Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.073
Filtrar
1.
Gut ; 69(2): 343-354, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-30926653

RESUMO

OBJECTIVE: This study aimed to develop a novel therapeutic vaccine based on a unique B cell epitope and investigate its therapeutic potential against chronic hepatitis B (CHB) in animal models. METHODS: A series of peptides and carrier proteins were evaluated in HBV-tolerant mice to obtain an optimised therapeutic molecule. The immunogenicity, therapeutic efficacy and mechanism of the candidate were investigated systematically. RESULTS: Among the HBsAg-aa119-125-containing peptides evaluated in this study, HBsAg-aa113-135 (SEQ13) exhibited the most striking therapeutic effects. A novel immunoenhanced virus-like particle carrier (CR-T3) derived from the roundleaf bat HBV core antigen (RBHBcAg) was created and used to display SEQ13, forming candidate molecule CR-T3-SEQ13. Multiple copies of SEQ13 displayed on the surface of this particulate antigen promote the induction of a potent anti-HBs antibody response in mice, rabbits and cynomolgus monkeys. Sera and purified polyclonal IgG from the immunised animals neutralised HBV infection in vitro and mediated efficient HBV/hepatitis B virus surface antigen (HBsAg) clearance in the mice. CR-T3-SEQ13-based vaccination induced long-term suppression of HBsAg and HBV DNA in HBV transgenic mice and eradicated the virus completely in hydrodynamic-based HBV carrier mice. The suppressive effects on HBsAg were strongly correlated with the anti-HBs level after vaccination, suggesting that the main mechanism of CR-T3-SEQ13 vaccination therapy was the induction of a SEQ13-specific antibody response that mediated HBV/HBsAg clearance. CONCLUSIONS: The novel particulate protein CR-T3-SEQ13 suppressed HBsAg effectively through induction of a humoural immune response in HBV-tolerant mice. This B cell epitope-based therapeutic vaccine may provide a novel immunotherapeutic agent against chronic HBV infection in humans.


Assuntos
Epitopos de Linfócito B/imunologia , Antígenos de Superfície da Hepatite B/sangue , Vacinas contra Hepatite B/imunologia , Hepatite B Crônica/imunologia , Adjuvantes Imunológicos , Animais , Antivirais/uso terapêutico , Terapia Combinada , DNA Viral/sangue , Relação Dose-Resposta Imunológica , Feminino , Anticorpos Anti-Hepatite B/biossíntese , Vacinas contra Hepatite B/uso terapêutico , Vírus da Hepatite B/genética , Hepatite B Crônica/terapia , Hepatite B Crônica/virologia , Imunidade Humoral/imunologia , Imunoterapia/métodos , Macaca fascicularis , Masculino , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Coelhos
2.
Mol Immunol ; 116: 106-116, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31634814

RESUMO

Shigellosis is a severe diarrheal disease with high mortality and morbidity rate. Until now, there is no approved vaccine against the disease. Therefore, the present study was planned to design a novel multi-epitope vaccine against Shigella spp., the causative agents of the disease based on the immunoinformatic tools. For this end, firstly seven conserved antigens of the bacteria, including IpaA, IpaB, IpaC, IpaD, OmpC, OmpF and VirG were selected. Then, linear B-cell epitope mapping of these proteins was carried out and top-ranked and shared epitopes were selected based on antigenicity, allergenicity, stability, toxicity and physicochemical properties for further analysis. In next step, B-cell derived T-cell epitopes were determined and appropriate epitopes were selected for incorporation into the final construct. Moreover, the selected epitopes and two mucosal adjuvants including ctxB and LT-IIc were joined using appropriate linkers. The three dimensional structure of the final construct was modeled and evaluated in term of structural quality and presence of conformational B-cell epitopes. Furthermore, binding affinity of the proposed vaccine to MHC I and II molecules were evaluated through molecular docking method using Hex 8.0. as well as the stability of the vaccine-MHC complexes was monitored by molecular dynamics method using the NAMD graphical user interface embedded in visual molecular dynamics. Finally, to evaluate the immunogenicity of the designed protein, the protein was administered to BALB/c mice and the serum IgG was determined by ELISA. The results indicated that the proposed vaccine has high structural quality and binding affinity to both MHC I and II molecules. Moreover, molecular dynamics studies confirmed that the vaccine-MHC docked complexes were stable during simulation time. Animal study showed that the proposed protein is able to evoke mice's humoral immune response. In sum, the results suggested that the proposed candidate vaccine could be considered as a promising anti-shigellosis vaccine.


