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1.
J Med Microbiol ; 69(9): 1183-1196, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32812860

RESUMO

Introduction. PCV2 is a DNA virus that exists widely in pigs and has caused great economic losses to the pig industry worldwide. In the existing commercial PCV2 enzyme-linked immunosorbent assay (ELISA) kits both natural infection with PCV2 and vaccine immunization produce results that are positive for PCV2 Cap antibodies and therefore they cannot diagnose PCV2 infection in immunized pig farms.Aim. To establish a PCV2 non-structural protein antibody detection method that distinguishes between antibodies resulting from natural prior exposure (infection) and those induced by subunit vaccine immunization.Methodology. Based on the non-structural Rep' protein, we established an indirect ELISA (iELISA) using sera from guinea pigs and piglets.Results. The results for iELISA for guinea pig serum showed that animals vaccinated with a whole-virus inactivated PCV2 vaccine had 100 % (10/10) Cap antibody positivity and 100 % (10/10) Rep' antibody positivity. Guinea pigs vaccinated with a recombinant subunit PCV2 vaccine had 100 % (10/10) Cap antibody positivity, while no (0/10) guinea pigs were Rep' antibody-positive. The combined detection results for the Rep' iELISA and a PCV2 Antibody Test kit (Commercial) showed that pigs vaccinated with a whole-virus inactivated PCV2 vaccine or PCV2 SD/2017 had 100 % (5/5) Cap antibody positivity and 100 % (5/5) Rep' antibody positivity. Pigs vaccinated with a recombinant subunit PCV2 vaccine had 100 % (5/5) Cap antibody positivity, while no (0/10) pigs were Rep' antibody-positive.Conclusion. This paper describes an effective iELISA method that can distinguish natural infection with PCV2 (Cap and Rep positive) or inoculation with a whole-virus inactivated vaccine (Cap and Rep positive) from subunit vaccine immunization (Cap-positive, Rep-negative). These comparative assays could be very useful in the control of PCV2 in pig herds.


Assuntos
Anticorpos Antivirais/imunologia , Infecções por Circoviridae/sangue , Infecções por Circoviridae/veterinária , Circovirus/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Doenças dos Suínos/sangue , Proteínas Virais/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/análise , Infecções por Circoviridae/imunologia , Circovirus/genética , Imunização , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/virologia , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/genética , Vacinas de Subunidades/imunologia , Proteínas Virais/administração & dosagem , Proteínas Virais/genética , Vacinas Virais/administração & dosagem , Vacinas Virais/genética
2.
Chem Commun (Camb) ; 56(61): 8683-8686, 2020 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-32613971

RESUMO

Herein, we report that a recombinant fusion protein, containing a 457 amino acid SARS-CoV-2 receptor binding domain (RBD, residues 319-541) and a mouse IgG1 Fc domain, could induce highly potent neutralizing antibodies and stimulate humoral and cellular immunity in mice. The antibodies also effectively suppressed SARS-CoV-2 RBD binding to soluble ACE2, indicating that RBD-mFc may be further developed as a safe and effective SARS-CoV-2 vaccine.


Assuntos
Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Proteínas Recombinantes de Fusão/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas de Subunidades/administração & dosagem , Vacinas Virais/administração & dosagem , Animais , Anticorpos Neutralizantes/imunologia , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Ligação Proteica , Glicoproteína da Espícula de Coronavírus/metabolismo
3.
Cancer Immunol Immunother ; 69(10): 2001-2007, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32393999

RESUMO

Cancer immunotherapy including vaccine therapy is a promising modality for cancer treatment, but few patients show its clinical benefits currently. The identification of biomarkers that can identify patients who will benefit from cancer immunotherapy is thus important. Here, we investigated the potential utility of the circulating cell-free DNA (cfDNA) integrity-a ratio of necrotic cell-derived, longer DNA fragments versus apoptotic cell-derived shorter fragments of Alu gene-as a biomarker of vaccine therapy for patients with ovarian cancer. We analyzed plasma samples from 39 patients with advanced or recurrent ovarian cancer enrolled in clinical trials for personalized peptide vaccinations. We observed that (1) the cfDNA integrity was decreased after the first cycle of vaccination, and (2) the decreased levels of cfDNA integrity were correlated with vaccine-induced immune responses; i.e., decreased cfDNA integrity was observed in 91.7% and 59.3% of the IgG-positive and negative patients, respectively (p = 0.0445). Similarly, decreased cfDNA integrity was observed in 92.9% and 56.0% of CTL response-positive and negative patients, respectively (p = 0.0283). These results suggest that the circulating cfDNA integrity is a possible biomarker for cancer vaccine therapy.


