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1.
Nat Immunol ; 23(9): 1324-1329, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36038709

RESUMO

T cells can contribute to clearance of respiratory viruses that cause acute-resolving infections such as SARS-CoV-2, helping to provide long-lived protection against disease. Recent studies have suggested an additional role for T cells in resisting overt infection: pre-existing cross-reactive responses were preferentially enriched in healthcare workers who had abortive infections1, and in household contacts protected from infection2. We hypothesize that such early viral control would require pre-existing cross-reactive memory T cells already resident at the site of infection; such airway-resident responses have been shown to be critical for mediating protection after intranasal vaccination in a murine model of SARS-CoV3. Bronchoalveolar lavage samples from the lower respiratory tract of healthy donors obtained before the COVID-19 pandemic revealed airway-resident, SARS-CoV-2-cross-reactive T cells, which correlated with the strength of human seasonal coronavirus immunity. We therefore demonstrate the potential to harness functional airway-resident SARS-CoV-2-reactive T cells in next-generation mucosal vaccines.


Assuntos
COVID-19 , SARS-CoV-2 , Animais , Anticorpos Antivirais , Reações Cruzadas , Humanos , Camundongos , Pandemias , Sistema Respiratório
2.
Nature ; 601(7891): 110-117, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34758478

RESUMO

Individuals with potential exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) do not necessarily develop PCR or antibody positivity, suggesting that some individuals may clear subclinical infection before seroconversion. T cells can contribute to the rapid clearance of SARS-CoV-2 and other coronavirus infections1-3. Here we hypothesize that pre-existing memory T cell responses, with cross-protective potential against SARS-CoV-2 (refs. 4-11), would expand in vivo to support rapid viral control, aborting infection. We measured SARS-CoV-2-reactive T cells, including those against the early transcribed replication-transcription complex (RTC)12,13, in intensively monitored healthcare workers (HCWs) who tested repeatedly negative according to PCR, antibody binding and neutralization assays (seronegative HCWs (SN-HCWs)). SN-HCWs had stronger, more multispecific memory T cells compared with a cohort of unexposed individuals from before the pandemic (prepandemic cohort), and these cells were more frequently directed against the RTC than the structural-protein-dominated responses observed after detectable infection (matched concurrent cohort). SN-HCWs with the strongest RTC-specific T cells had an increase in IFI27, a robust early innate signature of SARS-CoV-2 (ref. 14), suggesting abortive infection. RNA polymerase within RTC was the largest region of high sequence conservation across human seasonal coronaviruses (HCoV) and SARS-CoV-2 clades. RNA polymerase was preferentially targeted (among the regions tested) by T cells from prepandemic cohorts and SN-HCWs. RTC-epitope-specific T cells that cross-recognized HCoV variants were identified in SN-HCWs. Enriched pre-existing RNA-polymerase-specific T cells expanded in vivo to preferentially accumulate in the memory response after putative abortive compared to overt SARS-CoV-2 infection. Our data highlight RTC-specific T cells as targets for vaccines against endemic and emerging Coronaviridae.


Assuntos
Infecções Assintomáticas , COVID-19/imunologia , COVID-19/virologia , RNA Polimerases Dirigidas por DNA/imunologia , Células T de Memória/imunologia , SARS-CoV-2/imunologia , Soroconversão , Proliferação de Células , Estudos de Coortes , RNA Polimerases Dirigidas por DNA/metabolismo , Evolução Molecular , Feminino , Pessoal de Saúde , Humanos , Masculino , Proteínas de Membrana/imunologia , Células T de Memória/citologia , Complexos Multienzimáticos/imunologia , SARS-CoV-2/enzimologia , SARS-CoV-2/crescimento & desenvolvimento , Transcrição Gênica/imunologia
3.
Immunol Rev ; 310(1): 6-26, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35661178

RESUMO

Antibodies against epitopes in S1 give the most accurate CoP against infection by the SARS-CoV-2 coronavirus. Measurement of those antibodies by neutralization or binding assays both have predictive value, with binding antibody titers giving the highest statistical correlation. However, the protective functions of antibodies are multiple. Antibodies with multiple functions other than neutralization influence efficacy. The role of cellular responses can be discerned with respect to CD4+ T cells and their augmentation of antibodies, and with respect to CD8+ cells with regard to control of viral replication, particularly in the presence of insufficient antibody. More information is needed on mucosal responses.


Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19 , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/imunologia , COVID-19/prevenção & controle , Epitopos/imunologia , Humanos , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia
4.
PLoS Pathog ; 19(9): e1011138, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37695784

RESUMO

Pneumonia is a worldwide threat, making discovery of novel means to combat lower respiratory tract infection an urgent need. Manipulating the lungs' intrinsic host defenses by therapeutic delivery of certain pathogen-associated molecular patterns protects mice against pneumonia in a reactive oxygen species (ROS)-dependent manner. Here we show that antimicrobial ROS are induced from lung epithelial cells by interactions of CpG oligodeoxynucleotides (ODN) with mitochondrial voltage-dependent anion channel 1 (VDAC1). The ODN-VDAC1 interaction alters cellular ATP/ADP/AMP localization, increases delivery of electrons to the electron transport chain (ETC), increases mitochondrial membrane potential (ΔΨm), differentially modulates ETC complex activities and consequently results in leak of electrons from ETC complex III and superoxide formation. The ODN-induced mitochondrial ROS yield protective antibacterial effects. Together, these studies identify a therapeutic metabolic manipulation strategy to broadly protect against pneumonia without reliance on antibiotics.


Assuntos
Anti-Infecciosos , Pneumonia , Camundongos , Animais , Espécies Reativas de Oxigênio/metabolismo , Mitocôndrias/metabolismo , Pulmão/metabolismo , Pneumonia/metabolismo , Anti-Infecciosos/farmacologia , Potencial da Membrana Mitocondrial
5.
J Infect Dis ; 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38530917

RESUMO

BACKGROUND: Streptococcus pneumoniae serotype 3 remains a problem globally. Malawi introduced 13-valent pneumococcal conjugate vaccine (PCV13) in 2011, but there has been no direct protection against serotype 3 carriage. We explored whether vaccine escape by serotype 3 is due to clonal expansion of a lineage with a competitive advantage. METHODS: The distribution of serotype 3 Global Pneumococcal Sequence Clusters (GPSCs) and sequence types (STs) globally was assessed using sequences from the Global Pneumococcal Sequencing Project. Whole-genome sequences of 135 serotype 3 carriage isolates from Blantyre, Malawi (2015-2019) were analyzed. Comparative analysis of the capsule locus, entire genomes, antimicrobial resistance, and phylogenetic reconstructions were undertaken. Opsonophagocytosis was evaluated using serum samples from vaccinated adults and children. RESULTS: Serotype 3 GPSC10-ST700 isolates were most prominent in Malawi. Compared with the prototypical serotype 3 capsular polysaccharide locus sequence, 6 genes are absent, with retention of capsule polysaccharide biosynthesis. This lineage is characterized by increased antimicrobial resistance and lower susceptibility to opsonophagocytic killing. CONCLUSIONS: A serotype 3 variant in Malawi has genotypic and phenotypic characteristics that could enhance vaccine escape and clonal expansion after post-PCV13 introduction. Genomic surveillance among high-burden populations is essential to improve the effectiveness of next-generation pneumococcal vaccines.