Assuntos
Vacinas Bacterianas/imunologia , Proteção Cruzada/imunologia , Shigella/imunologia , Adjuvantes Imunológicos , Animais , Linfócitos B/imunologia , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Feminino , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Imunidade Humoral/imunologia , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Simulação de Acoplamento Molecular/métodos , Vacinologia/métodos
3.
Nat Med ; 25(10): 1589-1600, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31591605

RESUMO

Recombinant vesicular stomatitis virus-Zaire Ebola virus (rVSV-ZEBOV) is the most advanced Ebola virus vaccine candidate and is currently being used to combat the outbreak of Ebola virus disease (EVD) in the Democratic Republic of the Congo (DRC). Here we examine the humoral immune response in a subset of human volunteers enrolled in a phase 1 rVSV-ZEBOV vaccination trial by performing comprehensive single B cell and electron microscopy structure analyses. Four studied vaccinees show polyclonal, yet reproducible and convergent B cell responses with shared sequence characteristics. EBOV-targeting antibodies cross-react with other Ebolavirus species, and detailed epitope mapping revealed overlapping target epitopes with antibodies isolated from EVD survivors. Moreover, in all vaccinees, we detected highly potent EBOV-neutralizing antibodies with activities comparable or superior to the monoclonal antibodies currently used in clinical trials. These include antibodies combining the IGHV3-15/IGLV1-40 immunoglobulin gene segments that were identified in all investigated individuals. Our findings will help to evaluate and direct current and future vaccination strategies and offer opportunities for novel EVD therapies.


Assuntos
Vacinas contra Ebola/administração & dosagem , Ebolavirus/imunologia , Doença pelo Vírus Ebola/prevenção & controle , Imunidade Humoral/imunologia , Adulto , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , Linfócitos B/imunologia , Linfócitos B/virologia , Vacinas contra Ebola/efeitos adversos , Vacinas contra Ebola/imunologia , Ebolavirus/patogenicidade , Feminino , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Vacinação/efeitos adversos , Vesiculovirus/genética , Voluntários
4.
Infect Immun ; 87(12)2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31548319

RESUMO

Antibodies are essential for immunity against Ehrlichia chaffeensis, and protective mechanisms involve blocking of ehrlichial attachment or complement and Fcγ-receptor-dependent destruction. In this study, we determined that major outer membrane protein 1 (OMP-19) hypervariable region 1 (HVR1)-specific human monoclonal antibodies (huMAbs) are protective through conventional extracellular neutralization and, more significantly, through a novel intracellular TRIM21-mediated mechanism. Addition of OMP-1-specific huMAb EHRL-15 (IgG1) prevented infection by blocking attachment/entry, a mechanism previously reported; conversely, OMP-1-specific huMAb EHRL-4 (IgG3) engaged intracellular TRIM21 and initiated an immediate innate immune response and rapid intracellular degradation of ehrlichiae. EHRL-4-TRIM21-mediated inhibition was significantly impaired in TRIM21 knockout THP-1 cells. EHRL-4 interacted with cytosolic Fc receptor TRIM21, observed by confocal microscopy and confirmed by co-immunoprecipitation. E. chaffeensis-EHRL-4-TRIM21 complexes caused significant upregulation of proinflammatory cytokine/chemokine transcripts and resulted in rapid (<30 min) nuclear accumulation of NF-κB and TRIM21 and ehrlichial destruction. We investigated the role of TRIM21 in the autophagic clearance of ehrlichiae in the presence of EHRL-4. Colocalization between EHRL-4-opsonized ehrlichiae, polyubiquitinated TRIM21, autophagy regulators (ULK1 and beclin 1) and effectors (LC3 and p62), and lysosome-associated membrane protein 2 (LAMP2) was observed. Moreover, autophagic flux defined by conversion of LC3I to LC3II and accumulation and degradation of p62 was detected, and EHRL-4-mediated degradation of E. chaffeensis was abrogated by the autophagy inhibitor 3-methyladenine. Our results demonstrate that huMAbs are capable of inhibiting E. chaffeensis infection by distinct effector mechanisms: extracellularly by neutralization and intracellularly by engaging TRIM21, which mediates a rapid innate immune response that mobilizes the core autophagy components, triggering localized selective autophagic degradation of ehrlichiae.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/imunologia , Ehrlichia chaffeensis/imunologia , Ribonucleoproteínas/genética , Adenina/análogos & derivados , Adenina/farmacologia , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Antígenos de Bactérias/genética , Autofagia/imunologia , Aderência Bacteriana/genética , Sistemas CRISPR-Cas , Linhagem Celular Tumoral , Ehrlichia chaffeensis/genética , Técnicas de Inativação de Genes , Humanos , Imunidade Humoral/imunologia , NF-kappa B/genética , Células THP-1
5.
Vet Res ; 50(1): 66, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31533826