Assuntos
Biomarcadores Tumorais/imunologia , Vacinas Anticâncer/imunologia , Carcinoma Epitelial do Ovário/imunologia , DNA Tumoral Circulante/sangue , Recidiva Local de Neoplasia/imunologia , Neoplasias Ovarianas/imunologia , Vacinas de Subunidades/imunologia , Vacinas Anticâncer/administração & dosagem , Carcinoma Epitelial do Ovário/sangue , Carcinoma Epitelial do Ovário/genética , DNA Tumoral Circulante/genética , Feminino , Seguimentos , Humanos , Recidiva Local de Neoplasia/sangue , Recidiva Local de Neoplasia/genética , Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/genética , Prognóstico , Vacinas de Subunidades/administração & dosagem
4.
EBioMedicine ; 55: 102743, 2020 May.
Artigo em Inglês | MEDLINE | ID: covidwho-27911

RESUMO

BACKGROUND: Coronaviruses pose a serious threat to global health as evidenced by Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and COVID-19. SARS Coronavirus (SARS-CoV), MERS Coronavirus (MERS-CoV), and the novel coronavirus, previously dubbed 2019-nCoV, and now officially named SARS-CoV-2, are the causative agents of the SARS, MERS, and COVID-19 disease outbreaks, respectively. Safe vaccines that rapidly induce potent and long-lasting virus-specific immune responses against these infectious agents are urgently needed. The coronavirus spike (S) protein, a characteristic structural component of the viral envelope, is considered a key target for vaccines for the prevention of coronavirus infection. METHODS: We first generated codon optimized MERS-S1 subunit vaccines fused with a foldon trimerization domain to mimic the native viral structure. In variant constructs, we engineered immune stimulants (RS09 or flagellin, as TLR4 or TLR5 agonists, respectively) into this trimeric design. We comprehensively tested the pre-clinical immunogenicity of MERS-CoV vaccines in mice when delivered subcutaneously by traditional needle injection, or intracutaneously by dissolving microneedle arrays (MNAs) by evaluating virus specific IgG antibodies in the serum of vaccinated mice by ELISA and using virus neutralization assays. Driven by the urgent need for COVID-19 vaccines, we utilized this strategy to rapidly develop MNA SARS-CoV-2 subunit vaccines and tested their pre-clinical immunogenicity in vivo by exploiting our substantial experience with MNA MERS-CoV vaccines. FINDINGS: Here we describe the development of MNA delivered MERS-CoV vaccines and their pre-clinical immunogenicity. Specifically, MNA delivered MERS-S1 subunit vaccines elicited strong and long-lasting antigen-specific antibody responses. Building on our ongoing efforts to develop MERS-CoV vaccines, promising immunogenicity of MNA-delivered MERS-CoV vaccines, and our experience with MNA fabrication and delivery, including clinical trials, we rapidly designed and produced clinically-translatable MNA SARS-CoV-2 subunit vaccines within 4 weeks of the identification of the SARS-CoV-2 S1 sequence. Most importantly, these MNA delivered SARS-CoV-2 S1 subunit vaccines elicited potent antigen-specific antibody responses that were evident beginning 2 weeks after immunization. INTERPRETATION: MNA delivery of coronaviruses-S1 subunit vaccines is a promising immunization strategy against coronavirus infection. Progressive scientific and technological efforts enable quicker responses to emerging pandemics. Our ongoing efforts to develop MNA-MERS-S1 subunit vaccines enabled us to rapidly design and produce MNA SARS-CoV-2 subunit vaccines capable of inducing potent virus-specific antibody responses. Collectively, our results support the clinical development of MNA delivered recombinant protein subunit vaccines against SARS, MERS, COVID-19, and other emerging infectious diseases.


Assuntos
Betacoronavirus/imunologia , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas Virais/administração & dosagem , Adjuvantes Imunológicos/administração & dosagem , Animais , Anticorpos Antivirais/biossíntese , Anticorpos Antivirais/sangue , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Feminino , Imunização Secundária , Imunoglobulina G/biossíntese , Imunoglobulina G/sangue , Injeções Subcutâneas , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/imunologia , Organismos Livres de Patógenos Específicos , Fatores de Tempo , Vacinas de Subunidades/administração & dosagem , Vacinas Virais/imunologia
5.
EBioMedicine ; 55: 102743, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32249203

RESUMO

BACKGROUND: Coronaviruses pose a serious threat to global health as evidenced by Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and COVID-19. SARS Coronavirus (SARS-CoV), MERS Coronavirus (MERS-CoV), and the novel coronavirus, previously dubbed 2019-nCoV, and now officially named SARS-CoV-2, are the causative agents of the SARS, MERS, and COVID-19 disease outbreaks, respectively. Safe vaccines that rapidly induce potent and long-lasting virus-specific immune responses against these infectious agents are urgently needed. The coronavirus spike (S) protein, a characteristic structural component of the viral envelope, is considered a key target for vaccines for the prevention of coronavirus infection. METHODS: We first generated codon optimized MERS-S1 subunit vaccines fused with a foldon trimerization domain to mimic the native viral structure. In variant constructs, we engineered immune stimulants (RS09 or flagellin, as TLR4 or TLR5 agonists, respectively) into this trimeric design. We comprehensively tested the pre-clinical immunogenicity of MERS-CoV vaccines in mice when delivered subcutaneously by traditional needle injection, or intracutaneously by dissolving microneedle arrays (MNAs) by evaluating virus specific IgG antibodies in the serum of vaccinated mice by ELISA and using virus neutralization assays. Driven by the urgent need for COVID-19 vaccines, we utilized this strategy to rapidly develop MNA SARS-CoV-2 subunit vaccines and tested their pre-clinical immunogenicity in vivo by exploiting our substantial experience with MNA MERS-CoV vaccines. FINDINGS: Here we describe the development of MNA delivered MERS-CoV vaccines and their pre-clinical immunogenicity. Specifically, MNA delivered MERS-S1 subunit vaccines elicited strong and long-lasting antigen-specific antibody responses. Building on our ongoing efforts to develop MERS-CoV vaccines, promising immunogenicity of MNA-delivered MERS-CoV vaccines, and our experience with MNA fabrication and delivery, including clinical trials, we rapidly designed and produced clinically-translatable MNA SARS-CoV-2 subunit vaccines within 4 weeks of the identification of the SARS-CoV-2 S1 sequence. Most importantly, these MNA delivered SARS-CoV-2 S1 subunit vaccines elicited potent antigen-specific antibody responses that were evident beginning 2 weeks after immunization. INTERPRETATION: MNA delivery of coronaviruses-S1 subunit vaccines is a promising immunization strategy against coronavirus infection. Progressive scientific and technological efforts enable quicker responses to emerging pandemics. Our ongoing efforts to develop MNA-MERS-S1 subunit vaccines enabled us to rapidly design and produce MNA SARS-CoV-2 subunit vaccines capable of inducing potent virus-specific antibody responses. Collectively, our results support the clinical development of MNA delivered recombinant protein subunit vaccines against SARS, MERS, COVID-19, and other emerging infectious diseases.


