fab de Inmunoglobulinas/química , Macaca mulatta , Polisacáridos/química , Receptores de Antígenos de Linfocitos B/química , Virus de la Inmunodeficiencia de los Simios/genética , Vacunas/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/química , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genéticaRESUMEN
The intestinal immune system interacts with commensal microbiota to maintain gut homeostasis. Furthermore, stress alters the microbiome composition, leading to impaired brain function; yet how the intestinal immune system mediates these effects remains elusive. Here we report that colonic γδ T cells modulate behavioral vulnerability to chronic social stress via dectin-1 signaling. We show that reduction in specific Lactobacillus species, which are involved in T cell differentiation to protect the host immune system, contributes to stress-induced social-avoidance behavior, consistent with our observations in patients with depression. Stress-susceptible behaviors derive from increased differentiation in colonic interleukin (IL)-17-producing γδ T cells (γδ17 T cells) and their meningeal accumulation. These stress-susceptible cellular and behavioral phenotypes are causally mediated by dectin-1, an innate immune receptor expressed in γδ T cells. Our results highlight the previously unrecognized role of intestinal γδ17 T cells in the modulation of psychological stress responses and the importance of dectin-1 as a potential therapeutic target for the treatment of stress-induced behaviors.
Asunto(s)
Intestinos , Lectinas Tipo C , Colon , Transducción de Señal , Receptores de Antígenos de Linfocitos T gamma-deltaRESUMEN
Microglial reactivity to injury and disease is emerging as a heterogeneous, dynamic, and crucial determinant in neurological disorders. However, the plasticity and fate of disease-associated microglia (DAM) remain largely unknown. We established a lineage tracing system, leveraging the expression dynamics of secreted phosphoprotein 1ï¼Spp1ï¼ to label and track DAM-like microglia during brain injury and recovery. Fate mapping of Spp1+ microglia during stroke in juvenile mice revealed an irreversible state of DAM-like microglia that were ultimately eliminated from the injured brain. By contrast, DAM-like microglia in the neonatal stroke models exhibited high plasticity, regaining a homeostatic signature and integrating into the microglial network after recovery. Furthermore, neonatal injury had a lasting impact on microglia, rendering them intrinsically sensitized to subsequent immune challenges. Therefore, our findings highlight the plasticity and innate immune memory of neonatal microglia, shedding light on the fate of DAM-like microglia in various neuropathological conditions.
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Lesiones Encefálicas , Accidente Cerebrovascular , Animales , Ratones , Microglía , Encéfalo/metabolismo , Osteopontina/metabolismoRESUMEN
The prostate cancer (PCa) risk-associated SNP rs11672691 is positively associated with aggressive disease at diagnosis. We showed that rs11672691 maps to the promoter of a short isoform of long noncoding RNA PCAT19 (PCAT19-short), which is in the third intron of the long isoform (PCAT19-long). The risk variant is associated with decreased and increased levels of PCAT19-short and PCAT19-long, respectively. Mechanistically, the risk SNP region is bifunctional with both promoter and enhancer activity. The risk variants of rs11672691 and its LD SNP rs887391 decrease binding of transcription factors NKX3.1 and YY1 to the promoter of PCAT19-short, resulting in weaker promoter but stronger enhancer activity that subsequently activates PCAT19-long. PCAT19-long interacts with HNRNPAB to activate a subset of cell-cycle genes associated with PCa progression, thereby promoting PCa tumor growth and metastasis. Taken together, these findings reveal a risk SNP-mediated promoter-enhancer switching mechanism underlying both initiation and progression of aggressive PCa.
