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1.
ACG Case Rep J ; 11(4): e01345, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38638202

RESUMO

Meckel diverticulum is the most common congenital variation of the gastrointestinal tract arising from incomplete obliteration of the vitelline duct during gestation. In most cases, individuals are asymptomatic. This is a case of a 38-year-old patient with hematochezia in whom Meckel diverticulum was diagnosed. A mass was identified within the diverticulum. Histopathological and immunohistochemical studies revealed a well-differentiated neuroendocrine tumor. The development of tumors in Meckel diverticulum is rare, and when identified, only 0.5%-3.2% of these tumors are found to be malignant. Furthermore, gastrointestinal bleeding is an infrequent clinical feature of neuroendocrine tumors. A unique aspect of this case was that numerous imaging studies and endoscopic procedures were unable to definitively identify the presence of Meckle diverticulum and underlying neuroendocrine tumor. Through a high clinical suspicion and collaboration with surgical colleagues, an exploratory laparotomy was performed, which ultimately led to the identification and diagnosis of the underlying pathology.

2.
Clin Lymphoma Myeloma Leuk ; 24(5): e181-e190, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38433043

RESUMO

BACKGROUND: Little recent real-world evidence exists on overall survival, healthcare resource utilization (HCRU), and costs among R/R DLBCL patients treated with the combination of rituximab, gemcitabine, and oxaliplatin (R-GemOx), a widely-used regimen for patients ineligible for stem cell transplant due to age or comorbidities. PATIENTS AND METHODS: This retrospective analysis used 2014 to 2019 U.S. Medicare claims. Individuals aged ≥66 years with a new DLBCL diagnosis between October 1, 2015 and December 31, 2018 and continuous fee-for-service Medicare Part A, B, and D coverage in the 12 months pre- and postindex were followed to identify the sample of patients with evidence of R-GemOx treatment in the second-line (2L) or third-line (3L) setting. Outcomes included overall survival, all-cause and DLBCL-related HCRU, and costs after R-GemOx initiation. RESULTS: The final sample included 157 patients who received treatment with R-GemOx in the R/R settings (mean (SD) age 77.5 (6.0) years, 39.5% age>80 years; 66.9% male; 91.1% White). Of these, 126 received R-GemOx in the 2L setting and 31 received R-GemOx in the 3L setting. Median overall survival from R-GemOx initiation was 6.9 months and 6.8 months in the 2L and 3L setting, respectively. Rates of all-cause hospitalization (68.1% [2L] and >90% [3L]) and hospice use (42.9% [2L] and 51.7% [3L]) were high in the 12 months after R-GemOx initiation. All-cause total costs were substantial ($144,653 [2L] and $142,812 [3L]) and approximately 80% of costs were DLBCL-related within 12 months of R-GemOx initiation. CONCLUSION: Elderly U.S. Medicare beneficiaries diagnosed with DLBCL who initiated R-GemOx treatment in the R/R setting have poor overall survival, high rates of HCRU, and substantial costs.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Linfoma Difuso de Grandes Células B , Humanos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/mortalidade , Linfoma Difuso de Grandes Células B/economia , Idoso , Masculino , Feminino , Idoso de 80 Anos ou mais , Estudos Retrospectivos , Estados Unidos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/economia , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Gencitabina , Custos de Cuidados de Saúde/estatística & dados numéricos , Oxaliplatina/uso terapêutico , Oxaliplatina/economia , Rituximab/uso terapêutico , Rituximab/economia , Medicare
3.
Future Oncol ; 20(6): 317-328, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38050764

RESUMO

Aim: To examine real-world treatment patterns, survival, healthcare resource use and costs in elderly Medicare beneficiaries with diffuse large B-cell lymphoma (DLBCL). Methods: 11,880 Medicare patients aged ≥66 years with DLBCL between 1 October 2015 and 31 December 2018 were followed for ≥12 months after initiating front-line treatment. Results: Two-thirds (61.2%) of the patients received standard-of-care R-CHOP as first-line treatment. Hospitalization was common (57%) in the 12-months after initiation of 1L treatment; the mean DLCBL-related total costs were US$84,416 during the same period. Over a median follow-up of 2.1 years, 17.8% received at least 2L treatment. Overall survival was lower among later lines of treatment (median overall survival from initiation of 1L: not reached; 2L: 19.9 months; 3L: 9.8 months; 4L: 5.5 months). Conclusion: A large unmet need exists for more efficacious and well-tolerated therapies for older adults with DLBCL.