Assuntos
Betacoronavirus/imunologia , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas Virais/administração & dosagem , Adjuvantes Imunológicos/administração & dosagem , Animais , Anticorpos Antivirais/biossíntese , Anticorpos Antivirais/sangue , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Feminino , Imunização Secundária , Imunoglobulina G/biossíntese , Imunoglobulina G/sangue , Injeções Subcutâneas , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/imunologia , Organismos Livres de Patógenos Específicos , Fatores de Tempo , Vacinas de Subunidades/administração & dosagem , Vacinas Virais/imunologia
6.
PLoS Negl Trop Dis ; 14(4): e0007717, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32302312

RESUMO

BACKGROUND: The long term and complex nature of Chagas disease in humans has restricted studies on vaccine feasibility. Animal models also have limitations due to technical difficulties in monitoring the extremely low parasite burden that is characteristic of chronic stage infections. Advances in imaging technology offer alternative approaches that circumvent these problems. Here, we describe the use of highly sensitive whole body in vivo imaging to assess the efficacy of recombinant viral vector vaccines and benznidazole-cured infections to protect mice from challenge with Trypanosoma cruzi. METHODOLOGY/PRINCIPAL FINDINGS: Mice were infected with T. cruzi strains modified to express a red-shifted luciferase reporter. Using bioluminescence imaging, we assessed the degree of immunity to re-infection conferred after benznidazole-cure. Those infected for 14 days or more, prior to the onset of benznidazole treatment, were highly protected from challenge with both homologous and heterologous strains. There was a >99% reduction in parasite burden, with parasites frequently undetectable after homologous challenge. This level of protection was considerably greater than that achieved with recombinant vaccines. It was also independent of the route of infection or size of the challenge inoculum, and was long-lasting, with no significant diminution in immunity after almost a year. When the primary infection was benznidazole-treated after 4 days (before completion of the first cycle of intracellular infection), the degree of protection was much reduced, an outcome associated with a minimal T. cruzi-specific IFN-γ+ T cell response. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that a protective Chagas disease vaccine must have the ability to eliminate parasites before they reach organs/tissues, such as the GI tract, where once established, they become largely refractory to the induced immune response.


Assuntos
Doença de Chagas/imunologia , Doença de Chagas/prevenção & controle , Imunidade Heteróloga , Vacinas Protozoárias/imunologia , Trypanosoma cruzi/imunologia , Vacinação/métodos , Animais , Modelos Animais de Doenças , Feminino , Camundongos Endogâmicos BALB C , Vacinas Protozoárias/administração & dosagem , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia
7.
Mol Immunol ; 121: 118-126, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32199211

RESUMO

Foot-and-mouth disease (FMD) is an acute, severe, and highly contagious disease that affects cloven-hoofed animals and can lead to serious economic losses and social effects. Therefore, a safe and effective subunit vaccine is required to prevent and control FMD. Dendritic cells (DCs) are a type of professional antigen presenting cell (APC). Immature DCs are typically stimulated by various adjuvants via immune receptors (e.g., toll-like receptor 4 [TLR4]), which activate DCs to induce their maturation. TLR4 has been well-established to induce both innate and adaptive immune responses to various external microbial or internal damage-related molecular patterns. In this study, the multi-epitope immunogen, HAO, of foot-and-mouth disease virus (FMDV) serotypes A and O was fused with the recombinant protein, heparin-binding hemagglutinin (HBHA), a novel TLR4 agonist, to obtain a new recombinant fusion protein, termed HAO-HBHA. HAO-HBHA was found to be highly efficient at activating murine DCs by the TLR4 pathway, both in vitro and in vivo. HAO-HBHA elicited strong specific humoral immune responses detected with an ELISA and virus neutralizing antibody test (VNT). HAO-HBHA also elevated the cellular immune responses, as indicated by intracellular cytokine (e.g., IFN-γ, TNF-α, IL-4, IL-6, IL-10, and IL-12p70) expression in Th1 and Th2 cells. As a TLR4 agonist, HBHA has significant advantages for enhancing the immune efficacy of a FMDV serotype A and O bivalent multi-epitope vaccine. These findings provide a novel strategy for the development of a safe and effective multi-epitope vaccine candidate against FMDV and further extends the application of TLR agonist-based vaccine platforms.


