RESUMEN
Fungal airway infection (airway mycosis) is an important cause of allergic airway diseases such as asthma, but the mechanisms by which fungi trigger asthmatic reactions are poorly understood. Here, we leverage wild-type and mutant Candida albicans to determine how this common fungus elicits characteristic Th2 and Th17 cell-dependent allergic airway disease in mice. We demonstrate that rather than proteinases that are essential virulence factors for molds, C. albicans instead promoted allergic airway disease through the peptide toxin candidalysin. Candidalysin activated platelets through the Von Willebrand factor (VWF) receptor GP1bα to release the Wnt antagonist Dickkopf-1 (Dkk-1) to drive Th2 and Th17 cell responses that correlated with reduced lung fungal burdens. Platelets simultaneously precluded lethal pulmonary hemorrhage resulting from fungal lung invasion. Thus, in addition to hemostasis, platelets promoted protection against C. albicans airway mycosis through an antifungal pathway involving candidalysin, GP1bα, and Dkk-1 that promotes Th2 and Th17 responses.
Asunto(s)
Plaquetas/inmunología , Candida albicans/fisiología , Candidiasis/complicaciones , Candidiasis/inmunología , Susceptibilidad a Enfermedades , Interacciones Huésped-Patógeno/inmunología , Hipersensibilidad/complicaciones , Hipersensibilidad/inmunología , Subgrupos de Linfocitos T/inmunología , Plaquetas/metabolismo , Hipersensibilidad/metabolismo , Activación de Linfocitos/inmunología , Subgrupos de Linfocitos T/metabolismo , Células Th17/inmunología , Células Th17/metabolismo , Células Th2/inmunología , Células Th2/metabolismoRESUMEN
Hershey and Chase used bacteriophage T2 genome delivery inside Escherichia coli to demonstrate that DNA, not protein, is the genetic material. Seventy years later, our understanding of viral genome delivery in prokaryotes remains limited, especially for short-tailed phages of the Podoviridae family. These viruses expel mysterious ejection proteins found inside the capsid to form a DNA-ejectosome for genome delivery into bacteria. Here, we reconstitute the phage T7 DNA-ejectosome components gp14, gp15, and gp16 and solve the periplasmic tunnel structure at 2.7 Å resolution. We find that gp14 forms an outer membrane pore, gp15 assembles into a 210 Å hexameric DNA tube spanning the host periplasm, and gp16 extends into the host cytoplasm forming a â¼4,200 residue hub. Gp16 promotes gp15 oligomerization, coordinating peptidoglycan hydrolysis, DNA binding, and lipid insertion. The reconstituted gp15:gp16 complex lacks channel-forming activity, suggesting that the pore for DNA passage forms only transiently during genome ejection.
Asunto(s)
Bacteriófago T7/genética , ADN Viral/química , Periplasma/química , Proteínas del Núcleo Viral/química , Biología Computacional , Microscopía por Crioelectrón , Citoplasma/química , ADN Viral/metabolismo , Membrana Dobles de Lípidos/metabolismo , Periplasma/genética , Periplasma/metabolismo , Podoviridae/química , Podoviridae/genética , Proteínas del Núcleo Viral/metabolismoRESUMEN
Interleukin-6 (IL-6) is a pleiotropic cytokine with roles in immunity, tissue regeneration, and metabolism. Rapid production of IL-6 contributes to host defense during infection and tissue injury, but excessive synthesis of IL-6 and dysregulation of IL-6 receptor signaling is involved in disease pathology. Therapeutic agents targeting the IL-6 axis are effective in rheumatoid arthritis, and applications are being extended to other settings of acute and chronic inflammation. Recent studies reveal that selective blockade of different modes of IL-6 receptor signaling has different outcomes on disease pathology, suggesting novel strategies for therapeutic intervention. However, some inflammatory diseases do not seem to respond to IL-6 blockade. Here, we review the current state of IL-6-targeting approaches in the clinic and discuss how to apply the growing understanding of the immunobiology of IL-6 to clinical decisions.
Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Inflamación/tratamiento farmacológico , Interleucina-6/antagonistas & inhibidores , Terapia Molecular Dirigida , Transducción de Señal/efectos de los fármacos , Animales , Anticuerpos Monoclonales/inmunología , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/inmunología , Ensayos Clínicos como Asunto , Receptor gp130 de Citocinas/antagonistas & inhibidores , Receptor gp130 de Citocinas/inmunología , Humanos , Inflamación/inmunología , Interleucina-6/biosíntesis , Interleucina-6/deficiencia , Interleucina-6/inmunología , Quinasas Janus/antagonistas & inhibidores , Quinasas Janus/fisiología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Ratones , Ratones Noqueados , Receptores de Interleucina-6/inmunología , Ribonucleasas/deficiencia , Factor de Transcripción STAT3/fisiología , Proteína 1 Supresora de la Señalización de Citocinas/fisiología , Proteína 3 Supresora de la Señalización de Citocinas/fisiologíaRESUMEN
HIV- and SIV-envelope (Env) trimers are both extensively glycosylated, and antibodies identified to date have been unable to fully neutralize SIVmac239. Here, we report the isolation, structure, and glycan interactions of antibody ITS90.03, a monoclonal antibody that completely neutralized the highly neutralization-resistant isolate, SIVmac239. The co-crystal structure of a fully glycosylated SIVmac239-gp120 core in complex with rhesus CD4 and the antigen-binding fragment of ITS90.03 at 2.5-Å resolution revealed that ITS90 recognized an epitope comprised of 45% glycan. SIV-gp120 core, rhesus CD4, and their complex could each be aligned structurally to their human counterparts. The structure revealed that glycans masked most of the SIV Env protein surface, with ITS90 targeting a glycan hole, which is occupied in â¼83% of SIV strains by glycan N238. Overall, the SIV glycan shield appears to functionally resemble its HIV counterpart in coverage of spike, shielding from antibody, and modulation of receptor accessibility.
Asunto(s)
Anticuerpos Monoclonales/química , Anticuerpos Neutralizantes/química , Infecciones por VIH/inmunología , VIH/fisiología , Polisacáridos/química , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Virus de la Inmunodeficiencia de los Simios/fisiología , Animales , Anticuerpos Monoclonales/aislamiento & purificación , Anticuerpos Monoclonales/metabolismo , Anticuerpos Neutralizantes/aislamiento & purificación , Anticuerpos Neutralizantes/metabolismo , Antígenos CD4/metabolismo , Células Cultivadas , Cristalización , Cristalografía por Rayos X , Modelos Animales de Enfermedad , Glicosilación , Anticuerpos Anti-VIH/inmunología , Anticuerpos Anti-VIH/metabolismo , Proteína gp120 de Envoltorio del VIH/metabolismo , Humanos , Macaca mulatta , Glicoproteínas de Membrana/metabolismo , Polisacáridos/metabolismo , Unión Proteica , Relación Estructura-Actividad , Proteínas del Envoltorio Viral/metabolismoRESUMEN
Elevated endogenous retrovirus (ERV) transcription and anti-ERV antibody reactivity are implicated in lupus pathogenesis. Overproduction of non-ecotropic ERV (NEERV) envelope glycoprotein gp70 and resultant nephritis occur in lupus-prone mice, but whether NEERV mis-expression contributes to lupus etiology is unclear. Here we identified suppressor of NEERV (Snerv) 1 and 2, Krüppel-associated box zinc-finger proteins (KRAB-ZFPs) that repressed NEERV by binding the NEERV long terminal repeat to recruit the transcriptional regulator KAP1. Germline Snerv1/Snerv2 deletion increased activating chromatin modifications, transcription, and gp70 expression from NEERV loci. F1 crosses of lupus-prone New Zealand Black (NZB) and 129 mice to Snerv1/Snerv2-/- mice failed to restore NEERV repression, demonstrating that loss of SNERV underlies the lupus autoantigen gp70 overproduction that promotes nephritis in susceptible mice and that SNERV encodes for Sgp3 (in NZB mice) and Gv-1 loci (in 129 mice). Increased ERV expression in lupus patients inversely correlated with three putative ERV-suppressing KRAB-ZFPs, suggesting that loss of KRAB-ZFP-mediated ERV control may contribute to human lupus pathogenesis.