Diffuse large B-cell lymphoma (DLBCL) is the most common form of Non-Hodgkin lymphoma, and it becomes more common with age. While researchers continue to develop newer, more effective treatments for DLBCL, it is important to understand how patients use existing treatments and the associated costs, particularly among the elderly. In our real-world analysis of nearly 12,000 older patients with DLBCL, we found high rates of hospitalization and hospice use, short length of life in later lines of therapy and substantial healthcare costs. Our findings suggest a large current unmet need for more effective and well-tolerated therapies for older adults with DLBCL in both the front-line and relapse/refractory settings.


Assuntos
Linfoma Difuso de Grandes Células B , Medicare , Humanos , Idoso , Estados Unidos/epidemiologia , Rituximab/uso terapêutico , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Recursos em Saúde , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Estudos Retrospectivos
4.
Br J Cancer ; 130(3): 425-433, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38097739

RESUMO

BACKGROUND: CA-125 alone is widely used to diagnose progressive disease (PD) in platinum-sensitive recurrent ovarian cancer (PSROC) on chemotherapy. However, there are increasing concerns regarding its accuracy. We assessed concordance between progression defined by CA-125 and RECIST using data from the CALYPSO trial. METHODS: We computed concordance rates for PD by CA-125 and RECIST to determine the positive (PPV) and negative predictive values (NPV). RESULTS: Of 769 (79%) evaluable participants, 387 had CA-125 PD, where only 276 had concordant RECIST PD (PPV 71%, 95% CI 67-76%). For 382 without CA-125 PD, 255 had RECIST PD but 127 did not (NPV 33%, 95% CI 29-38). There were significant differences in NPV according to baseline CA-125 (≤100 vs >100: 42% vs 25%, P < 0.001); non-measurable vs measurable disease (51% vs 26%, P < 0.001); and platinum-free-interval (>12 vs 6-12 months: 41% vs 14%, P < 0.001). We observed falling CA-125 levels in 78% of patients with RECIST PD and CA-125 non-PD. CONCLUSION: Approximately 2 in 3 women with PSROC have RECIST PD but not CA-125 PD by GCIG criteria. Monitoring CA-125 levels alone is not reliable for detecting PD. Further research is required to investigate the survival impact of local therapy in radiological detected early asymptomatic PD.


Assuntos
Neonicotinoides , Neoplasias Ovarianas , Tiazinas , Humanos , Feminino , Neoplasias Ovarianas/diagnóstico por imagem , Neoplasias Ovarianas/tratamento farmacológico , Critérios de Avaliação de Resposta em Tumores Sólidos , Recidiva Local de Neoplasia/tratamento farmacológico , Carcinoma Epitelial do Ovário
5.
Leuk Lymphoma ; 64(11): 1752-1770, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37497877

RESUMO

Studies evaluating real-world outcomes and health care utilization for mantle cell lymphoma are limited. We utilized national Medicare claims (2009-2019) to examine treatment patterns, healthcare resource utilization, costs, and survival in 3664 elderly patients receiving 1 L treatment for MCL. Over a median follow-up of 2.8 years, 40.3% received at least 2 L treatment. The most common 1 L regimen was bendamustine-rituximab (50.1%), with increased use of BTKi-based regimens observed in 2 L (39.4%). Half (51.8%) of patients had an all-cause hospitalization within 12 months of initiating 1 L; hospitalization rates were higher in later lines. Healthcare costs were substantial and most costs (>80%) were MCL-related. Overall survival was poorer among later lines of treatment (median OS from initiation of 1 L: 53.5 months; 2 L: 22.0 months; 3 L: 11.8 months; 4 L: 7.8 months). These results suggest a large unmet need and future work should evaluate whether novel therapies have improved outcomes among elderly patients with MCL.


