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1.
Commun Biol ; 7(1): 871, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39020082

RESUMO

Antibodies to Ebola virus glycoprotein (EBOV GP) represent an important correlate of the vaccine efficiency and infection survival. Both neutralization and some of the Fc-mediated effects are known to contribute the protection conferred by antibodies of various epitope specificities. At the same time, the role of the complement system remains unclear. Here, we compare complement activation by two groups of representative monoclonal antibodies (mAbs) interacting with the glycan cap (GC) or the membrane-proximal external region (MPER) of GP. Binding of GC-specific mAbs to GP induces complement-dependent cytotoxicity (CDC) in the GP-expressing cell line via C3 deposition on GP in contrast to MPER-specific mAbs. In the mouse model of EBOV infection, depletion of the complement system leads to an impairment of protection exerted by one of the GC-specific, but not MPER-specific mAbs. Our data suggest that activation of the complement system represents an important mechanism of antiviral protection by GC antibodies.


Assuntos
Anticorpos Monoclonais , Anticorpos Antivirais , Ebolavirus , Doença pelo Vírus Ebola , Polissacarídeos , Proteínas do Envelope Viral , Animais , Ebolavirus/imunologia , Anticorpos Monoclonais/imunologia , Camundongos , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/virologia , Doença pelo Vírus Ebola/prevenção & controle , Polissacarídeos/imunologia , Anticorpos Antivirais/imunologia , Humanos , Proteínas do Envelope Viral/imunologia , Proteínas do Envelope Viral/metabolismo , Ativação do Complemento , Camundongos Endogâmicos BALB C , Feminino , Proteínas do Sistema Complemento/imunologia , Proteínas do Sistema Complemento/metabolismo , Glicoproteínas/imunologia
2.
Yale J Biol Med ; 97(2): 253-263, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38947109

RESUMO

Environmental mismatches are defined as changes in the environment that induce public health crises. Well known mismatches leading to chronic disease include the availability of technologies that facilitate unhealthy diets and sedentary lifestyles, both factors that adversely affect cardiovascular health. This commentary puts these mismatches in context with biota alteration, an environmental mismatch involving hygiene-related technologies necessary for avoidance of infectious disease. Implementation of hygiene-related technologies causes a loss of symbiotic helminths and protists, profoundly affecting immune function and facilitating a variety of chronic conditions, including allergic disorders, autoimmune diseases, and several inflammation-associated neuropsychiatric conditions. Unfortunately, despite an established understanding of the biology underpinning this and other environmental mismatches, public health agencies have failed to stem the resulting tide of increased chronic disease burden. Both biomedical research and clinical practice continue to focus on an ineffective and reactive pharmaceutical-based paradigm. It is argued that the healthcare of the future could take into account the biology of today, effectively and proactively dealing with environmental mismatch and the resulting chronic disease burden.


Assuntos
Doenças do Sistema Imunitário , Humanos , Doença Crônica , Animais , Meio Ambiente
3.
Immunity ; 57(6): 1413-1427.e9, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38823390

RESUMO

Influenza B viruses (IBVs) comprise a substantial portion of the circulating seasonal human influenza viruses. Here, we describe the isolation of human monoclonal antibodies (mAbs) that recognized the IBV neuraminidase (NA) glycoprotein from an individual following seasonal vaccination. Competition-binding experiments suggested the antibodies recognized two major antigenic sites. One group, which included mAb FluB-393, broadly inhibited IBV NA sialidase activity, protected prophylactically in vivo, and bound to the lateral corner of NA. The second group contained an active site mAb, FluB-400, that broadly inhibited IBV NA sialidase activity and virus replication in vitro in primary human respiratory epithelial cell cultures and protected against IBV in vivo when administered systemically or intranasally. Overall, the findings described here shape our mechanistic understanding of the human immune response to the IBV NA glycoprotein through the demonstration of two mAb delivery routes for protection against IBV and the identification of potential IBV therapeutic candidates.