Asunto(s)
Proteínas Portadoras/inmunología , Retrovirus Endógenos/inmunología , Glicoproteínas/inmunología , Nefritis Lúpica/inmunología , Chaperonas Moleculares/inmunología , Proteínas Nucleares/inmunología , Proteínas Represoras/inmunología , Animales , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Retrovirus Endógenos/genética , Retrovirus Endógenos/metabolismo , Regulación de la Expresión Génica/inmunología , Predisposición Genética a la Enfermedad/genética , Glicoproteínas/genética , Glicoproteínas/metabolismo , Células HEK293 , Humanos , Lupus Eritematoso Sistémico/genética , Lupus Eritematoso Sistémico/inmunología , Lupus Eritematoso Sistémico/metabolismo , Nefritis Lúpica/genética , Nefritis Lúpica/metabolismo , Ratones , Ratones de la Cepa 129 , Ratones Endogámicos C57BL , Ratones Endogámicos NZB , Ratones Noqueados , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismoRESUMEN
CCR5 is the primary chemokine receptor utilized by HIV to infect leukocytes, whereas CCR5 ligands inhibit infection by blocking CCR5 engagement with HIV gp120. To guide the design of improved therapeutics, we solved the structure of CCR5 in complex with chemokine antagonist [5P7]CCL5. Several structural features appeared to contribute to the anti-HIV potency of [5P7]CCL5, including the distinct chemokine orientation relative to the receptor, the near-complete occupancy of the receptor binding pocket, the dense network of intermolecular hydrogen bonds, and the similarity of binding determinants with the FDA-approved HIV inhibitor Maraviroc. Molecular modeling indicated that HIV gp120 mimicked the chemokine interaction with CCR5, providing an explanation for the ability of CCR5 to recognize diverse ligands and gp120 variants. Our findings reveal that structural plasticity facilitates receptor-chemokine specificity and enables exploitation by HIV, and provide insight into the design of small molecule and protein inhibitors for HIV and other CCR5-mediated diseases.
Asunto(s)
Quimiocina CCL5/química , Proteína gp120 de Envoltorio del VIH/química , Infecciones por VIH/inmunología , VIH-1/fisiología , Modelos Moleculares , Imitación Molecular , Receptores CCR5/química , Animales , Antagonistas de los Receptores CCR5/química , Antagonistas de los Receptores CCR5/farmacología , Quimiocina CCL5/metabolismo , Clonación Molecular , Cristalografía por Rayos X , Ciclohexanos/química , Ciclohexanos/farmacología , Proteína gp120 de Envoltorio del VIH/metabolismo , Inhibidores de Fusión de VIH/química , Infecciones por VIH/tratamiento farmacológico , Humanos , Maraviroc , Unión Proteica , Conformación Proteica , Receptores CCR5/metabolismo , Células Sf9 , Spodoptera , Relación Estructura-Actividad , Triazoles/química , Triazoles/farmacología , Internalización del Virus/efectos de los fármacosRESUMEN
Binding to the host cell receptors, CD4 and CCR5/CXCR4, triggers large-scale conformational changes in the HIV-1 envelope glycoprotein (Env) trimer [(gp120/gp41)3] that promote virus entry into the cell. CD4-mimetic compounds (CD4mcs) comprise small organic molecules that bind in the highly conserved CD4-binding site of gp120 and prematurely induce inactivating Env conformational changes, including shedding of gp120 from the Env trimer. By inducing more "open," antibody-susceptible Env conformations, CD4mcs also sensitize HIV-1 virions to neutralization by antibodies and infected cells to antibody-dependent cellular cytotoxicity (ADCC). Here, we report the design, synthesis, and evaluation of novel CD4mcs based on an indoline scaffold. Compared with our current lead indane scaffold CD4mc, BNM-III-170, several indoline CD4mcs exhibit increased potency and breadth against HIV-1 variants from different geographic clades. Viruses that were selected for resistance to the lead indane CD4mc, BNM-III-170, are susceptible to inhibition by the indoline CD4mcs. The indoline CD4mcs also potently sensitize HIV-1-infected cells to ADCC mediated by plasma from HIV-1-infected individuals. Crystal structures indicate that the indoline CD4mcs gain potency compared to the indane CD4mcs through more favorable π-π overlap from the indoline pose and by making favorable contacts with the vestibule of the CD4-binding pocket on gp120. The rational design of indoline CD4mcs thus holds promise for further improvements in antiviral activity, potentially contributing to efforts to treat and prevent HIV-1 infection.