Assuntos
Vírus da Febre Aftosa/imunologia , Febre Aftosa/prevenção & controle , Lectinas/farmacologia , Vacinas Virais/administração & dosagem , Adjuvantes Imunológicos/farmacologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Células Dendríticas/imunologia , Epitopos de Linfócito B/genética , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Feminino , Febre Aftosa/sangue , Febre Aftosa/imunologia , Febre Aftosa/virologia , Vírus da Febre Aftosa/genética , Imunidade Celular , Imunogenicidade da Vacina , Lectinas/imunologia , Camundongos , Mycobacterium tuberculosis/imunologia , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Sorogrupo , Receptor 4 Toll-Like/agonistas , Receptor 4 Toll-Like/imunologia , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/genética , Vacinas de Subunidades/imunologia , Vacinas Virais/genética , Vacinas Virais/imunologia
8.
Vet Microbiol ; 242: 108604, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32122610

RESUMO

Here, we examined the efficacy of are combinant subunit antigen-based oral vaccine for preventing porcine epidemic diarrhea virus (PEDV). First, we generated a soluble recombinant partial spike S1 protein (aP2) from PEDV in E. coli and then evaluated the utility of aP2 subunit vaccine-loaded hydroxypropyl methylcellulose phthalate microspheres (HPMCP) and RANKL-secreting L. lactis (LLRANKL) as a candidate oral vaccine in pregnant sows. Pregnant sows were vaccinated twice (with a 2 week interval between doses) at 4 weeks before farrowing. Titers of virus-specific IgA antibodies in colostrum, and neutralizing antibodies in serum, of sows vaccinated with HPMCP (aP2) plus LL RANKL increased significantly at 4 weeks post-first vaccination. Furthermore, the survival rate of newborn suckling piglets delivered by sows vaccinated with HPMCP (aP2) plus LL RANKL was similar to that of piglets delivered by sows vaccinated with a commercial killed porcine epidemic diarrhea virus (PED) vaccine. The South Korean government promotes a PED vaccine program (live-killed-killed) to increase the titers of IgA and IgG antibodies in pregnant sows and prevent PEDV. The oral vaccine strategy described herein, which is based on a safe and efficient recombinant subunit antigen, is an alternative PED vaccination strategy that could replace the traditional strategy, which relies on attenuated live oral vaccines or artificial infection with virulent PEDV.


Assuntos
Infecções por Coronavirus/veterinária , Lactobacillus/imunologia , Metilcelulose/análogos & derivados , Ligante RANK/imunologia , Doenças dos Suínos/prevenção & controle , Vacinas Virais/imunologia , Administração Oral , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Colostro/imunologia , Infecções por Coronavirus/prevenção & controle , Feminino , Metilcelulose/administração & dosagem , Microesferas , Vírus da Diarreia Epidêmica Suína , Gravidez , Ligante RANK/administração & dosagem , Suínos , Doenças dos Suínos/virologia , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/imunologia , Proteínas Virais/genética , Proteínas Virais/imunologia , Vacinas Virais/administração & dosagem
9.
Eur J Cancer ; 129: 80-96, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32145473

RESUMO

The main goal of peptide-based cancer vaccines is to induce the immune system and activation of effective T cell responses against cancerous cells. Nevertheless, the potency of peptide vaccines is insufficient in most of cases and had limited clinical success. Therefore, the optimization of peptide-based cancer vaccine is essential to achieve powerful therapeutic outcomes. One strategy to enhanced potency of peptide vaccines and induce strong immune responses is the preparation of multi-epitope peptide formulation containing both Th- and cytotoxic T lymphocyte-induced responses epitope using suitable delivery system. For this reason, we studied the effect of Dioleoylphosphatidylethanolamine-containing liposomal vaccine composed of a mixture of short peptides AE36 and E75 (HER2/neu-derived peptides) and long multi-epitope peptide E75-AE36 (linkage of short peptides) in combination with a Pan HLA-DR epitope (PADRE) peptide. These formulations were examined using a series of subcutaneously injection to HER-2+ TUBO-tumoured mice in prophylactic and therapeutic model. We observed that mice vaccinated with liposomal long peptide in combination with PADRE resulted in the superior induction of CD4+ and CD8+ T cells responses and significantly enhanced production of IFN-γ compared with liposomal short peptides and non-liposomal peptides formulations. Moreover, liposome-long peptide with PADRE led to the considerable reduction of tumour growth and lifespan induction in mouse model. In conclusion, our study indicated that liposomal formulation containing long multi-epitope peptide E75-AE36 with PADRE could be used as an effective multi-epitope prophylactic/therapeutic vaccine to generate potent antigen-specific CD8+ T-cell immune response and may be introduced as a possible candidate peptide vaccine for breast cancer.