Assuntos
Linfoma de Célula do Manto , Adulto , Humanos , Idoso , Estados Unidos/epidemiologia , Linfoma de Célula do Manto/tratamento farmacológico , Linfoma de Célula do Manto/epidemiologia , Medicare , Rituximab/uso terapêutico , Custos de Cuidados de Saúde , Aceitação pelo Paciente de Cuidados de Saúde , Estudos Retrospectivos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos
6.
BMJ Case Rep ; 16(7)2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37495372

RESUMO

Chylous effusions are a rare complication of disseminated non-tuberculous mycobacterial (NTM) infection. This is a case couplet reporting on the treatment challenge of chylous effusions secondary to NTM infection in two individuals living with advanced HIV. Their treatment was complicated by associated immune reconstitution inflammatory syndrome. They both required intermittent paracentesis, steroid treatment and transitioning on to fat-free diets alongside NTM treatment. Only after months of this treatment regimen was successful resolution of the associated chylous effusions achieved. Chylous effusions in immunosuppressed patients living with NTM infection are rarely reported and difficult to manage. This report discusses treatment approaches and highlights the difficulties faced by the treating team.


Assuntos
Infecções por HIV , Infecções por Mycobacterium não Tuberculosas , Transtornos Respiratórios , Humanos , Infecções por Mycobacterium não Tuberculosas/complicações , Exsudatos e Transudatos , Infecções por HIV/complicações
8.
Artigo em Inglês | MEDLINE | ID: mdl-37179659

RESUMO

The gut microbiota plays crucial roles in maintaining the health and homeostasis of its host throughout lifespan, including through its ability to impact brain function and regulate behaviour during ageing. Studies have shown that there are disparate rates of biologic ageing despite equivalencies in chronologic age, including in the development of neurodegenerative diseases, which suggests that environmental factors may play an important role in determining health outcomes in ageing. Recent evidence demonstrates that the gut microbiota may be a potential novel target to ameliorate symptoms of brain ageing and promote healthy cognition. This review highlights the current knowledge around the relationships between the gut microbiota and host brain ageing, including potential contributions to age-related neurodegenerative diseases. Furthermore, we assess key areas for which gut microbiota-based strategies may present as opportunities for intervention.

9.
Clin Liver Dis ; 27(2): 373-395, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37024214

RESUMO

As the prevalence of obesity and type 2 diabetes increases around the world, the prevalence of nonalcoholic fatty liver disease (NAFLD) has grown proportionately. Although most patients with NAFLD do not experience progressive liver disease, about 15% to 20% of those with nonalcoholic steatohepatitis can and do progress. Because liver biopsy's role in NAFLD has become increasingly limited, efforts have been undertaken to develop non-invasive tests (NITs) to help identify patients at high risk of progression. The following article discusses the NITs that are available to determine the presence of NAFLD as well as high-risk NAFLD.


Assuntos
Diabetes Mellitus Tipo 2 , Técnicas de Imagem por Elasticidade , Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Cirrose Hepática/etiologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/epidemiologia , Imageamento por Ressonância Magnética , Fígado/patologia , Medição de Risco
11.
Aliment Pharmacol Ther ; 57(6): 709-722, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36380111

RESUMO

BACKGROUND: Mortality benefits of vigorous leisure time physical activity (LTPA) among adults with NAFLD is not known. AIM: To investigate association between LTPA and reduction in all-cause mortality among adults with NAFLD. METHODS: We used NHANES (1999-2006) self-reported PA data for adults (≥40 years) with mortality follow-up through December 31, 2015. US-Fatty Liver Index in absence of secondary causes identified NAFLD. Moderate and vigorous LTPA were calculated by the 2018 PA Guidelines for Americans. RESULTS: NAFLD prevalence among 5211 adults (46.2% male; 75.8% white; mean age 53.2 years) was 32.7%. Adults with NAFLD were less likely to report the recommended minimal PA (≥ 150 min/week, 55.5% vs 64.8%) or highly active PA (≥300 min/week, 39.2% vs 48.5%) compared to adults without NAFLD. Over a median follow-up of 12.3 years, 355 deaths among adults with NAFLD and 510 deaths among adults without NAFLD were registered. In the metabolic comorbidities-adjusted model, adults with NAFLD who reported ≥50% of their total PA as vigorous activity had a 56% reduction in all-cause mortality risk (HR:0.44, 95%CI: 0.25-0.76) and cancer-specific mortality risk (HR: 0.21, 0.06-0.66) but not cardiac-specific mortality (p > 0.05) compared to adults with NAFLD who did not report any LTPA. This association remained significant even among adults with NAFLD who met the recommended minimal PA, among adults with NAFLD who reported any LTPA, and among adults with NAFLD who had metabolic abnormalities and in sensitivity analysis. CONCLUSIONS: Engaging in vigorous activity is beneficial for adults with NAFLD - especially those with metabolic abnormalities.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Humanos , Adulto , Masculino , Estados Unidos , Pessoa de Meia-Idade , Feminino , Exercício Físico , Inquéritos Nutricionais , Atividade Motora , Comorbidade
13.
iScience ; 25(11): 105308, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36388952

