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1.
Annu Rev Immunol ; 40: 615-649, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35134315

RESUMO

Alphaviruses are emerging and reemerging viruses that cause disease syndromes ranging from incapacitating arthritis to potentially fatal encephalitis. While infection by arthritogenic and encephalitic alphaviruses results in distinct clinical manifestations, both virus groups induce robust innate and adaptive immune responses. However, differences in cellular tropism, type I interferon induction, immune cell recruitment, and B and T cell responses result in differential disease progression and outcome. In this review, we discuss aspects of immune responses that contribute to protective or pathogenic outcomes after alphavirus infection.


Assuntos
Infecções por Alphavirus , Alphavirus , Interferon Tipo I , Infecções por Alphavirus/patologia , Animais , Humanos , Imunidade , Tropismo
2.
Cell ; 187(2): 360-374.e19, 2024 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-38176410

RESUMO

The very-low-density lipoprotein receptor (VLDLR) comprises eight LDLR type A (LA) domains and supports entry of distantly related alphaviruses, including Eastern equine encephalitis virus (EEEV) and Semliki Forest virus (SFV). Here, by resolving multiple cryo-electron microscopy structures of EEEV-VLDLR complexes and performing mutagenesis and functional studies, we show that EEEV uses multiple sites (E1/E2 cleft and E2 A domain) to engage more than one LA domain simultaneously. However, no single LA domain is necessary or sufficient to support efficient EEEV infection. Whereas all EEEV strains show conservation of two VLDLR-binding sites, the EEEV PE-6 strain and a few other EEE complex members feature a single amino acid substitution that enables binding of LA domains to an additional site on the E2 B domain. These structural and functional analyses informed the design of a minimal VLDLR decoy receptor that neutralizes EEEV infection and protects mice from lethal challenge.


Assuntos
Microscopia Crioeletrônica , Vírus da Encefalite Equina do Leste , Encefalomielite Equina , Receptores de LDL , Animais , Camundongos , Alphavirus/fisiologia , Vírus da Encefalite Equina do Leste/fisiologia , Vírus da Encefalite Equina do Leste/ultraestrutura , Encefalomielite Equina/metabolismo , Cavalos , Ligação Proteica , Receptores de LDL/ultraestrutura
3.
Cell ; 187(12): 2919-2934.e20, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38761800

RESUMO

A critical roadblock to HIV vaccine development is the inability to induce B cell lineages of broadly neutralizing antibodies (bnAbs) in humans. In people living with HIV-1, bnAbs take years to develop. The HVTN 133 clinical trial studied a peptide/liposome immunogen targeting B cell lineages of HIV-1 envelope (Env) membrane-proximal external region (MPER) bnAbs (NCT03934541). Here, we report MPER peptide-liposome induction of polyclonal HIV-1 B cell lineages of mature bnAbs and their precursors, the most potent of which neutralized 15% of global tier 2 HIV-1 strains and 35% of clade B strains with lineage initiation after the second immunization. Neutralization was enhanced by vaccine selection of improbable mutations that increased antibody binding to gp41 and lipids. This study demonstrates proof of concept for rapid vaccine induction of human B cell lineages with heterologous neutralizing activity and selection of antibody improbable mutations and outlines a path for successful HIV-1 vaccine development.


Assuntos
Vacinas contra a AIDS , Anticorpos Neutralizantes , Linfócitos B , Anticorpos Anti-HIV , HIV-1 , Humanos , Vacinas contra a AIDS/imunologia , HIV-1/imunologia , Anticorpos Neutralizantes/imunologia , Linfócitos B/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , Infecções por HIV/virologia , Linhagem da Célula , Lipossomos , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Mutação , Proteína gp41 do Envelope de HIV/imunologia
4.
Cell ; 186(18): 3826-3844.e26, 2023 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-37536338