RESUMO

Although it is known that gestation could influence the clinical course of ovine toxoplasmosis, the precise effect of the term of gestation when sheep are infected are yet mostly unknown. The aim of this study was to evaluate the peripheral and placental immune responses developed in pregnant sheep after experimental infection with Toxoplasma gondii at different times of gestation. Thirty-six pregnant sheep were allocated in different groups, orally inoculated with sporulated oocysts of T. gondii at early, mid and late gestation and culled within 30 days post-infection. The peripheral humoral and cytokine responses were evaluated, as well as the transcription of cytokines at the placenta. Serological analysis revealed that, regardless the term of gestation when infected, specific IgG against T. gondii were detected from day 8 post-infection and there was an early peripheral release of IFN-γ at the first week post-infection followed by a short peak of IL10 and TNF-α at the second week post-infection. There were no significant differences in this response between infected groups. At the placenta, a similar increase in transcription of IFN-γ, and TNF-α was found at the three terms of gestation, while IL-4 increased mainly at the first and second terms and IL-10 transcription was higher at the last term. While these findings show that both Th1 and Th2 cytokines play a key role in the pathogenesis of ovine toxoplasmosis and that placental and peripheral immune responses do not closely correlate, there seems to be no clear modulation of these responses along the gestation.


Assuntos
Imunidade Humoral/imunologia , Placenta/imunologia , Doenças dos Ovinos/imunologia , Toxoplasma/fisiologia , Toxoplasmose Animal/imunologia , Animais , Anticorpos Antiprotozoários , Feminino , Idade Gestacional , Oocistos/fisiologia , Gravidez , Ovinos , Doenças dos Ovinos/parasitologia , Fatores de Tempo , Toxoplasmose Animal/parasitologia
6.
PLoS Med ; 16(8): e1002854, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31386660

RESUMO

BACKGROUND: Exposure to a nutritionally deficient environment during fetal life and early infancy may adversely alter the ontogeny of the immune system and affect an infant's ability to mount an optimal immune response to vaccination. We examined the effects of maternal nutritional supplementation during pregnancy on infants' antibody responses to the diphtheria-tetanus-pertussis (DTP) vaccine included in the Expanded Programme on Immunisation (EPI). METHODS AND FINDINGS: The Early Nutrition and Immune Development (ENID) trial was a randomised, partially blinded trial conducted between April 2010 and February 2015 in the rural West Kiang region of The Gambia, a resource-poor region affected by chronic undernutrition. Pregnant women (<20 weeks' gestation) with a singleton pregnancy (n = 875) were randomised to receive one of four supplements: iron-folic acid (FeFol; standard of care), multiple micronutrient (MMN), protein-energy (PE), or PE + MMN daily from enrolment (mean [SD] 13.7 [3.3] weeks' gestation) until delivery. Infants were administered the DTP vaccine at 8, 12, and 16 weeks of age according to the Gambian Government protocol. Results for the primary outcome of the trial (infant thymic size) were described previously; here, we report on a secondary outcome, infant antibody response to vaccination. The effects of supplementation on mean DTP antibody titres measured in blood samples collected from infants at 12 weeks (n = 710) and 24 weeks (n = 662) were analysed with adjustment for confounders including maternal age, compliance to supplement, and infant sex and season. At 12 weeks, following a single dose of the vaccine, compared with FeFol (mean 95% confidence interval [CI]; 0.11 IU/mL, 0.09-0.12), antenatal supplementation with MMN or MMN + PE resulted in 42.4% (95% CI 20.1-64.6; p < 0.001) and 29.4% (6.4-52.5; p = 0.012) higher mean anti-diphtheria titres, respectively. Mean anti-tetanus titres were higher by 9.0% (5.5-12.5), 7.8% (4.3-11.4), and 7.3% (4.0-10.7) in MMN, PE, and PE + MMN groups (all, p < 0.001), respectively, than in the FeFol group (0.55 IU/mL, 0.52-0.58). Mean anti-pertussis titres were not significantly different in the FeFol, MMN, and PE + MNN groups but were all higher than in the PE group (all, p < 0.001). At 24 weeks, following all three doses, no significant differences in mean anti-diphtheria titres were detected across the supplement groups. Mean anti-tetanus titres were 3.4% (0.19-6.5; p = 0.038) higher in the PE + MMN group than in the FeFol group (3.47 IU/mL, 3.29-3.66). Mean anti-pertussis titres were higher by 9.4% (3.3-15.5; p = 0.004) and 15.4% (9.6-21.2; p < 0.001) in PE and PE + MMN groups, compared with the FeFol group (74.9 IU/mL, 67.8-82.8). Limitations of the study included the lack of maternal antibody status (breast milk or plasma) or prevaccination antibody measurements in the infants. CONCLUSION: According to our results from rural Gambia, maternal supplementation with MMN combined with PE during pregnancy enhanced antibody responses to the DTP vaccine in early infancy. Provision of nutritional supplements to pregnant women in food insecure settings may improve infant immune development and responses to EPI vaccines. TRIAL REGISTRATION: ISRCTN49285450.


