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1.
Nat Commun ; 11(1): 4994, 2020 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-33020485

RESUMO

Serogroup B meningococcus (MenB) is a leading cause of meningitis and sepsis across the world and vaccination is the most effective way to protect against this disease. 4CMenB is a multi-component vaccine against MenB, which is now licensed for use in subjects >2 months of age in several countries. In this study, we describe the development and use of an ad hoc protein microarray to study the immune response induced by the three major 4CMenB antigenic components (fHbp, NHBA and NadA) in individual sera from vaccinated infants, adolescents and adults. The resulting 4CMenB protein antigen fingerprinting allowed the identification of specific human antibody repertoire correlating with the bactericidal response elicited in each subject. This work represents an example of epitope mapping of the immune response induced by a multicomponent vaccine in different age groups with the identification of protective signatures. It shows the high flexibility of this microarray based methodology in terms of high-throughput information and minimal volume of biological samples needed.


Assuntos
Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Infecções Meningocócicas/imunologia , Vacinas Meningocócicas/imunologia , Neisseria meningitidis Sorogrupo B/imunologia , Adolescente , Adulto , Anticorpos Antibacterianos/sangue , Criança , Pré-Escolar , Mapeamento de Epitopos , Humanos , Lactente , Infecções Meningocócicas/prevenção & controle , Biblioteca de Peptídeos , Análise Serial de Proteínas , Ensaios de Anticorpos Bactericidas Séricos , Adulto Jovem
2.
BMC Infect Dis ; 20(1): 677, 2020 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-32942991

RESUMO

BACKGROUND: Approximately 80% - 90% of individuals infected with latent Mycobacterium tuberculosis (Mtb) remain protected throughout their life-span. The release of unique, latent-phase antigens are known to have a protective role in the immune response against Mtb. Although the BCG vaccine has been administered for nine decades to provide immunity against Mtb, the number of TB cases continues to rise, thereby raising doubts on BCG vaccine efficacy. The shortcomings of BCG have been associated with inadequate processing and presentation of its antigens, an inability to optimally activate T cells against Mtb, and generation of regulatory T cells. Furthermore, BCG vaccination lacks the ability to eliminate latent Mtb infection. With these facts in mind, we selected six immunodominant CD4 and CD8 T cell epitopes of Mtb expressed during latent, acute, and chronic stages of infection and engineered a multi-epitope-based DNA vaccine (C6). RESULT: BALB/c mice vaccinated with the C6 construct along with a BCG vaccine exhibited an expansion of both CD4 and CD8 T cell memory populations and augmented IFN-γ and TNF-α cytokine release. Furthermore, enhancement of dendritic cell and macrophage activation was noted. Consequently, illustrating the elicitation of immunity that helps in the protection against Mtb infection; which was evident by a significant reduction in the Mtb burden in the lungs and spleen of C6 + BCG administered animals. CONCLUSION: Overall, the results suggest that a C6 + BCG vaccination approach may serve as an effective vaccination strategy in future attempts to control TB.


Assuntos
Vacina BCG/imunologia , Epitopos de Linfócito T , Tuberculose/prevenção & controle , Vacinas de DNA/imunologia , Animais , Antígenos de Bactérias/imunologia , Vacina BCG/genética , Vacina BCG/farmacologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Epitopos de Linfócito T/genética , Feminino , Memória Imunológica , Interferon gama/metabolismo , Tuberculose Latente/prevenção & controle , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Mycobacterium tuberculosis/imunologia , Tuberculose/imunologia , Fator de Necrose Tumoral alfa/metabolismo , Vacinas de DNA/farmacologia
3.
Nat Commun ; 11(1): 3763, 2020 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-32724132

RESUMO

In both animals and plants, the perception of bacterial flagella by immune receptors elicits the activation of defence responses. Most plants are able to perceive the highly conserved epitope flg22 from flagellin, the main flagellar protein, from most bacterial species. However, flagellin from Ralstonia solanacearum, the causal agent of the bacterial wilt disease, presents a polymorphic flg22 sequence (flg22Rso) that avoids perception by all plants studied to date. In this work, we show that soybean has developed polymorphic versions of the flg22 receptors that are able to perceive flg22Rso. Furthermore, we identify key residues responsible for both the evasion of perception by flg22Rso in Arabidopsis and the gain of perception by the soybean receptors. Heterologous expression of the soybean flg22 receptors in susceptible plant species, such as tomato, enhances resistance to bacterial wilt disease, demonstrating the potential of these receptors to enhance disease resistance in crop plants.