RESUMO

Previous studies have identified topologically associating domains (TADs) as basic units of genome organization. We present evidence of a previously unreported level of genome folding, where distant TAD pairs, megabases apart, interact to form meta-domains. Within meta-domains, gene promoters and structural intergenic elements present in distant TADs are specifically paired. The associated genes encode neuronal determinants, including those engaged in axonal guidance and adhesion. These long-range associations occur in a large fraction of neurons but support transcription in only a subset of neurons. Meta-domains are formed by diverse transcription factors that are able to pair over long and flexible distances. We present evidence that two such factors, GAF and CTCF, play direct roles in this process. The relative simplicity of higher-order meta-domain interactions in Drosophila, compared with those previously described in mammals, allowed the demonstration that genomes can fold into highly specialized cell-type-specific scaffolds that enable megabase-scale regulatory associations.


Assuntos
Cromossomos de Insetos , Drosophila , Animais , Cromatina/genética , Empacotamento do DNA , Drosophila/genética , Mamíferos/genética , Neurogênese , Neurônios , Fatores de Transcrição , Proteínas de Drosophila , Genoma de Inseto , Regulação da Expressão Gênica
5.
Cell ; 186(13): 2802-2822.e22, 2023 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-37220746

RESUMO

Systemic candidiasis is a common, high-mortality, nosocomial fungal infection. Unexpectedly, it has emerged as a complication of anti-complement C5-targeted monoclonal antibody treatment, indicating a critical niche for C5 in antifungal immunity. We identified transcription of complement system genes as the top biological pathway induced in candidemic patients and as predictive of candidemia. Mechanistically, C5a-C5aR1 promoted fungal clearance and host survival in a mouse model of systemic candidiasis by stimulating phagocyte effector function and ERK- and AKT-dependent survival in infected tissues. C5ar1 ablation rewired macrophage metabolism downstream of mTOR, promoting their apoptosis and enhancing mortality through kidney injury. Besides hepatocyte-derived C5, local C5 produced intrinsically by phagocytes provided a key substrate for antifungal protection. Lower serum C5a concentrations or a C5 polymorphism that decreases leukocyte C5 expression correlated independently with poor patient outcomes. Thus, local, phagocyte-derived C5 production licenses phagocyte antimicrobial function and confers innate protection during systemic fungal infection.


Assuntos
Antifúngicos , Candidíase , Animais , Camundongos , Complemento C5/metabolismo , Fagócitos/metabolismo
6.
Cell ; 186(13): 2765-2782.e28, 2023 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-37327786

RESUMO

Cancer is characterized by hypomethylation-associated silencing of large chromatin domains, whose contribution to tumorigenesis is uncertain. Through high-resolution genome-wide single-cell DNA methylation sequencing, we identify 40 core domains that are uniformly hypomethylated from the earliest detectable stages of prostate malignancy through metastatic circulating tumor cells (CTCs). Nested among these repressive domains are smaller loci with preserved methylation that escape silencing and are enriched for cell proliferation genes. Transcriptionally silenced genes within the core hypomethylated domains are enriched for immune-related genes; prominent among these is a single gene cluster harboring all five CD1 genes that present lipid antigens to NKT cells and four IFI16-related interferon-inducible genes implicated in innate immunity. The re-expression of CD1 or IFI16 murine orthologs in immuno-competent mice abrogates tumorigenesis, accompanied by the activation of anti-tumor immunity. Thus, early epigenetic changes may shape tumorigenesis, targeting co-located genes within defined chromosomal loci. Hypomethylation domains are detectable in blood specimens enriched for CTCs.