Assuntos
Suplementos Nutricionais , Vacina contra Difteria, Tétano e Coqueluche/imunologia , Imunidade Humoral/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal/imunologia , Adolescente , Adulto , Vacina contra Difteria, Tétano e Coqueluche/farmacologia , Feminino , Gâmbia , Humanos , Imunidade Humoral/imunologia , Fenômenos Fisiológicos da Nutrição Materna/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição Materna/imunologia , Pessoa de Meia-Idade , Estado Nutricional , Gravidez , Adulto Jovem
7.
Acta Vet Scand ; 61(1): 41, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31455410

RESUMO

BACKGROUND: Villegas-Glisson/University of Georgia (VG/GA) strain of Newcastle disease virus (NDV) is recommended for the initial vaccination of commercially reared turkey poults. However, the vaccine-induced antibody responses have not been studied in this species. The level of systemic humoral immune responses against the NDV was investigated in commercial turkey poults vaccinated with the VG/GA vaccine. One hundred eighty-two hybrid strain of turkey poults (Meleagris gallopavo) were divided randomly into vaccinated and unvaccinated groups. The vaccinated group was given the VG/GA vaccine at 10 and 20 days of age. To investigate the vaccine immunity, the level of specific IgY and IgA in serum samples were determined using ELISA and haemagglutination inhibition assays (HI). The biological half-life of maternal antibodies was also determined before the immunization. RESULTS: VG/GA-specific antibodies were detected in the vaccinated turkey poults and were significantly higher in the vaccinated group compared to the unvaccinated group. IgY and IgA antibodies showed a significant increase in titers 14 days after the second vaccination and reached a peak on day 35 of age. The correlation coefficient and intra-rater reliability showed a significant correlation between the HI titers and IgY/IgA ELISA values. Maternal IgY and IgA levels were found to decline in the serum with half-lifes of 7.68 ± 2.35 and 2.18 ± 0.82 days, respectively. CONCLUSIONS: Enterotropic lentogenic VG/GA vaccine induced a marked humoral immune response against the NDV in turkey poults. The positive correlation between IgY and IgA highlights the role of these two antibody classes in controlling the Newcastle disease in turkey poults.


Assuntos
Imunidade Humoral/imunologia , Doença de Newcastle/imunologia , Vírus da Doença de Newcastle/imunologia , Doenças das Aves Domésticas/imunologia , Perus , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/sangue , Doença de Newcastle/prevenção & controle , Doenças das Aves Domésticas/prevenção & controle
8.
Int J Biol Macromol ; 137: 790-800, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31279887

RESUMO

Anthrax is an acute and highly lethal disease caused by Bacillus anthracis. Protective antigen (PA) is the primary candidate antigen for the anthrax vaccines. However, PA suffers from poor immunogenicity with short-term anti-PA antibody response. High effectiveness, durable immunity, and minimal risk are required for development of an effective anthrax vaccine. In the present study, PA was self-conjugated by 8-arm polyethylene glycol (PEG) and further by thioester chemistry. As a result, 3-5 PA molecules were covalently conjugated and functioned as an antigen delivery system. The conjugate (PA-PEG) could maintain the structural properties of PA and increase the thermal stability of PA. PA-PEG could elicit a robust anti-PA IgG and neutralization antibody response in the magnitude and quality. The antibodies could be largely maintained for 180 days after three immunizations of PA-PEG. PA-PEG effectively stimulated the maturation of dendritic cell and rapidly induced the germinal center (GC) reaction. The percentages of the GC B-cells and T follicular helper (Tfh) cells were thus significantly augmented. The inflammatory response elicited by PA-PEG was comparable to those by PBS and PA. Therefore, PA-PEG is expected as an effective anthrax vaccine candidate with durable immunoprotection against anthrax.


Assuntos
Vacinas contra Antraz/química , Vacinas contra Antraz/imunologia , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/química , Antígenos de Bactérias/imunologia , Bacillus anthracis/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Células Dendríticas/imunologia , Imunidade Humoral/imunologia , Imunoglobulina G/imunologia , Camundongos , Polietilenoglicóis/química
9.
Fish Shellfish Immunol ; 92: 802-812, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31284047

RESUMO

Like other ciliates, Philasterides dicentrarchi, the scuticociliate parasite of turbot, produces a feeding-only or growing stage called a trophont during its life cycle. Exposure of the trophonts to heat-inactivated serum extracted from the turbot host and containing specific antibodies that induce agglutination/immobilization leads to the production of a mucoid capsule from which the trophonts later emerge. We investigated how these capsules are generated, observing that the mechanism was associated with the process of exocytosis involved in the release of a matrix material from the extrusomes. The extruded material contains mucin-like glycoproteins that were deposited on the surface of the cell and whose expression increased with time of exposure to the heat-inactivated immune serum, at both protein expression and gene expression levels. Stimulation of the trophonts with the immune serum also caused an increase in discharge of the intracellular storage compartments of calcium necessary for the exocytosis processes in the extrusomes. The results obtained suggest that P. dicentrarchi uses the extrusion mechanism to generate a physical barrier protecting the ciliate from attack by soluble factors of the host immune system. Data on the proteins involved and the potential development of molecules that interfere with this exocytic process could contribute to improving the prevention and control of scuticociliatosis in turbot.