6.
Clin Infect Dis ; 78(3): 594-602, 2024 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-37647517

RESUMO

BACKGROUND: To protect healthcare workers (HCWs) from the consequences of disease due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), it is necessary to understand the risk factors that drive exposure and infection within hospitals. Insufficient consideration of key socioeconomic variables is a limitation of existing studies that can lead to bias and residual confounding of proposed risk factors for infection. METHODS: The Co-STARs study prospectively enrolled 3679 HCWs between April 2020 and September 2020. We used multivariate logistic regression to comprehensively characterize the demographic, occupational, socioeconomic, and environmental risk factors for SARS-CoV-2 seropositivity. RESULTS: After adjusting for key confounders, relative household overcrowding (odds ratio [OR], 1.4 [95% confidence interval {CI}, 1.1-1.9]; P = .006), Black, Black British, Caribbean, or African ethnicity (OR, 1.7 [95% CI, 1.2-2.3]; P = .003), increasing age (ages 50-60 years: OR, 1.8 [95% CI, 1.3-2.4]; P < .001), lack of access to sick pay (OR, 1.8 [95% CI, 1.3-2.4]; P < .001). CONCLUSIONS: Socioeconomic and demographic factors outside the hospital were the main drivers of infection and exposure to SARS-CoV-2 during the first wave of the pandemic in an urban pediatric referral hospital. Overcrowding and out-of-hospital SARS-CoV-2 contact are less amenable to intervention. However, lack of access to sick pay among externally contracted staff is more easily rectifiable. Our findings suggest that providing easier access to sick pay would lead to a decrease in SARS-CoV-2 transmission and potentially that of other infectious diseases in hospital settings. CLINICAL TRIALS REGISTRATION: NCT04380896.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Pessoa de Meia-Idade , COVID-19/epidemiologia , Demografia , Pessoal de Saúde , Hospitais , Estudos Prospectivos , Fatores de Risco , Fatores Socioeconômicos , Reino Unido/epidemiologia , População Negra , População do Caribe , População Africana
7.
N Engl J Med ; 384(23): 2202-2211, 2021 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-33861525

RESUMO

BACKGROUND: The mainstay of control of the coronavirus disease 2019 (Covid-19) pandemic is vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Within a year, several vaccines have been developed and millions of doses delivered. Reporting of adverse events is a critical postmarketing activity. METHODS: We report findings in 23 patients who presented with thrombosis and thrombocytopenia 6 to 24 days after receiving the first dose of the ChAdOx1 nCoV-19 vaccine (AstraZeneca). On the basis of their clinical and laboratory features, we identify a novel underlying mechanism and address the therapeutic implications. RESULTS: In the absence of previous prothrombotic medical conditions, 22 patients presented with acute thrombocytopenia and thrombosis, primarily cerebral venous thrombosis, and 1 patient presented with isolated thrombocytopenia and a hemorrhagic phenotype. All the patients had low or normal fibrinogen levels and elevated d-dimer levels at presentation. No evidence of thrombophilia or causative precipitants was identified. Testing for antibodies to platelet factor 4 (PF4) was positive in 22 patients (with 1 equivocal result) and negative in 1 patient. On the basis of the pathophysiological features observed in these patients, we recommend that treatment with platelet transfusions be avoided because of the risk of progression in thrombotic symptoms and that the administration of a nonheparin anticoagulant agent and intravenous immune globulin be considered for the first occurrence of these symptoms. CONCLUSIONS: Vaccination against SARS-CoV-2 remains critical for control of the Covid-19 pandemic. A pathogenic PF4-dependent syndrome, unrelated to the use of heparin therapy, can occur after the administration of the ChAdOx1 nCoV-19 vaccine. Rapid identification of this rare syndrome is important because of the therapeutic implications.


Assuntos
Autoanticorpos/sangue , Vacinas contra COVID-19/imunologia , Fator Plaquetário 4/imunologia , Trombocitopenia/imunologia , Trombose/imunologia , Adulto , Idoso , Algoritmos , Anticorpos Antivirais/sangue , Anticoagulantes/efeitos adversos , COVID-19/prevenção & controle , Vacinas contra COVID-19/efeitos adversos , ChAdOx1 nCoV-19 , Feminino , Citometria de Fluxo , Heparina/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Trombocitopenia/etiologia , Trombose/etiologia
8.
Biologicals ; 85: 101723, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37976940

RESUMO

In February 2023, a meeting about correlates of protection (CoPs) against COVID-19 was organized by the International Alliance for Biological Standardization, the European Plotkin Institute for Vaccinology, and Vaccinopolis. The meeting aimed at reviewing the evidence, drawing conclusions, and identifying knowledge gaps. Collection of evidence is not straightforward. Neutralizing antibodies correlate with protection and are used for immunobridging studies within and between vaccine platforms for approval of new COVID-19 vaccines. In preparation for the next pandemic, it is vital that rapidly authorized initial vaccines are available to perform immunobridging studies very early. Additional components of the immune response likely contribute to protection against symptomatic infection. Current evidence is strongest for T lymphocytes and binding antibodies. Further studies are needed to consolidate this evidence and define their potential role in the evaluation of vaccines. For evaluation of mucosal vaccines, identifying CoPs against infection and transmission is key; further research is needed to identify and standardize methods suitable for clinical studies. CoPs for broadly protective beta-coronavirus vaccines remain a critical area of research. The knowledge, expertise, and capacity exist to conduct clinical studies using different designs in different populations to discover and validate CoPs, facilitating and accelerating evaluation of novel vaccines/vaccination platforms.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Humanos , COVID-19/prevenção & controle , Anticorpos Neutralizantes , Pandemias/prevenção & controle , Vacinação , Anticorpos Antivirais
9.
J Clin Microbiol ; 61(1): e0080222, 2023 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-36515506