Assuntos
Anticorpos Monoclonais , Anticorpos Antivirais , Vírus da Influenza B , Influenza Humana , Neuraminidase , Neuraminidase/imunologia , Humanos , Vírus da Influenza B/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Influenza Humana/imunologia , Influenza Humana/prevenção & controle , Vacinas contra Influenza/imunologia , Camundongos , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Proteínas Virais/imunologia , Replicação Viral/efeitos dos fármacos
4.
Innate Immun ; 29(8): 161-170, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37802127

RESUMO

Sepsis is a leading cause of mortality. Plasma cytokine levels may identify those at increased risk of mortality from sepsis. Our aim was to understand how obesity alters cytokine levels during early sepsis and its correlation with survival. Six-week-old C57BL/6 male mice were randomized to control (non-obese) or high fat diet (obese) for 5-7 weeks. Sepsis was induced by cecal ligation and perforation (CLP). Cytokine levels were measured from cheek bleeds 8 h after CLP, and mice were monitored for survival. Other cohorts were sacrificed 1 h after CLP for plasma and tissue. Septic obese mice had higher survival. At 8 h after sepsis, obese mice had higher adiponectin, leptin, and resistin but lower TNFα and IL-6 compared to non-obese mice. When stratified by 24-h survival, adipokines were not significantly different in obese and non-obese mice. TNFα and IL-6 were higher in non-obese, compared to obese, mice that died within 24 h of sepsis. Diet and to sepsis significantly impacted the cecal microbiome. IL-6 is a prognostic biomarker during early sepsis in non-obese and obese mice. A plausible mechanism for the survival difference in non-obese and obese mice may be the difference in gut microbiome and its evolution during sepsis.


Assuntos
Microbioma Gastrointestinal , Sepse , Animais , Masculino , Camundongos , Citocinas , Interleucina-6 , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade/complicações , Fator de Necrose Tumoral alfa
5.
J Infect Dis ; 228(Suppl 6): S414-S426, 2023 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-37849399

RESUMO

The Togaviridae family, genus, Alphavirus, includes several mosquito-borne human pathogens with the potential to spread to near pandemic proportions. Most of these are zoonotic, with spillover infections of humans and domestic animals, but a few such as chikungunya virus (CHIKV) have the ability to use humans as amplification hosts for transmission in urban settings and explosive outbreaks. Most alphaviruses cause nonspecific acute febrile illness, with pathogenesis sometimes leading to either encephalitis or arthralgic manifestations with severe and chronic morbidity and occasional mortality. The development of countermeasures, especially against CHIKV and Venezuelan equine encephalitis virus that are major threats, has included vaccines and antibody-based therapeutics that are likely to also be successful for rapid responses with other members of the family. However, further work with these prototypes and other alphavirus pathogens should target better understanding of human tropism and pathogenesis, more comprehensive identification of cellular receptors and entry, and better understanding of structural mechanisms of neutralization.


Assuntos
Vírus Chikungunya , Culicidae , Animais , Cavalos , Humanos , Pesquisa
6.
Cell Host Microbe ; 31(8): 1288-1300.e6, 2023 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-37516111

RESUMO

Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) infections pose a significant health burden. Using pre-fusion conformation fusion (F) proteins, we isolated a panel of anti-F antibodies from a human donor. One antibody (RSV-199) potently cross-neutralized 8 RSV and hMPV strains by recognizing antigenic site III, which is partially conserved in RSV and hMPV F. Next, we determined the cryoelectron microscopy (cryo-EM) structures of RSV-199 bound to RSV F trimers, hMPV F monomers, and an unexpected dimeric form of hMPV F. These structures revealed how RSV-199 engages both RSV and hMPV F proteins through conserved interactions of the antibody heavy-chain variable region and how variability within heavy-chain complementarity-determining region 3 (HCDR3) can be accommodated at the F protein interface in site-III-directed antibodies. Furthermore, RSV-199 offered enhanced protection against RSV A and B strains and hMPV in cotton rats. These findings highlight the mechanisms of broad neutralization and therapeutic potential of RSV-199.


Assuntos
Metapneumovirus , Vírus Sincicial Respiratório Humano , Humanos , Metapneumovirus/metabolismo , Anticorpos Neutralizantes , Anticorpos Antivirais , Microscopia Crioeletrônica , Região Variável de Imunoglobulina , Proteínas Virais de Fusão
7.
Proc Natl Acad Sci U S A ; 120(13): e2213690120, 2023 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-36961925