Assuntos
Metilação de DNA , Neoplasias da Próstata , Animais , Humanos , Masculino , Camundongos , Carcinogênese/genética , DNA , Epigênese Genética , Neoplasias da Próstata/genética , Células Neoplásicas Circulantes
7.
Cell ; 186(21): 4652-4661.e13, 2023 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-37734373

RESUMO

The mpox outbreak of 2022-2023 involved rapid global spread in men who have sex with men. We infected 18 rhesus macaques with mpox by the intravenous, intradermal, and intrarectal routes and observed robust antibody and T cell responses following all three routes of infection. Numerous skin lesions and high plasma viral loads were observed following intravenous and intradermal infection. Skin lesions peaked on day 10 and resolved by day 28 following infection. On day 28, we re-challenged all convalescent and 3 naive animals with mpox. All convalescent animals were protected against re-challenge. Transcriptomic studies showed upregulation of innate and inflammatory responses and downregulation of collagen formation and extracellular matrix organization following challenge, as well as rapid activation of T cell and plasma cell responses following re-challenge. These data suggest key mechanistic insights into mpox pathogenesis and immunity. This macaque model should prove useful for evaluating mpox vaccines and therapeutics.


Assuntos
Macaca mulatta , Monkeypox virus , Mpox , Animais , Humanos , Masculino , Homossexualidade Masculina , Mpox/imunologia , Minorias Sexuais e de Gênero , Monkeypox virus/fisiologia
8.
Cell ; 186(22): 4818-4833.e25, 2023 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-37804831

RESUMO

MXRA8 is a receptor for chikungunya (CHIKV) and other arthritogenic alphaviruses with mammalian hosts. However, mammalian MXRA8 does not bind to alphaviruses that infect humans and have avian reservoirs. Here, we show that avian, but not mammalian, MXRA8 can act as a receptor for Sindbis, western equine encephalitis (WEEV), and related alphaviruses with avian reservoirs. Structural analysis of duck MXRA8 complexed with WEEV reveals an inverted binding mode compared with mammalian MXRA8 bound to CHIKV. Whereas both domains of mammalian MXRA8 bind CHIKV E1 and E2, only domain 1 of avian MXRA8 engages WEEV E1, and no appreciable contacts are made with WEEV E2. Using these results, we generated a chimeric avian-mammalian MXRA8 decoy-receptor that neutralizes infection of multiple alphaviruses from distinct antigenic groups in vitro and in vivo. Thus, different alphaviruses can bind MXRA8 encoded by different vertebrate classes with distinct engagement modes, which enables development of broad-spectrum inhibitors.


Assuntos
Alphavirus , Animais , Humanos , Febre de Chikungunya , Vírus Chikungunya/química , Mamíferos , Receptores Virais/metabolismo
9.
Cell ; 186(2): 305-326.e27, 2023 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-36638792

RESUMO

All living things experience an increase in entropy, manifested as a loss of genetic and epigenetic information. In yeast, epigenetic information is lost over time due to the relocalization of chromatin-modifying proteins to DNA breaks, causing cells to lose their identity, a hallmark of yeast aging. Using a system called "ICE" (inducible changes to the epigenome), we find that the act of faithful DNA repair advances aging at physiological, cognitive, and molecular levels, including erosion of the epigenetic landscape, cellular exdifferentiation, senescence, and advancement of the DNA methylation clock, which can be reversed by OSK-mediated rejuvenation. These data are consistent with the information theory of aging, which states that a loss of epigenetic information is a reversible cause of aging.


Assuntos
Envelhecimento , Epigênese Genética , Animais , Envelhecimento/genética , Metilação de DNA , Epigenoma , Mamíferos/genética , Nucleoproteínas , Saccharomyces cerevisiae/genética
10.
Cell ; 185(7): 1157-1171.e22, 2022 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-35259335

RESUMO

Enterococci are a part of human microbiota and a leading cause of multidrug resistant infections. Here, we identify a family of Enterococcus pore-forming toxins (Epxs) in E. faecalis, E. faecium, and E. hirae strains isolated across the globe. Structural studies reveal that Epxs form a branch of ß-barrel pore-forming toxins with a ß-barrel protrusion (designated the top domain) sitting atop the cap domain. Through a genome-wide CRISPR-Cas9 screen, we identify human leukocyte antigen class I (HLA-I) complex as a receptor for two members (Epx2 and Epx3), which preferentially recognize human HLA-I and homologous MHC-I of equine, bovine, and porcine, but not murine, origin. Interferon exposure, which stimulates MHC-I expression, sensitizes human cells and intestinal organoids to Epx2 and Epx3 toxicity. Co-culture with Epx2-harboring E. faecium damages human peripheral blood mononuclear cells and intestinal organoids, and this toxicity is neutralized by an Epx2 antibody, demonstrating the toxin-mediated virulence of Epx-carrying Enterococcus.