RESUMO

Streptococcus mitis is a common oral commensal and an opportunistic pathogen that causes bacteremia and infective endocarditis; however, the species has received little attention compared to other pathogenic streptococcal species. Effective and easy-to-use molecular typing tools are essential for understanding bacterial population diversity and biology, but schemes specific for S. mitis are not currently available. We therefore developed a multilocus sequence typing (MLST) scheme and defined sequence clusters or lineages of S. mitis using a comprehensive global data set of 322 genomes (148 publicly available and 174 newly sequenced). We used internal 450-bp sequence fragments of seven housekeeping genes (accA, gki, hom, oppC, patB, rlmN, and tsf) to define the MLST scheme and derived the global S. mitis sequence clusters using the PopPUNK clustering algorithm. We identified an initial set of 259 sequence types (STs) and 258 global sequence clusters. The schemes showed high concordance (100%), capturing extensive S. mitis diversity with strains assigned to multiple unique STs and global sequence clusters. The tools also identified extensive within- and between-host S. mitis genetic diversity among isolates sampled from a cohort of healthy individuals, together with potential transmission events, supported by both phylogeny and pairwise single nucleotide polymorphism (SNP) distances. Our novel molecular typing and strain clustering schemes for S. mitis allow for the integration of new strain data, are electronically portable at the PubMLST database (https://pubmlst.org/smitis), and offer a standardized approach to understanding the population structure of S. mitis. These robust tools will enable new insights into the epidemiology of S. mitis colonization, disease and transmission.


Assuntos
Streptococcus mitis , Streptococcus , Humanos , Tipagem de Sequências Multilocus , Streptococcus mitis/genética , Streptococcus/genética , Análise por Conglomerados , Filogenia
10.
J Infect Dis ; 225(2): 327-331, 2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-34888662

RESUMO

A significant correlation has been shown between the binding antibody responses against original severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein and vaccine efficacy of 4 approved coronavirus disease 2019 vaccines. We therefore assessed the immune response against original SARS-CoV-2 elicited by the adjuvanted S-Trimer vaccine, SCB-2019 + CpG/alum, in the same assay and laboratory. Responses to SCB-2019 were comparable or superior for antibody to original and Alpha variant when compared with 4 approved vaccines. The comparison accurately predicted success of the recently reported efficacy trial of SCB-2019 vaccine. Immunogenicity comparisons to original strain and variants of concern should be considered as a basis for authorization of vaccines.


Assuntos
Vacinas contra COVID-19 , COVID-19/prevenção & controle , Imunogenicidade da Vacina , Pandemias/prevenção & controle , SARS-CoV-2/imunologia , Anticorpos Neutralizantes , Anticorpos Antivirais , Humanos , SARS-CoV-2/efeitos dos fármacos , Glicoproteína da Espícula de Coronavírus/imunologia , Eficácia de Vacinas , Vacinas de Subunidades Antigênicas
11.
J Infect Dis ; 226(8): 1401-1406, 2022 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-35723969

RESUMO

The highly transmissible severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant has caused high rates of breakthrough infections in those previously vaccinated with ancestral strain coronavirus disease 2019 (COVID-19) vaccines. Here, we demonstrate that a booster dose of UB-612 vaccine candidate delivered 7-9 months after primary vaccination increased neutralizing antibody levels by 131-, 61-, and 49-fold against ancestral SARS-CoV-2 and the Omicron BA.1 and BA.2 variants, respectively. Based on the receptor-binding domain protein binding antibody responses, the UB-612 third-dose booster may lead to an estimated approximately 95% efficacy against symptomatic COVID-19 caused by the ancestral strain. Our results support UB-612 as a potential potent booster against current and emerging SARS-CoV-2 variants.