RESUMO

Selection and development of monoclonal antibody (mAb) therapeutics against pathogenic viruses depends on certain functional characteristics. Neutralization potency, or the half-maximal inhibitory concentration (IC50) values, is an important characteristic of candidate therapeutic antibodies. Structural insights into the bases of neutralization potency differences between antiviral neutralizing mAbs are lacking. In this report, we present cryo-electron microscopy (EM) reconstructions of three anti-Eastern equine encephalitis virus (EEEV) neutralizing human mAbs targeting overlapping epitopes on the E2 protein, with greater than 20-fold differences in their respective IC50 values. From our structural and biophysical analyses, we identify several constraints that contribute to the observed differences in the neutralization potencies. Cryo-EM reconstructions of EEEV in complex with these Fab fragments reveal structural constraints that dictate intravirion or intervirion cross-linking of glycoprotein spikes by their IgG counterparts as a mechanism of neutralization. Additionally, we describe critical features for the recognition of EEEV by these mAbs including the epitope-paratope interaction surface, occupancy, and kinetic differences in on-rate for binding to the E2 protein. Each constraint contributes to the extent of EEEV inhibition for blockade of virus entry, fusion, and/or egress. These findings provide structural and biophysical insights into the differences in mechanism and neutralization potencies of these antibodies, which help inform rational design principles for candidate vaccines and therapeutic antibodies for all icosahedral viruses.


Assuntos
Vírus da Encefalite Equina do Leste , Encefalomielite Equina , Humanos , Cavalos , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais , Microscopia Crioeletrônica , Epitopos , Anticorpos Monoclonais , Testes de Neutralização
8.
Shock ; 59(5): 779-790, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36840516

RESUMO

ABSTRACT: Introduction: Sepsis is a dysregulated host response to infection that can lead to life-threatening organ dysfunction. Clinical and animal studies consistently demonstrate that female subjects are less susceptible to the adverse effects of sepsis, demonstrating the importance of understanding how sex influences sepsis outcomes. The signal transducer and activator of transcription 3 (STAT3) pathway are a major signaling pathway that facilitates inflammation during sepsis. STAT3 is abundantly expressed in white adipose tissue; however, little is known about the contribution of white adipose tissue STAT3 activation during sepsis. We hypothesize that adipocyte STAT3 inhibition during severe sepsis will exaggerate the inflammatory response and impact organ injury, in a sex-dependent manner. Methods: We generated STAT3 flox/flox (wild-type [WT]) and adipocyte STAT3 knock out (A-STAT3 KO) mice using Cre-lox technology. Studies were done in 12- to 16-week-old male and female mice. Polymicrobial sepsis was induced by cecal ligation and puncture (CLP). Control nonseptic mice did not undergo CLP (0 h CLP). Tissues were harvested 18 h after CLP. Body composition was determined by echo magnetic resonance imaging. Energy metabolism was determined by indirect calorimetry. White adipose tissue morphology was determined by hematoxylin and eosin staining, while STAT3 activation in the white adipose tissue was determined by western blot analysis and immunohistochemistry staining of STAT3 activation/phosphorylation at tyrosine 705. Plasma cytokines (TNF-α, IL-6, and leptin) were determined by luminex assay. Neutrophil infiltration of the lung and liver was assessed by myeloperoxidase activity assay. Histological signs of organ injury on lung and liver tissue were assessed by hematoxylin and eosin staining. Liver injury was further assessed by measuring plasma alanine and aspartate aminotransferase. In a separate cohort of mice, sepsis was induced by CLP and mice were monitored every 6-12 h over a 7-day period to assess survival rate. Results: We demonstrate that neither body composition nor energy metabolism is altered with adipocyte STAT3 inhibition in male or female mice, under nonseptic conditions. Sepsis was associated with reduced adipocyte size in female WT and A-STAT3 KO mice, suggesting that this event is STAT3 independent. Sepsis did not alter adipocyte size in male WT and A-STAT3 KO mice, suggesting that this event is also sex dependent. Although STAT3 phosphorylation at tyrosine 705 expression is negligible in male and female A-STAT3 KO mice, septic female WT and A-STAT3 KO mice have higher white adipose tissue STAT3 activation than male WT and A-STAT3 KO mice. Adipocyte STAT3 inhibition did not alter the proinflammatory cytokine response during sepsis in male or female mice, as measured by plasma TNF-α, IL-6, and leptin levels. Adipocyte STAT3 inhibition reduced lung neutrophil infiltration and histological signs of lung injury during sepsis in male mice. On the contrary, adipocyte STAT3 inhibition had no effect on lung neutrophil infiltration or lung injury in female mice. We further demonstrate that neither liver neutrophil infiltration nor histological signs of liver injury are altered by adipocyte STAT3 inhibition during sepsis, in male or female mice. Lastly, adipocyte STAT3 inhibition did not affect survival rate of male or female mice during sepsis. Conclusions: Our study demonstrates that sex influences white adipose tissue STAT3 activation and morphology during sepsis, which is not dependent on the presence of functional STAT3 in mature adipocytes. Furthermore, genetic inhibition of adipocyte STAT3 activation in male, but not female mice, results in reduced lung neutrophil infiltration and lung injury during sepsis. The results from our study demonstrate the importance of considering biological sex and the white adipose tissue as potential sources and targets of inflammation during sepsis.


