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1.
Clin Lab ; 70(2)2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38345990

RESUMO

BACKGROUND: Clostridium perfringens type B and D strains produce epsilon toxin (ETX), which can lead to enterotoxemia, an extremely lethal disease that has significant consequences for the farming of domestic ruminants, specifically sheep and goats. The bacterin-toxoids/toxoids enterotoxemia vaccines need time-consuming detoxification steps. Genetically derived toxoids (GTs) can be the alternative vaccines against ETX-associated enterotoxemia. This study was aimed to design, synthesize, and evaluate of five epsilon toxin mutants of C. perfringens by site-directed mutagenesis (SDM). METHODS: In this study, five ETX mutants (H106P, I51C, V56C, A114C, and F118C), as ETX-GTs, were designed and synthesized by SDM, which were then cloned in pET-26b (+) and expressed in Escherichia coli /BL21 (DE3). The expression of recombinant ETX-GTs was evaluated by SDS-PAGE, blotting, and ELISA and their toxicity was evaluated by the residual toxicity test based on BP Pharmacopoeia, 2021. RESULTS: The findings showed that the ETX-GTs could be considered alternative vaccine candidates against ETX-associated enterotoxemia. CONCLUSIONS: These data suggest that I51C mutant could form the basis of an improved recombinant vaccine against enterotoxemia.


Assuntos
Clostridium perfringens , Enterotoxemia , Ovinos , Animais , Enterotoxemia/prevenção & controle , Clostridium perfringens/genética , Vacinas Sintéticas , Toxoides
2.
Anaerobe ; 85: 102817, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38163631

RESUMO

OBJECTIVES: This study aimed to produce and purify Clostridium perfringens type C beta-toxin, sheep anti-beta toxin immunoglobulin G (IgG) and chicken immunoglobulin Y (IgY). METHODS: Two methods were used for beta-toxin purification: single-step metal affinity chromatography (MAC) using zinc as a chelator and ion exchange chromatography (IEX). The purified and inactivated beta-toxoids were then administered to sheep and chickens in order to produce IgG and IgY. RESULTS: All assays using the IEX failed. In contrast, MAC purified more than 21 mg of toxin per run in a single-step protocol. The purified and inactivated beta-toxoids were then administered to sheep and chickens, and IgG and IgY were purified with a high yield, medium antibody titer of 50 IU/mL, and high avidity (73.2 %). CONCLUSIONS: C. perfringens type C beta-toxin and sheep or chicken anti-beta toxin IgG and IgY antibodies were successfully produced and purified using a simple protocol. This protocol can be used for the production of components used in the diagnosis and research of necrotic enteritis caused by C. perfringens type C, as well as for the evaluation of existing vaccines and the development of new preventive methods against this disease.


Assuntos
Antitoxinas , Infecções por Clostridium , Enterite , Imunoglobulinas , Doenças das Aves Domésticas , Animais , Ovinos , Clostridium perfringens , Infecções por Clostridium/veterinária , Enterite/veterinária , Galinhas , Toxoides , Imunoglobulina G , Doenças das Aves Domésticas/prevenção & controle
3.
MMWR Morb Mortal Wkly Rep ; 72(39): 1065-1071, 2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37768879

RESUMO

Influenza, tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap), and COVID-19 vaccines can reduce the risk for influenza, pertussis, and COVID-19 among pregnant women and their infants. To assess influenza, Tdap, and COVID-19 vaccination coverage among women pregnant during the 2022-23 influenza season, CDC analyzed data from an Internet panel survey conducted during March 28-April 16, 2023. Among 1,814 survey respondents who were pregnant at any time during October 2022-January 2023, 47.2% reported receiving influenza vaccine before or during their pregnancy. Among 776 respondents with a live birth by their survey date, 55.4% reported receiving Tdap vaccine during pregnancy. Among 1,252 women pregnant at the time of the survey, 27.3% reported receipt of a COVID-19 bivalent booster dose before or during the current pregnancy. Data from the same questions included in surveys conducted during influenza seasons 2019-20 through 2022-23 show that the proportion of pregnant women who reported being very hesitant about influenza and Tdap vaccinations during pregnancy increased from 2019-20 to 2022-23. Pregnant women who received a provider recommendation for vaccination were less hesitant about influenza and Tdap vaccines. Promotion of efforts to improve vaccination coverage among pregnant women, such as provider recommendation for vaccination and informative conversations with patients to address vaccine hesitancy, might reduce vaccine hesitancy and increase coverage with these important vaccines to protect mothers and their infants against severe respiratory diseases.