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Neoplasias de la Próstata/genética , ARN Largo no Codificante/genética , Alelos , Línea Celular Tumoral , Elementos de Facilitación Genéticos/genética , Regulación Neoplásica de la Expresión Génica/genética , Frecuencia de los Genes/genética , Predisposición Genética a la Enfermedad/genética , Proteínas de Homeodominio/metabolismo , Humanos , Masculino , Polimorfismo de Nucleótido Simple/genética , Regiones Promotoras Genéticas/genética , Unión Proteica , Isoformas de ARN/genética , Factores de Riesgo , Factores de Transcripción/metabolismo , Factor de Transcripción YY1/metabolismoRESUMEN
While mutations affecting protein-coding regions have been examined across many cancers, structural variants at the genome-wide level are still poorly defined. Through integrative deep whole-genome and -transcriptome analysis of 101 castration-resistant prostate cancer metastases (109X tumor/38X normal coverage), we identified structural variants altering critical regulators of tumorigenesis and progression not detectable by exome approaches. Notably, we observed amplification of an intergenic enhancer region 624 kb upstream of the androgen receptor (AR) in 81% of patients, correlating with increased AR expression. Tandem duplication hotspots also occur near MYC, in lncRNAs associated with post-translational MYC regulation. Classes of structural variations were linked to distinct DNA repair deficiencies, suggesting their etiology, including associations of CDK12 mutation with tandem duplications, TP53 inactivation with inverted rearrangements and chromothripsis, and BRCA2 inactivation with deletions. Together, these observations provide a comprehensive view of how structural variations affect critical regulators in metastatic prostate cancer.
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Variación Estructural del Genoma/genética , Neoplasias de la Próstata/genética , Anciano , Anciano de 80 o más Años , Proteína BRCA2/metabolismo , Quinasas Ciclina-Dependientes/metabolismo , Variaciones en el Número de Copia de ADN , Exoma , Perfilación de la Expresión Génica/métodos , Genómica/métodos , Humanos , Masculino , Persona de Mediana Edad , Mutación , Metástasis de la Neoplasia/genética , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Receptores Androgénicos/genética , Receptores Androgénicos/metabolismo , Secuencias Repetidas en Tándem/genética , Proteína p53 Supresora de Tumor/metabolismo , Secuenciación Completa del Genoma/métodosRESUMEN
Group 2 innate lymphoid cells (ILC2s) are crucial in promoting type 2 inflammation that contributes to both anti-parasite immunity and allergic diseases. However, the molecular checkpoints in ILC2s that determine whether to immediately launch a proinflammatory response are unknown. Here, we found that retinoid X receptor gamma (Rxrg) was highly expressed in small intestinal ILC2s and rapidly suppressed by alarmin cytokines. Genetic deletion of Rxrg did not impact ILC2 development but facilitated ILC2 responses and the tissue inflammation induced by alarmins. Mechanistically, RXRγ maintained the expression of its target genes that support intracellular cholesterol efflux, which in turn reduce ILC2 proliferation. Furthermore, RXRγ expression prevented ILC2 response to mild stimulations, including low doses of alarmin cytokine and mechanical skin injury. Together, we propose that RXRγ expression and its mediated lipid metabolic states function as a cell-intrinsic checkpoint that confers the threshold of ILC2 activation in the small intestine.
Asunto(s)
Inmunidad Innata , Receptor gamma X Retinoide , Humanos , Alarminas , Linfocitos , Inflamación , Citocinas/metabolismo , Intestino Delgado/metabolismoRESUMEN
Apart from the canonical serotonin (5-hydroxytryptamine [5-HT])-receptor signaling transduction pattern, 5-HT-involved post-translational serotonylation has recently been noted. Here, we report a glyceraldehyde-3-phosphate dehydrogenase (GAPDH) serotonylation system that promotes the glycolytic metabolism and antitumor immune activity of CD8+ T cells. Tissue transglutaminase 2 (TGM2) transfers 5-HT to GAPDH glutamine 262 and catalyzes the serotonylation reaction. Serotonylation supports the cytoplasmic localization of GAPDH, which induces a glycolytic metabolic shift in CD8+ T cells and contributes to antitumor immunity. CD8+ T cells accumulate intracellular 5-HT for serotonylation through both synthesis by tryptophan hydroxylase 1 (TPH1) and uptake from the extracellular compartment via serotonin transporter (SERT). Monoamine oxidase A (MAOA) degrades 5-HT and acts as an intrinsic negative regulator of CD8+ T cells. The adoptive transfer of 5-HT-producing TPH1-overexpressing chimeric antigen receptor T (CAR-T) cells induced a robust antitumor response. Our findings expand the known range of neuroimmune interaction patterns by providing evidence of receptor-independent serotonylation post-translational modification.