Assuntos
Toxinas Bacterianas/metabolismo , Enterococcus , Leucócitos Mononucleares , Fatores de Virulência/metabolismo , Animais , Bovinos , Enterococcus/metabolismo , Enterococcus/patogenicidade , Cavalos , Camundongos , Testes de Sensibilidade Microbiana , Suínos
11.
Cell ; 185(9): 1572-1587.e11, 2022 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-35452622

RESUMO

The large number of spike substitutions in Omicron lineage variants (BA.1, BA.1.1., and BA.2) could jeopardize the efficacy of SARS-CoV-2 vaccines. We evaluated in mice the protective efficacy of the Moderna mRNA-1273 vaccine against BA.1 before or after boosting. Whereas two doses of mRNA-1273 vaccine induced high levels of neutralizing antibodies against historical WA1/2020 strains, lower levels against BA.1 were associated with breakthrough infection and inflammation in the lungs. A primary vaccination series with mRNA-1273.529, an Omicron-matched vaccine, potently neutralized BA.1 but inhibited historical or other SARS-CoV-2 variants less effectively. However, boosting with either mRNA-1273 or mRNA-1273.529 vaccines increased neutralizing titers and protection against BA.1 and BA.2 infection. Nonetheless, the neutralizing antibody titers were higher, and lung viral burden and cytokines were slightly lower in mice boosted with mRNA-1273.529 and challenged with BA.1. Thus, boosting with mRNA-1273 or mRNA-1273.529 enhances protection against Omicron infection with limited differences in efficacy measured.


Assuntos
COVID-19 , SARS-CoV-2 , Vacina de mRNA-1273 contra 2019-nCoV , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , Camundongos , SARS-CoV-2/genética , Vacinação , Vacinas Sintéticas , Vacinas de mRNA
12.
Nat Immunol ; 25(3): 537-551, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38337035

RESUMO

A nasally delivered chimpanzee adenoviral-vectored severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine (ChAd-SARS-CoV-2-S) is currently used in India (iNCOVACC). Here, we update this vaccine by creating ChAd-SARS-CoV-2-BA.5-S, which encodes a prefusion-stabilized BA.5 spike protein. Whereas serum neutralizing antibody responses induced by monovalent or bivalent adenoviral vaccines were poor against the antigenically distant XBB.1.5 strain and insufficient to protect in passive transfer experiments, mucosal antibody and cross-reactive memory T cell responses were robust, and protection was evident against WA1/2020 D614G and Omicron variants BQ.1.1 and XBB.1.5 in mice and hamsters. However, depletion of memory CD8+ T cells before XBB.1.5 challenge resulted in loss of protection against upper and lower respiratory tract infection. Thus, nasally delivered vaccines stimulate mucosal immunity against emerging SARS-CoV-2 strains, and cross-reactive memory CD8+ T cells mediate protection against lung infection by antigenically distant strains in the setting of low serum levels of cross-reactive neutralizing antibodies.


Assuntos
COVID-19 , Infecções Respiratórias , Vacinas , Cricetinae , Animais , Camundongos , Linfócitos T CD8-Positivos , SARS-CoV-2 , COVID-19/prevenção & controle , Anticorpos Neutralizantes , Anticorpos Amplamente Neutralizantes , Pan troglodytes
13.
Cell ; 184(1): 15-17, 2021 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-33338422

RESUMO

Complementary genome-wide CRISPR-Cas9 screens performed by multiple groups reveal new insights into SARS-CoV-2 biology including aspects of viral entry, translation, replication, egress, and the genes regulating these processes. Comparisons with other coronaviruses enhances our understanding of the cellular life cycle of this medically important family of emerging viruses.