Assuntos
COVID-19 , Vacinas Virais , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Humanos , SARS-CoV-2
12.
J Infect Dis ; 225(9): 1626-1631, 2022 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-34159375

RESUMO

Pneumococcal conjugate vaccine (PCV) efficacy is lower for noninvasive pneumonia than invasive disease. In this study, participants were immunized with 13-valent PCV (PCV13) or hepatitis A vaccine (control). Bronchoalveolar lavage samples were taken between 2 and 6 months and serum at 4 and 7 weeks postvaccination. In the lung, anti-capsular immunoglobulin G (IgG) levels were higher in the PCV13 group compared to controls for all serotypes, except 3 and 6B. Systemically, IgG levels were elevated in the PCV13 group at 4 weeks for all serotypes, except serotype 3. IgG in bronchoalveolar lavage and serum positively correlated for nearly all serotypes. PCV13 shows poor immunogenicity to serotype 3, implying lack of protective efficacy. Clinical Trials Registration. ISRCTN 45340436.


Assuntos
Infecções Pneumocócicas , Anticorpos Antibacterianos , Humanos , Imunoglobulina G , Lactente , Pulmão , Vacinas Pneumocócicas , Sorogrupo , Vacinas Conjugadas
13.
J Infect Dis ; 226(7): 1243-1255, 2022 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-35403683

RESUMO

BACKGROUND: Human immunodeficiency virus-exposed uninfected (HEU) infants are a rapidly expanding population in sub-Saharan Africa and are highly susceptible to encapsulated bacterial disease in the first year of life. The mechanism of this increased risk is still poorly understood. We investigated whether human immunodeficiency virus (HIV)-exposure dysregulates HEU immunity, vaccine-antibody production, and human herpes virus amplify this effect. METHODS: Thirty-four HIV-infected and 44 HIV-uninfected pregnant women were recruited into the birth cohort and observed up to 6 weeks of age; and then a subsequent 43 HIV-infected and 61 HIV-uninfected mother-infant pairs were recruited into a longitudinal infant cohort at either: 5-7 to 14-15; or 14-15 to 18-23 weeks of age. We compared monocyte function, innate and adaptive immune cell phenotype, and vaccine-induced antibody responses between HEU and HIV-unexposed uninfected (HU) infants. RESULTS: We demonstrate (1) altered monocyte phagosomal function and B-cell subset homeostasis and (2) lower vaccine-induced anti-Haemophilus influenzae type b (Hib) and anti-tetanus toxoid immunoglobulin G titers in HEU compared with HU infants. Human herpes virus infection was similar between HEU and HU infants. CONCLUSIONS: In the era of antiretroviral therapy-mediated viral suppression, HIV exposure may dysregulate monocyte and B-cell function, during the vulnerable period of immune maturation. This may contribute to the high rates of invasive bacterial disease and pneumonia in HEU infants.


Assuntos
Infecções por HIV , Monócitos , Feminino , HIV , Humanos , Imunoglobulina G , Lactente , Fenótipo , Gravidez , Toxoide Tetânico
14.
Infect Immun ; 90(1): e0084618a, 2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35076289

RESUMO

Current vaccination against Streptococcus pneumoniae uses vaccines based on capsular polysaccharides from selected serotypes and has led to nonvaccine serotype replacement disease. We have investigated an alternative serotype-independent approach, using multiple-antigen vaccines (MAV) prepared from S. pneumoniae TIGR4 lysates enriched for surface proteins by a chromatography step after culture under conditions that induce expression of heat shock proteins (Hsp; thought to be immune adjuvants). Proteomics and immunoblot analyses demonstrated that, compared to standard bacterial lysates, MAV was enriched with Hsps and contained several recognized protective protein antigens, including pneumococcal surface protein A (PspA) and pneumolysin (Ply). Vaccination of rodents with MAV induced robust antibody responses to multiple serotypes, including nonpneumococcal conjugate vaccine serotypes. Homologous and heterologous strains of S. pneumoniae were opsonized after incubation in sera from vaccinated rodents. In mouse models, active vaccination with MAV significantly protected against pneumonia, while passive transfer of rabbit serum from MAV-vaccinated rabbits significantly protected against sepsis caused by both homologous and heterologous S. pneumoniae strains. Direct comparison of MAV preparations made with or without the heat shock step showed no clear differences in protein antigen content and antigenicity, suggesting that the chromatography step rather than Hsp induction improved MAV antigenicity. Overall, these data suggest that the MAV approach may provide serotype-independent protection against S. pneumoniae.