Assuntos
Flagelina/imunologia , Imunidade Vegetal , Proteínas de Plantas/imunologia , Receptores Imunológicos/imunologia , Soja/imunologia , Antígenos de Bactérias/genética , Antígenos de Bactérias/imunologia , Antígenos de Bactérias/metabolismo , Arabidopsis/genética , Arabidopsis/imunologia , Arabidopsis/metabolismo , Resistência à Doença/genética , Resistência à Doença/imunologia , Epitopos/imunologia , Flagelina/genética , Flagelina/metabolismo , Evasão da Resposta Imune/genética , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Polimorfismo Genético/imunologia , Ralstonia solanacearum/imunologia , Ralstonia solanacearum/patogenicidade , Receptores Imunológicos/genética , Receptores Imunológicos/metabolismo , Soja/genética , Soja/metabolismo , Soja/microbiologia
4.
Mol Immunol ; 125: 123-130, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32659597

RESUMO

The development of a more efficient vaccine is needed to improve tuberculosis control. One of the current approaches is to identify immunogenic T-cell peptides that can elicit a protective and specific immune response. These peptides come from immunogenic proteins of the pathogen. The PE_PGRS33 protein of Mycobacterium tuberculosis has been proved immunogenic. However, little is known about immunogenic T-cell peptides of PE_PGRS33 and their interactions with MHC-II molecules. Therefore, we used the SYFPHEITHI database to determine the immunogenic PE_PGRS33 T-cell peptides. Next, we built homology models by using MOE v2018.1 software in order to obtain information about the specific interactions between the peptides and I-Ak. The AlgPred server was employed to look for allergenic sites in PE_PGRS33. We developed a sequence alignment between PE_PGRS33 and all the human proteins by using BLAST. Three peptides were commercially synthesized, and their activity was evaluated in vitro by the stimulation of PBMC from household contacts of TB patients. Our in silico results showed five immunogenic T-cell peptides. BLAST analysis showed low homology of PE_PGRS33 with human proteins and AlgPred did not reveal allergenic sites in PE_PGRS33. The three peptides triggered the activation of CD4+ T cells from the households contacts, showed by the production of IFN-γ. We identified three immunogenic peptides of PE_PGRS33 that demonstrated activity in vitro which allows to deepen into the immune response towards mycobacterial antigens, moving forward to the identification of new vaccine candidates.


Assuntos
Antígenos de Bactérias/imunologia , Linfócitos T CD4-Positivos/imunologia , Mycobacterium tuberculosis/imunologia , Vacinas contra a Tuberculose/imunologia , Humanos , Ativação Linfocitária/imunologia , Peptídeos/imunologia , Vacinas de Subunidades/imunologia
5.
BMC Infect Dis ; 20(1): 459, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32611401

RESUMO

BACKGROUND: Extra pulmonary manifestation of tuberculosis (TB) accounts for approximately one-half of TB cases in HIV-infected individuals with pleural TB as the second most common location. Even though mycobacteria are cleared, mycobacterial antigens may persist in infected tissues, causing sustained inflammation and chronicity of the disease. The aim of this study was to explore various mycobacterial antigens in pleural effusions, the impact of HIV infection and CD4+ T-cell depletion on the presence of antigens, and the diagnostic potential of antigens for improved and rapid diagnosis of pleural TB. METHODS: Pleural fluid specimens were collected from patients presenting with clinically suspected pleural TB, and processed routinely for culture, cytology, and adenosine deaminase activity analysis. HIV status and CD4+ T-cell counts were recorded. Pleural fluid mononuclear cells (PFMC) were isolated, and cell smears were stained with acid-fast staining and immunocytochemistry for various mycobacterial antigens. Real-time and nested-PCR were performed. Patients were categorized as pleural TB or non-TB cases using a composite reference standard. Performance of the mycobacterial antigens as diagnostic test was assessed. RESULTS: A total of 41 patients were enrolled, of which 32 were classified as pleural TB and 9 as non-TB. Thirteen patients had culture confirmed pleural TB, 26 (81%) were HIV-TB co-infected, and 64% had < 100 CD4+ T-cells/microL. Both secreted and cell-wall mycobacterial antigens were detected in PFMC. Lipoarabinomannan (LAM) was the most frequently detected antigen. There was no direct correlation between positive culture and antigens. Cases with low CD4+ T-cell counts had higher bacterial and antigen burden. By combining detection of secreted antigen or LAM, the sensitivity and specificity to diagnose pleural TB was 56 and 78%, respectively, as compared to 41 and 100% for culture, 53 and 89% for nested PCR, and 6 and 100% for real-time PCR. CONCLUSION: Mycobacterial antigens were detectable in PFMC from tuberculous pleural effusions, even in cases where viable mycobacteria or bacterial DNA were not always detected. Thus, a combination of secreted antigen and LAM detection by immunocytochemistry may be a complement to acid-fast staining and contribute to rapid and accurate diagnosis of pleural TB.


Assuntos
Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Linfócitos T CD4-Positivos/imunologia , Coinfecção/diagnóstico , Testes Diagnósticos de Rotina/métodos , Lipopolissacarídeos/genética , Lipopolissacarídeos/imunologia , Mycobacterium tuberculosis/imunologia , Derrame Pleural/microbiologia , Tuberculose Pleural/diagnóstico , Adulto , Idoso , Antígenos de Bactérias/genética , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Contagem de Linfócito CD4 , Coinfecção/microbiologia , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/isolamento & purificação , Derrame Pleural/patologia , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade , Adulto Jovem
6.
BMC Infect Dis ; 20(1): 469, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32615981