Assuntos
Infecções por Cilióforos/veterinária , Doenças dos Peixes/imunologia , Linguados , Imunidade Humoral/imunologia , Oligoimenóforos/fisiologia , Animais , Infecções por Cilióforos/imunologia , Infecções por Cilióforos/parasitologia , Doenças dos Peixes/parasitologia
10.
J Nutr Sci Vitaminol (Tokyo) ; 65(3): 278-282, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31257269

RESUMO

We examined the effect of nobiletin (5,6,7,8,3',4'-hexamethoxyflavone) on immune response in ovalbumin (OVA)-immunized mice. Treatment with nobiletin increased OVA-specific IL-4 and IL-10 production. In addition, mice that received nobiletin showed higher levels of OVA-specific IgE, IgG and IgG1 production than did control mice. The antibody response to the thymus-independent antigen 2,4,6-trinitrophenyl-Ficoll was not different in the control and nobiletin groups, suggesting that nobiletin does not directly stimulate antibody production. An in vitro study showed that treatment with nobiletin enhanced the ability of antigen presentation of bone marrow-derived dendritic cells. The in vivo and in vitro results indicate that nobiletin regulates immune function.


Assuntos
Flavonas/farmacologia , Imunidade Celular , Imunidade Humoral , Ovalbumina/imunologia , Animais , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/imunologia , Células Cultivadas , Citocinas/imunologia , Citocinas/metabolismo , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Ficoll/análogos & derivados , Ficoll/imunologia , Imunidade Celular/efeitos dos fármacos , Imunidade Celular/imunologia , Imunidade Humoral/efeitos dos fármacos , Imunidade Humoral/imunologia , Imunização , Camundongos , Camundongos Endogâmicos BALB C , Trinitrobenzenos/imunologia
11.
Fish Shellfish Immunol ; 93: 436-448, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31362092

RESUMO

Mud crabs, Scylla paramamosain, are one of the most economical and nutritious crab species in China and South Asia. Inconsistent with the high development of commercial mud crab aquaculture, effective immunological methods to prevent frequently-occurring diseases have not yet been developed. Thus, high mortalities often occur throughout the different developmental stages of this species resulting in large economic losses. In recent years, numerous attempts have been made to use various advanced biological technologies to understand the innate immunity of S. paramamosain as well as to characterize specific immune components. This review summarizes these research advances regarding cellular and humoral responses of the mud crab during pathogen infection, highlighting hemocytes and gills defense, pattern recognition, immune-related signaling pathways (Toll, IMD, JAK/STAT, and prophenoloxidase (proPO) cascades), immune effectors (antimicrobial peptides), production of reactive oxygen species and the antioxidant system. Diseases affecting the development of mud crab aquaculture and potential disease control strategies are discussed.


Assuntos
Braquiúros/imunologia , Brânquias/imunologia , Hemócitos/imunologia , Imunidade Inata/imunologia , Animais , Imunidade Celular/imunologia , Imunidade Humoral/imunologia
12.
PLoS One ; 14(6): e0216533, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31166987

RESUMO

BACKGROUND: New influenza vaccines eliciting more effective protection are needed, particularly for the elderly who paid a large and disproportional toll of hospitalization and dead during seasonal influenza epidemics. Low (≤15 µg/strain) doses of a new plant-derived virus-like-particle (VLP) vaccine candidate have been shown to induce humoral and cellular responses against both homologous and heterologous strains in healthy adults 18-64 years of age. The two clinical trials reported here addressed the safety and immunogenicity of higher doses (≥15 µg/strain) of quadrivalent VLP candidate vaccine on 18-49 years old and ≥50 years old subjects. We also investigated the impact of alum on the immunogenicity induced by lower doses of the vaccine candidate. METHOD: In the first Phase II trial reported here (NCT02233816), 18-49 year old subjects received 15, 30 or 60 µg/strain of a hemagglutinin-bearing quadrivalent virus-like particle (QVLP) vaccine or placebo. In the second trial (NCT02236052), ≥50 years old subjects received QVLP as above or placebo with additional groups receiving 7.5 or 15 µg/strain with alum. Along with safety recording, the humoral and cell-mediated immune responses were analyzed. RESULTS: Local and systemic side-effects were similar to those reported previously. The QVLP vaccine induced significant homologous and heterologous antibody responses at the two higher doses, the addition of alum having little-to-no effect. Serologic outcomes tended to be lower in ≥50 years old subjects previously vaccinated. The candidate vaccine also consistently elicited both homologous and heterologous antigen-specific CD4+ T cells characterized by their production of interferon-gamma (IFN-γ), interleukine-2 (IL-2) and/or tumor-necrosis factor alpha (TNF-α) upon ex vivo antigenic restimulation. CONCLUSION: Overall, the 30 µg dose produced the most consistent humoral and cellular responses in both 18-49 and ≥50 years old subjects, strongly supporting the clinical development of this candidate vaccine. That particular dose was chosen to test in the ongoing Phase III clinical trial.