Asunto(s)
Infecciones por VIH , Seropositividad para VIH , VIH-1 , Humanos , Citotoxicidad Celular Dependiente de Anticuerpos , Proteína gp120 de Envoltorio del VIH , Antígenos CD4/metabolismo , Anticuerpos Anti-VIH/farmacologíaRESUMEN
Ciliary neurotrophic factor (CNTF) activates cells via the non-signaling α-receptor CNTF receptor (CNTFR) and the two signaling ß-receptors glycoprotein 130 (gp130) and leukemia inhibitory factor receptor (LIFR). The CNTF derivate, Axokine, was protective against obesity and insulin resistance, but clinical development was halted by the emergence of CNTF antibodies. The chimeric cytokine IC7 used the framework of interleukin (IL-)6 with the LIFR-binding site from CNTF to activate cells via IL-6R:gp130:LIFR complexes. Similar to CNTF/Axokine, IC7 protected mice from obesity and insulin resistance. Here, we developed CNTF-independent chimeras that specifically target the IL-6R:gp130:LIFR complex. In GIL-6 and GIO-6, we transferred the LIFR binding site from LIF or OSM to IL-6, respectively. While GIO-6 signals via gp130:IL-6R:LIFR and gp130:IL-6R:OSMR complexes, GIL-6 selectively activates the IL-6R:gp130:LIFR receptor complex. By re-evaluation of IC7 and CNTF, we discovered the Oncostatin M receptor (OSMR) as an alternative non-canonical high-affinity receptor leading to IL-6R:OSMR:gp130 and CNTFR:OSMR:gp130 receptor complexes, respectively. The discovery of OSMR as an alternative high-affinity receptor for IC7 and CNTF designates GIL-6 as the first truly selective IL-6R:gp130:LIFR cytokine, whereas GIO-6 is a CNTF-free alternative for IC7.
Asunto(s)
Factor Neurotrófico Ciliar , Receptor gp130 de Citocinas , Interleucina-6 , Transducción de Señal , Animales , Humanos , Ratones , Factor Neurotrófico Ciliar/metabolismo , Factor Neurotrófico Ciliar/genética , Receptor gp130 de Citocinas/metabolismo , Receptor gp130 de Citocinas/genética , Interleucina-6/metabolismo , Interleucina-6/genética , Subunidad alfa del Receptor del Factor Inhibidor de Leucemia/metabolismo , Subunidad alfa del Receptor del Factor Inhibidor de Leucemia/genética , Modelos Moleculares , Ingeniería de Proteínas/métodos , Estructura Terciaria de Proteína , Receptores de Interleucina-6/metabolismo , Receptores de Interleucina-6/genética , Receptores OSM-LIF/metabolismo , Receptores OSM-LIF/genética , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Recombinantes de Fusión/genética , Ratones Endogámicos C57BLRESUMEN
Metalloprotease-gp63 is a virulence factor secreted by Leishmania. However, secretory pathway in Leishmania is not well defined. Here, we cloned and expressed the GRASP homolog from Leishmania. We found that Leishmania expresses one GRASP homolog of 58 kDa protein (LdGRASP) which localizes in LdRab1- and LPG2-positive Golgi compartment in Leishmania. LdGRASP was found to bind with COPII complex, LdARF1, LdRab1 and LdRab11 indicating its role in ER and Golgi transport in Leishmania. To determine the function of LdGRASP, we generated LdGRASP knockout parasites using CRISPR-Cas9. We found fragmentation of Golgi in Ld:GRASPKO parasites. Our results showed enhanced transport of non-GPI-anchored gp63 to the cell surface leading to higher secretion of this form of gp63 in Ld:GRASPKO parasites in comparison to Ld:WT cells. In contrast, we found that transport of GPI-anchored gp63 to the cell surface is blocked in Ld:GRASPKO parasites and thereby inhibits its secretion. The overexpression of dominant-negative mutant of LdRab1 or LdSar1 in Ld:GRASPKO parasites significantly blocked the secretion of non-GPI-anchored gp63. Interestingly, we found that survival of transgenic parasites overexpressing Ld:GRASP-GFP is significantly compromised in macrophages in comparison to Ld:WT and Ld:GRASPKO parasites. These results demonstrated that LdGRASP differentially regulates Ldgp63 secretory pathway in Leishmania.