Assuntos
Neoplasias da Mama/terapia , Vacinas Anticâncer/administração & dosagem , Imunogenicidade da Vacina , Vacinas Antimaláricas/administração & dosagem , Fragmentos de Peptídeos/administração & dosagem , Animais , Neoplasias da Mama/imunologia , Vacinas Anticâncer/imunologia , Linhagem Celular Tumoral/transplante , Modelos Animais de Doenças , Feminino , Humanos , Lipossomos , Vacinas Antimaláricas/imunologia , Camundongos , Nanopartículas , Fragmentos de Peptídeos/imunologia , Receptor ErbB-2/imunologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/imunologia
10.
J Appl Microbiol ; 129(2): 443-452, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32118336

RESUMO

AIM: Category A classified Bacillus anthracis is highly fatal pathogen that causes anthrax and creates challenges for global security and public health. In this study, development of a safe and ideal next-generation subunit anthrax vaccine has been evaluated in mouse model. METHOD AND RESULTS: Protective antigen (PA) and BA3338, a surface layer homology (SLH) domain possessing protein were cloned, expressed in heterologous system and purified by IMAC. Recombinant PA and BA3338 with alum were administered in mouse alone or in combination. The humoral and cell-mediated immune response was measured by ELISA and vaccinated animals were challenged with B. anthracis spores via intraperitoneal route. The circulating IgG antibody titre of anti-PA and anti-BA3338 was found significantly high in the first and second booster sera. A significant enhanced level of IL-4, IFN-γ and IL-12 was observed in antigens stimulated supernatant of splenocytes of PA + BA3338 vaccinated animals. A combination of PA and BA3338 provided 80% protection against 20 LD50 lethal dose of B. anthracis spores. CONCLUSION: Both antigens induced admirable humoral and cellular immune response as well as protective efficacy against B. anthracis spores. SIGNIFICANCE AND IMPACT OF THE STUDY: This study has been evaluated for the first time using BA3338 as a vaccine candidate alone or in combination with well-known anthrax vaccine candidate PA. The findings of this study demonstrated that BA3338 could be a co-vaccine candidate for development of dual subunit vaccine against anthrax.


Assuntos
Vacinas contra Antraz/administração & dosagem , Antraz/prevenção & controle , Antígenos de Bactérias/imunologia , Bacillus anthracis/imunologia , Toxinas Bacterianas/imunologia , Glicoproteínas de Membrana/imunologia , Adjuvantes Imunológicos/administração & dosagem , Compostos de Alúmen/administração & dosagem , Animais , Antraz/imunologia , Vacinas contra Antraz/imunologia , Anticorpos Antibacterianos/sangue , Citocinas/metabolismo , Modelos Animais de Doenças , Imunização/métodos , Camundongos , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/imunologia
11.
Infect Immun ; 88(4)2020 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-32014894

RESUMO

Unbiased identification of individual immunogenic B-cell epitopes in major antigens of a pathogen remains a technology challenge for vaccine discovery. We therefore developed a platform for rapid phage display screening of deep recombinant libraries consisting of as few as one major pathogen antigen. Using the bicomponent pore-forming leukocidin (Luk) exotoxins of the major pathogen Staphylococcus aureus as a prototype, we randomly fragmented and separately ligated the hemolysin gamma A (HlgA) and LukS genes into a custom-built phage display system, termed pComb-Opti8. Deep sequence analysis of barcoded amplimers of the HlgA and LukS gene fragment libraries demonstrated that biopannng against a cross-reactive anti-Luk monoclonal antibody (MAb) recovered convergent molecular clones with short overlapping homologous sequences. We thereby identified an 11-amino-acid sequence that is highly conserved in four Luk toxin subunits and is ubiquitous in representation within S. aureus clinical isolates. The isolated 11-amino-acid peptide probe was predicted to retain the native three-dimensional (3D) conformation seen within the Luk holotoxin. Indeed, this peptide was recognized by the selecting anti-Luk MAb, and, using mutated peptides, we showed that a particular amino acid side chain was essential for these interactions. Furthermore, murine immunization with this peptide elicited IgG responses that were highly reactive with both the autologous synthetic peptide and the full-length Luk toxin homologues. Thus, using a gene fragment- and phage display-based pipeline, we have identified and validated immunogenic B-cell epitopes that are cross-reactive between members of the pore-forming leukocidin family. This approach could be harnessed to identify novel epitopes for a much-needed S. aureus-protective subunit vaccine.