Assuntos
Vacinas contra Influenza/efeitos adversos , Vacinas contra Influenza/imunologia , Plantas , Segurança , Vacinas de Partículas Semelhantes a Vírus/efeitos adversos , Vacinas de Partículas Semelhantes a Vírus/imunologia , Adolescente , Adulto , Idoso , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Relação Dose-Resposta Imunológica , Feminino , Humanos , Imunidade Celular/imunologia , Imunidade Humoral/imunologia , Masculino , Pessoa de Meia-Idade , Adulto Jovem
13.
Int J Biol Macromol ; 137: 126-131, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31238071

RESUMO

Vibrio parahaemolyticus is the main etiological agent of human gastroenteritis by seafood consumption and some strains from this species causing the Acute Hepatopancreatic Necrosis Disease in shrimp have been recently reported. The PirA-like toxin from V. parahaemolyticus (ToxA) has been recently reported as an attractive antigen implicated in subunit vaccine development. Since plants are attractive hosts for the production and delivery of vaccines in the present study plants expressing ToxA were developed to account with a low cost platform for the production and oral delivery of ToxA. Tobacco plants were genetically engineered by Agrobacterium-mediated transformation to stably integrate the ToxA-coding gene into the nuclear genome. Transgenic lines were rescued in kanamycin-containing medium and analyzed by ELISA to determine ToxA yields observing levels up to 9 µg g-1 FW leaf tissues. Western blot analysis confirmed the presence of the ToxA protein in plant extracts. Immunogenicity assessment of the plant-made ToxA was performed in mice, comprising a 4-dose oral immunization scheme; revealing the induction of anti-ToxA humoral responses (IgG in serum and IgA in feces). This study opens the path for the development of low cost plant-based vaccines against Vibrio parahaemolyticus.


Assuntos
Toxinas Bacterianas/biossíntese , Toxinas Bacterianas/imunologia , Tabaco/genética , Tabaco/metabolismo , Vibrio parahaemolyticus/genética , Administração Oral , Sequência de Aminoácidos , Animais , Toxinas Bacterianas/química , Toxinas Bacterianas/genética , Biotecnologia , Imunidade Humoral/imunologia , Camundongos , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas
14.
Vet Immunol Immunopathol ; 211: 25-34, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31084890

RESUMO

Red Mark Syndrome (RMS) is a skin disease reported from farmed rainbow trout. Since the turn of the millennium it has been spreading through Europe. RMS is probably a bacterial disease caused by a Midichloria-like organism (MLO). It is non-lethal and causes little obvious changes in appetite or behavior but results in red hyperaemic skin lesions, which may lead to economic losses due to downgrading. Here we transfer RMS to naïve specific pathogen free (SPF) fish by cohabitation with RMS-affected seeder fish. During disease development we characterize local cellular immune responses and regulations of immunologically relevant genes in skin of the cohabitants by immunohistochemistry and qPCR. Skin samples from SPF controls and cohabitants (areas with and without lesions) were taken at 18, 61, 82 and 97 days post-cohabitation. Gene expression results showed that lesions had a Th1-type profile, but with concurrent high expression levels of all three classes of immunoglobulins (IgD, IgM and IgT). The marked local infiltration of IgD + cells in the skin lesions as well as a highly up-regulated expression of the genes encoding sIgD and mIgD indicate that this immunoglobulin class plays an important role in skin immunity in general and in RMS pathology in particular. The co-occurrence of an apparent B cell dominated immune reaction with a Th1-type profile suggests that the local production of antibodies is independent of the classical Th2 pathway.


Assuntos
Doenças dos Peixes/imunologia , Imunidade Humoral/imunologia , Oncorhynchus mykiss/imunologia , Pele/imunologia , Animais , Doenças dos Peixes/microbiologia , Expressão Gênica , Imunoglobulina D/imunologia , Oncorhynchus mykiss/microbiologia , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Pele/metabolismo
15.
BMC Vet Res ; 15(1): 161, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31118011