14.
Cell ; 184(14): 3689-3701.e22, 2021 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-34139175

RESUMO

The cholesterol-sensing protein Scap induces cholesterol synthesis by transporting membrane-bound transcription factors called sterol regulatory element-binding proteins (SREBPs) from the endoplasmic reticulum (ER) to the Golgi apparatus for proteolytic activation. Transport requires interaction between Scap's two ER luminal loops (L1 and L7), which flank an intramembrane sterol-sensing domain (SSD). Cholesterol inhibits Scap transport by binding to L1, which triggers Scap's binding to Insig, an ER retention protein. Here we used cryoelectron microscopy (cryo-EM) to elucidate two structures of full-length chicken Scap: (1) a wild-type free of Insigs and (2) mutant Scap bound to chicken Insig without cholesterol. Strikingly, L1 and L7 intertwine tightly to form a globular domain that acts as a luminal platform connecting the SSD to the rest of Scap. In the presence of Insig, this platform undergoes a large rotation accompanied by rearrangement of Scap's transmembrane helices. We postulate that this conformational change halts Scap transport of SREBPs and inhibits cholesterol synthesis.


Assuntos
Colesterol/metabolismo , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Sequência de Aminoácidos , Animais , Anticorpos/metabolismo , Galinhas , Proteínas de Membrana/isolamento & purificação , Proteínas de Membrana/ultraestrutura , Modelos Biológicos , Modelos Moleculares , Ligação Proteica , Domínios Proteicos , Estrutura Secundária de Proteína , Relação Estrutura-Atividade
15.
Cell ; 184(6): 1636-1647, 2021 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-33639085

RESUMO

Rapid increases of energy consumption and human dependency on fossil fuels have led to the accumulation of greenhouse gases and consequently, climate change. As such, major efforts have been taken to develop, test, and adopt clean renewable fuel alternatives. Production of bioethanol and biodiesel from crops is well developed, while other feedstock resources and processes have also shown high potential to provide efficient and cost-effective alternatives, such as landfill and plastic waste conversion, algal photosynthesis, as well as electrochemical carbon fixation. In addition, the downstream microbial fermentation can be further engineered to not only increase the product yield but also expand the chemical space of biofuels through the rational design and fine-tuning of biosynthetic pathways toward the realization of "designer fuels" and diverse future applications.


Assuntos
Biocombustíveis/análise , Desenvolvimento Sustentável , Vias Biossintéticas , Ciclo do Carbono , Humanos , Lignina/metabolismo , Resíduos
16.
Cell ; 184(5): 1214-1231.e16, 2021 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-33636133

RESUMO

Although enteric helminth infections modulate immunity to mucosal pathogens, their effects on systemic microbes remain less established. Here, we observe increased mortality in mice coinfected with the enteric helminth Heligmosomoides polygyrus bakeri (Hpb) and West Nile virus (WNV). This enhanced susceptibility is associated with altered gut morphology and transit, translocation of commensal bacteria, impaired WNV-specific T cell responses, and increased virus infection in the gastrointestinal tract and central nervous system. These outcomes were due to type 2 immune skewing, because coinfection in Stat6-/- mice rescues mortality, treatment of helminth-free WNV-infected mice with interleukin (IL)-4 mirrors coinfection, and IL-4 receptor signaling in intestinal epithelial cells mediates the susceptibility phenotypes. Moreover, tuft cell-deficient mice show improved outcomes with coinfection, whereas treatment of helminth-free mice with tuft cell-derived cytokine IL-25 or ligand succinate worsens WNV disease. Thus, helminth activation of tuft cell-IL-4-receptor circuits in the gut exacerbates infection and disease of a neurotropic flavivirus.