RESUMO

BACKGROUND: Interferon-γ release assays (IGRA) with Resuscitation promoting factor (Rpf) proteins enhanced tuberculosis (TB) screening and diagnosis in adults but have not been evaluated in children. Children often develop paucibacillary TB and their immune response differs from that of adults, which together affect TB disease diagnostics and immunodiagnostics. We assessed the ability of Rpf to identify infection among household TB-exposed children in The Gambia and investigated their ability to discriminate Mycobacterium tuberculosis complex (MTBC) infection from active TB disease in children. METHODS: Detailed clinical investigations were done on 93 household TB-exposed Gambian children and a tuberculin skin test (TST) was administered to asymptomatic children. Venous blood was collected for overnight stimulation with ESAT-6/CFP-10-fusion protein (EC), purified protein derivative and RpfA, B, C, D and E. Interferon gamma (IFN-γ) production was measured by ELISA in supernatants and corrected for the background level. Infection status was defined by IGRA with EC and TB disease by mycobacterial confirmation and/or clinical diagnosis. We compared IFN-γ levels between infected and uninfected children and between infected and TB diseased children using a binomial logistic regression model while correcting for age and sex. A Receiver Operating Characteristics analysis was done to find the best cut-off for IFN-γ level and calculate sensitivity and specificity. RESULTS: Interferon gamma production was significantly higher in infected (IGRA+, n = 45) than in uninfected (IGRA-, n = 20) children after stimulation with RpfA, B, C, and D (P = 0.03; 0.007; 0.03 and 0.003, respectively). Using RpfB and D-specific IFN-γ cut-offs (33.9 pg/mL and 67.0 pg/mL), infection was classified with a sensitivity-specificity combination of 73-92% and 77-72% respectively, which was similar to and better than 65-75% for TST. Moreover, IFN-γ production was higher in infected than in TB diseased children (n = 28, 5 bacteriologically confirmed, 23 clinically diagnosed), following RpfB and D stimulation (P = 0.02 and 0.03, respectively). CONCLUSION: RpfB and RpfD show promising results for childhood MTBC infection screening, and both performed similar to and better than the TST in our study population. Additionally, both antigens appear to discriminate between infection and disease in children and thus warrant further investigation as screening and diagnostic antigens for childhood TB.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Citocinas/imunologia , Testes de Liberação de Interferon-gama/métodos , Tuberculose Latente/diagnóstico , Tuberculose Latente/epidemiologia , Programas de Rastreamento/métodos , Mycobacterium tuberculosis/imunologia , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Características da Família , Feminino , Gâmbia/epidemiologia , Humanos , Interferon gama/imunologia , Interferon gama/metabolismo , Tuberculose Latente/microbiologia , Masculino , Sensibilidade e Especificidade , Teste Tuberculínico
7.
PLoS One ; 15(6): e0234130, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32497095

RESUMO

Better triage tests for screening tuberculosis (TB) disease are needed for people living with HIV (PLHIV). We performed the first evaluation of a previously-validated 8-antigen serological panel to screen PLHIV for pulmonary TB in Kampala, Uganda. We selected a random 1:1 sample with and without TB (defined by sputum culture) from a cohort of PLHIV initiating antiretroviral therapy. We used a multiplex microbead immunoassay and an ensemble machine learning classifier to determine the area under the receiver operating characteristic curve (AUC) for Ag85A, Ag85B, Ag85C, Rv0934-P38, Rv3881, Rv3841-BfrB, Rv3873, and Rv2878c. We then assessed the performance with the addition of four TB-specific antigens ESAT-6, CFP-10, Rv1980-MPT64, and Rv2031-HSPX, and every antigen combination. Of 262 participants (median CD4 cell-count 152 cells/µL [IQR 65-279]), 138 (53%) had culture-confirmed TB. The 8-antigen panel had an AUC of 0.53 (95% CI 0.40-0.66), and the additional 4 antigens did not improve performance (AUC 0.51, 95% CI 0.39-0.64). When sensitivity was restricted to ≥90% for the 8- and 12-antigen panel, specificity was 2.2% (95% CI 0-17.7%) and 8.1% (95% CI 0-23.9%), respectively. A three-antigen combination (Rv0934-P38, Ag85A, and Rv2031-HSPX) outperformed both panels, with an AUC of 0.60 (95% CI 0.48-0.73), 90% sensitivity (95% CI 78.2-96.7%) and 29.7% specificity (95% CI 15.9-47%). The multi-antigen panels did not achieve the target accuracy for a TB triage test among PLHIV. We identified a new combination that improved performance for TB screening in an HIV-positive sample compared to an existing serological panel in Uganda, and suggests an approach to identify novel antigen combinations specifically for screening TB in PLHIV.


Assuntos
Antígenos de Bactérias/imunologia , Infecções por HIV/complicações , Tuberculose/complicações , Tuberculose/diagnóstico , Adulto , Fármacos Anti-HIV/uso terapêutico , Estudos de Casos e Controles , Feminino , Infecções por HIV/tratamento farmacológico , Humanos , Imunoensaio , Masculino , Testes Sorológicos , Tuberculose/imunologia
8.
J Vis Exp ; (159)2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32510489