Assuntos
Lesão Pulmonar , Sepse , Masculino , Camundongos , Animais , Leptina , Lesão Pulmonar/complicações , Fator de Necrose Tumoral alfa , Interleucina-6 , Fator de Transcrição STAT3/genética , Amarelo de Eosina-(YS) , Hematoxilina , Sepse/patologia , Citocinas , Inflamação , Adipócitos , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças
9.
Shock ; 59(3): 409-416, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36597767

RESUMO

ABSTRACT: Obesity is an ongoing epidemic that influences pathobiology in numerous disease states. Obesity is associated with increased plasma leptin levels, a hormone that activates the signal transducer and activator of transcription 3 (STAT3) pathway. Pneumonia is a significant cause of morbidity and mortality. During pneumonia, inflammatory pathways including STAT3 are activated. Outcomes in obese patients with pneumonia are mixed, with some studies showing obesity increases harm and others showing benefit. It is unclear whether obesity alters STAT3 activation during bacterial pneumonia and how this might impact outcomes from pneumonia. We used a murine model of obesity and pneumonia challenge with Pseudomonas aeruginosa in obese and nonobese mice to investigate the effect of obesity on STAT3 activation. We found obese mice with bacterial pneumonia had increased mortality compared with nonobese mice. Inflammatory markers, IL-6 and TNF-α, and lung neutrophil infiltration were elevated at 6 h after pneumonia in both nonobese and obese mice. Obese mice had greater lung injury compared with nonobese mice at 6 h after pneumonia. Leptin and insulin levels were higher in obese mice compared with nonobese mice, and obese mice with pneumonia had higher pulmonary STAT3 activation compared with nonobese mice.


Assuntos
Leptina , Pneumonia Bacteriana , Animais , Camundongos , Camundongos Obesos , Fator de Transcrição STAT3/metabolismo , Pulmão/metabolismo , Obesidade/complicações , Pneumonia Bacteriana/complicações
10.
Behav Brain Res ; 442: 114320, 2023 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-36720350

RESUMO

In learning and memory tasks, immune overactivation is associated with impaired performance, while normal immune activation is associated with optimal performance. In one specific domain of memory, context discrimination memory, peripheral immune stimulation has been shown to impair performance on the context-object discrimination memory task in male rats. In order to evaluate potential sex differences in this task, as well as potential mechanisms for the memory impairment, we evaluated the ability of peripheral immune stimulation to impair task performance in both males and females. Next, we examined whether treatment with interleukin-1 receptor antagonist (IL-1ra), a receptor antagonist for the pro-inflammatory cytokine interleukin (IL)-1ß, was able to rescue the memory deficit. We examined microglial morphology in the hippocampus and cytokine mRNA and protein expression in the hippocampus and the periphery. Male rats displayed memory impairment in response to LPS, and this impairment was not rescued by IL-1ra. Female rats did not have significant memory impairments and IL-1ra administration improved memory following inflammation. A subset of cytokines and chemokines were increased only in LPS-treated males. Inflammation alone did not alter microglia morphology, but IL-1ra did in certain sub-regions of the hippocampus. Together, these results indicate that sex differences exist in the ability of a peripheral immune stimulus to influence context discrimination memory and specific cytokine signals may be altered in impaired males. This study highlights the importance of sex differences in response to inflammatory challenges, especially related to memory impairments in context discrimination memory.