Assuntos
Coinfecção , Nematospiroides dubius/fisiologia , Transdução de Sinais , Infecções por Strongylida/patologia , Vírus do Nilo Ocidental/fisiologia , Animais , Linfócitos T CD8-Positivos/imunologia , Modelos Animais de Doenças , Suscetibilidade a Doenças , Mucosa Intestinal/parasitologia , Mucosa Intestinal/virologia , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/parasitologia , Neurônios/virologia , Receptores de Interleucina-4/metabolismo , Fator de Transcrição STAT6/genética , Índice de Gravidade de Doença , Infecções por Strongylida/parasitologia
17.
Cell ; 184(9): 2316-2331.e15, 2021 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-33773105

RESUMO

Most human monoclonal antibodies (mAbs) neutralizing SARS-CoV-2 recognize the spike (S) protein receptor-binding domain and block virus interactions with the cellular receptor angiotensin-converting enzyme 2. We describe a panel of human mAbs binding to diverse epitopes on the N-terminal domain (NTD) of S protein from SARS-CoV-2 convalescent donors and found a minority of these possessed neutralizing activity. Two mAbs (COV2-2676 and COV2-2489) inhibited infection of authentic SARS-CoV-2 and recombinant VSV/SARS-CoV-2 viruses. We mapped their binding epitopes by alanine-scanning mutagenesis and selection of functional SARS-CoV-2 S neutralization escape variants. Mechanistic studies showed that these antibodies neutralize in part by inhibiting a post-attachment step in the infection cycle. COV2-2676 and COV2-2489 offered protection either as prophylaxis or therapy, and Fc effector functions were required for optimal protection. Thus, natural infection induces a subset of potent NTD-specific mAbs that leverage neutralizing and Fc-mediated activities to protect against SARS-CoV-2 infection using multiple functional attributes.


Assuntos
Anticorpos Monoclonais/farmacologia , Anticorpos Neutralizantes/farmacologia , Substâncias Protetoras/farmacologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia , Animais , Ligação Competitiva , COVID-19/imunologia , COVID-19/virologia , Quimiocinas/metabolismo , Chlorocebus aethiops , Células HEK293 , Humanos , Fragmentos Fab das Imunoglobulinas/metabolismo , Imunoglobulina G/metabolismo , Pulmão/metabolismo , Camundongos Endogâmicos C57BL , Modelos Moleculares , Mutagênese/genética , Testes de Neutralização , Domínios Proteicos , Células Vero
18.
Cell ; 184(8): 2229-2238.e13, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33691138

RESUMO

The biosafety level 3 (BSL-3) requirement to culture severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a bottleneck for research. Here, we report a trans-complementation system that produces single-round infectious SARS-CoV-2 that recapitulates authentic viral replication. We demonstrate that the single-round infectious SARS-CoV-2 can be used at BSL-2 laboratories for high-throughput neutralization and antiviral testing. The trans-complementation system consists of two components: a genomic viral RNA containing ORF3 and envelope gene deletions, as well as mutated transcriptional regulator sequences, and a producer cell line expressing the two deleted genes. Trans-complementation of the two components generates virions that can infect naive cells for only one round but does not produce wild-type SARS-CoV-2. Hamsters and K18-hACE2 transgenic mice inoculated with the complementation-derived virions exhibited no detectable disease, even after intracranial inoculation with the highest possible dose. Thus, the trans-complementation platform can be safely used at BSL-2 laboratories for research and countermeasure development.