RESUMO

Glaucoma is an optic neuropathy characterized by permanent visual field loss caused by the death of retinal ganglion cells (RGCs) and it is the leading cause of irreversible blindness worldwide. Consequently, there is an unmet need for the development of new strategies for its treatment. We investigated RGC replacement therapy as a treatment for ganglion cell loss. Human-induced pluripotent stem cells (hiPSCs) were differentiated into mature, functional RGCs in vitro, labeled with AAV2.7m8-SNCG-eGFP, and transplanted intravitreally in wild-type 4-month-old C57BL/6J mice. Survival of the transplanted hiPSC-RGCs was assessed by color fundus photography and histological studies confirmed the localization of the transplanted hiPSC-RGCs within the retina. Two-photon live imaging of retinal explants and electrophysiological studies confirmed that the morphology and function of the transplanted hiPSC-RGCs were similar to native RGCs. These experiments will provide key strategies to enhance the efficiency of stem cell replacement therapy for neurodegenerative diseases, including glaucoma.

14.
Pathogens ; 10(10)2021 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-34684188

RESUMO

The inflammatory response in pediatric sepsis is highly dynamic and includes both pro- and anti-inflammatory elements that involve the innate and adaptive immune systems. While the pro-inflammatory response is responsible for the initial clinical signs and symptoms of sepsis, a concurrent compensatory anti-inflammatory response often results in an occult, but highly clinically relevant, form of acquired immunodeficiency. When severe, this is termed "immunoparalysis" and is associated with increased risks for nosocomial infection, prolonged organ dysfunction, and death. This review focuses on the pathophysiology and clinical implications of both over- and under-active immune function in septic children. Host-, disease-, and treatment-specific risk factors for immunoparalysis are reviewed along with immune phenotype-specific approaches for immunomodulation in pediatric sepsis which are currently the subject of clinical trials.

16.
Am J Cardiol ; 158: 81-89, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34509293

RESUMO

In women with mitral stenosis (MS), mitral valve gradients and right ventricular systolic pressure (RVSP) can increase in response to the physiologic stress of pregnancy. The prognostic significance of these echocardiographic changes has not been well studied. Pregnancy outcomes and serial echocardiograms were collected in women with MS prospectively recruited as part of a larger study on pregnancy outcomes. Third trimester echocardiograms were compared with baseline echocardiograms. Changes in mitral valve area (MVA), transmitral mean gradient (MG), and RVSP during pregnancy and their relationship to adverse cardiac events (CE) were examined. Fifty-six pregnancies in 47 women with MS were included. The MVA did not change during pregnancy (1.6 ± 0.6 cm2 at baseline vs 1.7 ± 0.6 cm2 in the third trimester, p = 0.46). There was an increase in the MG (8 ± 3 vs 11 ± 6 mm Hg, p <0.001) and the RVSP (39 ± 14 vs 47 ± 20 mm Hg, p <0.001) during the third trimester. Adverse CE occurred in 45% (25/56) of pregnancies. CE were associated with baseline MG>10 mm Hg, baseline RVSP >40 mm Hg, third-trimester MG>10 mm Hg, and RVSP >40 mm Hg. Women with mitral valve MG ≤10 mm Hg who had a normal RVSP at baseline and in the third trimester were at lowest risk for CE (11%) with a negative predictive value of 89%. In conclusion, baseline echocardiographic assessment of MS severity as well as changing echocardiographic parameters during pregnancy can help identify women at risk for cardiac complications during pregnancy.