RESUMO

The opsono-adherence assay is a functional assay that enumerates the attachment of bacterial pathogens to professional phagocytes. Because adherence is requisite to phagocytosis and killing, the assay is an alternative method to opsono-phagocytic killing assays. An advantage of the opsono-adherence assay is the option of using inactivated pathogens and mammalian cell lines, which allows standardization across multiple experiments. The use of an inactivated pathogen in the assay also facilitates work with biosafety level 3 infectious agents and other virulent pathogens. In our work, the opsono-adherence assay was used to assess the functional ability of antibodies, from sera of animals immunized with an anthrax capsule-based vaccine, to induce adherence of fixed Bacillus anthracis to a mouse macrophage cell line, RAW 264.7. Automated fluorescence microscopy was used to capture images of bacilli adhering to macrophages. Increased adherence was correlated with the presence of anti-capsule antibodies in the serum. Non-human primates that exhibited high serum anti-capsule antibody concentrations were protected from anthrax challenge. Thus, the opsono-adherence assay can be used to elucidate the biological functions of antigen specific antibodies in sera, to evaluate the efficacy of vaccine candidates and other therapeutics, and to serve as a possible correlate of immunity.


Assuntos
Vacinas contra Antraz/imunologia , Antraz/imunologia , Anticorpos Antibacterianos/imunologia , Bacillus anthracis/imunologia , Aderência Bacteriana , Proteínas Opsonizantes/imunologia , Animais , Antraz/microbiologia , Antraz/prevenção & controle , Antígenos de Bactérias/imunologia , Fluoresceína-5-Isotiocianato/metabolismo , Fluorescência , Humanos , Macrófagos/imunologia , Camundongos , Primatas/imunologia , Primatas/microbiologia , Células RAW 264.7
9.
BMC Infect Dis ; 20(1): 444, 2020 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-32576149

RESUMO

BACKGROUND: The syphilis epidemic continues to cause substantial morbidity and mortality worldwide, particularly in low- and middle-income countries, despite several recent disease control initiatives. Though our understanding of the pathogenesis of this disease and the biology of the syphilis agent, Treponema pallidum subsp. pallidum has improved over the last two decades, further research is necessary to improve clinical diagnosis and disease management protocols. Additionally, such research efforts could contribute to the identification of possible targets for the development of an effective vaccine to stem syphilis spread. METHODS: This study will recruit two cohorts of participants with active syphilis infection, one with de novo infection, one with repeat infection. Whole blood specimens will be collected from each study participant at baseline, 4, 12, 24, 36, and 48 weeks, to track specific markers of their immunological response, as well as to compare humoral reactivity to Treponema pallidum antigens between the two groups. Additionally, we will use serum specimens to look for unique cytokine patterns in participants with early syphilis. Oral and blood samples, as well as samples from any syphilitic lesions present, will also be collected to sequence any Treponema pallidum DNA found. DISCUSSION: By furthering our understanding of syphilis pathogenesis and human host immune response to Treponema pallidum, we will provide important data that will help in development of new point-of-care tests that could better identify active infection, leading to improved syphilis diagnosis and management. Findings could also contribute to vaccine development efforts.


Assuntos
Vacinas Bacterianas/uso terapêutico , Sífilis/epidemiologia , Sífilis/prevenção & controle , Treponema pallidum/imunologia , Vacinação , Antígenos de Bactérias/imunologia , Sequência de Bases , Estudos de Coortes , Citocinas/análise , DNA Bacteriano/genética , Seguimentos , Humanos , Tipagem Molecular , Peru/epidemiologia , Sífilis/sangue , Sífilis/imunologia , Treponema pallidum/genética
10.
PLoS One ; 15(6): e0235139, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32574205

RESUMO

Viral infections complicated by a bacterial infection are typically referred to as coinfections or superinfections. Streptococcus pyogenes, the group A streptococcus (GAS), is not the most common bacteria associated with influenza A virus (IAV) superinfections but did cause significant mortality during the 2009 influenza pandemic even though all isolates are susceptible to penicillin. One approach to improve the outcome of these infections is to use passive immunization targeting GAS. To test this idea, we assessed the efficacy of passive immunotherapy using antisera against either the streptococcal M protein or streptolysin O (SLO) in a murine model of IAV-GAS superinfection. Prophylactic treatment of mice with antiserum to either SLO or the M protein decreased morbidity compared to mice treated with non-immune sera; however, neither significantly decreased mortality. Therapeutic use of antisera to SLO decreased morbidity compared to mice treated with non-immune sera but neither antisera significantly reduced mortality. Overall, the results suggest that further development of antibodies targeting the M protein or SLO may be a useful adjunct in the treatment of invasive GAS diseases, including IAV-GAS superinfections, which may be particularly important during influenza pandemics.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas de Transporte/imunologia , Imunoterapia/métodos , Vírus da Influenza A/imunologia , Infecções por Orthomyxoviridae/imunologia , Infecções Estreptocócicas/imunologia , Streptococcus pyogenes/imunologia , Estreptolisinas/imunologia , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/metabolismo , Proteínas da Membrana Bacteriana Externa/antagonistas & inibidores , Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/metabolismo , Proteínas de Transporte/antagonistas & inibidores , Proteínas de Transporte/metabolismo , Coinfecção/microbiologia , Coinfecção/terapia , Coinfecção/virologia , Feminino , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/imunologia , Humanos , Soros Imunes/imunologia , Soros Imunes/farmacologia , Vírus da Influenza A/fisiologia , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/terapia , Infecções por Orthomyxoviridae/virologia , Coelhos , Infecções Estreptocócicas/microbiologia , Infecções Estreptocócicas/terapia , Streptococcus pyogenes/metabolismo , Streptococcus pyogenes/fisiologia , Estreptolisinas/antagonistas & inibidores , Estreptolisinas/metabolismo , Superinfecção/microbiologia , Superinfecção/terapia , Superinfecção/virologia
11.
Vet Immunol Immunopathol ; 224: 110059, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32408182