Assuntos
COVID-19 , Vacinas contra Difteria, Tétano e Coqueluche Acelular , Vacinas contra Influenza , Influenza Humana , Coqueluche , Lactente , Feminino , Humanos , Gravidez , Estados Unidos/epidemiologia , Gestantes , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Vacinas contra COVID-19 , Cobertura Vacinal , Toxoides , Coqueluche/prevenção & controle , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinação
4.
Prev Med ; 164: 107218, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36007751

RESUMO

The Centers for Disease Control and Prevention (CDC) promotes taking a 'bundling approach' (i.e., administering Tetanus, diphtheria toxoids, and acellular pertussis [Tdap] and human papillomavirus [HPV] vaccines in the same way and on the same day) for adolescent vaccinations. Recent trends and patterns in Tdap-HPV vaccination bundling in the USA remain undocumented. In addition, the implications of bundling Tdap-HPV vaccination for HPV vaccine series completion remain unknown. To address these critical knowledge gaps, we performed a retrospective study using a nationwide sample of privately insured adolescents (Optum's de-identified Clinformatics® Data Mart Database). Tdap-HPV vaccination bundling (per 100 Tdap vaccination encounters) during 2014-2018 was estimated overall, for 50 states, and by adolescents' age, sex, and provider specialties. Survival model estimated the likelihood of series completion among 9-14-year-old adolescents. From 2014 to 2018, 560,806 adolescents received a Tdap vaccine of which 172,604 (30.8%) received the HPV vaccines on the same day. Tdap-HPV vaccination bundling (per 100 Tdap vaccinations) increased nationally, from 22.9 in 2014 to 39.1 in 2018 (Ptrend < 0.001); bundling was lowest in New York and New Jersey. The likelihood of receiving the Tdap and HPV vaccines bundled was higher for young and female adolescents. Adolescents who received their first HPV vaccine bundled with the Tdap vaccine were more likely to complete the series compared to those who received it alone (Hazards Ratio = 1.45; 1.43-1.48). HPV vaccination bundling has increased in recent years in the USA. The increased likelihood of HPV vaccine series completion provides important evidence supporting the adoption of same-day Tdap-HPV vaccine administration in clinical practice to boost HPV vaccination coverage.


Assuntos
Infecções por Papillomavirus , Vacinas contra Papillomavirus , Feminino , Estados Unidos , Adolescente , Humanos , Criança , Toxoides , Estudos Retrospectivos , Vacinação
5.
Infect Immun ; 89(10): e0034221, 2021 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-34227839

RESUMO

In the Gram-positive pathogen Staphylococcus aureus, pore-forming toxins (PFTs), such as leukocidins and hemolysins, play prominent roles in staphylococcal pathogenesis by killing host immune cells and red blood cells (RBCs). However, it remains unknown which combination of toxin antigens would induce the broadest protective immune response against those toxins. In this study, by targeting six major staphylococcal PFTs (i.e., gamma-hemolysin AB [HlgAB], gamma-hemolysin CB [HlgCB], leukocidin AB [LukAB], leukocidin ED [LukED], Panton-Valentine leukocidin [LukSF-PV], and alpha-hemolysin [Hla]), we generated 10 recombinant toxins or toxin subunits, 3 toxoids, and their rabbit antibodies. Using the cytolytic assay for RBCs and polymorphonuclear cells (PMNs), we determined the best combination of toxin antibodies conferring the broadest protection against those staphylococcal PFTs. Although anti-HlgA IgG (HlgA-IgG) showed low cross-reactivity to other toxin components, it was essential to protect rabbit and human RBCs and human PMNs. For the protection of rabbit RBCs, HlaH35L toxoid-IgG was also required, whereas for human PMNs, LukS-IgG and LukAE323AB-IgG were essential too. When the toxin/toxoid antigens HlgA, LukS-PV, HlaH35L, and LukAE323AB were used to immunize rabbits, they increased rabbit survival; however, they did not block staphylococcal abscess formation in kidneys. Based on these results, we proposed that the combination of HlgA, LukS, HlaH35L, and LukAE323AB is the optimal vaccine component to protect human RBCs and PMNs from staphylococcal PFTs. We also concluded that a successful S. aureus vaccine requires not only those toxin antigens but also other antigens that can induce immune responses blocking staphylococcal colonization.


Assuntos
Infecções Estafilocócicas/imunologia , Staphylococcus aureus/imunologia , Vacinas Combinadas/imunologia , Animais , Proteínas de Bactérias/imunologia , Toxinas Bacterianas/imunologia , Reações Cruzadas/imunologia , Eritrócitos/imunologia , Eritrócitos/microbiologia , Exotoxinas/imunologia , Proteínas Hemolisinas/imunologia , Humanos , Imunização/métodos , Leucocidinas/imunologia , Neutrófilos/imunologia , Neutrófilos/microbiologia , Coelhos , Infecções Estafilocócicas/microbiologia , Toxoides/imunologia
6.
Appl Microbiol Biotechnol ; 105(21-22): 8297-8311, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34609523

RESUMO

Staphylococcus aureus is a serious pathogen unleashing its virulence through several classes of exotoxins such as hemolysins and enterotoxins. In this study, we designed a novel multi-antigen subunit vaccine which can induce innate, humoral and cellular immune responses. Alpha hemolysin, enterotoxins A and B were selected as protective antigens for combining into a triple antigen chimeric protein (HAB). Immunoinformatics analysis predicted HAB protein as a suitable vaccine candidate for inducing both humoral and cellular immune responses. Tertiary structure of the HAB protein was predicted and validated through computational approaches. Docking studies were performed between the HAB protein and mice TLR2 receptor. Furthermore, we constructed and generated recombinant HAB (r-HAB) protein in E. coli and studied its toxicity, immunogenicity and protective efficacy in a mouse model. Triple antigen chimeric protein (r-HAB) was found to be highly immunogenic in mouse as the anti-r-HAB hyperimmune serum was strongly reactive to all three native exotoxins on Western blot. In vitro toxin neutralization assay using anti-r-HAB antibodies demonstrated > 75% neutralization of toxins on RAW 264.7 cell line. Active immunization with r-HAB toxoid gave ~ 83% protection against 2 × lethal dosage of secreted exotoxins. The protection was mediated by induction of strong antibody responses that neutralized the toxins. Passive immunization with anti-r-HAB antibodies gave ~ 50% protection from lethal challenge. In conclusion, in vitro and in vivo testing of r-HAB found the molecule to be nontoxic, highly immunogenic and induced excellent protection towards native toxins in actively immunized and partial protection to passively immunized mice groups. KEY POINTS: • HAB protein was computationally designed to induce humoral and cellular responses. • r-HAB protein was found to be nontoxic, immunogenic and protective in mouse model. • r-HAB conferred protection against lethal challenge in active and passive immunization.


Assuntos
Toxinas Bacterianas , Toxemia , Animais , Anticorpos Antibacterianos , Toxinas Bacterianas/genética , Enterotoxinas , Escherichia coli/genética , Camundongos , Camundongos Endogâmicos BALB C , Staphylococcus aureus , Toxoides
7.
Anaerobe ; 72: 102465, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34662696

RESUMO

Herd vaccination is an important preventive measure against enterotoxemia in ruminants. Vaccination in goats should be performed every four months, and recent studies have shown that immunity in cattle lasts for less than one year. One of the mechanisms for increasing the duration of the immune response is to use purified toxoids as immunogens. The aim of the present study was to evaluate the humoral response in cattle and goats after vaccination with purified and semi-purified Clostridium perfringens type D epsilon toxoid. The following three different vaccines were used: vaccine 1 (V1), a semi-purified toxoid adsorbed to aluminum hydroxide; vaccine 2 (V2), a purified toxoid adsorbed to aluminum hydroxide; and vaccine (V3), a purified toxoid adsorbed on chitosan microparticles. Groups of cattle (n = 6-7) and goats (n = 6-7) were vaccinated on days 0 and 30, and serum samples for antitoxin titration were collected every 30 days for one-year post-vaccination. Goats were revaccinated on day 360, and their serum was evaluated on days 367 and 374. The antibody peaks ranged between 6.90 and 11.47 IU/mL in cattle and from 1.11 to 4.40 IU/mL in goats. In cattle administered with the V1 and V2 vaccines, we observed that the antibody titers were maintained above 0.2 IU/mL until the end of the experiment. In goats, V2 elicited long-lasting antibodies, and all animals maintained the protective titers for 210 days after the first dose. In conclusion, the purified toxoid vaccine with aluminum hydroxide adjuvant was able to induce strong and long-lasting humoral responses in both species and could be an alternative for improving the immunization schedule against enterotoxemia in goats and cattle.


Assuntos
Toxinas Bacterianas/imunologia , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/microbiologia , Infecções por Clostridium/veterinária , Clostridium perfringens/imunologia , Doenças das Cabras/microbiologia , Doenças das Cabras/prevenção & controle , Toxoides/administração & dosagem , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Toxinas Bacterianas/administração & dosagem , Toxinas Bacterianas/química , Vacinas Bacterianas/administração & dosagem , Vacinas Bacterianas/química , Vacinas Bacterianas/imunologia , Bovinos , Clostridium perfringens/classificação , Enterotoxemia/prevenção & controle , Cabras , Imunidade Humoral , Imunização , Coelhos
8.
Anaerobe ; 69: 102326, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33508438

RESUMO

Beta toxins (CPB) produced by Clostridium perfringens type B and C cause various diseases in animals, and the use of toxoids is an important prophylactic measure against such diseases. Promising recombinant toxoids have been developed recently. However, both soluble and insoluble proteins expressed in Escherichia coli can interfere with the production and immunogenicity of these antigens. In this context, bioinformatics tools have been used to design new versions of the beta toxin, and levels of expression and solubility were evaluated in different strains of E. coli. The immunogenicity in sheep was assessed using the molecule with the greatest potential that was selected on analyzing these results. In silico analyzes, greater mRNA stability (-169.70 kcal/mol), solubility (-0.755), and better tertiary structure (-0.12) were shown by rCPB-C. None of the strains of E. coli expressed rFH8-CPB, but a high level of expression and solubility was shown by rCPB-C. Higher levels of total and neutralizing anti-CPB antibodies were observed in sheep inoculated with bacterins containing rCPB-C. Thus, this study suggests that due to higher productivity of rCPB-C in E. coli and immunogenicity, it is considered as the most promising molecule for the production of a recombinant vaccine against diseases caused by the beta toxin produced by C. perfringens type B and C.


Assuntos
Anticorpos Neutralizantes/farmacologia , Infecções por Clostridium/prevenção & controle , Infecções por Clostridium/veterinária , Clostridium perfringens/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Toxoides/farmacologia , Vacinas Sintéticas/farmacologia , Animais , Imunogenicidade da Vacina , Ovinos
9.
Med J Malaysia ; 76(6): 865-869, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34806674

RESUMO

INTRODUCTION: This study aimed to determine the coverage of tetanus toxoid vaccination (TT) among pregnant women in Cambodia, and its association with health services and pregnancy factors. METHODS: A cross-sectional study was conducted by utilising the data from the Cambodia Demographic Health Survey (CDHS). The records of 5901 pregnant women who fulfilled the inclusion criteria were reviewed. Multiple logistic regression was used to identify the association on the influence of health services and pregnancy factors on incomplete TT vaccination while controlling other covariates. Adjusted odds ratio (aOR) and 95% confidence interval (95%CI) was reported. RESULTS: More than one-third of the respondents had incomplete TT vaccination (38.25%, 95%CI: 37.00, 39.48%). Health services as well as pregnancy factors were statistically associated with incomplete TT vaccination such as received antenatal care (ANC) from other health personnel beside midwife (aOR=1.83; 95%CI: 1.49, 2.24), had

Assuntos
Gestantes , Toxoide Tetânico , Adulto , Camboja , Estudos Transversais , Feminino , Humanos , Gravidez , Cuidado Pré-Natal , História Reprodutiva , Toxoides , Vacinação
10.
Fish Shellfish Immunol ; 105: 310-318, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32702476

RESUMO

Oral vaccines are highly demanded by aquaculture sector that requires alternatives to injectable vaccines, involving fish handling, stress-related immunosuppression and mortalities. However, most previous attempts to obtain effective oral vaccines have failed due to a restricted tolerance mechanisms in intestine, whose mucosa is at the frontline of antigen encounter and has to balance the equilibrium between tolerance and immunity in a microbe-rich environment. Thus, the search for oral adjuvants that could augment immune responses triggered by antigens allowing them to circumvent intestinal tolerance is of great relevance. The present work focuses on the adjuvant potential of the Escherichia coli LT(R192G/L211A) toxoid (dmLT). To undertake an initial screening of the potential that dmLT has as an oral adjuvant in rainbow trout (Oncorhynchus mykiss), we have analyzed its transcriptional effects alone or in combination with Aeromonas salmonicida subsp. salmonicida or viral hemorrhagic septicemia virus (VHSV) on rainbow trout intestinal epithelial cell line RTgutGC and gut explants. Our results show that although dmLT provoked no significant effects by itself, it increased the transcription of pro-inflammatory cytokines and antimicrobial genes induced by the bacteria. In contrast, when combined with VHSV, dmLT only increased the transcription of Mx and the intracellular adhesion molecule 1 (ICAM1). Therefore, the protocol designed is an effective method to initially evaluate the effects of potential oral adjuvants, and points to dmLT as an effective adjuvant for oral antibacterial vaccines.


Assuntos
Adjuvantes Imunológicos/metabolismo , Escherichia coli/imunologia , Oncorhynchus mykiss/imunologia , Toxoides/imunologia , Aeromonas/fisiologia , Animais , Linhagem Celular , Mucosa Intestinal/imunologia , Novirhabdovirus/fisiologia , Oncorhynchus mykiss/genética , Transcrição Gênica/imunologia
11.
Nano Lett ; 19(7): 4760-4769, 2019 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-31184899

RESUMO

Infections caused by multidrug-resistant Gram-negative bacteria have emerged as a major threat to public health worldwide. The high mortality and prevalence, along with the slow pace of new antibiotic discovery, highlight the necessity for new disease management paradigms. Here, we report on the development of a multiantigenic nanotoxoid vaccine based on macrophage membrane-coated nanoparticles for eliciting potent immunity against pathogenic Pseudomonas aeruginosa. The design of this biomimetic nanovaccine leverages the specific role of macrophages in clearing pathogens and their natural affinity for various virulence factors secreted by the bacteria. It is demonstrated that the macrophage nanotoxoid is able to display a wide range of P. aeruginosa antigens, and the safety of the formulation is confirmed both in vitro and in vivo. When used to vaccinate mice via different administration routes, the nanotoxoid is capable of eliciting strong humoral immune responses that translate into enhanced protection against live bacterial infection in a pneumonia model. Overall, the work presented here provides new insights into the design of safe, multiantigenic antivirulence vaccines using biomimetic nanotechnology and the application of these nanovaccines toward the prevention of difficult-to-treat Gram-negative infections.


Assuntos
Vacinas Bacterianas , Farmacorresistência Bacteriana , Infecções por Pseudomonas , Pseudomonas aeruginosa/imunologia , Toxoides , Vacinação , Fatores de Virulência/imunologia , Animais , Vacinas Bacterianas/imunologia , Vacinas Bacterianas/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/imunologia , Imunidade Humoral/efeitos dos fármacos , Camundongos , Infecções por Pseudomonas/imunologia , Infecções por Pseudomonas/patologia , Infecções por Pseudomonas/prevenção & controle , Pseudomonas aeruginosa/patogenicidade , Toxoides/imunologia , Toxoides/farmacologia
12.
Nano Lett ; 19(3): 1914-1921, 2019 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-30724085

RESUMO

Vaccination represents one of the most effective means of preventing infectious disease. In order to maximize the utility of vaccines, highly potent formulations that are easy to administer and promote high patient compliance are desired. In the present work, a biomimetic self-propelling micromotor formulation is developed for use as an oral antivirulence vaccine. The propulsion is provided by a magnesium-based core, and a biomimetic cell membrane coating is used to detain and neutralize a toxic antigenic payload. The resulting motor toxoids leverage their propulsion properties in order to more effectively elicit mucosal immune responses. After demonstrating the successful fabrication of the motor toxoids, their uptake properties are shown in vitro. When delivered to mice via an oral route, it is then confirmed that the propulsion greatly improves retention and uptake of the antigenic material in the small intestine in vivo. Ultimately, this translates into markedly elevated generation of antibody titers against a model toxin. This work provides a proof-of-concept highlighting the benefits of active oral delivery for vaccine development, opening the door for a new set of applications, in which biomimetic motor technology can provide significant benefits.


Assuntos
Antígenos/administração & dosagem , Antivirais/administração & dosagem , Biomimética , Doenças Transmissíveis/terapia , Administração Oral , Animais , Antígenos/imunologia , Antivirais/imunologia , Doenças Transmissíveis/imunologia , Doenças Transmissíveis/patologia , Humanos , Imunidade nas Mucosas/efeitos dos fármacos , Magnésio/química , Camundongos , Toxoides/metabolismo , Toxoides/toxicidade , Vacinação/métodos
13.
Infect Immun ; 87(10)2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31308088

RESUMO

Acute otitis media is one of the most common childhood infections worldwide. Currently licensed vaccines against the common otopathogen Streptococcus pneumoniae target the bacterial capsular polysaccharide and confer no protection against nonencapsulated strains or capsular types outside vaccine coverage. Mucosal infections such as acute otitis media remain prevalent, even those caused by vaccine-covered serotypes. Here, we report that a protein-based vaccine, a fusion construct of epitopes of CbpA to pneumolysin toxoid, confers effective protection against pneumococcal acute otitis media for non-PCV-13 serotypes and enhances protection for PCV-13 serotypes when coadministered with PCV-13. Having cross-reactive epitopes, the fusion protein also induces potent antibody responses against nontypeable Haemophilus influenzae and S. pneumoniae, engendering protection against acute otitis media caused by emerging unencapsulated otopathogens. These data suggest that augmenting capsule-based vaccination with conserved, cross-reactive protein-based vaccines broadens and enhances protection against acute otitis media.


Assuntos
Anticorpos Antibacterianos/biossíntese , Infecções por Haemophilus/prevenção & controle , Haemophilus influenzae/imunologia , Otite Média/prevenção & controle , Vacinas Pneumocócicas/biossíntese , Proteínas Recombinantes de Fusão/biossíntese , Streptococcus pneumoniae/imunologia , Doença Aguda , Animais , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Proteção Cruzada , Reações Cruzadas , Feminino , Expressão Gênica , Infecções por Haemophilus/imunologia , Infecções por Haemophilus/microbiologia , Haemophilus influenzae/efeitos dos fármacos , Haemophilus influenzae/patogenicidade , Humanos , Imunogenicidade da Vacina , Camundongos , Camundongos Endogâmicos BALB C , Otite Média/imunologia , Otite Média/microbiologia , Vacinas Pneumocócicas/administração & dosagem , Vacinas Pneumocócicas/genética , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/genética , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/patogenicidade , Estreptolisinas/biossíntese , Estreptolisinas/genética , Toxoides/biossíntese , Toxoides/genética , Vacinação , Vacinas Sintéticas
14.
Anaerobe ; 59: 72-75, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31129336

RESUMO

The aim of this study was to evaluate the titers of neutralizing antibodies in cattle inoculated with multivalent commercial clostridial vaccines containing C. botulinum type C (BoNTC), C. botulinum type D (BoNTD), and C. perfringens epsilon (ETX) toxoids for a period of one year. Cattle (Bos taurus), aged 4-6 months and not previously immunized, were vaccinated under four different protocols at days 0 and 30 and followed over one year. Individual serum titration was performed by a serum neutralization test in mice or in MDCK cells. The number of animals with detectable neutralizing antibodies ranged from 40.6% to 78.1%, but only 12.5% of animals showed neutralizing antibodies against all tested antigens. Neutralizing antibodies were found only until 60 days for ETX, 120 days for BoNTC, and 180 days for BoNTD. The absence of detectable neutralizing antibodies against the three antigens before 360 days, suggests that cattle remained unprotected for a long period before the recommended booster vaccination.


Assuntos
Toxinas Bacterianas/imunologia , Toxinas Botulínicas/imunologia , Imunidade Humoral , Toxoides/imunologia , Animais , Antitoxinas/sangue , Bovinos , Cães , Células Madin Darby de Rim Canino , Camundongos , Testes de Neutralização , Fatores de Tempo , Toxoides/administração & dosagem
15.
Infect Immun ; 86(10)2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30012638

RESUMO

Bordetella pertussis is the primary causative agent of pertussis (whooping cough), which is a respiratory infection that leads to a violent cough and can be fatal in infants. There is a need to develop more effective vaccines because of the resurgence of cases of pertussis in the United States since the switch from the whole-cell pertussis vaccines (wP) to the acellular pertussis vaccines (aP; diphtheria-tetanus-acellular-pertussis vaccine/tetanus-diphtheria-pertussis vaccine). Adenylate cyclase toxin (ACT) is a major virulence factor of B. pertussis that is (i) required for establishment of infection, (ii) an effective immunogen, and (iii) a protective antigen. The C-terminal repeats-in-toxin domain (RTX) of ACT is sufficient to induce production of toxin-neutralizing antibodies. In this study, we characterized the effectiveness of vaccines containing the RTX antigen against experimental murine infection with B. pertussis RTX was not protective as a single-antigen vaccine against B. pertussis challenge, and adding RTX to 1/5 human dose of aP did not enhance protection. Since the doses of aP used in murine studies are not proportionate to mouse/human body masses, we titrated the aP from 1/20 to 1/160 of the human dose. Mice receiving 1/80 human aP dose had bacterial burden comparable to those of naive controls. Adding RTX antigen to the 1/80 aP base resulted in enhanced bacterial clearance. Inclusion of RTX induced production of antibodies recognizing RTX, enhanced production of anti-pertussis toxin, decreased secretion of proinflammatory cytokines, such as interleukin-6, and decreased recruitment of total macrophages in the lung. This study shows that adding RTX antigen to an appropriate dose of aP can enhance protection against B. pertussis challenge in mice.


Assuntos
Adenilil Ciclases/imunologia , Bordetella pertussis/imunologia , Vacina contra Coqueluche/imunologia , Toxoides/imunologia , Coqueluche/imunologia , Adenilil Ciclases/administração & dosagem , Adenilil Ciclases/genética , Animais , Anticorpos Antibacterianos/imunologia , Anticorpos Neutralizantes/imunologia , Bordetella pertussis/genética , Avaliação Pré-Clínica de Medicamentos , Humanos , Camundongos , Vacina contra Coqueluche/administração & dosagem , Vacina contra Coqueluche/genética , Toxoides/administração & dosagem , Toxoides/genética , Coqueluche/microbiologia
16.
Infect Immun ; 86(3)2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29263112

RESUMO

Enterotoxigenic Escherichia coli (ETEC) strains are a leading cause of children's diarrhea and travelers' diarrhea. Vaccines inducing antibodies to broadly inhibit bacterial adherence and to neutralize toxin enterotoxicity are expected to be effective against ETEC-associated diarrhea. 6×His-tagged adhesin-toxoid fusion proteins were shown to induce neutralizing antibodies to several adhesins and LT and STa toxins (X. Ruan, D. A. Sack, W. Zhang, PLoS One 10:e0121623, 2015, https://doi.org/10.1371/journal.pone.0121623). However, antibodies derived from His-tagged CFA/I/II/IV-2xSTaA14Q-dmLT or CFA/I/II/IV-2xSTaN12S-dmLT protein were less effective in neutralizing STa enterotoxicity and were not evaluated in vivo for efficacy against ETEC diarrhea. Additionally, His-tagged proteins are considered less desirable for human vaccines. In this study, we produced a tagless adhesin-toxoid MEFA (multiepitope fusion antigen) protein, enhanced anti-STa immunogenicity by including a third copy of STa toxoid STaN12S, and examined antigen immunogenicity in a murine model. Moreover, we immunized pregnant pigs with the tagless adhesin-toxoid MEFA protein and evaluated passive antibody protection against STa+ or LT+ ETEC infection in a pig challenge model. Results showed that tagless adhesin-toxoid MEFA CFA/I/II/IV-3xSTaN12S-mnLTR192G/L211A induced broad antiadhesin and antitoxin antibody responses in the intraperitoneally immunized mice and the intramuscularly immunized pigs. Mouse and pig serum antibodies significantly inhibited adherence of seven colonization factor antigen (CFA) adhesins (CFA/I and CS1 to CS6) and effectively neutralized both toxins. More importantly, suckling piglets born to the immunized mothers acquired antibodies and were protected against STa+ ETEC and LT+ ETEC diarrhea. These results indicated that tagless CFA/I/II/IV-3xSTaN12S-mnLTR192G/L211A induced broadly protective antiadhesin and antitoxin antibodies and demonstrate that this adhesin-toxoid MEFA is a potential antigen for developing broadly protective ETEC vaccines.


Assuntos
Adesinas Bacterianas/administração & dosagem , Diarreia/prevenção & controle , Escherichia coli Enterotoxigênica/imunologia , Infecções por Escherichia coli/prevenção & controle , Proteínas de Escherichia coli/administração & dosagem , Vacinas contra Escherichia coli/administração & dosagem , Toxoides/administração & dosagem , Adesinas Bacterianas/genética , Adesinas Bacterianas/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Anticorpos Neutralizantes/imunologia , Antígenos de Superfície/administração & dosagem , Antígenos de Superfície/genética , Antígenos de Superfície/imunologia , Aderência Bacteriana/efeitos dos fármacos , Toxinas Bacterianas/administração & dosagem , Toxinas Bacterianas/genética , Toxinas Bacterianas/imunologia , Diarreia/imunologia , Diarreia/microbiologia , Escherichia coli Enterotoxigênica/genética , Escherichia coli Enterotoxigênica/fisiologia , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/imunologia , Vacinas contra Escherichia coli/genética , Vacinas contra Escherichia coli/imunologia , Feminino , Proteínas de Fímbrias/administração & dosagem , Proteínas de Fímbrias/genética , Proteínas de Fímbrias/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Suínos , Toxoides/genética , Toxoides/imunologia
17.
Appl Environ Microbiol ; 84(2)2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-29079628

RESUMO

Heat-stable toxin (STa)-producing enterotoxigenic Escherichia coli (ETEC) strains are a top cause of moderate-to-severe diarrhea in children from developing countries and a common cause of travelers' diarrhea. Recent progress in using STa toxoids and toxoid fusions to induce neutralizing anti-STa antibodies has accelerated ETEC vaccine development. However, concern remains regarding whether the derived anti-STa antibodies cross-react with STa-like guanylin and uroguanylin, two guanylate cyclase C (GC-C) ligands regulating fluid and electrolyte transportation in human intestinal and renal epithelial cells. To further divert STa from guanylin and uroguanylin structurally and antigenically and to eliminate anti-STa antibody cross-reactivity with guanylin and uroguanylin, we mutated STa at the 9th (leucine), 12th (asparagine), and 14th (alanine) residues for the double and triple mutants STaL9A/N12S, STaL9A/A14H, STaN12S/A14T, and STaL9A/N12S/A14H We then fused each STa mutant (three copies) to a monomeric heat-labile toxin (LT) mutant (mnLTR192G/L211A) for the toxoid fusions 3×STaL9A/N12S-mnLTR192G/L211A, 3×STaL9A/A14H-mnLTR192G/L211A, 3×STaN12S/A14T-mnLTR192G/L211A, and 3×STaL9A/N12S/A14H-mnLTR192G/L211A; examined each fusion for anti-STa immunogenicity; and assessed the derived antibodies for in vitro neutralization activity against STa toxicity and for cross-reactivity with guanylin and uroguanylin. Mice subcutaneously immunized with each fusion protein developed anti-STa antibodies, and the antibodies derived from 3×STaN12S-mnLTR192G/L211A, 3×STaL9A/N12S-mnLTR192G/L211A, or 3×STaN12S/A14T-mnLTR192G/L211A prevented STa from the stimulation of intracellular cGMP in T-84 cells. Competitive enzyme-linked immunosorbent assays (ELISAs) showed that guanylin and uroguanylin hardly blocked the binding of anti-STa antibodies to the coated STa-ovalbumin conjugate. These results indicated that antibodies derived from 3×STaN12S-mnLTR192G/L211A, 3×STaL9A/N12S-mnLTR192G/L211A, or 3×STaN12S/A14T-mnLTR192G/L211A neutralized STa and had little cross-reactivity with guanylin and uroguanylin, suggesting that these toxoid fusions are suitable antigens for ETEC vaccines.IMPORTANCE Enterotoxigenic Escherichia coli (ETEC) strains are a leading cause of children's diarrhea and travelers' diarrhea. Currently, there is no licensed vaccine against ETEC diarrhea. One key challenge is to identify safe antigens to induce antibodies neutralizing the key STa without cross-reacting with guanylin and uroguanylin, two important ligands controlling homeostasis in human intestinal and renal epithelial cells. In this study, we generated nontoxic fusion antigens that induced antibodies that neutralize STa enterotoxicity in vitro and do not cross-react with guanylin or uroguanylin. These fusions have become the preferred antigens for the development of ETEC vaccines to potentially prevent the deaths of hundreds of thousands of young children and hundreds of millions of diarrheal cases each year.


Assuntos
Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Toxinas Bacterianas/imunologia , Escherichia coli Enterotoxigênica/imunologia , Hormônios Gastrointestinais/imunologia , Peptídeos Natriuréticos/imunologia , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Antígenos de Bactérias/administração & dosagem , Antígenos de Bactérias/genética , Antígenos de Bactérias/metabolismo , Criança , Reações Cruzadas , Escherichia coli Enterotoxigênica/genética , Enterotoxinas/genética , Enterotoxinas/imunologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/prevenção & controle , Feminino , Temperatura Alta , Humanos , Imunização , Camundongos , Mutação , Toxoides/imunologia
18.
Bioconjug Chem ; 29(3): 604-612, 2018 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-29241006

RESUMO

As nanoparticles exhibit unique properties attractive for vaccine development, they have been progressively implemented as antigen delivery platforms and immune potentiators. Recently, cell membrane-coated nanoparticles have provided a novel approach for intercepting and neutralizing bacterial toxins by leveraging their natural affinity to cellular membranes. Such toxin-nanoparticle assemblies, termed nanotoxoids, allow rapid loading of different types of toxins and have been investigated for their ability to effectively confer protection against bacterial infection. This topical review will cover the current progress in antibacterial vaccine nanoformulations and highlight the nanotoxoid platform as a novel class of nanoparticulate vaccine. We aim to provide insights into the potential of nanotoxoids as a platform that is facile to implement and can be broadly applied to help address the rising threat of super pathogens.


Assuntos
Bactérias/imunologia , Infecções Bacterianas/prevenção & controle , Toxinas Bacterianas/administração & dosagem , Vacinas Bacterianas/administração & dosagem , Membrana Celular/química , Nanopartículas/química , Toxoides/administração & dosagem , Animais , Infecções Bacterianas/imunologia , Toxinas Bacterianas/química , Toxinas Bacterianas/imunologia , Vacinas Bacterianas/química , Vacinas Bacterianas/imunologia , Humanos , Nanotecnologia/métodos , Toxoides/química , Toxoides/imunologia , Vacinação/métodos , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/química , Vacinas de Subunidades Antigênicas/imunologia
19.
Vet Res ; 49(1): 28, 2018 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-29514704

RESUMO

The principal virulence factor of Shiga toxin (Stx)-producing Escherichia coli (STEC), the eponymous Stx, modulates cellular immune responses in cattle, the primary STEC reservoir. We examined whether immunization with genetically inactivated recombinant Shiga toxoids (rStx1MUT/rStx2MUT) influences STEC shedding in a calf cohort. A group of 24 calves was passively (colostrum from immunized cows) and actively (intra-muscularly at 5th and 8th week) vaccinated. Twenty-four calves served as unvaccinated controls (fed with low anti-Stx colostrum, placebo injected). Each group was divided according to the vitamin E concentration they received by milk replacer (moderate and high supplemented). The effective transfer of Stx-neutralizing antibodies from dams to calves via colostrum was confirmed by Vero cell assay. Serum antibody titers in calves differed significantly between the vaccinated and the control group until the 16th week of life. Using the expression of activation marker CD25 on CD4+CD45RO+ cells and CD8αhiCD45RO+ cells as flow cytometry based read-out, cells from vaccinated animals responded more pronounced than those of control calves to lysates of STEC and E. coli strains isolated from the farm as well as to rStx2MUT in the 16th week. Summarized for the entire observation period, less fecal samples from vaccinated calves were stx1 and/or stx2 positive than samples from control animals when calves were fed a moderate amount of vitamin E. This study provides first evidence, that transfer to and induction in young calves of Stx-neutralizing antibodies by Shiga toxoid vaccination offers the opportunity to reduce the incidence of stx-positive fecal samples in a calf cohort.


Assuntos
Derrame de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Doenças dos Bovinos/prevenção & controle , Imunização Passiva/veterinária , Escherichia coli Shiga Toxigênica/fisiologia , Toxoides/imunologia , Vacinação/veterinária , Ração Animal/análise , Animais , Bovinos , Doenças dos Bovinos/imunologia , Estudos de Coortes , Colostro/imunologia , Dieta/veterinária , Suplementos Nutricionais/análise , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/prevenção & controle , Infecções por Escherichia coli/veterinária , Imunidade Materno-Adquirida/imunologia , Injeções Intramusculares/veterinária , Masculino , Vacinas Sintéticas/administração & dosagem
20.
J Anim Physiol Anim Nutr (Berl) ; 102(5): 1167-1180, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29905984

RESUMO

Vitamin E (vit E), an essential antioxidant for maintaining the stability of biological membranes and the function of the immune system, is considered to support adaptive immune responses and performance in cattle. The principal virulence factor of Shiga toxin (Stx)-producing Escherichia coli (STEC), the eponymous Stx, modulates cellular immune responses in cattle, the primary STEC reservoir. Active and passive immunization of calves with Shiga toxoids (rStxMUT ) was recently shown to reduce the STEC shedding. Here, we examined the influence of vit E on calves' serum α-tocopherol, performance, haematology, blood chemistry and its interaction with rStxMUT immunization. Data from calves having received passive (colostrum from immunized cows) and active (intramuscularly at 5th and 8th weeks of life) vaccination with rStxMUT (n = 24) were compared to unvaccinated controls (n = 24; fed with low anti-Stx colostrum, placebo injected). For each vaccination group, data were analysed according to the level of vit E supplementation offered by milk replacer (188 IU all-rac-α-tocopheryl acetate daily [VitEM ] vs. 354 IU [VitEH ]). An increase by 79% in daily vit E supplementation led to slightly higher serum α-tocopherol level and earlier concentrate intake at the beginning of the experiment without significant differences in live weight gain, haematology, blood chemistry parameters and peripheral CD4+ and CD8+ T-cell subpopulations. rStxMUT vaccination modulated the CD4+ /CD8+ ratio irrespective of vit E supplementation but decreased concentrate intake in VitEH in a time-dependent manner. Results of our study indicate that an increase in daily vit E supplementation vastly fails to exert effects on laboratory parameters and growth performance. However, observed interactive effects of vit E supply and vaccination on the regulation of feed intake deserves further attention.


Assuntos
Bovinos/sangue , Bovinos/crescimento & desenvolvimento , Toxoides/imunologia , Vitamina E/farmacologia , alfa-Tocoferol/sangue , Ração Animal , Animais , Vacinas Bacterianas/imunologia , Suplementos Nutricionais , Masculino , Vacinação/veterinária
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