Asunto(s)
Leishmania , Metaloendopeptidasas , Proteínas Protozoarias , Factores de Virulencia , Animales , Sistemas CRISPR-Cas , Retículo Endoplásmico/metabolismo , Aparato de Golgi/metabolismo , Proteínas de la Matriz de Golgi/metabolismo , Proteínas de la Matriz de Golgi/genética , Leishmania/metabolismo , Leishmania/genética , Macrófagos/parasitología , Macrófagos/metabolismo , Metaloendopeptidasas/metabolismo , Metaloendopeptidasas/genética , Transporte de Proteínas , Proteínas Protozoarias/metabolismo , Proteínas Protozoarias/genética , Factores de Virulencia/metabolismo , Factores de Virulencia/genéticaRESUMEN
Nucleoside-modified mRNA technology has revolutionized vaccine development with the success of mRNA COVID-19 vaccines. We used modified mRNA technology for the design of envelopes (Env) to induce HIV-1 broadly neutralizing antibodies (bnAbs). However, unlike SARS-CoV-2 neutralizing antibodies that are readily made, HIV-1 bnAb induction is disfavored by the immune system because of the rarity of bnAb B cell precursors and the cross-reactivity of bnAbs targeting certain Env epitopes with host molecules, thus requiring optimized immunogen design. The use of protein nanoparticles (NPs) has been reported to enhance B cell germinal center responses to HIV-1 Env. Here, we report our experience with the expression of Env-ferritin NPs compared with membrane-bound Env gp160 when encoded by modified mRNA. We found that well-folded Env-ferritin NPs were a minority of the protein expressed by an mRNA design and were immunogenic at 20 µg but minimally immunogenic in mice at 1 µg dose in vivo and were not expressed well in draining lymph nodes (LNs) following intramuscular immunization. In contrast, mRNA encoding gp160 was more immunogenic than mRNA encoding Env-NP at 1 µg dose and was expressed well in draining LN following intramuscular immunization. Thus, analysis of mRNA expression in vitro and immunogenicity at low doses in vivo are critical for the evaluation of mRNA designs for optimal immunogenicity of HIV-1 immunogens.IMPORTANCEAn effective HIV-1 vaccine that induces protective antibody responses remains elusive. We have used mRNA technology for designs of HIV-1 immunogens in the forms of membrane-bound full-length envelope gp160 and envelope ferritin nanoparticle. Here, we demonstrated in a mouse model that the membrane-bound form induced a better response than envelope ferritin nanoparticle because of higher in vivo protein expression. The significance of our research is in highlighting the importance of analysis of mRNA design expression and low-dose immunogenicity studies for HIV-1 immunogens before moving to vaccine clinical trials.
RESUMEN
Ebola virus disease (EVD) caused by Ebola virus (EBOV) is a severe, often fatal, hemorrhagic disease. A critical component of the public health response to curb EVD epidemics is the use of a replication-competent, recombinant vesicular stomatitis virus (rVSV)-vectored Ebola vaccine, rVSVΔG-ZEBOV-GP (ERVEBO). In this Gem, we will discuss the past and ongoing development of rVSVΔG-ZEBOV-GP, highlighting the importance of basic science and the strength of public-private partnerships to translate fundamental virology into a licensed VSV-vectored Ebola vaccine.
Asunto(s)
Vacunas contra el Virus del Ébola , Ebolavirus , Vectores Genéticos , Fiebre Hemorrágica Ebola , Vesiculovirus , Humanos , Vacunas contra el Virus del Ébola/genética , Vacunas contra el Virus del Ébola/inmunología , Ebolavirus/genética , Ebolavirus/inmunología , Vectores Genéticos/genética , Fiebre Hemorrágica Ebola/inmunología , Fiebre Hemorrágica Ebola/prevención & control , Vesiculovirus/genética , Asociación entre el Sector Público-PrivadoRESUMEN
Systemic viral infection of insects typically begins with the primary infection of midgut epithelial cells (enterocytes) and subsequent transit of the progeny virus in an apical-to-basal orientation into the hemocoel. For insect-vectored viruses, an oppositely oriented process (basal-to-apical transit) occurs upon secondary infection of salivary glands and is necessary for virus transmission to non-insect hosts. To examine this inversely oriented virus transit in these polarized tissues, we assessed the intracellular trafficking of two model viral envelope proteins (baculovirus GP64 and vesicular stomatitis virus G) in the midgut and salivary gland cells of the model insect, Drosophila melanogaster. Using fly lines that inducibly express either GP64 or VSV G, we found that each protein, expressed alone, was trafficked basally in midgut enterocytes. In salivary gland cells, VSV G was trafficked apically in most but not all cells, whereas GP64 was consistently trafficked basally. We demonstrated that a YxxØ motif present in both proteins was critical for basal trafficking in midgut enterocytes but dispensable for trafficking in salivary gland cells. Using RNAi, we found that clathrin adaptor protein complexes AP-1 and AP-3, as well as seven Rab GTPases, were involved in polarized VSV G trafficking in midgut enterocytes. Our results indicate that these viral envelope proteins encode the requisite information and require no other viral factors for appropriately polarized trafficking. In addition, they exploit tissue-specific differences in protein trafficking pathways to facilitate virus egress in the appropriate orientation for establishing systemic infections and vectoring infection to other hosts. IMPORTANCE: Viruses that use insects as hosts must navigate specific routes through different insect tissues to complete their life cycles. The routes may differ substantially depending on the life cycle of the virus. Both insect pathogenic viruses and insect-vectored viruses must navigate through the polarized cells of the midgut epithelium to establish a systemic infection. In addition, insect-vectored viruses must also navigate through the polarized salivary gland epithelium for transmission. Thus, insect-vectored viruses appear to traffic in opposite directions in these two tissues. In this study, we asked whether two viral envelope proteins (VSV G and baculovirus GP64) alone encode the signals necessary for the polarized trafficking associated with their respective life cycles. Using Drosophila as a model to examine tissue-specific polarized trafficking of these viral envelope proteins, we identified one of the virus-encoded signals and several host proteins associated with regulating the polarized trafficking in the midgut epithelium.