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Linfocitos T CD8-positivos , Serotonina , Linfocitos T CD8-positivos/metabolismo , Serotonina/metabolismo , Serotonina/farmacología , Procesamiento Proteico-Postraduccional , Transducción de SeñalRESUMEN
The mechanisms by which the sensitivity of naive CD4+ T cells to stimulation by the cognate antigen via the T cell antigen receptor (TCR) determines their differentiation into distinct helper T cell subsets remain elusive. Here we demonstrate functional collaboration of the ubiquitin E3 ligases Itch and WWP2 in regulating the strength of the TCR signal. Mice lacking both Itch and WWP2 in T cells showed spontaneous autoimmunity and lung inflammation. CD4+ T cells deficient in Itch and WWP2 exhibited hypo-responsiveness to TCR stimulation and a bias toward differentiation into the TH2 subset of helper T cells. Itch and WWP2 formed a complex and cooperated to enhance TCR-proximal signaling by catalyzing the conjugation of atypical ubiquitin chains to the phosphatase SHP-1 and reducing the association of SHP-1 with the tyrosine kinase Lck. These findings indicate that targeted ubiquitination regulates the strength of the TCR signal and differentiation toward the TH2 lineage.
Asunto(s)
Receptores de Antígenos de Linfocitos T/metabolismo , Células Th2/inmunología , Ubiquitina-Proteína Ligasas/fisiología , Animales , Autoinmunidad , Diferenciación Celular , Humanos , Inflamación/genética , Células Jurkat , Proteína Tirosina Quinasa p56(lck) Específica de Linfocito/metabolismo , Ratones , Ratones Noqueados , Proteína Tirosina Fosfatasa no Receptora Tipo 6/metabolismo , Proteínas Represoras/metabolismo , Transducción de Señal , Células Th2/enzimología , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , UbiquitinaciónRESUMEN
Viral mutations are an emerging concern in reducing SARS-CoV-2 vaccination efficacy. Second-generation vaccines will need to elicit neutralizing antibodies against sites that are evolutionarily conserved across the sarbecovirus subgenus. Here, we immunized mice containing a human antibody repertoire with diverse sarbecovirus receptor-binding domains (RBDs) to identify antibodies targeting conserved sites of vulnerability. Antibodies with broad reactivity against diverse clade B RBDs targeting the conserved class 4 epitope, with recurring IGHV/IGKV pairs, were readily elicited but were non-neutralizing. However, rare class 4 antibodies binding this conserved RBD supersite showed potent neutralization of SARS-CoV-2 and all variants of concern. Structural analysis revealed that the neutralizing ability of cross-reactive antibodies was reserved only for those with an elongated CDRH3 that extends the antiparallel beta-sheet RBD core and orients the antibody light chain to obstruct ACE2-RBD interactions. These results identify a structurally defined pathway for vaccine strategies eliciting escape-resistant SARS-CoV-2 neutralizing antibodies.
Asunto(s)
Betacoronavirus/fisiología , Vacunas contra la COVID-19/inmunología , Infecciones por Coronavirus/inmunología , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/fisiología , Glicoproteína de la Espiga del Coronavirus/metabolismo , Animales , Anticuerpos Neutralizantes/metabolismo , Anticuerpos Antivirales/metabolismo , Secuencia Conservada/genética , Evolución Molecular , Humanos , Inmunización , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Unión Proteica , Dominios Proteicos/genética , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Desarrollo de VacunasRESUMEN
Prime editing enables the precise modification of genomes through reverse transcription of template sequences appended to the 3' ends of CRISPR-Cas guide RNAs1. To identify cellular determinants of prime editing, we developed scalable prime editing reporters and performed genome-scale CRISPR-interference screens. From these screens, a single factor emerged as the strongest mediator of prime editing: the small RNA-binding exonuclease protection factor La. Further investigation revealed that La promotes prime editing across approaches (PE2, PE3, PE4 and PE5), edit types (substitutions, insertions and deletions), endogenous loci and cell types but has no consistent effect on genome-editing approaches that rely on standard, unextended guide RNAs. Previous work has shown that La binds polyuridine tracts at the 3' ends of RNA polymerase III transcripts2. We found that La functionally interacts with the 3' ends of polyuridylated prime editing guide RNAs (pegRNAs). Guided by these results, we developed a prime editor protein (PE7) fused to the RNA-binding, N-terminal domain of La. This editor improved prime editing with expressed pegRNAs and engineered pegRNAs (epegRNAs), as well as with synthetic pegRNAs optimized for La binding. Together, our results provide key insights into how prime editing components interact with the cellular environment and suggest general strategies for stabilizing exogenous small RNAs therein.