Assuntos
Proteínas de Bactérias/imunologia , Mapeamento de Epitopos , Epitopos de Linfócito B/imunologia , Exotoxinas/imunologia , Staphylococcus aureus/imunologia , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Anticorpos Monoclonais/imunologia , Imunoglobulina G/sangue , Camundongos , Biblioteca de Peptídeos , Vacinas Antiestafilocócicas/administração & dosagem , Vacinas Antiestafilocócicas/imunologia , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia
12.
Cancer Sci ; 111(4): 1124-1131, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32058620

RESUMO

The identification of useful biomarkers is an urgent issue in cancer treatment, particularly for immunotherapy, as only some patients experience benefits from this treatment. The early induction of the IgG response has been reported as a useful biomarker of favorable prognosis for cancer patients treated with a personalized peptide vaccination, but a portion of these patients (IgG nonresponders) fail to achieve an early induction of IgG response yet experience long-term survival. It is thus necessary to identify other biomarkers of favorable prognosis among these patients. Here we report the usefulness of classical T-cell markers (ie, the CD8 content and the CD4/CD8 ratio in peripheral blood) in IgG nonresponders among advanced or recurrent ovarian cancer patients treated with a personalized peptide vaccination. Among IgG nonresponders (n = 25), the overall survival (OS) of the increased-CD8 group (n = 7) was significantly longer than that of the decreased-CD8 group (n = 18; P = .018), and the OS of the patients with a decreased CD4/CD8 ratio (n = 10) was significantly longer than that of the patients with an increased ratio (n = 15; P = .0055). Thus, an increased content of CD8 and a decreased CD4/CD8 ratio are each favorable prognosis markers in IgG nonresponders treated with a personalized peptide vaccination.


Assuntos
Antígenos CD4/sangue , Antígenos CD8/sangue , Neoplasias Ovarianas/tratamento farmacológico , Vacinas de Subunidades/administração & dosagem , Adulto , Idoso , Biomarcadores Tumorais/sangue , Vacinas Anticâncer/administração & dosagem , Vacinas Anticâncer/efeitos adversos , Feminino , Humanos , Imunoglobulina G/efeitos adversos , Imunoglobulina G/sangue , Imunoterapia , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/sangue , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/imunologia , Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/imunologia , Neoplasias Ovarianas/patologia , Medicina de Precisão , Prognóstico , Linfócitos T Citotóxicos/efeitos dos fármacos , Linfócitos T Citotóxicos/imunologia , Vacinas de Subunidades/efeitos adversos
13.
Int J Nanomedicine ; 15: 761-777, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32099364

RESUMO

Purpose: Salmonellosis in poultry is a serious economic burden. A major concern is the public health hazard caused by consumption of Salmonella-contaminated poultry products. Currently used Salmonella vaccines are ineffective in combating poultry Salmonellosis warranting the need of a potent vaccine, especially an oral vaccine that can elicit robust local intestinal immunity. Materials and Methods: A Salmonella subunit chitosan nanoparticles (NPs)-based vaccine was prepared that contained immunogenic outer membrane proteins (OMPs) and -flagellin (F) protein (OMPs-F-CS NPs). OMPs-F-CS NPs were administered as an oral vaccine in layer chickens and the resultant humoral and cell-mediated immune responses and localization of NPs were examined using standard detection methods. Results: We demonstrated targeting of surface F-protein coated chitosan NPs to immune cells when delivered orally to layer chickens, the particles were localized in ileal Peyer's patches. The OMPs-F-CS NPs vaccinated layer chickens had significantly higher OMPs-specific mucosal IgA production and lymphocyte proliferation response. The candidate vaccine increased the expression of toll-like receptor (TLR)-2, TLR-4, IFN-γ, TGF-ß and IL-4 mRNA expression in chicken cecal tonsils. Conclusion: Our study demonstrated that the chitosan-based oral Salmonella nanovaccine targets immune cells of chickens and induced antigen-specific B and T cell responses. This candidate oral Salmonella nanovaccine has the potential to mitigate Salmonellosis in poultry.


Assuntos
Galinhas , Salmonelose Animal/prevenção & controle , Vacinas contra Salmonella/administração & dosagem , Vacinas contra Salmonella/imunologia , Administração Oral , Animais , Galinhas/imunologia , Quitosana/química , Feminino , Imunidade Celular , Interleucina-4/genética , Mucosa Intestinal/efeitos dos fármacos , Nanopartículas/administração & dosagem , Nanopartículas/química , Porinas/química , Salmonelose Animal/imunologia , Salmonella enteritidis/imunologia , Receptores Toll-Like/genética , Fator de Crescimento Transformador beta/genética , Vacinas de Subunidades/administração & dosagem
14.
Cancer Immunol Immunother ; 69(5): 847-857, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32025848