RESUMO

There are currently no licensed vaccines against Clostridium perfringens which causes necrotic enteritis in poultry. Chitosan nanoparticles were formulated with native (CN) or toxoids (CT) of extracellular proteins (ECP) of C. perfringens, both surface-tagged with Salmonella flagellar proteins. In a pH stability assay, CN and CT nanoparticles released 6% and 0% of their protein at 8.0 pH. In a protein release assay, CN and CT nanoparticles released 16% and 10% of their protein respectively at 7.4 pH after 24 h. CN and CT nanoparticles incubated at 100 µg/mL PBS with Chicken RBCs released 1% and 0% hemoglobin respectively. Ninety broilers were randomly assigned to treatments; sham-vaccinated (Control), CN-vaccinated (CN), and CT-vaccinated (CT). Each bird was orally gavaged with 50 µg vaccine in 0.5 mL PBS or 0.5 mL PBS only on d 0, 3, 7 and 14 of age. At 21 d of age, the CN group had higher anti-ECP IgA than control (P < 0.05). At 21 d of age, the CN and CT group had higher anti-ECP IgA than control (P < 0.05). At 17 d of age, the CN group had higher anti-flagellar IgG than control (P < 0.05). At 10 d of age, the CN group had higher anti-flagellar IgA than control (P < 0.05). Splenic T cells from chickens in the CN and CT group ex-vivo stimulated with 0.05 mg/mL ECP, had higher proliferation control (P < 0.05, P < 0.01 respectively). Splenic T cells from chickens in the CN and CT groups ex-vivo stimulated with 0.1 mg/mL ECP had proliferation than control (P < 0.05). Pooled serum from 17 d of age CN and CT-vaccinated birds partially neutralized toxins in 50 µg of ECP (P < 0.05). Pooled serum from 28 d of age CN-vaccinated birds also partially neutralized toxins in 50 µg of ECP. The result from this study indicates the potential for chitosan loaded with Clostridium perfringens extracellular proteins to be applied to necrotic enteritis challenge studies.


Assuntos
Vacinas Bacterianas/imunologia , Quitosana/química , Infecções por Clostridium/veterinária , Enterocolite Necrosante/veterinária , Nanopartículas/química , Administração Oral , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Neutralizantes/sangue , Antígenos de Bactérias/imunologia , Toxinas Bacterianas/imunologia , Galinhas/imunologia , Galinhas/microbiologia , Infecções por Clostridium/imunologia , Infecções por Clostridium/prevenção & controle , Clostridium perfringens , Enterocolite Necrosante/imunologia , Enterocolite Necrosante/prevenção & controle , Flagelos/imunologia , Imunogenicidade da Vacina , Imunoglobulina A/análise , Imunoglobulina G/sangue , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/prevenção & controle , Salmonella , Vacinas Atenuadas/imunologia
12.
Nat Commun ; 11(1): 2465, 2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32424289

RESUMO

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare lymphoma of B-cell origin with frequent expression of functional B-cell receptors (BCRs). Here we report that expression cloning followed by antigen screening identifies DNA-directed RNA polymerase beta' (RpoC) from Moraxella catarrhalis as frequent antigen of BCRs of IgD+ LP cells. Patients show predominance of HLA-DRB1*04/07 and the IgVH genes encode extraordinarily long CDR3s. High-titer, light-chain-restricted anti-RpoC IgG1/κ-type serum-antibodies are additionally found in these patients. RpoC and MID/hag, a superantigen co-expressed by Moraxella catarrhalis that is known to activate IgD+ B cells by binding to the Fc domain of IgD, have additive activation effects on the BCR, the NF-κB pathway and the proliferation of IgD+ DEV cells expressing RpoC-specific BCRs. This suggests an additive antigenic and superantigenic stimulation of B cells with RpoC-specific IgD+ BCRs under conditions of a permissive MHC-II haplotype as a model of NLPHL lymphomagenesis, implying future treatment strategies.


Assuntos
Antígenos de Bactérias/imunologia , Linfócitos B/imunologia , Doença de Hodgkin/imunologia , Doença de Hodgkin/microbiologia , Moraxella catarrhalis/imunologia , Adolescente , Adulto , Idoso , Autoantígenos/imunologia , Linhagem Celular Tumoral , Proliferação de Células , Criança , RNA Polimerases Dirigidas por DNA/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Doença de Hodgkin/sangue , Humanos , Imunoglobulina D/metabolismo , Fragmentos Fab das Imunoglobulinas/imunologia , Região Variável de Imunoglobulina/genética , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Receptores de Antígenos de Linfócitos B/metabolismo
13.
Zhonghua Yu Fang Yi Xue Za Zhi ; 54(5): 539-545, 2020 May 06.
Artigo em Chinês | MEDLINE | ID: mdl-32388956