RESUMEN
VRC01-class antibodies neutralize diverse HIV-1 strains by targeting the conserved CD4-binding site. Despite extensive investigations, crucial events in the early stage of VRC01 development remain elusive. We demonstrated how VRC01-class antibodies emerged in a Chinese donor by antigen-specific single B cell sorting, structural and functional studies, and longitudinal antibody and virus repertoire analyses. A monoclonal antibody DRVIA7 with modest neutralizing breadth was isolated that displayed a subset of VRC01 signatures. X-ray and EM structures revealed a VRC01-like angle of approach, but less favorable interactions between the DRVIA7 light-chain CDR1 and the N terminus with N276 and V5 glycans of gp120. Although the DRVIA7 lineage was unable to acquire broad neutralization, longitudinal analysis revealed a repertoire-encoded VRC01 light-chain CDR3 signature and VRC01-like neutralizing heavy-chain precursors that rapidly matured within 2 years. Thus, light chain accommodation of the glycan shield should be taken into account in vaccine design targeting this conserved site of vulnerability.
Asunto(s)
Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/inmunología , Sitios de Unión de Anticuerpos/inmunología , Anticuerpos Anti-VIH/inmunología , Proteína gp120 de Envoltorio del VIH/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Secuencia de Aminoácidos , Anticuerpos ampliamente neutralizantes , Linfocitos T CD4-Positivos/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Humanos , Datos de Secuencia MolecularRESUMEN
The architectural protein histone-like protein from Escherichia coli strain U93 (HU) is the most abundant bacterial DNA binding protein and highly conserved among bacteria and Apicomplexan parasites. It not only binds to double-stranded DNA (dsDNA) to maintain DNA stability but also, interacts with RNAs to regulate transcription and translation. Importantly, HU is essential to cell viability for many bacteria; hence, it is an important antibiotic target. Here, we report that Gp46 from bacteriophage SPO1 of Bacillus subtilis is an HU inhibitor whose expression prevents nucleoid segregation and causes filamentous morphology and growth defects in bacteria. We determined the solution structure of Gp46 and revealed a striking negatively charged surface. An NMR-derived structural model for the Gp46-HU complex shows that Gp46 occupies the DNA binding motif of the HU and therefore, occludes DNA binding, revealing a distinct strategy for HU inhibition. We identified the key residues responsible for the interaction that are conserved among HUs of bacteria and Apicomplexans, including clinically significant Mycobacterium tuberculosis, Acinetobacter baumannii, and Plasmodium falciparum, and confirm that Gp46 can also interact with these HUs. Our findings provide detailed insight into a mode of HU inhibition that provides a useful foundation for the development of antibacteria and antimalaria drugs.
Asunto(s)
Proteínas Bacterianas/antagonistas & inhibidores , Bacteriófagos/metabolismo , Proteínas de Unión al ADN/antagonistas & inhibidores , Glicoproteínas/metabolismo , Proteínas Virales/metabolismo , Proteínas Bacterianas/metabolismo , ADN/metabolismo , Proteínas de Unión al ADN/metabolismo , Unión ProteicaRESUMEN
Bacteriophage T7 gp4 helicase has served as a model system for understanding mechanisms of hexameric replicative helicase translocation. The mechanistic basis of how nucleoside 5'-triphosphate hydrolysis and translocation of gp4 helicase are coupled is not fully resolved. Here, we used a thermodynamically benchmarked coarse-grained protein force field, Associative memory, Water mediated, Structure and Energy Model (AWSEM), with the single-stranded DNA (ssDNA) force field 3SPN.2C to investigate gp4 translocation. We found that the adenosine 5'-triphosphate (ATP) at the subunit interface stabilizes the subunit-subunit interaction and inhibits subunit translocation. Hydrolysis of ATP to adenosine 5'-diphosphate enables the translocation of one subunit, and new ATP binding at the new subunit interface finalizes the subunit translocation. The LoopD2 and the N-terminal primase domain provide transient protein-protein and protein-DNA interactions that facilitate the large-scale subunit movement. The simulations of gp4 helicase both validate our coarse-grained protein-ssDNA force field and elucidate the molecular basis of replicative helicase translocation.