15.
Clin Infect Dis ; 74(7): 1220-1229, 2022 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-34218284

RESUMO

BACKGROUND: Antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been shown to neutralize the virus in vitro and prevent disease in animal challenge models on reexposure. However, the current understanding of SARS-CoV-2 humoral dynamics and longevity is conflicting. METHODS: The COVID-19 Staff Testing of Antibody Responses Study (Co-Stars) prospectively enrolled 3679 healthcare workers to comprehensively characterize the kinetics of SARS-CoV-2 spike protein (S), receptor-binding domain, and nucleoprotein (N) antibodies in parallel. Participants screening seropositive had serial monthly serological testing for a maximum of 7 months with the Meso Scale Discovery Assay. Survival analysis determined the proportion of seroreversion, while 2 hierarchical gamma models predicted the upper and lower bounds of long-term antibody trajectory. RESULTS: A total of 1163 monthly samples were provided from 349 seropositive participants. At 200 days after symptoms, >95% of participants had detectable S antibodies, compared with 75% with detectable N antibodies. S antibody was predicted to remain detectable in 95% of participants until 465 days (95% confidence interval, 370-575 days) using a "continuous-decay" model and indefinitely using a "decay-to-plateau" model to account for antibody secretion by long-lived plasma cells. S-antibody titers were correlated strongly with surrogate neutralization in vitro (R2 = 0.72). N antibodies, however, decayed rapidly with a half-life of 60 days (95% confidence interval, 52-68 days). CONCLUSIONS: The Co-Stars data presented here provide evidence for long-term persistence of neutralizing S antibodies. This has important implications for the duration of functional immunity after SARS-CoV-2 infection. In contrast, the rapid decay of N antibodies must be considered in future seroprevalence studies and public health decision-making. This is the first study to establish a mathematical framework capable of predicting long-term humoral dynamics after SARS-CoV-2 infection. CLINICAL TRIALS REGISTRATION: NCT04380896.


Assuntos
COVID-19 , Glicoproteína da Espícula de Coronavírus , Anticorpos Neutralizantes , Anticorpos Antivirais , Humanos , SARS-CoV-2 , Estudos Soroepidemiológicos
16.
Am J Respir Crit Care Med ; 203(5): 604-613, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-32941735

RESUMO

Rationale: Pneumococcal colonization is key to the pathogenesis of invasive disease but is also immunogenic in young adults, protecting against recolonization. Colonization is rarely detected in older adults, despite high rates of pneumococcal disease.Objectives: To establish experimental human pneumococcal colonization in healthy adults aged 50-84 years, to measure the immune response to pneumococcal challenge, and to assess the protective effect of prior colonization against autologous strain rechallenge.Methods: Sixty-four participants were inoculated with Streptococcus pneumoniae (serotype 6B; 80,000 cfu in each nostril). Colonization was determined by bacterial culture of nasal wash, and humoral immune responses were assessed by anticapsular and antiprotein IgG concentrations.Measurements and Main Results: Experimental colonization was established in 39% of participants (25/64) with no adverse events. Colonization occurred in 47% (9/19) of participants aged 50-59 compared with 21% (3/14) in those aged ≥70 years. Previous pneumococcal polysaccharide vaccination did not protect against colonization. Colonization did not confer serotype-specific immune boosting, with a geometric mean titer (95% confidence interval) of 2.7 µg/ml (1.9-3.8) before the challenge versus 3.0 (1.9-4.7) 4 weeks after colonization (P = 0.53). Furthermore, pneumococcal challenge without colonization led to a drop in specific antibody concentrations from 2.8 µg/ml (2.0-3.9) to 2.2 µg/ml (1.6-3.0) after the challenge (P = 0.006). Antiprotein antibody concentrations increased after successful colonization. Rechallenge with the same strain after a median of 8.5 months (interquartile range, 6.7-10.1) led to recolonization in 5/16 (31%).Conclusions: In older adults, experimental pneumococcal colonization is feasible and safe but demonstrates different immunological outcomes compared with younger adults in previous studies.