Assuntos
Citocinas , Proteína Antagonista do Receptor de Interleucina 1 , Ratos , Feminino , Masculino , Animais , Citocinas/metabolismo , Proteína Antagonista do Receptor de Interleucina 1/farmacologia , Proteína Antagonista do Receptor de Interleucina 1/metabolismo , Lipopolissacarídeos/farmacologia , Inflamação/metabolismo , Aprendizagem , Hipocampo/metabolismo , Transtornos da Memória/metabolismo
11.
Children (Basel) ; 11(1)2023 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-38255358

RESUMO

Based on available data that include approximately 20 lines of evidence from studies in laboratory animal models, observations in humans, correlations in time, and pharmacological/toxicological considerations, it has been concluded without reasonable doubt and with no evidence to the contrary that exposure of susceptible babies and children to acetaminophen (paracetamol) induces many, if not most, cases of autism spectrum disorder (ASD). However, the relative number of cases of ASD that might be induced by acetaminophen has not yet been estimated. Here, we examine a variety of evidence, including the acetaminophen-induced reduction of social awareness in adults, the prevalence of ASD through time, and crude estimates of the relative number of ASD cases induced by acetaminophen during various periods of neurodevelopment. We conclude that the very early postpartum period poses the greatest risk for acetaminophen-induced ASD, and that nearly ubiquitous use of acetaminophen during early development could conceivably be responsible for the induction in the vast majority, perhaps 90% or more, of all cases of ASD. Despite over a decade of accumulating evidence that acetaminophen is harmful for neurodevelopment, numerous studies demonstrate that acetaminophen is frequently administered to children in excess of currently approved amounts and under conditions in which it provides no benefit. Further, studies have failed to demonstrate long-term benefits of acetaminophen for the pediatric population, leaving no valid rationale for continued use of the drug in that population given its risks to neurodevelopment.

12.
Br J Nurs ; 31(19): 976-982, 2022 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-36306233

RESUMO

BACKGROUND: With increasing demand for nursing services worldwide, the onus is on healthcare systems to implement measures to improve retention. The DAISY Award was designed to celebrate nursing with the suggestion that it may improve staff retention. AIM: To describe the experience and impact of winning the DAISY Award. METHOD: Data were collected through virtual semistructured interviews from award winners (n=4), nominees (n=4) and nominators (n=4). An analytical framework was developed to allow the responses of the three groups to be compared. FINDINGS: Four major themes emerged from the responses: awareness of the DAISY Award; the nomination process, the impact on retention and winner benefits. CONCLUSION: Being nominated or winning a DAISY Award had a positive impact on nurses' feelings towards their role. This was a small evaluation in a single organisation, so the value of adopting the DAISY Award for recognising nurses' contributions to patient care merits further investigation, especially with regards to its effects on retention.


Assuntos
Distinções e Prêmios , Humanos , Sistema Imunitário
13.
J Nurs Manag ; 30(7): 2845-2853, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36056545

RESUMO

AIMS: This article reports the results of a scoping review to identify initiatives for improving recruitment and retention of nurses in health care and ascertain their effectiveness. BACKGROUND: The global shortage of nurses has results in greater competition for vacant posts and an increased need to retain existing post holders. While there are a large number of publications discussing ways to improve recruitment and retention, the effectiveness of these needs to be established. EVALUATION: Thirteen papers met the inclusion criteria. There was no literature identified focusing on recruitment and only one paper reported a formal evaluation of a retention initiative. KEY ISSUES: Five themes summarized the initiatives for retaining nurses: leadership and support, ongoing professional development, recognition, work environment and flexible scheduling. CONCLUSION: While strategies have been proposed to retain nurses, there is a dearth of evidence supporting the effectiveness of these. IMPLICATIONS FOR NURSING MANAGEMENT: Although there is a lack of evaluations of retention strategies, the review identified a number of initiatives that warrant consideration. With the launch of the National Health Service People Plan in England in 2021, which is recommending initiatives identified in this review without robust evidence, an integrated programme of research evaluating this is recommended.


Assuntos
Recursos Humanos de Enfermagem , Medicina Estatal , Humanos , Liderança , Atenção à Saúde , Recursos Humanos
14.
Pediatr Pulmonol ; 57(12): 3035-3043, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36039394