RESUMO

Objective: The cellular immunity of 5 Mycobacterium tuberculosis recombinant proteins and their compositions was evaluated. Method: A total of 88 fresh venous blood from peripheral heparin anticoagulant population, 42 of which were from tuberculosis patients treated by The Tuberculosis Prevention and Treatment Center of Changping District, Beijing, and 46 of healthy volunteers were provided by the Infection Diseases of Chinese Center for Disease Control and Prevention. Healthy volunteers without a history of tuberculosis exposure and any clinical signs and symptoms. Using the Mycobacterium tuberculosis standard strain H37Rv DNA as a template, complete genes of the selected 5 recombinant proteins Rv3874, Rv3875, Rv2031c, Rv1411c and Rv3418c by PCR amplified; 5 recombinant proteins were cloned, expressed and purified as stimulants by genetic recombination and protein purification techniques, and the effector T cell enzyme-linked immunospot assay (ELISPOT) was used to detect cellular immunity in the population. Results: The recombinant proteins Rv3874, Rv3875, Rv2031c, Rv1411c and Rv3418c were successfully cloned, expressed and purified; And the sensitivities were 50.00%, 71.43%, 69.04%, 73.81% and 76.19%, and the specificities were 86.96%, 76.09%, 71.74%, 39.13% and 36.96%. In addition, the positive predictive value, negative predictive value, area under the curve and Youden index were 52.46% to 77.78%, 62.96% to 74.47%, 0.511 to 0.754 and 0.129 to 0.475, respectively. Except for Rv1411c and Rv3418c, the number of spot-forming cell (SFC) detected by Rv3874, Rv3875 and Rv2031c in tuberculosis patients was higher than healthy volunteers, and the differences were statistically significant (P<0.001). Among the 26 compositions composed of 5 recombinant proteins, the sensitivity was 80.95% to 95.24%, and the specificity was 68.89% to 24.44%. As the number of recombinant proteins in the composition increases, the sensitivity gradually increased, but the specificity decreased. Conclusion: The recombinant proteins of Mycobacterium tuberculosis Rv3874, Rv3875 and Rv2031c have strong ability to stimulate T cells to produce immune response, and have certain antigenicity. The efficacy of Rv1411c and Rv3418c alone as diagnostic antigens is not ideal, and the composition composed of multi-component antigens has certain application value. This article provides experimental evidence for the immune diagnosis of tuberculosis and the preparation of new anti-tuberculosis vaccines.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Imunidade Celular , Proteínas Recombinantes/imunologia , Tuberculose/imunologia , Pequim , Humanos , Mycobacterium tuberculosis
14.
PLoS Negl Trop Dis ; 14(5): e0008292, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32407387

RESUMO

Bacillus cereus biovar anthracis (Bcbva) is an untypical anthrax-causing pathogen responsible for high wildlife mortality in Taï National Park (TNP), Côte d'Ivoire. However, nothing is known about its effect on the rural population living in the region bordering TNP. Contact to bushmeat is a known risk factor for exposure to a variety of zoonotic pathogens, but no human infections with Bcbva were noted so far. Therefore, we performed a retrospective seroprevalence analysis with sera from 1,386 study volunteers. We used assays which detect antibodies against the protective antigen PA, which is synthesized by both Bcbva and classic B. anthracis, and against the recently described antigen pXO2-60, a 35-kDa protein only produced by Bcbva. We found a high seroprevalence (22.37%) of antibodies against PA, and approximately half of those sera (10.46%) were also positive for the Bcbva-specific antigen pXO2-60. All sera negative for PA were also negative for antibodies against pXO2-60, confirming specificity and suitability of the PA/pXO2-60 combined serological assay. The fact that a large fraction of sera was positive for PA but negative for pXO2-60 can most likely be explained by lower immunogenicity of pXO2-60, but exposure to classic B. anthracis cannot be excluded. As only Bcbva has been detected in the TNP area so far, exposure to Bcbva can be suspected from the presence of antibodies against PA alone. In a questionnaire, most study participants reported contact to bushmeat and livestock carcasses. Unfortunately, risk factor analysis indicated that neither animal contacts, sex, age, nor country of origin were significant predictors of Bcbva seroprevalence. Nevertheless, our study added to an assessment of the distribution of Bcbva and its impact on the human population, and our data can serve to raise awareness of anthrax in the affected regions.


Assuntos
Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/imunologia , Bacillus cereus/imunologia , Exposição Ambiental , Parques Recreativos , População Rural , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Costa do Marfim , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Estudos Soroepidemiológicos , Inquéritos e Questionários , Adulto Jovem
15.
PLoS Negl Trop Dis ; 14(5): e0008326, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32463817