Assuntos
Estenose da Valva Mitral/complicações , Estenose da Valva Mitral/fisiopatologia , Complicações Cardiovasculares na Gravidez/fisiopatologia , Adulto , Pressão Sanguínea , Ecocardiografia , Feminino , Humanos , Estenose da Valva Mitral/diagnóstico por imagem , Gravidez , Complicações Cardiovasculares na Gravidez/diagnóstico por imagem , Estudos Retrospectivos , Função Ventricular Direita/fisiologia
17.
Immunohorizons ; 5(5): 322-335, 2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-34001652

RESUMO

SARS-CoV-2 has caused over 100,000,000 cases and almost 2,500,000 deaths globally. Comprehensive assessment of the multifaceted antiviral Ab response is critical for diagnosis, differentiation of severity, and characterization of long-term immunity, especially as COVID-19 vaccines become available. Severe disease is associated with early, massive plasmablast responses. We developed a multiplex immunoassay from serum/plasma of acutely infected and convalescent COVID-19 patients and prepandemic and postpandemic healthy adults. We measured IgA, IgG, and/or IgM against SARS-CoV-2 nucleocapsid (N), spike domain 1 (S1), S1-receptor binding domain (RBD) and S1-N-terminal domain. For diagnosis, the combined [IgA + IgG + IgM] or IgG levels measured for N, S1, and S1-RBD yielded area under the curve values ≥0.90. Virus-specific Ig levels were higher in patients with severe/critical compared with mild/moderate infections. A strong prozone effect was observed in sera from severe/critical patients-a possible source of underestimated Ab concentrations in previous studies. Mild/moderate patients displayed a slower rise and lower peak in anti-N and anti-S1 IgG levels compared with severe/critical patients, but anti-RBD IgG and neutralization responses reached similar levels at 2-4 mo after symptom onset. Measurement of the Ab responses in sera from 18 COVID-19-vaccinated patients revealed specific responses for the S1-RBD Ag and none against the N protein. This highly sensitive, SARS-CoV-2-specific, multiplex immunoassay measures the magnitude, complexity, and kinetics of the Ab response and can distinguish serum Ab responses from natural SARS-CoV-2 infections (mild or severe) and mRNA COVID-19 vaccines.


Assuntos
Anticorpos Antivirais , Vacinas contra COVID-19/administração & dosagem , COVID-19 , SARS-CoV-2 , Índice de Gravidade de Doença , Vacinação , Adulto , Idoso , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , COVID-19/sangue , COVID-19/imunologia , COVID-19/prevenção & controle , Feminino , Humanos , Imunoensaio , Masculino , Pessoa de Meia-Idade , SARS-CoV-2/imunologia , SARS-CoV-2/metabolismo
18.
BMJ Case Rep ; 14(3)2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33782063

RESUMO

Tracheoarterial fistula is a complication of tracheostomy with a high associated mortality. A 25-year-old male patient with Duchenne's muscular dystrophy underwent a percutaneous tracheostomy using the single tapered dilator (Blue Rhino) technique to facilitate weaning from mechanical ventilation. Nine weeks after the procedure, he developed significant upper airway bleeding, leading to haemodynamic instability. A CT angiogram of the neck and thorax did not reveal a source of the bleeding. The patient was subsequently transferred to the operating theatre where a 1 cm defect in the right common carotid artery was found and repaired with a graft from the left short saphenous vein. Clinicians who undertake tracheostomy formation should be aware of the possibility of tracheoarterial defect and may wish to discuss it at tracheostomy formation. It should be considered early in the event of a significant bleed. This case identifies deep tissue infection and misplacement of the tracheostomy tube as major contributing factors to fistula formation.