RESUMO

A novel cancer vaccine consisting of 20 mixed peptides (KRM-20) was designed to induce cytotoxic T lymphocytes (CTL) against twelve different tumor-associated antigens. The aim of this phase II trial was to examine whether KRM-20 in combination with docetaxel and dexamethasone enhances the antitumor effects in patients with castration-resistant prostate cancer (CRPC). In this double-blind, placebo-controlled, randomized phase II study, we enrolled chemotherapy-naïve patients with CRPC from ten medical centers in Japan. Eligible patients were randomly assigned 1:1 centrally to receive either KRM-20 combined with docetaxel and dexamethasone (n = 25) or placebo with docetaxel and dexamethasone (n = 26). The primary endpoint was the difference in prostate-specific antigen (PSA) decline between each treatment. The rates of > 50% PSA decline in the two arms were similar (56.5% versus 53.8%; P = 0.851). Human leukocyte antigen (HLA)-matched peptide-specific immunoglobulin G (P = 0.018) and CTL (P = 0.007) responses in the KRM-20 arm significantly increased after treatment. The addition of KRM-20 did not increase toxicity. There were no between-group differences in progression-free or overall survival (OS). The addition of KRM-20 was safe, and similar PSA decline and HLA-matched peptide-specific CTL and IgG responses increased in combination with docetaxel and dexamethasone in CRPC patients. Subgroup analysis suggested that this treatment is favorable for CRPC patients with ≥ 26% lymphocytes or PSA levels of < 11.2 ng/ml, but further clinical trials comparing OS are required.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Vacinas Anticâncer/administração & dosagem , Calicreínas/sangue , Antígeno Prostático Específico/sangue , Neoplasias de Próstata Resistentes à Castração/terapia , Linfócitos T Citotóxicos/imunologia , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Vacinas Anticâncer/efeitos adversos , Vacinas Anticâncer/imunologia , Terapia Combinada/efeitos adversos , Terapia Combinada/métodos , Dexametasona/administração & dosagem , Dexametasona/efeitos adversos , Docetaxel/administração & dosagem , Docetaxel/efeitos adversos , Método Duplo-Cego , Esquema de Medicação , Humanos , Infusões Intravenosas , Injeções Subcutâneas , Masculino , Pessoa de Meia-Idade , Intervalo Livre de Progressão , Neoplasias de Próstata Resistentes à Castração/sangue , Neoplasias de Próstata Resistentes à Castração/imunologia , Neoplasias de Próstata Resistentes à Castração/mortalidade , Critérios de Avaliação de Resposta em Tumores Sólidos , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/efeitos adversos , Vacinas de Subunidades/imunologia
15.
Infect Immun ; 88(2)2020 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-31740525

RESUMO

Despite promising progress in malaria vaccine development in recent years, an efficacious subunit vaccine against Plasmodium falciparum remains to be licensed and deployed. Cell-mediated protection from liver-stage malaria relies on a sufficient number of antigen-specific T cells reaching the liver during the time that parasites are present. A single vaccine expressing two antigens could potentially increase both the size and breadth of the antigen-specific response while halving vaccine production costs. In this study, we investigated combining two liver-stage antigens, P. falciparum LSA1 (PfLSA1) and PfLSAP2, and investigated the induction of protective efficacy by coadministration of single-antigen vectors or vaccination with dual-antigen vectors, using simian adenovirus and modified vaccinia virus Ankara vectors. The efficacy of these vaccines was assessed in mouse malaria challenge models using chimeric P. berghei parasites expressing the relevant P. falciparum antigens and challenging mice at the peak of the T cell response. Vaccination with a combination of the single-antigen vectors expressing PfLSA1 or PfLSAP2 was shown to improve protective efficacy compared to vaccination with each single-antigen vector alone. Vaccination with dual-antigen vectors expressing both PfLSA1 and PfLSAP2 resulted in responses to both antigens, particularly in outbred mice, and most importantly, the efficacy was equivalent to that of vaccination with a mixture of single-antigen vectors. Based on these promising data, dual-antigen vectors expressing PfLSA1 and PfLSAP2 will now proceed to manufacturing and clinical assessment under good manufacturing practice (GMP) guidelines.


Assuntos
Adenovirus dos Símios/genética , Antígenos de Protozoários/imunologia , Portadores de Fármacos , Vacinas Antimaláricas/imunologia , Malária/prevenção & controle , Proteínas Recombinantes de Fusão/imunologia , Vírus Vaccinia/genética , Animais , Antígenos de Protozoários/genética , Modelos Animais de Doenças , Feminino , Humanos , Imunidade Celular , Vacinas Antimaláricas/administração & dosagem , Vacinas Antimaláricas/genética , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos ICR , Proteínas Recombinantes de Fusão/genética , Resultado do Tratamento , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/genética , Vacinas de Subunidades/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia
16.
BMC Vet Res ; 15(1): 448, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31823789

RESUMO

BACKGROUND: Streptococcus suis is a major swine pathogen causing arthritis, meningitis and sudden death in post-weaning piglets and is also a zoonotic agent. S. suis comprises 35 different serotypes of which the serotype 2 is the most prevalent in both pigs and humans. In the absence of commercial vaccines, bacterins (mostly autogenous), are used in the field, with controversial results. In the past years, the focus has turned towards the development of sub-unit vaccine candidates. However, published results are sometimes contradictory regarding the protective effect of a same candidate. Moreover, the adjuvant used may significantly influence the protective capacity of a given antigen. This study focused on two protective candidates, the dipeptidyl peptidase IV (DPPIV) and the enolase (SsEno). Both proteins are involved in S. suis pathogenesis, and while contradictory protection results have been obtained with SsEno in the past, no data on the protective capacity of DPPIV was available. RESULTS: Results showed that among all the field strains tested, 86 and 88% were positive for the expression of the SsEno and DPPIV proteins, respectively, suggesting that they are widely expressed by strains of different serotypes. However, no protection was obtained after two vaccine doses in a CD-1 mouse model of infection, regardless of the use of four different adjuvants. Even though no protection was obtained, significant amounts of antibodies were produced against both antigens, and this regardless of the adjuvant used. CONCLUSIONS: Taken together, these results demonstrate that S. suis DPPIV and SsEno are probably not good vaccine candidates, at least not in the conditions evaluated in this study. Further studies in the natural host (pig) should still be carried out. Moreover, this work highlights the importance of confirming results obtained by different research groups.