RESUMO

Salmonella and Shigella species are food- and water-borne pathogens that are responsible for enteric infections in both humans and animals and are still the major cause of morbidity and mortality in the emerging countries. The existence of multiple Salmonella and Shigella serotypes as well as the emergence of strains resistant to antibiotics require the development of broadly protective therapies. Those bacteria utilize a Type III Secretion System (T3SS), necessary for their pathogenicity. The structural proteins composing the T3SS are common to all virulent Salmonella and Shigella spp., particularly the needle-tip proteins SipD (Salmonella) and IpaD (Shigella). We investigated the immunogenicity and protective efficacy of SipD and IpaD administered by intranasal and intragastric routes, in a mouse model of Salmonella enterica serotype Typhimurium (S. Typhimurium) intestinal challenge. Robust IgG (in all immunization routes) and IgA (in intranasal and oral immunization routes) antibody responses were induced against both proteins. Mice immunized with SipD or IpaD were protected against lethal intestinal challenge with S. Typhimurium or Shigella flexneri (100 Lethal Dose 50%). We have shown that SipD and IpaD are able to induce a cross-protection in a murine model of infection by Salmonella and Shigella. We provide the first demonstration that Salmonella and Shigella T3SS SipD and IpaD are promising antigens for the development of a cross-protective Salmonella-Shigella vaccine. These results open the way to the development of cross-protective therapeutic molecules.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Proteção Cruzada , Disenteria Bacilar/prevenção & controle , Proteínas de Membrana/imunologia , Infecções por Salmonella/prevenção & controle , Vacinas contra Salmonella/imunologia , Vacinas contra Shigella/imunologia , Administração Intranasal , Administração Oral , Animais , Anticorpos Antibacterianos/análise , Modelos Animais de Doenças , Feminino , Imunoglobulina A/análise , Imunoglobulina G/análise , Camundongos Endogâmicos BALB C , Vacinas contra Salmonella/administração & dosagem , Salmonella typhimurium/imunologia , Vacinas contra Shigella/administração & dosagem , Shigella flexneri/imunologia , Análise de Sobrevida
16.
Can J Microbiol ; 66(9): 529-534, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32396022

RESUMO

Fusobacterium nucleatum is becoming increasingly recognised as an emerging pathogen, gaining attention as a potential factor for exacerbating colorectal cancer and is strongly linked with pregnancy complications including pre-term and still births. Little is known about the virulence factors of this organism; thus, we have initiated studies to examine the bacterium's surface glycochemistry. In an effort to characterise the surface carbohydrates of F. nucleatum, the aims of this study were to investigate the structure of the lipopolysaccharide (LPS) O-antigen of the cancer-associated isolate F. nucleatum strain CC 7/3 JVN3 C1 (hereafter C1) and to develop monoclonal antibodies (mAbs) to the LPS O-antigen that may be beneficial to the growing field of F. nucleatum research. In this study, we combined several technologies, including nuclear magnetic resonance (NMR) spectroscopy, to elucidate the structure of the LPS O-antigen repeat unit as -[-4-ß-Gal-3-α-FucNAc4N-4-α-NeuNAc-]-. We have previously identified this structure as the LPS O-antigen repeat unit from strain 10953. In this present study, we developed a mAb to the C1 LPS O-antigen and confirmed the mAbs cross-reactivity to the 10953 strain, thus confirming the structural identity.


Assuntos
Anticorpos Antibacterianos/imunologia , Anticorpos Monoclonais/imunologia , Fusobacterium nucleatum/imunologia , Antígenos O/química , Antígenos O/imunologia , Animais , Antígenos de Bactérias/imunologia , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Espectroscopia de Ressonância Magnética , Camundongos , Camundongos Endogâmicos BALB C , Sorotipagem , Fatores de Virulência
17.
Mem Inst Oswaldo Cruz ; 115: e190396, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32321154

RESUMO

BACKGROUND: Nanoparticles (NPs) are viable candidates as carriers of exogenous materials into cells via transfection and can be used in the DNA vaccination strategy against leptospirosis. OBJECTIVES: We evaluated the efficiency of halloysite clay nanotubes (HNTs) and amine-functionalised multi-walled carbon nanotubes (NH2-MWCNTs) in facilitating recombinant LemA antigen (rLemA) expression and protecting Golden Syrian hamsters (Mesocricetus auratus) against Leptospira interrogans lethal infection. METHODS: An indirect immunofluorescent technique was used to investigate the potency of HNTs and NH2-MWCNTs in enhancing the transfection and expression efficiency of the DNA vaccine in Chinese hamster ovary (CHO) cells. Hamsters were immunised with two doses of vaccines HNT-pTARGET/lemA, NH2-MWCNTs-pTARGET/lemA, pTARGET/lemA, and empty pTARGET (control), and the efficacy was determined in terms of humoral immune response and protection against a lethal challenge. FINDINGS: rLemA DNA vaccines carried by NPs were able to transfect CHO cells effectively, inducing IgG immune response in hamsters (p < 0.05), and did not exhibit cytotoxic effects. Furthermore, 83.3% of the hamsters immunised with NH2-MWCNTs-pTARGET/lemA were protected against the lethal challenge (p < 0.01), and 66.7% of hamsters immunised with HNT-pTARGET/lemA survived (p < 0.05). MAIN CONCLUSIONS: NH2-MWCNTs and HNTs can act as antigen carriers for mammalian cells and are suitable for DNA nanovaccine delivery.