Assuntos
Doenças da Traqueia , Traqueostomia , Adulto , Tronco Braquiocefálico , Humanos , Masculino , Veia Safena/diagnóstico por imagem , Veia Safena/cirurgia , Traqueia , Doenças da Traqueia/cirurgia , Traqueostomia/efeitos adversos
19.
JMIR Res Protoc ; 10(1): e19770, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33404514

RESUMO

BACKGROUND: Black sexual minority men (BSMM) are disproportionately affected by HIV. Los Angeles County (LAC) carries a substantial burden of the HIV epidemic in California. Negative effects of both psychosocial and structural barriers highlight the timely need to increase HIV treatment among BSMM. Successful HIV interventions based on social media and mobile phone technology have been demonstrated. This protocol describes LINX LA, a study that tests LINX, a web-based mobile app that provides tailored social services, legal resources, and peer support for BSMM living with HIV (BSMM+) in LAC using a randomized comparison trial. OBJECTIVE: During phase 1, the LINX LA study aims to engage in an iterative design process to develop the LINX App using qualitative data to inform and tailor the mobile app technology and its functionality. In phase 2 of LINX LA, we will test the efficacy of the LINX App compared with the LINX App Plus to improve HIV treatment outcomes (ie, antiretroviral therapy adherence, viral suppression) among BSMM+ in LAC by addressing social work and legal needs and developing a forum for peer support. METHODS: In this study funded by the California HIV/AIDS Research Program, we will recruit and enroll BSMM+ participants (aged ≥18 years) in LAC (N=400) to participate in a 12-month study that includes access to the LINX App, which provides a forum for peer support and tailored content aimed at improving the use of social and legal resources. All participants will also receive survey-based interviews at 3 time points (at baseline and 6- and 12-month intervals) and weekly text message surveys that assess medication and treatment adherence. Treatment adherence and viral suppression will be extracted from medical record data. Half of the participants will also be randomly assigned to receive 3 individualized coaching sessions (at 1-, 3-, and 6-month intervals) and the ability to directly message their coach via the LINX App. Over the course of the study, LINX App participants will receive a minimum of US $130 in cash and LINX App Plus participants will receive a minimum of US $190. We hypothesize that participants enrolled in LINX App Plus will demonstrate greater improvement in HIV outcomes compared with LINX App participants. RESULTS: The LINX study will test the efficacy of a web-based mobile app intervention for BSMM+ in LAC (N=400). The LINX App seeks to increase participants' knowledge of HIV; to facilitate access to necessary social and legal services, including information and referrals; and to increase social support across participants by providing a mediated forum for engagement. CONCLUSIONS: The implementation of LINX LA aims to develop and test a culturally tailored approach to improve the HIV treatment outcomes of BSMM+. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/19770.

20.
Viruses ; 12(12)2020 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-33353101

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the most recent global pandemic that has caused more than a million deaths around the world. The spike glycoprotein (S) drives the entry and fusion of this virus and is the main determinant of cell tropism. To explore S requirements for entry under BSL2 conditions, S has been pseudotyped onto vesicular stomatitis virus (VSV) or retroviral particles with varied success. Several alterations to S were demonstrated to improve pseudoparticle titers, but they have not been systematically compared. In this study, we produced pseudotyped VSV particles with multiple modifications to S, including truncation, mutation, and tagging strategies. The main objective of this study was to determine which modifications of the S protein optimize cell surface expression, incorporation into pseudotyped particles, and pseudoparticle entry. Removal of the last 19 residues of the cytoplasmic tail produced a hyper-fusogenic S, while removal of 21 residues increased S surface production and VSV incorporation. Additionally, we engineered a replication-competent VSV (rVSV) virus to produce the S-D614G variant with a truncated cytoplasmic tail. While the particles can be used to assess S entry requirements, the rVSV∆G/SMet1D614G∆21 virus has a poor specific infectivity (particle to infectious titer ratio).


Assuntos
SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genética , Vírus da Estomatite Vesicular Indiana/genética , Proteínas do Envelope Viral/genética , Replicação Viral , Animais , Linhagem Celular , Células Cultivadas , Chlorocebus aethiops , Imunofluorescência , Expressão Gênica , Genes Reporter , Engenharia Genética , Células Gigantes , Humanos , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/metabolismo , Células Vero , Vírus da Estomatite Vesicular Indiana/metabolismo , Internalização do Vírus
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