RESUMO

INTRODUCTION: Lower socioeconomic status is associated with significantly poorer outcomes in weight, lung function, and pulmonary exacerbation rates in people with cystic fibrosis (PwCF). GLOBAL AIM: We aim to reduce health disparities and inequities faced by PwCF by screening for and addressing unmet social needs. SPECIFIC AIMS: We aimed to increase routine social determinants of health (SDoH) screening of eligible PwCF from 0% to 95% and follow-up within 2 weeks for those PwCF who screened positive and requested assistance from 0% to 95% by December 31, 2021. METHODS: The Model for Improvement methodology was used. A process map and a simplified failure mode effects analysis chart were created for the screening and SDoH follow-up process. For those who screened positive for SDoH and requested assistance, follow-up contact was made to offer intervention. INTERVENTION: Adult PwCF who had at least one UVA Clinic encounter in 2021 were screened for SDoH. The SDoH screening tool included eight domains: housing, food, transportation, utilities, health-care access, medication access, income/employment, and education. Follow-up was completed with all PwCF who screened positive for SDoH. RESULTS: A total of 132 of 142 (93.0%) PwCF eligible for screening completed the SDoH screening. Of the PwCF who completed screening, 56 (42.4%) screened positive for SDoH. A follow-up rate of 100% was achieved in June 2021 and maintained through December 2021. CONCLUSION: Implementing screening for SDOH and follow-up to mitigate social difficulties in adult PwCF at UVA was successful and could be reproduced at other CF care centers.


Assuntos
Fibrose Cística , Determinantes Sociais da Saúde , Adulto , Humanos , Melhoria de Qualidade , Fibrose Cística/diagnóstico , Programas de Rastreamento/métodos , Renda
15.
PLoS Pathog ; 18(5): e1010518, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35584193

RESUMO

The three human pathogenic ebolaviruses: Zaire (EBOV), Bundibugyo (BDBV), and Sudan (SUDV) virus, cause severe disease with high fatality rates. Epitopes of ebolavirus glycoprotein (GP) recognized by antibodies with binding breadth for all three ebolaviruses are of major interest for rational vaccine design. In particular, the heptad repeat 2 -membrane-proximal external region (HR2-MPER) epitope is relatively conserved between EBOV, BDBV, and SUDV GP and targeted by human broadly-neutralizing antibodies. To study whether this epitope can serve as an immunogen for the elicitation of broadly-reactive antibody responses, protein design in Rosetta was employed to transplant the HR2-MPER epitope identified from a co-crystal structure with the known broadly-reactive monoclonal antibody (mAb) BDBV223 onto smaller scaffold proteins. From computational analysis, selected immunogen designs were produced as recombinant proteins and functionally validated, leading to the identification of a sterile alpha motif (SAM) domain displaying the BDBV-HR2-MPER epitope near its C terminus as a promising candidate. The immunogen was fused to one component of a self-assembling, two-component nanoparticle and tested for immunogenicity in rabbits. Robust titers of cross-reactive serum antibodies to BDBV and EBOV GPs and moderate titers to SUDV GP were induced following immunization. To confirm the structural composition of the immunogens, solution NMR studies were conducted and revealed structural flexibility in the C-terminal residues of the epitope. Overall, our study represents the first report on an epitope-focused immunogen design based on the structurally challenging BDBV-HR2-MPER epitope.


Assuntos
Ebolavirus , Doença pelo Vírus Ebola , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais , Epitopos , Glicoproteínas , Coelhos
16.
J Exp Med ; 219(4)2022 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-35297953

RESUMO

Venezuelan equine encephalitis virus (VEEV) remains a risk for epidemic emergence or use as an aerosolized bioweapon. To develop possible countermeasures, we isolated VEEV-specific neutralizing monoclonal antibodies (mAbs) from mice and a human immunized with attenuated VEEV strains. Functional assays and epitope mapping established that potently inhibitory anti-VEEV mAbs bind distinct antigenic sites in the A or B domains of the E2 glycoprotein and block multiple steps in the viral replication cycle including attachment, fusion, and egress. A 3.2-Å cryo-electron microscopy reconstruction of VEEV virus-like particles bound by a human Fab suggests that antibody engagement of the B domain may result in cross-linking of neighboring spikes to prevent conformational requirements for viral fusion. Prophylaxis or postexposure therapy with these mAbs protected mice against lethal aerosol challenge with VEEV. Our study defines functional and structural mechanisms of mAb protection and suggests that multiple antigenic determinants on VEEV can be targeted for vaccine or antibody-based therapeutic development.