Assuntos
Antígenos de Bactérias/administração & dosagem , Proteínas de Bactérias/administração & dosagem , Vacinas Bacterianas/administração & dosagem , Leptospirose/prevenção & controle , Fatores de Transcrição/administração & dosagem , Vacinas de DNA/administração & dosagem , Animais , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Cricetinae , Modelos Animais de Doenças , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Leptospira interrogans/imunologia , Leptospirose/imunologia , Nanopartículas , Fatores de Transcrição/imunologia , Vacinas de DNA/imunologia
18.
Int J Infect Dis ; 96: 240-243, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32339714

RESUMO

OBJECTIVES: Between-person variability in T-cell-specific interferon-gamma release assay (IGRA) responses and discordance between IGRA test formats are poorly understood. METHODS: We evaluated the IFN-γ responses (QuantiFERON-TB Gold-In-Tube [QFT-GIT] and TSPOT-TB) stratified according to the Mycobacterium tuberculosis spoligotype of the culture isolate obtained from the same patients with confirmed active tuberculosis (n = 91). We further analysed differences within the RD-1-encoding ESX-1 region between the different strain types using whole genome sequencing. RESULTS: In HIV-uninfected patients, TSPOT.TB and QFT-GIT IFN-γ responses were 5-fold (p < 0.01) and 2-fold higher (p < 0.05) for those infected with family 33 compared to the LAM strain (additionally, TSPOT.TB responses were 5.6-fold [p < 0.05] and 2.6-fold higher [p < 0.05] for the patients infected with the family 33 versus the X strain and Beijing versus the LAM strain, respectively). Multivariate analysis revealed that strain type (determined by spoligotyping) was independently associated with the magnitude of the IGRA response (varied by IGRA test type) and this is likely explained by variability in the ESX-1 region of Mycobacteriumtuberculosis (determined by next-generation sequencing). CONCLUSIONS: These data have implications for the understanding of between-person heterogeneity in IGRA responses, Mycobateriumtuberculosis-specific host immunity, and the discordance between different IGRA test formats.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Interferon gama/metabolismo , Mycobacterium tuberculosis/imunologia , Tuberculose Pulmonar/imunologia , Adulto , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Pequim , Feminino , Genótipo , Humanos , Testes de Liberação de Interferon-gama , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/isolamento & purificação , Linfócitos T/imunologia
19.
Klin Lab Diagn ; 65(5): 289-293, 2020.
Artigo em Russo | MEDLINE | ID: mdl-32298544

RESUMO

The glycoconjugates with BSA (bovine serum albumin) were synthesized using a next saccharide: disaccharide derivative M.leprae PGL-1 (phenolic glycolipid-1); a complex of the disaccharide fragment and the branched hexasaccharide fragment LAM (lipoarabinomannan); diarabinofuranose fragment LAM. These glycoconjugates were used as antigenic components for leprosy rapid serotest construction in immunochromatographic format (leprosy LF serotest). The data obtained with sera of leprosy patients, patients who have been in contact with leprosy, and healthy donors indicate that the most promising antigenic component is a BSA conjugate with two synthetic epitopes - a disaccharide derivative of PGL-1 and a branched hexasaccharide fragment of LAM. The leprosy LF serotest with such glycoconjugate demonstrated the greatest diagnostic sensitivity for main forms of leprosy - paucibacillary (PB) and multibacillary (MB).


Assuntos
Antígenos de Bactérias/imunologia , Glicoconjugados/química , Glicolipídeos/imunologia , Hanseníase/diagnóstico , Anticorpos Antibacterianos , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoensaio , Hanseníase/sangue , Lipopolissacarídeos/química , Mycobacterium leprae , Testes Sorológicos
20.
PLoS One ; 15(4): e0230782, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32294093

RESUMO

Understanding immune responses to native antigens in response to natural infections can lead to improved approaches to vaccination. This study sought to characterize the humoral immune response to anthrax toxin components, capsule and spore antigens in individuals (n = 46) from the Kayseri and Malatya regions of Turkey who had recovered from mild or severe forms of cutaneous anthrax infection, compared to regional healthy controls (n = 20). IgG antibodies to each toxin component, the poly-γ-D-glutamic acid capsule, the Bacillus collagen-like protein of anthracis (BclA) spore antigen, and the spore carbohydrate anthrose, were detected in the cases, with anthrax toxin neutralization and responses to Protective Antigen (PA) and Lethal Factor (LF) being higher following severe forms of the disease. Significant correlative relationships among responses to PA, LF, Edema Factor (EF) and capsule were observed among the cases. Though some regional control sera exhibited binding to a subset of the tested antigens, these samples did not neutralize anthrax toxins and lacked correlative relationships among antigen binding specificities observed in the cases. Comparison of serum binding to overlapping decapeptides covering the entire length of PA, LF and EF proteins in 26 cases compared to 8 regional controls revealed that anthrax toxin-neutralizing antibody responses elicited following natural cutaneous anthrax infection are directed to conformational epitopes. These studies support the concept of vaccination approaches that preserve conformational epitopes.


Assuntos
Antraz/imunologia , Anticorpos Antibacterianos/imunologia , Anticorpos Neutralizantes/imunologia , Antígenos de Bactérias/imunologia , Toxinas Bacterianas/imunologia , Epitopos/imunologia , Dermatopatias Bacterianas/imunologia , Adulto , Vacinas contra Antraz/imunologia , Especificidade de Anticorpos/imunologia , Bacillus anthracis/imunologia , Feminino , Humanos , Imunidade Humoral/imunologia , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Testes de Neutralização/métodos , Turquia , Adulto Jovem
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