Asunto(s)
Bacteriófago T7 , ADN Helicasas , ADN de Cadena Simple , Adenosina Difosfato/metabolismo , Adenosina Trifosfato/metabolismo , Bacteriófago T7/enzimología , Bacteriófago T7/genética , ADN Helicasas/metabolismo , ADN Primasa/metabolismo , Conformación ProteicaRESUMEN
Despite more than 300,000 rVSVΔG-ZEBOV-glycoprotein (GP) vaccine doses having been administered during Ebola virus disease (EVD) outbreaks in the Democratic Republic of the Congo (DRC) between 2018 and 2020, seroepidemiologic studies of vaccinated Congolese populations are lacking. This study examines the antibody response at 21 d and 6 mo postvaccination after single-dose rVSVΔG-ZEBOV-GP vaccination among EVD-exposed and potentially exposed populations in the DRC. We conducted a longitudinal cohort study of 608 rVSVΔG-ZEBOV-GP-vaccinated individuals during an EVD outbreak in North Kivu Province, DRC. Participants provided questionnaires and blood samples at three study visits (day 0, visit 1; day 21, visit 2; and month 6, visit 3). Anti-GP immunoglobulin G (IgG) antibody titers were measured in serum by the Filovirus Animal Nonclinical Group anti-Ebola virus GP IgG enzyme-linked immunosorbent assay. Antibody response was defined as an antibody titer that had increased fourfold from visit 1 to visit 2 and was above four times the lower limit of quantification at visit 2; antibody persistence was defined as a similar increase from visit 1 to visit 3. We then examined demographics for associations with follow-up antibody titers using generalized linear mixed models. A majority of the sample, 87.2%, had an antibody response at visit 2, and 95.6% demonstrated antibody persistence at visit 3. Being female and of young age was predictive of a higher antibody titer postvaccination. Antibody response and persistence after Ebola vaccination was robust in this cohort, confirming findings from outside of the DRC.
Asunto(s)
Vacunas contra el Virus del Ébola/inmunología , Ebolavirus/inmunología , Fiebre Hemorrágica Ebola/inmunología , Inmunogenicidad Vacunal/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Antivirales/inmunología , Niño , República Democrática del Congo , Brotes de Enfermedades/prevención & control , Femenino , Glicoproteínas/inmunología , Humanos , Masculino , Persona de Mediana Edad , Estudios Seroepidemiológicos , Vacunación/métodos , Proteínas del Envoltorio Viral/inmunología , Adulto JovenRESUMEN
BACKGROUND AND AIMS: Glycoprotein (GP) IIb/IIIa inhibitors are recommended in acute myocardial infarction (AMI) for bailout treatment in case of angiographic microvascular obstruction (MVO), also termed no-reflow phenomenon, after percutaneous coronary intervention (PCI) with, however, lacking evidence (class IIa, level C). METHODS: The investigator-initiated, international, multicenter REVERSE-FLOW trial randomized 120 patients with AMI and Thrombolysis In Myocardial Infarction flow grade ≤2 after primary PCI to optimal medical therapy with or without GP IIb/IIIa inhibitor. The primary endpoint was infarct size (%LV) assessed by cardiac magnetic resonance (CMR). Secondary endpoints included CMR-derived MVO and 30-day adverse clinical events. The trial is registered with ClinicalTrials.gov: NCT02739711. RESULTS: The population was predominantly male (76.7%) with a median age of 66 years and ST-elevation myocardial infarction in 73.3% of patients. Clinical and angiographic characteristics were well balanced between the cohorts. Patients in the treatment group (n=62) received eptifibatide (n=41) or tirofiban (n=21). Infarct size assessed by CMR imaging was similar in both study groups (25.4% of left ventricular mass [LV] vs. 25.2%LV; p=0.386). However, the number of patients with evidence of CMR-derived MVO (74.5% vs. 92.2%; p=0.017) and the extent of MVO (2.1%LV vs. 3.4%LV; p=0.025) were significantly reduced in the GP IIb/IIIa inhibitor group compared to controls. Thirty-day outcome showed an increased bleeding risk after GP IIb/IIIa inhibitor administration restricted to non-life-threatening bleedings (22.6% vs. 6.9%; p=0.016) without differences in all-cause mortality (4.8% vs. 3.4%; p=0.703). CONCLUSIONS: Bailout GP IIb/IIIa inhibition in AMI patients with angiographic MVO failed to reduce the primary endpoint infarct size but decreased CMR-derived MVO and led to an increase in non-fatal bleeding events.