Assuntos
Vírus da Encefalite Equina Venezuelana , Encefalomielite Equina Venezuelana , Vacinas Virais , Aerossóis , Animais , Anticorpos Monoclonais , Anticorpos Neutralizantes , Anticorpos Antivirais , Microscopia Crioeletrônica , Encefalomielite Equina Venezuelana/prevenção & controle , Cavalos , Camundongos
17.
Am J Physiol Endocrinol Metab ; 321(3): E433-E442, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34370596

RESUMO

Sepsis is a dysregulated systemic response to infection and can lead to organ damage and death. Obesity is a significant problem worldwide and affects outcomes from sepsis. Our laboratory demonstrated that white adipose tissue (WAT) undergoes browning during sepsis, a process whereby WAT adopts a brown adipose tissue phenotype. However, this browning process was not observed in obese mice during sepsis. White adipose tissue browning is detrimental in patients with burn injury and cancer. We hypothesize that norepinephrine (NE) induces WAT browning in nonobese mice but not in obese mice similarly to sepsis-induced WAT browning. Six-week-old C57BL/6 male mice were randomized to a high-fat diet or normal diet. After 6-7 wk of feeding, polymicrobial sepsis was induced by cecal ligation and puncture (CLP). Norepinephrine was administered intraperitoneally via osmotic minipumps for 18 h or 72 h (no CLP) at which time tissue and plasma were harvested. Controls were mice that underwent CLP (no NE) with 18-h harvest. A separate group of mice underwent pretreatment with NE or vehicle infusion for 72 h, CLP was performed, and at 18 h had tissue and plasma harvested. Sepsis resulted in significant weight loss in both nonobese and obese mice. NE treatment alone caused weight loss in obese mice. Septic nonobese mice had higher uncoupling protein-1 (UCP1) expression compared with control and obese septic mice. NE treatment increased UCP1 expression in nonobese, but not obese mice. NE-treated obese septic mice had lower lung myeloperoxidase (MPO) activity, alanine aminotransferase (ALT), aspartate aminotransferase (AST), TNFα, and IL-6 levels compared with NE-treated nonobese septic mice. Obesity protects mice from septic-induced and NE-induced WAT browning.NEW & NOTEWORTHY White adipose tissue browning is detrimental in patients with burn injury and cancer. WAT browning occurs in nonobese mice and can be induced by ß receptor norepinephrine infusion, but obese mice are resistant to sepsis-induced and norepinephrine-induced WAT browning. We propose that the lack of WAT browning and unchanged inflammatory cytokine response may contribute to the protection of obese mice from sepsis.


Assuntos
Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Branco/metabolismo , Norepinefrina/administração & dosagem , Obesidade/metabolismo , Sepse/metabolismo , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Branco/diagnóstico por imagem , Animais , Dieta Hiperlipídica , Masculino , Camundongos Endogâmicos C57BL , Obesidade/complicações , Sepse/complicações
18.
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
19.
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
20.
BMJ Open Qual ; 10(3)2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34433580

RESUMO

IntroductionThe Cystic Fibrosis (CF) Foundation chronic care guidelines recommend monitoring spirometry during quarterly multidisciplinary visits to identify early lung function decline. During the COVID-19 pandemic, the CF adult clinic at University of Virginia (UVA) transitioned from the classic CF care model to a model that included quarterly multidisciplinary telemedicine visits. While using telemedicine, CF care needed to include spirometry monitoring. Only a fraction of adult CF patients at UVA owned and used home spirometers (HS) in March 2020. AIM: The specific aims of this quality improvement (QI) project were to increase the percentage of eligible adult CF patients who owned an HSs from 37% to 85% and to increase the percentage of adult CF patients seen at UVA with available spirometry in telemedicine from 50% to 95% by 31 December 2020. METHODS: Following the Model for Improvement QI methodology, a standardised process was developed for monitoring forced expiratory volume in 1 s with HS during multidisciplinary telemedicine visits during the COVID-19 pandemic. INTERVENTION: (1) HSs were distributed to eligible patients and (2) Home spirometry was monitored in eligible patients with each telemedicine visit and results were used for clinical care decisions. RESULTS: Both specific aims were achieved ahead of expected date. In March 2020, the beginning of the pandemic, 37% (49/131) of patients owned an HS and 50% (9/18) of patients seen via telemedicine performed spirometry at home. By September 2020, 97% (127/131) of adult patients at UVA owned an HS and by October 2020, 96% (24/25) of patients provided spirometry results during their telemedicine encounters. CONCLUSION: Employing QI tools to standardise the process of monitoring spirometry data with home devices via telemedicine is reliable and sustainable and can be replicated across centres that provide care for patients with CF.


Assuntos
COVID-19 , Fibrose Cística , Telemedicina , Adulto , Fibrose Cística/diagnóstico , Fibrose Cística/epidemiologia , Fibrose Cística/terapia , Humanos , Pandemias , Melhoria de Qualidade , SARS-CoV-2 , Espirometria
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