Assuntos
Anticorpos Antibacterianos/imunologia , Portador Sadio/imunologia , Infecções Pneumocócicas/imunologia , Streptococcus pneumoniae/imunologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Infecções Assintomáticas , Técnicas de Cultura , Estudos de Viabilidade , Feminino , Humanos , Imunidade Humoral/imunologia , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Cavidade Nasal , Líquido da Lavagem Nasal , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/uso terapêutico
17.
Am J Respir Cell Mol Biol ; 63(6): 758-766, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32853024

RESUMO

Viral pneumonias remain global health threats, as exemplified in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, requiring novel treatment strategies both early and late in the disease process. We have reported that mice treated before or soon after infection with a combination of inhaled Toll-like receptor (TLR) 2/6 and 9 agonists (Pam2-ODN) are broadly protected against microbial pathogens including respiratory viruses, but the mechanisms remain incompletely understood. The objective of this study was to validate strategies for immune modulation in a preclinical model of viral pneumonia and determine their mechanisms. Mice were challenged with the Sendai paramyxovirus in the presence or absence of Pam2-ODN treatment. Virus burden and host immune responses were assessed to elucidate Pam2-ODN mechanisms of action and to identify additional opportunities for therapeutic intervention. Enhanced survival of Sendai virus pneumonia with Pam2-ODN treatment was associated with reductions in lung virus burden and with virus inactivation before internalization. We noted that mortality in sham-treated mice corresponded with CD8+ T-cell lung inflammation on days 11-12 after virus challenge, after the viral burden had declined. Pam2-ODN blocked this injurious inflammation by minimizing virus burden. As an alternative intervention, depleting CD8+ T cells 8 days after viral challenge also decreased mortality. Stimulation of local innate immunity within the lungs by TLR agonists early in disease or suppression of adaptive immunity by systemic CD8+ T-cell depletion late in disease improves outcomes of viral pneumonia in mice. These data reveal opportunities for targeted immunomodulation to protect susceptible human subjects.


Assuntos
Imunidade Inata/imunologia , Lipopeptídeos/farmacologia , Pneumonia Viral/tratamento farmacológico , Pneumonia/prevenção & controle , Infecções por Respirovirus/tratamento farmacológico , Vírus Sendai/efeitos dos fármacos , Carga Viral/efeitos dos fármacos , Animais , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/imunologia , Células Epiteliais/virologia , Feminino , Imunidade Inata/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/virologia , Camundongos , Camundongos Endogâmicos C57BL , Pneumonia/imunologia , Pneumonia/patologia , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Infecções por Respirovirus/imunologia , Infecções por Respirovirus/virologia , Vírus Sendai/imunologia
18.
Clin Infect Dis ; 71(5): 1271-1280, 2020 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31586206

RESUMO

BACKGROUND: Children with acute lymphoblastic leukemia (ALL) are at increased risk of developing invasive pneumococcal disease. This study describes the immunogenicity of 13-valent pneumococcal conjugate vaccine (PCV13) during and after chemotherapy. METHODS: Children with ALL were allocated to study groups and received a single dose of PCV13: group 1, maintenance chemotherapy; group 2, end of chemotherapy; group 3, 6 months after chemotherapy. A protective vaccine response was defined as at least 10 of 12 serotypes (or >83% of serotypes with data) achieving postvaccination serotype-specific immunoglobulin G ≥0.35 µg/mL and ≥4-fold rise, compared to prevaccination at 1 and 12 months. RESULTS: One hundred eighteen children were recruited. Only 12.8% (5/39; 95% confidence interval [CI], 4.3%-27.4%) of patients vaccinated during maintenance (group 1) achieved a protective response at 1 month postvaccination and none had a protective response at 12 months. For group 2 patients, 59.5% (22/37; 95% CI, 42.1%-75.3%) achieved a response at 1 month and 37.9% (11/29; 95% CI, 20.7%-57.7%) maintained immunity at 12 months. For group 3 patients, 56.8% (21/37; 95% CI, 39.5%-72.9%) achieved a protective response at 1 month and 43.3% (13/30; 95% CI, 25.5%-62.6%) maintained immunity at 12 months. CONCLUSIONS: This study demonstrated that the earliest time point at which protective immunity can be achieved in children with ALL is on completion of chemotherapy. This is earlier than current recommendations and may improve protection during a period when children are most susceptible to infection. CLINICAL TRIALS REGISTRATION: EudraCT 2009-011587-11.