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Edición Génica , Proteínas de Unión al ARN , Humanos , Sistemas CRISPR-Cas/genética , Edición Génica/métodos , Células K562 , Poli U/genética , Poli U/metabolismo , ARN Polimerasa III/metabolismo , ARN Guía de Sistemas CRISPR-Cas/genética , ARN Guía de Sistemas CRISPR-Cas/metabolismo , Proteínas de Unión al ARN/metabolismoRESUMEN
Vision enables both image-forming perception, driven by a contrast-based pathway, and unconscious non-image-forming circadian photoentrainment, driven by an irradiance-based pathway1,2. Although two distinct photoreceptor populations are specialized for each visual task3-6, image-forming photoreceptors can additionally contribute to photoentrainment of the circadian clock in different species7-15. However, it is unknown how the image-forming photoreceptor pathway can functionally implement the segregation of irradiance signals required for circadian photoentrainment from contrast signals required for image perception. Here we report that the Drosophila R8 photoreceptor separates image-forming and irradiance signals by co-transmitting two neurotransmitters, histamine and acetylcholine. This segregation is further established postsynaptically by histamine-receptor-expressing unicolumnar retinotopic neurons and acetylcholine-receptor-expressing multicolumnar integration neurons. The acetylcholine transmission from R8 photoreceptors is sustained by an autocrine negative feedback of the cotransmitted histamine during the light phase of light-dark cycles. At the behavioural level, elimination of histamine and acetylcholine transmission impairs R8-driven motion detection and circadian photoentrainment, respectively. Thus, a single type of photoreceptor can achieve the dichotomy of visual perception and circadian photoentrainment as early as the first visual synapses, revealing a simple yet robust mechanism to segregate and translate distinct sensory features into different animal behaviours.
Asunto(s)
Ritmo Circadiano , Drosophila melanogaster , Células Fotorreceptoras de Invertebrados , Percepción Visual , Animales , Acetilcolina/metabolismo , Relojes Biológicos/fisiología , Relojes Biológicos/efectos de la radiación , Ritmo Circadiano/fisiología , Ritmo Circadiano/efectos de la radiación , Drosophila melanogaster/citología , Drosophila melanogaster/fisiología , Drosophila melanogaster/efectos de la radiación , Retroalimentación Fisiológica , Histamina/metabolismo , Neurotransmisores/metabolismo , Células Fotorreceptoras de Invertebrados/metabolismo , Células Fotorreceptoras de Invertebrados/efectos de la radiación , Receptores Colinérgicos/metabolismo , Receptores Histamínicos/metabolismo , Percepción Visual/fisiología , Percepción Visual/efectos de la radiaciónRESUMEN
Passive administration of HIV neutralizing antibodies (nAbs) can protect macaques from hard-to-neutralize (tier 2) chimeric simian-human immunodeficiency virus (SHIV) challenge. However, conditions for nAb-mediated protection after vaccination have not been established. Here, we selected groups of 6 rhesus macaques with either high or low serum nAb titers from a total of 78 animals immunized with recombinant native-like (SOSIP) Env trimers. Repeat intrarectal challenge with homologous tier 2 SHIVBG505 led to rapid infection in unimmunized and low-titer animals. High-titer animals, however, demonstrated protection that was gradually lost as nAb titers waned over time. An autologous serum ID50 nAb titer of â¼1:500 afforded more than 90% protection from medium-dose SHIV infection. In contrast, antibody-dependent cellular cytotoxicity and T cell activity did not correlate with protection. Therefore, Env protein-based vaccination strategies can protect against hard-to-neutralize SHIV challenge in rhesus macaques by inducing tier 2 nAbs, provided appropriate neutralizing titers can be reached and maintained.