RESUMO

BACKGROUND: Bovine coronavirus (BCV) is associated with respiratory infections in cattle of all ages; however, a temporal study to evaluate the effect of BCV immunity on virus shedding and bovine respiratory disease (BRD) incidence in pre-weaned beef calves has not been reported. Thus, we report here a prospective study in three herds of crossbred beef calves (n = 817) with endemic BCV. Serial blood samples for measurement of serum anti-BCV antibody titers and nasal swabs for detection of BCV and other common viral and bacterial BRD pathogens were collected from all calves or subsets of calves at predetermined times from birth through weaning. The calves were monitored for BRD and those that developed signs of respiratory disease were sampled for diagnostic testing. To discover additional risk factors that could have influenced BRD development, sequence analysis of the BCV strain(s) circulating in each herd, and the prevalence of common opportunistic bacterial pathogens in the upper respiratory tract of sick and apparently healthy cattle were also evaluated. RESULTS: Two hundred forty-eight of the 817 study calves (30.4%) were treated for BRD prior to weaning; 246 of those were from a single herd involved in two outbreaks of BRD leading to mass treatment of all calves in that group. Molecular diagnostic testing found BCV and Histophilus somni in nasal swabs taken at the time of BRD treatment. Between herd analyses revealed anti-BCV serum antibody abundance did not associate with the incidence of BRD or BCV shedding, though these measurements may have been hindered by the long periods between sample collections. Analysis of the BCV spike gene hypervariable region revealed four polymorphisms in 15 isolates from the three herds, making strain variation unlikely to account for differences in treatment rates between herds. Persistent or recurrent shedding episodes of BCV occurred in some animals treated for BRD. CONCLUSION: Co-detection of BCV and H. somni at the time of the disease outbreak suggests that these pathogens contributed to disease pathogenesis. Developing appropriate control measures for respiratory BCV infections may help decrease the incidence of pre-weaning BRD. The role of antibodies in protection must still be further defined.


Assuntos
Doenças dos Bovinos/imunologia , Infecções por Coronavirus/veterinária , Coronavirus Bovino/imunologia , Imunidade Humoral/imunologia , Animais , Anticorpos Antivirais/sangue , Bovinos , Doenças dos Bovinos/microbiologia , Coinfecção/veterinária , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/microbiologia , Coronavirus Bovino/genética , Pasteurellaceae/fisiologia , Polimorfismo Genético , Eliminação de Partículas Virais
16.
Cells ; 8(5)2019 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-31130710

RESUMO

Host immune responses play an important role in the outcome of infection with hepatitis C virus (HCV). They can lead to viral clearance and a positive outcome, or progression and severity of chronic disease. Extensive research in the past >25 years into understanding the immune responses against HCV have still resulted in many unanswered questions implicating a role for unknown factors and events. In our earlier studies, we made a surprising discovery that peptides derived from structural and non-structural proteins of HCV have substantial amino acid sequence homologies with various proteins of adenoviruses and that immunizing mice with a non-replicating, non-recombinant adenovirus vector leads to induction of a robust cross-reactive cellular and humoral response against various HCV antigens. In this work, we further demonstrate antibody cross-reactivity between Ad and HCV in vivo. We also extend this observation to show that recombinant adenoviruses containing antigens from unrelated pathogens also possess the ability to induce cross-reactive immune responses against HCV antigens along with the induction of transgene antigen-specific immunity. This cross-reactive immunity can (a) accommodate the making of dual-pathogen vaccines, (b) play an important role in the natural course of HCV infection and (c) provide a plausible answer to many unexplained questions regarding immunity to HCV.


Assuntos
Infecções por Adenoviridae/virologia , Adenoviridae/imunologia , Vacinas contra Adenovirus/imunologia , Reações Cruzadas/imunologia , Vetores Genéticos/imunologia , Hepacivirus/imunologia , Antígenos da Hepatite C/imunologia , Hepatite C/virologia , Imunidade Heteróloga/imunologia , Animais , Antígenos de Bactérias/imunologia , Células Cultivadas , Feminino , Antígenos HIV/imunologia , Imunidade Celular/imunologia , Imunidade Humoral/imunologia , Imunização/métodos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Baço/patologia , Vacinação/métodos
17.
Poult Sci ; 98(9): 3514-3522, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30993349

RESUMO

Fowl adenovirus serotype 4 (FAdV-4) is the causative agent of hydropericardium syndrome. To clarify the effects of FAdV-4 on immune organs in birds, we conducted a detailed examination of dynamic morphology and damage mechanisms in chickens randomly divided into 4 groups (FAdV-4, vaccination, FAdV-4 plus vaccination, and control). FAdV-4 caused the depletion of lymphocytes and subsequent growth impairment in the thymus and bursa. Chickens infected with FAdV-4 and subjected to vaccination experienced greater inhibition of antibody responses to inactivated vaccines against Newcastle disease and avian influenza virus subtype H9 than uninfected and vaccinated chickens. The mechanisms underlying adenovirus-mediated lymphoid organ damage were further investigated via transferase-mediated dUTP nick-end labeling and apoptotic genes transcription analyses. Notably, lymphocytes apoptosis in lymphoid organs and expression of specific gene transcripts was significantly upregulated after infection (P < 0.05). Furthermore, increased expression of interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-α mRNA was observed (P < 0.05), compared to the control group. Our collective findings suggested that FAdV-4 caused structural and functional damage of immune organs via apoptosis along with induction of a severe inflammatory response.