Assuntos
Infecções Pneumocócicas , Leucemia-Linfoma Linfoblástico de Células Precursoras , Anticorpos Antibacterianos , Criança , Humanos , Lactente , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Sorogrupo , Vacinas Conjugadas
19.
Infect Immun ; 87(3)2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30530620

RESUMO

Current vaccination against Streptococcus pneumoniae uses vaccines based on capsular polysaccharides from selected serotypes and has led to nonvaccine serotype replacement disease. We have investigated an alternative serotype-independent approach, using multiple-antigen vaccines (MAV) prepared from S. pneumoniae TIGR4 lysates enriched for surface proteins by a chromatography step after culture under conditions that induce expression of heat shock proteins (Hsp; thought to be immune adjuvants). Proteomics and immunoblot analyses demonstrated that, compared to standard bacterial lysates, MAV was enriched with Hsps and contained several recognized protective protein antigens, including pneumococcal surface protein A (PspA) and pneumolysin (Ply). Vaccination of rodents with MAV induced robust antibody responses to multiple serotypes, including nonpneumococcal conjugate vaccine serotypes. Homologous and heterologous strains of S. pneumoniae were opsonized after incubation in sera from vaccinated rodents. In mouse models, active vaccination with MAV significantly protected against pneumonia, while passive transfer of rabbit serum from MAV-vaccinated rabbits significantly protected against sepsis caused by both homologous and heterologous S. pneumoniae strains. Direct comparison of MAV preparations made with or without the heat shock step showed no clear differences in protein antigen content and antigenicity, suggesting that the chromatography step rather than Hsp induction improved MAV antigenicity. Overall, these data suggest that the MAV approach may provide serotype-independent protection against S. pneumoniae.


Assuntos
Antígenos de Bactérias/imunologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/imunologia , Streptococcus pneumoniae/patogenicidade , Animais , Camundongos
20.
J Clin Immunol ; 39(2): 195-199, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30868346

RESUMO

X-linked chronic granulomatous disease (XL-CGD), a rare primary immunodeficiency due to a defect in the gp91phox NADPH oxidase subunit, results in recurrent, severe infection, inflammation, and autoimmunity. Patients have an absent, or significantly reduced, neutrophil oxidative burst. Due to lyonization, XL-CGD carriers have a dual population of functional and non-functional phagocytes and experience a range of symptoms including increased risk of autoimmunity, fatigue, and infection. Patients with CGD have poorer quality of life (QoL) than normal controls. We evaluated QoL and psychological health in UK XL-CGD carriers. Recruited participants completed the Medical Outcomes Study Short Form 36 version 2 (SF-36 V2), providing an overall score for mental and physical health. Psychological health was assessed using the Hospital Anxiety and Depression Scale (HADS) questionnaire. Seventy-five XL-CGD carriers were recruited from 62 families, median age 43 years (range 3-77). Fifty-six were mothers, 6 grandmothers, and 13 siblings. Sixty-two completed the SF36v2 and had reduced QoL scores compared with adult CGD patients and a UK age-matched female control cohort, indicating a reduced QoL. Sixty-one completed a HADS questionnaire. Over 40% experienced moderate or greater levels of anxiety with only one third being classified as normal. Higher anxiety scores significantly correlated with higher depression scores, lower self-esteem, presence of joint or bowel symptoms, and higher levels of fatigue (p < 0.05). This is the first study to evaluate QoL of XL-CGD carriers, and demonstrates high rates of anxiety and significantly reduced QoL scores. XL-CGD carriers should be considered as potential patients and pro-actively assessed and managed.


Assuntos
Doença Granulomatosa Crônica/psicologia , Qualidade de Vida , Adolescente , Adulto , Idoso , Ansiedade/genética , Ansiedade/psicologia , Criança , Pré-Escolar , Depressão/genética , Depressão/psicologia , Feminino , Genes Ligados ao Cromossomo X , Doença Granulomatosa Crônica/genética , Humanos , Saúde Mental , Pessoa de Meia-Idade , Reino Unido , Adulto Jovem
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