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Vacunas contra el SIDA/inmunología , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/inmunología , VIH/fisiología , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Virus de la Inmunodeficiencia de los Simios/fisiología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Animales , Anticuerpos Neutralizantes/inmunología , Humanos , Macaca mulatta , VacunaciónRESUMEN
Thermal insulation under extreme conditions requires materials that can withstand complex thermomechanical stress and retain excellent thermal insulation properties at temperatures exceeding 1,000 degrees Celsius1-3. Ceramic aerogels are attractive thermal insulating materials; however, at very high temperatures, they often show considerably increased thermal conductivity and limited thermomechanical stability that can lead to catastrophic failure4-6. Here we report a multiscale design of hypocrystalline zircon nanofibrous aerogels with a zig-zag architecture that leads to exceptional thermomechanical stability and ultralow thermal conductivity at high temperatures. The aerogels show a near-zero Poisson's ratio (3.3 × 10-4) and a near-zero thermal expansion coefficient (1.2 × 10-7 per degree Celsius), which ensures excellent structural flexibility and thermomechanical properties. They show high thermal stability with ultralow strength degradation (less than 1 per cent) after sharp thermal shocks, and a high working temperature (up to 1,300 degrees Celsius). By deliberately entrapping residue carbon species in the constituent hypocrystalline zircon fibres, we substantially reduce the thermal radiation heat transfer and achieve one of the lowest high-temperature thermal conductivities among ceramic aerogels so far-104 milliwatts per metre per kelvin at 1,000 degrees Celsius. The combined thermomechanical and thermal insulating properties offer an attractive material system for robust thermal insulation under extreme conditions.
RESUMEN
The maintenance of appropriate arterial tone is critically important for normal physiological arterial function. However, the cellular and molecular mechanisms remain poorly defined. Here, we have shown that in the mouse aorta, resident macrophages prevented arterial stiffness and collagen deposition in the steady state. Using phenotyping, transcriptional profiling, and targeted deletion of Csf1r, we have demonstrated that these macrophages-which are a feature of blood vessels invested with smooth muscle cells (SMCs) in both mouse and human tissues-expressed the hyaluronan (HA) receptor LYVE-l. Furthermore, we have shown they possessed the unique ability to modulate collagen expression in SMCs by matrix metalloproteinase MMP-9-dependent proteolysis through engagement of LYVE-1 with the HA pericellular matrix of SMCs. Our study has unveiled a hitherto unknown homeostatic contribution of arterial LYVE-1+ macrophages through the control of collagen production by SMCs and has identified a function of LYVE-1 in leukocytes.
Asunto(s)
Colágeno/metabolismo , Glicoproteínas/metabolismo , Receptores de Hialuranos/metabolismo , Macrófagos/metabolismo , Músculo Liso Vascular/citología , Miocitos del Músculo Liso/metabolismo , Rigidez Vascular/fisiología , Animales , Aorta/fisiología , Femenino , Glicoproteínas/genética , Humanos , Ácido Hialurónico/metabolismo , Masculino , Metaloproteinasa 9 de la Matriz/metabolismo , Proteínas de Transporte de Membrana , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores de Factor Estimulante de Colonias de Granulocitos y Macrófagos/genéticaRESUMEN
Mare volcanics on the Moon are the key record of thermo-chemical evolution throughout most of lunar history1-3. Young mare basalts-mainly distributed in a region rich in potassium, rare-earth elements and phosphorus (KREEP) in Oceanus Procellarum, called the Procellarum KREEP Terrane (PKT)4-were thought to be formed from KREEP-rich sources at depth5-7. However, this hypothesis has not been tested with young basalts from the PKT. Here we present a petrological and geochemical study of the basalt clasts from the PKT returned by the Chang'e-5 mission8. These two-billion-year-old basalts are the youngest lunar samples reported so far9. Bulk rock compositions have moderate titanium and high iron contents with KREEP-like rare-earth-element and high thorium concentrations. However, strontium-neodymium isotopes indicate that these basalts were derived from a non-KREEP mantle source. To produce the high abundances of rare-earth elements and thorium, low-degree partial melting and extensive fractional crystallization are required. Our results indicate that the KREEP association may not be a prerequisite for young mare volcanism. Absolving the need to invoke heat-producing elements in their source implies a more sustained cooling history of the lunar interior to generate the Moon's youngest melts.