RESUMEN
Fibrous supercapacitors (SCs) are emerging promising power sources for flexible/wearable electronics and have attracted an extensive amount of attention from researchers. However, the low energy density has always hindered their further development. Here, a coaxial fibrous SC (CFSC) was fabricated by one-step wet-spinning combined with an electrodeposition strategy. Benefiting from the large surface area and abundant pore structure of carbon-modified nitrogen-doped MXene nanosheets (NS), as well as the high conductivity of silver (Ag) NS, the electrolyte ion/electron transport paths are significantly improved. Furthermore, the distributed GO in the P(VDF-HFP) separator could form a high-speed continuous ion transport channel, thus enhancing the ionic conductivity. At a power density of 40-200 µW cm-2, the CFSC shows a high energy density of 0.7-3.39 µWh cm-2. The as-prepared CFSC also maintains an excellent capacitance retention rate of 90.3% even after 15â¯000 charge-discharge cycles. This work provides a general strategy for manufacturing high-performance, flexible, and wearable SCs.
RESUMEN
Mild photothermal therapy (PTT) shows the potential for chemosensitization by tumor-localized P-glycoprotein (P-gp) modulation. However, conventional mild PTT struggles with real-time uniform temperature control, obscuring the temperature-performance relationship and resulting in thermal damage. Besides, the time-performance relationship and the underlying mechanism of mild PTT-mediated P-gp reversal remains elusive. Herein, we developed a temperature self-limiting lipid nanosystem (RFE@PD) that integrated a reversible organic heat generator (metal-phenolic complexes) and metal chelator (deferiprone, DFP) encapsulated phase change material. Upon NIR irradiation, RFE@PD released DFP for blocking ligand-metal charge transfer to self-limit temperature below 45 °C, and rapidly reduced P-gp within 3 h via Ubiquitin-proteasome degradation. Consequently, the DOX·HCl-loaded thermo-chemotherapeutic lipid nanosystem (RFE@PD-DOX) led to dramatically improved drug accumulation and 5-fold chemosensitization in MCF-7/ADR tumor models by synchronizing P-gp reversal and drug pulse liberation, achieving a tumor inhibition ratio of 82.42%. This lipid nanosystem integrated with "intrinsic temperature-control" and "temperature-responsive pulse release" casts new light on MDR tumor therapy.
Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP , Doxorrubicina , Humanos , Doxorrubicina/química , Doxorrubicina/farmacología , Doxorrubicina/administración & dosificación , Doxorrubicina/uso terapéutico , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Animales , Lípidos/química , Células MCF-7 , Terapia Fototérmica , Resistencia a Antineoplásicos/efectos de los fármacos , Ratones , Temperatura , Nanopartículas/química , Liberación de Fármacos , Antineoplásicos/química , Antineoplásicos/administración & dosificación , Antineoplásicos/farmacología , Resistencia a Múltiples Medicamentos/efectos de los fármacosRESUMEN
BACKGROUND: Chronic inflammation persists in some people living with human immunodeficiency virus (HIV) during antiretroviral therapy and is associated with premature aging. The glycoprotein 120 (gp120) subunit of HIV-1 envelope sheds and can be detected in plasma, showing immunomodulatory properties even in the absence of detectable viremia. We evaluated whether plasma soluble gp120 (sgp120) and a family of gp120-specific anti-cluster A antibodies, linked to CD4 depletion in vitro, contribute to chronic inflammation, immune dysfunction, and subclinical cardiovascular disease in participants of the Canadian HIV and Aging Cohort Study with undetectable viremia. METHODS: Cross-sectional assessment of sgp120 and anti-cluster A antibodies was performed in 386 individuals from the cohort. Their association with proinflammatory cytokines and subclinical coronary artery disease was assessed using linear regression models. RESULTS: High levels of sgp120 and anti-cluster A antibodies were inversely correlated with CD4+ T cell count and CD4/CD8 ratio. The presence of sgp120 was associated with increased levels of interleukin 6. In participants with detectable atherosclerotic plaque and detectable sgp120, anti-cluster A antibodies and their combination with sgp120 levels correlated positively with the total volume of atherosclerotic plaques. CONCLUSIONS: This study showed that sgp120 may act as a pan toxin causing immune dysfunction and sustained inflammation in a subset of people living with HIV, contributing to the development of premature comorbid conditions.