Assuntos
COVID-19/virologia , Contenção de Riscos Biológicos/métodos , SARS-CoV-2 , Células A549 , Animais , Chlorocebus aethiops , Cricetinae , Teste de Complementação Genética/métodos , Genoma Viral , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Transgênicos , RNA Viral , SARS-CoV-2/genética , SARS-CoV-2/patogenicidade , SARS-CoV-2/fisiologia , Células Vero , Virulência , Replicação Viral
19.
Cell ; 184(17): 4414-4429.e19, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34416146

RESUMO

Alphaviruses are emerging, mosquito-transmitted pathogens that cause musculoskeletal and neurological disease in humans. Although neutralizing antibodies that inhibit individual alphaviruses have been described, broadly reactive antibodies that protect against both arthritogenic and encephalitic alphaviruses have not been reported. Here, we identify DC2.112 and DC2.315, two pan-protective yet poorly neutralizing human monoclonal antibodies (mAbs) that avidly bind to viral antigen on the surface of cells infected with arthritogenic and encephalitic alphaviruses. These mAbs engage a conserved epitope in domain II of the E1 protein proximal to and within the fusion peptide. Treatment with DC2.112 or DC2.315 protects mice against infection by both arthritogenic (chikungunya and Mayaro) and encephalitic (Venezuelan, Eastern, and Western equine encephalitis) alphaviruses through multiple mechanisms, including inhibition of viral egress and monocyte-dependent Fc effector functions. These findings define a conserved epitope recognized by weakly neutralizing yet protective antibodies that could be targeted for pan-alphavirus immunotherapy and vaccine design.


Assuntos
Alphavirus/imunologia , Anticorpos Antivirais/imunologia , Sequência Conservada/imunologia , Epitopos/imunologia , Proteínas Virais/imunologia , Infecções por Alphavirus/imunologia , Infecções por Alphavirus/virologia , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/imunologia , Febre de Chikungunya/imunologia , Febre de Chikungunya/virologia , Vírus Chikungunya/imunologia , Chlorocebus aethiops , Mapeamento de Epitopos , Epitopos/química , Humanos , Masculino , Camundongos Endogâmicos C57BL , Modelos Biológicos , Monócitos/metabolismo , Células Vero , Proteínas Virais/química , Liberação de Vírus
20.
Cell ; 184(17): 4430-4446.e22, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-34416147

RESUMO

Alphaviruses cause severe arthritogenic or encephalitic disease. The E1 structural glycoprotein is highly conserved in these viruses and mediates viral fusion with host cells. However, the role of antibody responses to the E1 protein in immunity is poorly understood. We isolated E1-specific human monoclonal antibodies (mAbs) with diverse patterns of recognition for alphaviruses (ranging from Eastern equine encephalitis virus [EEEV]-specific to alphavirus cross-reactive) from survivors of natural EEEV infection. Antibody binding patterns and epitope mapping experiments identified differences in E1 reactivity based on exposure of epitopes on the glycoprotein through pH-dependent mechanisms or presentation on the cell surface prior to virus egress. Therapeutic efficacy in vivo of these mAbs corresponded with potency of virus egress inhibition in vitro and did not require Fc-mediated effector functions for treatment against subcutaneous EEEV challenge. These studies reveal the molecular basis for broad and protective antibody responses to alphavirus E1 proteins.


Assuntos
Alphavirus/imunologia , Anticorpos Antivirais/imunologia , Reações Cruzadas/imunologia , Proteínas Virais/imunologia , Liberação de Vírus/fisiologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/isolamento & purificação , Anticorpos Neutralizantes/imunologia , Antígenos Virais/imunologia , Linhagem Celular , Vírus Chikungunya/imunologia , Vírus da Encefalite Equina do Leste/imunologia , Encefalomielite Equina/imunologia , Encefalomielite Equina/virologia , Mapeamento de Epitopos , Feminino , Cavalos , Humanos , Concentração de Íons de Hidrogênio , Articulações/patologia , Masculino , Camundongos Endogâmicos C57BL , Modelos Biológicos , Ligação Proteica , RNA Viral/metabolismo , Receptores Fc/metabolismo , Temperatura , Vírion/metabolismo , Internalização do Vírus
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