RESUMEN
Aberrant expression of programmed death ligand-1 (PD-L1) in tumor cells promotes cancer progression by suppressing cancer immunity. The retinoblastoma protein RB is a tumor suppressor known to regulate the cell cycle, DNA damage response, and differentiation. Here, we demonstrate that RB interacts with nuclear factor κB (NF-κB) protein p65 and that their interaction is primarily dependent on CDK4/6-mediated serine-249/threonine-252 (S249/T252) phosphorylation of RB. RNA-seq analysis shows a subset of NF-κB pathway genes including PD-L1 are selectively upregulated by RB knockdown or CDK4/6 inhibitor. S249/T252-phosphorylated RB inversely correlates with PD-L1 expression in patient samples. Expression of a RB-derived S249/T252 phosphorylation-mimetic peptide suppresses radiotherapy-induced upregulation of PD-L1 and augments therapeutic efficacy of radiation in vivo. Our findings reveal a previously unrecognized tumor suppressor function of hyperphosphorylated RB in suppressing NF-κB activity and PD-L1 expression and suggest that the RB-NF-κB axis can be exploited to overcome cancer immune evasion triggered by conventional or targeted therapies.
Asunto(s)
Antígeno B7-H1/metabolismo , Neoplasias de la Próstata/metabolismo , Proteína de Retinoblastoma/metabolismo , Factor de Transcripción ReIA/metabolismo , Escape del Tumor , Animales , Antineoplásicos Inmunológicos/farmacología , Antígeno B7-H1/antagonistas & inhibidores , Antígeno B7-H1/genética , Antígeno B7-H1/inmunología , Quimioradioterapia/métodos , Quinasa 4 Dependiente de la Ciclina/metabolismo , Quinasa 6 Dependiente de la Ciclina/metabolismo , Regulación Neoplásica de la Expresión Génica , Células HEK293 , Humanos , Masculino , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Ratones Noqueados , Ratones SCID , Células PC-3 , Fosforilación , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/inmunología , Neoplasias de la Próstata/terapia , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Tolerancia a Radiación , Proteína de Retinoblastoma/genética , Proteína de Retinoblastoma/inmunología , Transducción de Señal , Factor de Transcripción ReIA/genética , Factor de Transcripción ReIA/inmunología , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Stable matching of neurotransmitters with their receptors is fundamental to synapse function and reliable communication in neural circuits. Presynaptic neurotransmitters regulate the stabilization of postsynaptic transmitter receptors. Whether postsynaptic receptors regulate stabilization of presynaptic transmitters has received less attention. Here, we show that blockade of endogenous postsynaptic acetylcholine receptors (AChR) at the neuromuscular junction destabilizes the cholinergic phenotype in motor neurons and stabilizes an earlier, developmentally transient glutamatergic phenotype. Further, expression of exogenous postsynaptic gamma-aminobutyric acid type A receptors (GABAA receptors) in muscle cells stabilizes an earlier, developmentally transient GABAergic motor neuron phenotype. Both AChR and GABAA receptors are linked to presynaptic neurons through transsynaptic bridges. Knockdown of specific components of these transsynaptic bridges prevents stabilization of the cholinergic or GABAergic phenotypes. Bidirectional communication can enforce a match between transmitter and receptor and ensure the fidelity of synaptic transmission. Our findings suggest a potential role of dysfunctional transmitter receptors in neurological disorders that involve the loss of the presynaptic transmitter.
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Receptores Colinérgicos , Sinapsis , Sinapsis/metabolismo , Receptores Colinérgicos/metabolismo , Transmisión Sináptica/fisiología , Neuronas Motoras/metabolismo , Receptores de GABA-A/metabolismo , Ácido gamma-Aminobutírico/metabolismo , Neurotransmisores/metabolismo , Colinérgicos , Receptores PresinapticosRESUMEN
All respiratory viruses establish primary infections in the nasal epithelium, where efficient innate immune induction may prevent dissemination to the lower airway and thus minimize pathogenesis. Human coronaviruses (HCoVs) cause a range of pathologies, but the host and viral determinants of disease during common cold versus lethal HCoV infections are poorly understood. We model the initial site of infection using primary nasal epithelial cells cultured at an air-liquid interface (ALI). HCoV-229E, HCoV-NL63, and human rhinovirus-16 are common cold-associated viruses that exhibit unique features in this model: early induction of antiviral interferon (IFN) signaling, IFN-mediated viral clearance, and preferential replication at nasal airway temperature (33 °C) which confers muted host IFN responses. In contrast, lethal SARS-CoV-2 and MERS-CoV encode antagonist proteins that prevent IFN-mediated clearance in nasal cultures. Our study identifies features shared among common cold-associated viruses, highlighting nasal innate immune responses as predictive of infection outcomes and nasally directed IFNs as potential therapeutics.