Assuntos
Infecções por Adenoviridae/veterinária , Galinhas , Adenovirus A das Aves/fisiologia , Tolerância Imunológica/imunologia , Imunidade Humoral/imunologia , Doenças das Aves Domésticas/imunologia , Tropismo Viral/imunologia , Infecções por Adenoviridae/imunologia , Animais , Apoptose , Adenovirus A das Aves/imunologia , Inflamação , Distribuição Aleatória , Sorogrupo
18.
Turk J Med Sci ; 49(2): 497-505, 2019 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-30997788

RESUMO

Background/aim: The serum immunoglobulin levels are used routinely in clinical practice because they provide key information on the humoral immune status. This study aimed to determine the age-related reference values of serum immunoglobulin levels in healthy children. Materials and methods: A total of 330 healthy children, aged between 0 and 18 years, were included in this study. The serum immunoglobulin levels were measured using a nephelometric method in a total of 11 groups, each group consisting of 30 individuals, and IgG subclasses in 6 groups of children aged more than 2 years. Results: The serum IgG levels were high during the newborn period, decreased until the sixth month, and again increased to a maximum level at the age of 18 years. The level of IgA was found to be extremely low in the newborn period and then increased with age. While the lowest value was in the newborn period for serum IgM level, the highest value was in the 16- to 18-year-old period. The IgG subclasses varied depending on the age groups. Conclusion: The updated reference intervals of immunoglobulin levels in children may be used for the accurate diagnosis of immune deficiencies.


Assuntos
Imunodeficiência de Variável Comum/sangue , Imunidade Humoral/imunologia , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Adolescente , Criança , Pré-Escolar , Imunodeficiência de Variável Comum/imunologia , Voluntários Saudáveis , Humanos , Lactente , Recém-Nascido , Masculino , Nefelometria e Turbidimetria , Valores de Referência , Reprodutibilidade dos Testes
19.
Biologicals ; 59: 6-11, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31014910

RESUMO

According to some difficulties against tuberculosis (TB) vaccination, development of new TB vaccines has been noted in recent years. Selection of proper route for vaccination is one of the most important factors for induction of good immune responses. Hence, in this study, the effects of different administration routes, including intranasal (I.N), subcutaneous (S.C) and intramuscular (I.M) on immune responses against Mycobacterium tuberculosis ESAT-6/CFP-10 recombinant protein has been considered. Recombinant ESAT-6/CFP-10 protein with or without adjuvant (MF59 or cholera toxin B (CTB)) was administered by three routes of I.M, I.N and S.C to mice for three times. Then, the levels of specific antibodies, lymphocyte proliferation and IFN-γ/IL-5 cytokine profile have been carried out to evaluate the humoral and cellular responses. The results showed that the titers of specific antibodies were quickly elevated in S.C and I.M groups after first immunization. Otherwise, the raise of antibody has delay in the I.N immunized animals. The levels of IFN-γ and lymphocyte proliferation have been increased in all of vaccinated groups. However, the I.N immunized mice have lower levels of IL-5 production. Based on our finding, the ESAT-6/CFP-10 recombinant protein is a potent stimulator of immune responses in all of three immunization strategies. However intranasal administration of this antigen has tended to reinforcement of cellular immune responses.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Mycobacterium tuberculosis/imunologia , Proteínas Recombinantes/imunologia , Vacinas contra a Tuberculose/imunologia , Tuberculose/imunologia , Administração Intranasal , Animais , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Feminino , Imunidade Celular/efeitos dos fármacos , Imunidade Celular/imunologia , Imunidade Humoral/efeitos dos fármacos , Imunidade Humoral/imunologia , Injeções Intramusculares , Injeções Subcutâneas , Camundongos , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose/microbiologia , Tuberculose/prevenção & controle , Vacinas contra a Tuberculose/administração & dosagem , Vacinação/métodos
20.
Parasitol Res ; 118(5): 1343-1352, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30941496

RESUMO

The peritoneal cavity has a microenvironment capable of promoting proliferation, differentiation, and activation of the resident cells and recruitment of blood cells through the capillary network involved in the peritoneum. Among the cells found in the peritoneal cavity, B-1 cells are a particular cell type that contains features that are not very well defined. These cells differ from conventional B lymphocytes (B-2) by phenotypic, functional, and molecular characteristics. B-1 cells can produce natural antibodies, migrate to the inflammatory focus, and have the ability to phagocytose pathogens. However, the role of B-1 cells in immunity against parasites is still not completely understood. Several experimental models have demonstrated that B-1 cells can affect the susceptibility or resistance to parasite infections depending on the model and species. Here, we review the literature to provide information on the peculiarities of B-1 lymphocytes as well as their interaction with parasites.


Assuntos
Subpopulações de Linfócitos B/imunologia , Helmintíase/imunologia , Helmintos/imunologia , Imunidade Humoral/imunologia , Parasitos/imunologia , Cavidade Peritoneal/citologia , Infecções por Protozoários/imunologia , Animais , Citocinas/biossíntese , Citocinas/imunologia , Helmintíase/parasitologia , Humanos , Camundongos , Peritônio/citologia , Peritônio/imunologia , Infecções por Protozoários/parasitologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA