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1.
Nat Commun ; 11(1): 4723, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32948778

RESUMO

O-Acetylation of the capsular polysaccharide (CPS) of Neisseria meningitidis serogroup A (NmA) is critical for the induction of functional immune responses, making this modification mandatory for CPS-based anti-NmA vaccines. Using comprehensive NMR studies, we demonstrate that O-acetylation stabilizes the labile anomeric phosphodiester-linkages of the NmA-CPS and occurs in position C3 and C4 of the N-acetylmannosamine units due to enzymatic transfer and non-enzymatic ester migration, respectively. To shed light on the enzymatic transfer mechanism, we solved the crystal structure of the capsule O-acetyltransferase CsaC in its apo and acceptor-bound form and of the CsaC-H228A mutant as trapped acetyl-enzyme adduct in complex with CoA. Together with the results of a comprehensive mutagenesis study, the reported structures explain the strict regioselectivity of CsaC and provide insight into the catalytic mechanism, which relies on an unexpected Gln-extension of a classical Ser-His-Asp triad, embedded in an α/ß-hydrolase fold.


Assuntos
Cápsulas Bacterianas/química , Cápsulas Bacterianas/metabolismo , Neisseria meningitidis Sorogrupo A/metabolismo , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/metabolismo , Acetilação , Acetiltransferases , Anticorpos Antibacterianos , Cápsulas Bacterianas/genética , Cápsulas Bacterianas/imunologia , Vacinas Bacterianas/imunologia , Hexosaminas , Modelos Moleculares , Neisseria meningitidis Sorogrupo A/genética , Polissacarídeos Bacterianos/genética , Polissacarídeos Bacterianos/imunologia , Conformação Proteica
2.
PLoS Pathog ; 16(9): e1008871, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32936831

RESUMO

Deconvolution of syphilis pathogenesis and selection of candidate syphilis vaccinogens requires detailed knowledge of the molecular architecture of the Treponema pallidum outer membrane (OM). The T. pallidum OM contains a low density of integral OM proteins, while the spirochete's many lipoprotein immunogens are periplasmic. TP0751, a lipoprotein with a lipocalin fold, is reportedly a surface-exposed protease/adhesin and protective antigen. The rapid expansion of calycin/lipocalin structures in the RCSB PDB database prompted a comprehensive reassessment of TP0751. Small angle X-ray scattering analysis of full-length protein revealed a bipartite topology consisting of an N-terminal, intrinsically disordered region (IDR) and the previously characterized C-terminal lipocalin domain. A DALI server query using the lipocalin domain yielded 97 hits, 52 belonging to the calycin superfamily, including 15 bacterial lipocalins, but no Gram-negative surface proteins. Surprisingly, Tpp17 (TP0435) was identified as a structural ortholog of TP0751. In silico docking predicted that TP0751 can bind diverse ligands along the rim of its eight-stranded ß-barrel; high affinity binding of one predicted ligand, heme, to the lipocalin domain was demonstrated. qRT-PCR and immunoblotting revealed very low expression of TP0751 compared to other T. pallidum lipoproteins. Immunoblot analysis of immune rabbit serum failed to detect TP0751 antibodies, while only one of five patients with secondary syphilis mounted a discernible TP0751-specific antibody response. In opsonophagocytosis assays, neither TP0751 nor Tpp17 antibodies promoted uptake of T. pallidum by rabbit peritoneal macrophages. Rabbits immunized with intact, full-length TP0751 showed no protection against local or disseminated infection following intradermal challenge with T. pallidum. Our data argue that, like other lipoprotein lipocalins in dual-membrane bacteria, TP0751 is periplasmic and binds small molecules, and we propose that its IDR facilitates ligand binding by and offloading from the lipocalin domain. The inability of TP0751 to elicit opsonic or protective antibodies is consistent with a subsurface location.


Assuntos
Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Imunização , Lipoproteínas/imunologia , Sífilis/imunologia , Treponema pallidum/imunologia , Animais , Proteínas de Bactérias/genética , Vacinas Bacterianas/genética , Humanos , Lipoproteínas/genética , Domínios Proteicos , Dobramento de Proteína , Coelhos , Sífilis/genética , Sífilis/patologia , Sífilis/prevenção & controle , Treponema pallidum/genética , Treponema pallidum/patogenicidade
3.
PLoS One ; 15(8): e0237181, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32813697

RESUMO

Multidrug-resistant Vibrio parahaemolyticus has become a significant public health concern. The development of effective drugs and vaccines against Vibrio parahaemolyticus is the current research priority. Thus, we aimed to find out effective drug and vaccine targets using a comprehensive genome-based analysis. A total of 4822 proteins were screened from V. parahaemolyticus proteome. Among 16 novel cytoplasmic proteins, 'VIBPA Type II secretion system protein L' and 'VIBPA Putative fimbrial protein Z' were subjected to molecular docking with 350 human metabolites, which revealed that Eliglustat, Simvastatin and Hydroxocobalamin were the top drug molecules considering free binding energy. On the contrary, 'Sensor histidine protein kinase UhpB' and 'Flagellar hook-associated protein of 25 novel membrane proteins were subjected to T-cell and B-cell epitope prediction, antigenicity testing, transmembrane topology screening, allergenicity and toxicity assessment, population coverage analysis and molecular docking analysis to generate the most immunogenic epitopes. Three subunit vaccines were constructed by the combination of highly antigenic epitopes along with suitable adjuvant, PADRE sequence and linkers. The designed vaccine constructs (V1, V2, V3) were analyzed by their physiochemical properties and molecular docking with MHC molecules- results suggested that the V1 is superior. Besides, the binding affinity of human TLR-1/2 heterodimer and construct V1 could be biologically significant in the development of the vaccine repertoire. The vaccine-receptor complex exhibited deformability at a minimum level that also strengthened our prediction. The optimized codons of the designed construct was cloned into pET28a(+) vector of E. coli strain K12. However, the predicted drug molecules and vaccine constructs could be further studied using model animals to combat V. parahaemolyticus associated infections.


Assuntos
Vacinas Bacterianas/imunologia , Descoberta de Drogas/métodos , Genoma Bacteriano , Vibrioses/tratamento farmacológico , Vibrioses/prevenção & controle , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/imunologia , Biologia Computacional/métodos , Farmacorresistência Bacteriana Múltipla/genética , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Escherichia coli K12/genética , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Mapas de Interação de Proteínas , Proteoma/genética , Proteômica/métodos , Vacinas de Subunidades/imunologia , Vibrioses/microbiologia
4.
Vet Clin North Am Food Anim Pract ; 36(2): 473-485, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32451036

RESUMO

Vaccination is the act of administering a vaccine, whereas immunization may occur if appropriate time is allowed for a competent host immune system to respond to the antigen contained in a vaccine. Timing is critical to ensure bovine respiratory disease (BRD) vaccine safety, efficacy, and efficiency. The current review provides temporal considerations of BRD vaccination within the North American beef production system with focus on vaccination timing in high-risk, newly received beef stocker and feedlot cattle.


Assuntos
Vacinas Bacterianas/administração & dosagem , Complexo Respiratório Bovino/prevenção & controle , Vacinas Virais/administração & dosagem , Animais , Vacinas Bacterianas/imunologia , Complexo Respiratório Bovino/imunologia , Bovinos , Esquema de Medicação , Carne Vermelha , Vacinação/veterinária , Vacinas Virais/imunologia
5.
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
6.
APMIS ; 128(7): 476-483, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32445596

RESUMO

Acinetobacter baumannii, one of the most life-threatening nosocomial drug-resistant pathogens, imposes high morbidity and mortality rates, thus highlighting immunization-based treatments or prevention measures. The selection of appropriate antigens can elicit protective immunity. The gene encoding a fimbrial protein introduced via reverse vaccinology was cloned, expressed and evaluated for immunogenicity in a murine model. Mice immunized with the recombinant protein were challenged with A. baumannii ATCC 19606. Adherence to A549 cell line of specific anti-sera treated A. baumannii was also assessed. Passive immunity was evaluated in a murine pneumonia model. Indirect ELISA showed a high specific antibody titre. Adherence of A. baumannii to A549 cell line decreased by 40% after incubation with 1:250 dilution of specific anti-sera. All the actively immunized mice survived. Bacterial load in the spleen and liver of the immunized mice was 3-fold lower than those of the control. The number of bacteria in the lungs of passively immunized mice was about 6-fold lower than the control mice. The fimbrial protein could be considered as a promising protective immunogen against A. baumannii.


Assuntos
Infecções por Acinetobacter/prevenção & controle , Acinetobacter baumannii/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Vacinas Bacterianas/imunologia , Infecção Hospitalar/prevenção & controle , Fímbrias Bacterianas/imunologia , Imunização , Células A549 , Animais , Aderência Bacteriana , Humanos , Camundongos , Camundongos Endogâmicos BALB C
7.
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
8.
Mol Immunol ; 120: 146-163, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32126449

RESUMO

Buruli ulcer is an emerging tissue-necrosis infectious disease, caused by the pathogen Mycobacterium ulcerans, leading to permanent deformity if untreated. Despite this debilitating condition, no specific disease-modifying therapeutics or vaccination is available to date. Therefore, we aimed to design an effective multi-epitope vaccine against M. ulcerans using vaccinomics approach. Briefly, the highest antigenic PE-PGRS protein was selected from which the promiscuous T- and B-cell epitopes were predicted. After rigorous assessment, 15 promising T- and B-cell epitopes were selected. The identified T-cell epitopes showed marked interactions towards their HLA-binding alleles and provided 99.8 % world population coverage. Consequently, a vaccine chimera was designed by connecting these epitopes with suitable linkers and LprG adjuvant. The vaccine construct was highly antigenic, immunogenic and non-allergenic; hence, subjected to homology modelling. The molecular docking and dynamics simulation revealed a strong and stable interaction between vaccine and toll-like receptor 2. The binding energy and dissociation constant were -15.3 kcal/mol and 5.9 × 10-12 M, respectively. The computer-simulated immune responses showed abundance of immunoglobulins, increased interferon-γ production, and macrophages activation which are crucial for immune response against M. ulcerans. Furthermore, disulfide bridging and in silico cloning were also performed. These results suggest that the vaccine, if validated experimentally, will be a promising candidate against M. ulcerans and prevent Buruli ulcer disease.


Assuntos
Antígenos de Bactérias/química , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/química , Proteínas de Bactérias/imunologia , Vacinas Bacterianas/química , Vacinas Bacterianas/imunologia , Proteínas de Membrana/química , Proteínas de Membrana/imunologia , Mycobacterium ulcerans/imunologia , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Vacinas Bacterianas/genética , Úlcera de Buruli/imunologia , Úlcera de Buruli/prevenção & controle , Simulação por Computador , Desenho de Fármacos , Epitopos de Linfócito B/química , Epitopos de Linfócito B/genética , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/química , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Antígenos HLA/química , Antígenos HLA/imunologia , Humanos , Proteínas de Membrana/genética , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Mycobacterium ulcerans/química , Mycobacterium ulcerans/genética , Engenharia de Proteínas , Vacinas de Subunidades/química , Vacinas de Subunidades/genética , Vacinas de Subunidades/imunologia , Vacinas Sintéticas/química , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia
9.
PLoS One ; 15(3): e0230460, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32218590

RESUMO

Pathogenic spirochetes from genus Leptospira are etiologic agents of leptospirosis. Cellular vaccines against Leptospira infection often elicit mainly response against the LPS antigen of the serovars present in the formulation. There is no suitable protein candidate capable of replacing whole-cell vaccines, thus requiring new approaches on vaccine development to improve leptospirosis prevention. Our goal was to develop a whole-cell vaccine sorovar-independent based on LPS removal and conservation of protein antigens exposure, to evaluate the protective capacity of monovalent or bivalent vaccines against homologous and heterologous virulent Leptospira in hamster. Leptospire were subjected to heat inactivation, or to LPS extraction with butanol and in some cases further inactivation with formaldehyde. Hamsters were immunized and challenged with homologous or heterologous virulent serovars, blood and organs were collected from the survivors for bacterial quantification, chemokine evaluation, and analysis of sera antibody reactivity and cross-reactivity by Western blot. Immunization with either heated or low LPS vaccines with serovar Copenhageni or Canicola resulted in 100% protection of the animals challenged with homologous virulent bacteria. Notably, different from the whole-cell vaccine, the low LPS vaccines produced with serovar Canicola provided only partial protection in heterologous challenge with the virulent Copenhageni serovar. Immunization with bivalent formulation results in 100% protection of immunized animals challenged with virulent serovar Canicola. All vaccines produced were able to eliminate bacteria from the kidney of challenged animals. All the vaccines raised antibodies capable to recognize antigens of serovars not present in the vaccine formulation. Transcripts of IFNγ, CXCL16, CCL5, CXCL10, CXCR6, and CCR5, increased in all immunized animals. Conclusion: Our results showed that bivalent vaccines with reduced LPS may be an interesting strategy for protection against heterologous virulent serovars. Besides the desirable multivalent protection, the low LPS vaccines are specially promising due to the expected lower reatogenicity.


Assuntos
Vacinas Bacterianas , Leptospira/imunologia , Leptospirose/imunologia , Lipopolissacarídeos/química , Vacinação , Animais , Anticorpos Antibacterianos/imunologia , Vacinas Bacterianas/química , Vacinas Bacterianas/imunologia , Cricetinae , Leptospira/química , Leptospirose/prevenção & controle
10.
Mol Immunol ; 121: 47-58, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32163758

RESUMO

Shigellosis is a diarrheal disease that causes high mortality every year, especially in children, elderly and immunocompromised patients. Recently, resistance strains to antibiotic therapy are in the rise and the World Health Organization prioritizes the development of a safe vaccine against the most common causal agent of shigellosis, Shigella flexneri. This pathogen uses autotransporter proteins such as SigA, Pic and Sap to increase virulence and some of them have been described as highly immunogenic proteins. In this study, we used immune-informatics analysis to identify the most antigenic epitope as a vaccine candidate on three passenger domains of auto-transporter proteins encoded on the pathogenic island SHI-1, to induce immunity against S. flexneri. Epitope identification was done using various servers such as Bepipred, Bcepred, nHLAPRED, NetMHCII, Rankpep and IEDB and the final selection was done based on its antigenicity using the VaxiJen server. Moreover, to enhance immunity, the GroEL adjuvant was added to the final construct as a Toll-like receptor 2 (TLR2) agonist. On the other hand, to predict the tertiary structure, the I-TASSER server was used, and the best model was structurally validated using the ProSA-web software and the Ramachandran plot. Subsequently, the model was refined and used for docking and molecular dynamics analyses with TLR2, which demonstrated an appropriate and stable interaction. In summary, a potential subunit vaccine candidate, that contains B and T cell epitopes with proper physicochemical properties was designed. This multiepitope vaccine is expected to elicit robust humoral and cellular immune responses and vest protective immunity against S. flexneri.


Assuntos
Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Disenteria Bacilar/terapia , Serina Proteases/imunologia , Shigella flexneri/imunologia , Sistemas de Secreção Tipo V/imunologia , Adjuvantes Imunológicos/farmacologia , Antígenos de Bactérias/imunologia , Vacinas Bacterianas/uso terapêutico , Chaperonina 60/imunologia , Chaperonina 60/farmacologia , Biologia Computacional , Simulação por Computador , Disenteria Bacilar/microbiologia , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Humanos , Imunidade Celular , Imunidade Humoral , Imunogenicidade da Vacina , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Domínios Proteicos/imunologia , Receptor 2 Toll-Like/agonistas , Vacinas de Subunidades/imunologia , Vacinas de Subunidades/uso terapêutico
11.
Transl Res ; 220: 122-137, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32119845

RESUMO

The sexually transmitted infection gonorrhea, caused by the Gram-negative bacterium Neisseria gonorrhoeae, can cause urethritis, cervicitis, and systemic disease, among other manifestations. N. gonorrhoeae has rapidly rising incidence along with increasing levels of antibiotic resistance to a broad range of drugs including first-line treatments. The rise in resistance has led to fears of untreatable gonorrhea causing substantial disease globally. In this review, we will describe multiple approaches being undertaken to slow and control this spread of resistance. First, a number of old drugs have been repurposed and new drugs are being developed with activity against Neisseria gonorrhoeae. Second, vaccine development, long an important goal, is advancing. Third, new diagnostics promise rapid detection of antibiotic resistance and a shift from empiric to tailored treatment. The deployment of these new tools for addressing the challenge of antibiotic resistance will require careful consideration to provide optimal care for all patients while extending the lifespan of treatment regimens.


Assuntos
Neisseria gonorrhoeae/efeitos dos fármacos , Vacinas Bacterianas/imunologia , Farmacorresistência Bacteriana , Gonorreia/complicações , Gonorreia/diagnóstico , Gonorreia/tratamento farmacológico , Neisseria gonorrhoeae/imunologia
12.
Vet Microbiol ; 242: 108588, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32122592

RESUMO

Coinfection with porcine circovirus type 2 (PCV2) and Mycoplasma hyorhinis (Mhr) can induce more-severe disease than a single infection with either. We evaluated the efficacy of a new vaccine combining inactivated PCV2 and Mhr, in a model of PCV2 and Mhr infection. Twenty-five 35-day-old PCV2- and Mhr-free pigs were randomly divided into five groups, with five pigs in each group. The pigs in groups 1 and 2 were vaccinated with the combined vaccine and then challenged with Mhr or PCV2, respectively. The pigs in groups 3 and 4 were not vaccinated and then challenged with PCV2 or Mhr, respectively, and group 5 was used as the unvaccinated unchallenged control. Two weeks after booster immunization via the intramuscular route, all the pigs except those in control group 5 were challenged with PCV2 or Mhr. All the pigs were euthanized 28 days after challenge. The pigs in vaccinated groups 1 and 2 showed a significant increase in weight after challenge with PCV2 or Mhr (P < 0.001), with an average daily gain (ADG) of 0.315 kg compared with unvaccinated groups 3 and 4 (0.279 kg). Mhr was isolated from the unvaccinated pig lungs after Mhr challenge, whereas it was not isolated from the vaccinated pigs. No PCV2 or Mhr was detected with PCR or histochemical staining in vaccinated groups 1 and 2. A statistical analysis showed that the PCV2 and Mhr combined vaccine providing protected against PCV2 infection causing viremia and inguinal lymphadenopathy (5 pigs protected out 5) or against Mhr infection causing fiber inflammation (4 pigs out 5). Thus, we have developed an effective combined vaccine for the prevention and control of PCV2 or Mhr infections in swine herds, this will help reduce prevalence of PCV2 and Mhr coinfections.


Assuntos
Vacinas Bacterianas/imunologia , Infecções por Circoviridae/veterinária , Infecções por Mycoplasma/veterinária , Doenças dos Suínos/prevenção & controle , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/sangue , Vacinas Bacterianas/administração & dosagem , Infecções por Circoviridae/prevenção & controle , Circovirus/classificação , Circovirus/imunologia , Coinfecção/microbiologia , Coinfecção/veterinária , Coinfecção/virologia , Imunização Secundária , Injeções Intramusculares , Infecções por Mycoplasma/prevenção & controle , Mycoplasma hyorhinis/imunologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/virologia , Vacinas Combinadas/administração & dosagem , Vacinas Combinadas/imunologia , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/imunologia , Vacinas Virais/administração & dosagem
13.
Infect Immun ; 88(5)2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32122943

RESUMO

Mycoplasma gallisepticum is the primary etiological agent of chronic respiratory disease in chickens. Live attenuated vaccines are most commonly used in the field to control the disease, but current vaccines have some limitations. Vaxsafe MG (strain ts-304) is a new vaccine candidate that is efficacious at a lower dose than the current commercial vaccine strain ts-11, from which it is derived. In this study, the transcriptional profiles of the trachea of unvaccinated chickens and chickens vaccinated with strain ts-304 were compared 2 weeks after challenge with M. gallisepticum strain Ap3AS during the chronic stage of infection. After challenge, genes, gene ontologies, pathways, and protein classes involved in inflammation, cytokine production and signaling, and cell proliferation were upregulated, while those involved in formation and motor movement of cilia, formation of intercellular junctional complexes, and formation of the cytoskeleton were downregulated in the unvaccinated birds compared to the vaccinated birds, reflecting immune dysregulation and the pathological changes induced in the trachea by infection with M. gallisepticum Vaccination appears to protect the structural and functional integrity of the tracheal mucosa 2 weeks after infection with M. gallisepticum.


Assuntos
Galinhas/imunologia , Galinhas/microbiologia , Mycoplasma gallisepticum/imunologia , Traqueia/imunologia , Traqueia/microbiologia , Transcrição Genética/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Vacinas Bacterianas/imunologia , Proliferação de Células/fisiologia , Membrana Mucosa/imunologia , Membrana Mucosa/microbiologia , Infecções por Mycoplasma/imunologia , Infecções por Mycoplasma/microbiologia , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/microbiologia , Regulação para Cima/imunologia , Vacinação/métodos , Vacinas Atenuadas/imunologia
14.
PLoS One ; 15(2): e0229301, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32084216

RESUMO

Anaplasma marginale is the most prevalent tick-borne livestock pathogen with worldwide distribution. Bovine anaplasmosis is a significant threat to cattle industry. Anaplasmosis outbreaks in endemic areas are prevented via vaccination with live A. centrale produced in splenectomized calves. Since A. centrale live vaccine can carry other pathogens and cause disease in adult cattle, research efforts are directed to develop safe recombinant subunit vaccines. Previous work found that the subdominant proteins of A. marginale type IV secretion system (T4SS) and the subdominant elongation factor-Tu (Ef-Tu) were involved in the protective immunity against the experimental challenge in cattle immunized with the A. marginale outer membrane (OM). This study evaluated the immunogenicity and protection conferred by recombinant VirB9.1, VirB9.2, VirB10, VirB11, and Ef-Tu proteins cloned and expressed in E. coli. Twenty steers were randomly clustered into four groups (G) of five animals each. Cattle from G1 and G2 were immunized with a mixture of 50 µg of each recombinant protein with Quil A® or Montanide™ adjuvants, respectively. Cattle from G3 and G4 (controls) were immunized with Quil A and Montanide adjuvants, respectively. Cattle received four immunizations at three-week intervals and were challenged with 107 A. marginale-parasitized erythrocytes 42 days after the fourth immunization. After challenge, all cattle showed clinical signs, with a significant drop of packed cell volume and a significant increase of parasitized erythrocytes (p<0.05), requiring treatment with oxytetracycline to prevent death. The levels of IgG2 induced in the immunized groups did not correlate with the observed lack of protection. Additional strategies are required to evaluate the role of these proteins and their potential utility in the development of effective vaccines.


Assuntos
Anaplasma marginale/imunologia , Anaplasma marginale/patogenicidade , Vacinas Bacterianas/imunologia , Proteínas Recombinantes/imunologia , Sistemas de Secreção Tipo IV/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Vacinas Bacterianas/genética , Bovinos , Imunização , Proteínas Recombinantes/genética , Sistemas de Secreção Tipo IV/genética , Virulência/imunologia
15.
Pesqui. vet. bras ; 40(2): 88-96, Feb. 2020. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1098441

RESUMO

Brucella ovis causes economic and reproductive losses in sheep herds. The goal of this study was to characterize infection with B. ovis field isolates in a murine model, and to evaluate protection induced by the candidate vaccine strain B. ovis ΔabcBA in mice challenged with these field isolates. B. ovis field strains were able to colonize and cause lesions in the liver and spleen of infected mice. After an initial screening, two strains were selected for further characterization (B. ovis 94 AV and B. ovis 266 L). Both strains had in vitro growth kinetics that was similar to that of the reference strain B. ovis ATCC 25840. Vaccination with B. ovis ΔabcBA encapsulated with 1% alginate was protective against the challenge with field strains, with the following protection indexes: 0.751, 1.736, and 2.746, for mice challenged with B. ovis ATCC25840, B. ovis 94 AV, and B. ovis 266 L, respectively. In conclusion, these results demonstrated that B. ovis field strains were capable of infecting and inducing lesions in experimentally infected mice. The attenuated vaccine strain B. ovis ΔabcBA induced protection in mice challenged with different B. ovis field isolates, resulting in higher protection indexes against more pathogenic strains.(AU)


Brucella ovis é responsável por perdas econômicas e reprodutivas em rebanhos ovinos. O objetivo deste trabalho foi caracterizar a infecção com as cepas isoladas de campo de B. ovis em modelo murino e avaliar a eficiência vacinal da mutante B. ovis ΔabcAB para proteção contra desafio com as cepas isoladas de campo. Foram utilizadas sete cepas isoladas de campo foram capazes de colonizar e provocar lesões no fígado e no baço de camundongos após sete dias pós-infecção. Após triagem, duas cepas foram selecionadas para a melhor caracterização (B. ovis 94 AV and B. ovis 266L). Ambas apresentaram crescimento em placa de cultivo semelhante ao da cepa de referência B. ovis ATCC 25840. A vacinação com a cepa de Brucella ovis ΔabcBA encapsulada com alginato a 1% foi capaz de proteger camundongos desafiados com as cepas isoladas de campo, com os seguintes índices de proteção: 0,751, 1,736 e 2,746, para camundongos desafiados com B. ovis ATCC 25840, B. ovis 94 AV e B. ovis 266 L, respectivamente. Estes resultados demonstraram que as cepas isoladas de campo de B. ovis são capazes de infectar e induzir lesão em camundongos experimentalmente infectados. O uso da cepa mutante atenuada B. ovis ΔabcBA para vacinação de fêmeas C57BL/6 desafiados com diferentes cepas de B. ovis induziu proteção nos camundongos desafiados com diferentes cepas de B. ovis. Deste modo, mostrando-se eficiente na proteção das cepas de campo de B. ovis.(AU)


Assuntos
Animais , Camundongos , Brucelose/prevenção & controle , Ovinos/microbiologia , Vacinas Bacterianas/imunologia , Brucella ovis/isolamento & purificação , Brucella ovis/imunologia , Brucella ovis/patogenicidade
16.
Emerg Microbes Infect ; 9(1): 207-220, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31985348

RESUMO

Nutrient procurement specifically from nutrient-limiting environment is essential for pathogenic bacteria to survive and/or persist within the host. Long-term survival or persistent infection is one of the main reasons for the overuse of antibiotics, and contributes to the development and spread of antibiotic resistance. Mycobacterium tuberculosis is known for long-term survival within the host, and develops multidrug resistance. Before and during infection, the pathogen encounters various harsh environmental conditions. To cope up with such nutrient-limiting conditions, it is crucial to uptake essential nutrients such as ions, sugars, amino acids, peptides, and metals, necessary for numerous vital biological activities. Among the various types of transporters, ATP-binding cassette (ABC) importers are essentially unique to bacteria, accessible as drug targets without penetrating the cytoplasmic membrane, and offer an ATP-dependent gateway into the cell by mimicking substrates of the importer and designing inhibitors against substrate-binding proteins, ABC importers endeavour for the development of successful drug candidates and antibiotics. Alternatively, the production of antibodies against substrate-binding proteins could lead to vaccine development. In this review, we will emphasize the role of M. tuberculosis ABC importers for survival and virulence within the host. Furthermore, we will elucidate their unique characteristics to discover emerging therapies to combat tuberculosis.


Assuntos
Transportadores de Cassetes de Ligação de ATP/imunologia , Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Mycobacterium tuberculosis/imunologia , Transportadores de Cassetes de Ligação de ATP/genética , Proteínas de Bactérias/genética , Transporte Biológico , Desenho de Fármacos , Humanos , Mycobacterium tuberculosis/genética
17.
J Biomed Sci ; 27(1): 9, 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31900143

RESUMO

Glycoconjugate vaccines based on bacterial capsular polysaccharides (CPS) have been extremely successful in preventing bacterial infections. The glycan antigens for the preparation of CPS based glycoconjugate vaccines are mainly obtained from bacterial fermentation, the quality and length of glycans are always inconsistent. Such kind of situation make the CMC of glycoconjugate vaccines are difficult to well control. Thanks to the advantage of synthetic methods for carbohydrates syntheses. The well controlled glycan antigens are more easily to obtain, and them are conjugated to carrier protein to from the so-call homogeneous fully synthetic glycoconjugate vaccines. Several fully glycoconjugate vaccines are in different phases of clinical trial for bacteria or cancers. The review will introduce the recent development of fully synthetic glycoconjugate vaccine.


Assuntos
Infecções Bacterianas/prevenção & controle , Carboidratos/uso terapêutico , Polissacarídeos/imunologia , Vacinas Sintéticas/imunologia , Antígenos/imunologia , Cápsulas Bacterianas/genética , Cápsulas Bacterianas/imunologia , Infecções Bacterianas/imunologia , Vacinas Bacterianas/química , Vacinas Bacterianas/imunologia , Vacinas Bacterianas/uso terapêutico , Carboidratos/química , Carboidratos/imunologia , Glicoconjugados/química , Glicoconjugados/imunologia , Glicoconjugados/uso terapêutico , Humanos , Polissacarídeos/química , Polissacarídeos/uso terapêutico , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/imunologia , Vacinas Conjugadas/química , Vacinas Conjugadas/imunologia , Vacinas Conjugadas/uso terapêutico , Vacinas Sintéticas/química , Vacinas Sintéticas/uso terapêutico
18.
Biochem Biophys Res Commun ; 523(3): 602-607, 2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-31941602

RESUMO

Scrub typhus is an acute vector-borne disease caused by infection with the intracellular gram-negative bacterium Orientia tsutsugamushi (Ot). The rapid production of an efficient vaccine against Ot using novel strategies is required because of the global increase in mortality caused by these infections; however, no commercial vaccine is currently available. Ot induces T-cell-mediated immunogenic responses upon infection; therefore, a new rapidly producible vaccine that maximizes T-cell responses against Ot is required. In this study, we sought to develop a model vaccine platform for T-cell-mediated Ot infection using T-cell-immunity associated Salmonella-derived extracellular vesicles (EVs). For this purpose, we optimized DNA sequences encoding the full-length Ot proteins, TSA56, ScaA, ScaC, ScaD, and ScaE, and their expression in Salmonella. The sequences were incorporated into a new platform vector, pKST, which ectopically and concurrently produces Ot proteins and EVs. Expression analysis using pKST-antigen plasmids showed that TSA56 and ScaC produced antigen-associated EVs and showed strong T-cell immunogenic responses. We found that mice vaccinated with EVs derived from TSA56-expressing cells were protected from Salmonella-induced mortality. Therefore, our findings showed that Salmonella EV-associated antigen is a model platform for T-cell immune response infections. Our system could help prepare EV-antigen vaccines against scrub typhus in an easy and rapid manner.


Assuntos
Antígenos de Bactérias/uso terapêutico , Vacinas Bacterianas/uso terapêutico , Vesículas Extracelulares/imunologia , Tifo por Ácaros/prevenção & controle , Animais , Antígenos de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Humanos , Camundongos , Orientia tsutsugamushi/imunologia , Salmonella/imunologia , Infecções por Salmonella/imunologia , Infecções por Salmonella/prevenção & controle , Tifo por Ácaros/imunologia , Linfócitos T/imunologia
19.
Infect Immun ; 88(4)2020 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-31932330

RESUMO

The development of vaccines for prevention of diseases caused by pathogenic species can encounter major obstacles if high sequence diversity is observed between individual strains. Therefore, development might be restricted either to conserved antigens, which are often rare, or to multivalent vaccines, which renders the production more costly and cumbersome. In light of this complexity, we applied a structure-based surface shaping approach for the development of a Lyme borreliosis (LB) vaccine suitable for the United States and Europe. The surface of the C-terminal fragment of outer surface protein A (OspA) was divided into distinct regions, based primarily on binding sites of monoclonal antibodies (MAbs). In order to target the six clinically most relevant OspA serotypes (ST) in a single protein, exposed amino acids of the individual regions were exchanged to corresponding amino acids of a chosen OspA serotype. Six chimeric proteins were constructed, and, based on their immunogenicity, four of these chimeras were tested in mouse challenge models. Significant protection could be demonstrated for all four proteins following challenge with infected ticks (OspA ST1, OspA ST2, and OspA ST4) or with in vitro-grown spirochetes (OspA ST1 and OspA ST5). Two of the chimeric proteins were linked to form a fusion protein, which provided significant protection against in vitro-grown spirochetes (OspA ST1) and infected ticks (OspA ST2). This article presents the proof-of-concept study for a multivalent OspA vaccine targeting a wide range of pathogenic LB Borrelia species with a single recombinant antigen for prevention of Lyme borreliosis.


Assuntos
Antígenos de Superfície/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Vacinas Bacterianas/imunologia , Borrelia/imunologia , Lipoproteínas/imunologia , Doença de Lyme/prevenção & controle , Proteínas Recombinantes/imunologia , Animais , Antígenos de Superfície/administração & dosagem , Antígenos de Superfície/genética , Proteínas da Membrana Bacteriana Externa/administração & dosagem , Proteínas da Membrana Bacteriana Externa/genética , Vacinas Bacterianas/administração & dosagem , Vacinas Bacterianas/genética , Borrelia/genética , Modelos Animais de Doenças , Lipoproteínas/administração & dosagem , Lipoproteínas/genética , Camundongos , Engenharia de Proteínas , Proteínas Recombinantes/genética , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia
20.
Appl Microbiol Biotechnol ; 104(5): 1915-1925, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31953560

RESUMO

Lyme borreliosis is a bacterial infection that can be spread to humans by infected ticks and may severely affect many organs and tissues. Nearly four decades have elapsed since the discovery of the disease agent called Borrelia burgdorferi. Although there is a plethora of knowledge on the infectious agent and thousands of scientific publications, an effective way on how to combat and prevent Lyme borreliosis has not been found yet. There is no vaccine for humans available, and only one active vaccine program in clinical development is currently running. A spirited search for possible disease interventions is of high public interest as surveillance data indicates that the number of cases of Lyme borreliosis is steadily increasing in Europe and North America. This review provides a condensed digest of the history of vaccine development up to new promising vaccine candidates and strategies that are targeted against Lyme borreliosis, including elements of the tick vector, the reservoir hosts, and the Borrelia pathogen itself.


Assuntos
Borrelia burgdorferi/imunologia , Doença de Lyme/prevenção & controle , Animais , Vacinas Bacterianas/genética , Vacinas Bacterianas/imunologia , Borrelia burgdorferi/genética , Borrelia burgdorferi/fisiologia , Vetores de Doenças , Humanos , Doença de Lyme/imunologia , Doença de Lyme/microbiologia , Carrapatos/microbiologia
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