Assuntos
Dipeptidil Peptidase 4 , Fosfopiruvato Hidratase , Streptococcus suis/imunologia , Vacinas de Subunidades/farmacologia , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/farmacologia , Animais , Anticorpos Antibacterianos , Modelos Animais de Doenças , Camundongos , Subunidades Proteicas/farmacologia , Infecções Estreptocócicas/imunologia , Vacinas Estreptocócicas/imunologia , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/imunologia
17.
Nat Commun ; 10(1): 5758, 2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31848332

RESUMO

The anti-VEGF antibody bevacizumab has shown efficacy for the treatment of neurofibromatosis type 2 (NF2). Theoretically, vascular endothelial growth factor receptors (VEGFRs)-specific cytotoxic T lymphocytes (CTLs) can kill both tumor vessel cells and tumor cells expressing VEGFRs. Here we show an exploratory clinical study of VEGFRs peptide vaccine in seven patients with progressive NF2-derived schwannomas. Hearing improves in 2/5 assessable patients (40%) as determined by international guidelines, with increases in word recognition scores. Tumor volume reductions of ≥20% are observed in two patients, including one in which bevacizumab had not been effective. There are no severe adverse events related to the vaccine. Both VEGFR1-specific and VEGFR2-specific CTLs are induced in six patients. Surgery is performed after vaccination in two patients, and significant reductions in the expression of VEGFRs in schwannomas are observed. Therefore, this clinical immunotherapy study demonstrates the safety and preliminary efficacy of VEGFRs peptide vaccination in patients with NF2.


Assuntos
Neoplasias Encefálicas/terapia , Vacinas Anticâncer/administração & dosagem , Neurofibromatose 2/terapia , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/imunologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/imunologia , Adolescente , Adulto , Bevacizumab/uso terapêutico , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Encéfalo/cirurgia , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/patologia , Vacinas Anticâncer/efeitos adversos , Vacinas Anticâncer/imunologia , Terapia Combinada/efeitos adversos , Terapia Combinada/métodos , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Neurofibromatose 2/imunologia , Neurofibromatose 2/patologia , Radiocirurgia , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Carga Tumoral/imunologia , Vacinação/efeitos adversos , Vacinação/métodos , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/efeitos adversos , Vacinas de Subunidades/imunologia , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Adulto Jovem
18.
PLoS One ; 14(11): e0224309, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31693710

RESUMO

In recent years, vaccines against tumor antigens have shown potential for combating invasive cancers, including primary tumors and metastatic lesions. This is particularly pertinent for breast cancer, which is the second-leading cause of cancer-related death in women. MUC1 is a glycoprotein that is normally expressed on glandular epithelium, but is overexpressed and under-glycosylated in most human cancers, including the majority of breast cancers. This under-glycosylation exposes the MUC1 protein core on the tumor-associated form of the protein. We have previously shown that a vaccine consisting of MUC1 core peptides stimulates a tumor-specific immune response. However, this immune response is dampened by the immunosuppressive microenvironment within breast tumors. Thus, in the present study, we investigated the effectiveness of MUC1 vaccination in combination with four different drugs that inhibit different components of the COX pathway: indomethacin (COX-1 and COX-2 inhibitor), celecoxib (COX-2 inhibitor), 1-methyl tryptophan (indoleamine 2,3 dioxygenase inhibitor), and AH6809 (prostaglandin E2 receptor antagonist). These treatment regimens were explored for the treatment of orthotopic MUC1-expressing breast tumors in mice transgenic for human MUC1. We found that the combination of vaccine and indomethacin resulted in a significant reduction in tumor burden. Indomethacin did not increase tumor-specific immune responses over vaccine alone, but rather appeared to reduce the proliferation and increase apoptosis of tumor cells, thus rendering them susceptible to immune cell killing.


Assuntos
Neoplasias da Mama/terapia , Vacinas Anticâncer/administração & dosagem , Inibidores de Ciclo-Oxigenase/administração & dosagem , Indometacina/administração & dosagem , Neoplasias Mamárias Experimentais/terapia , Mucina-1/imunologia , Animais , Neoplasias da Mama/imunologia , Vacinas Anticâncer/imunologia , Terapia Combinada/métodos , Feminino , Humanos , Imunogenicidade da Vacina/efeitos dos fármacos , Imunogenicidade da Vacina/imunologia , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/imunologia , Camundongos , Camundongos Transgênicos , Mucina-1/genética , Carga Tumoral/efeitos dos fármacos , Carga Tumoral/imunologia , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologia , Vacinas de Subunidades/administração & dosagem , Vacinas de Subunidades/imunologia
19.
Artigo em Inglês | MEDLINE | ID: mdl-31739554

RESUMO

The effects of immunization with subunit inactivated quadrivalent influenza vaccine (QIV) are not generally well assessed in the elderly Polish population. Therefore, this study evaluated vaccine-induced antibody response and its determinants. METHODS: Consecutive patients ≥ 55 years old, attending a Primary Care Clinic in Gryfino, Poland, received QIV (A/Michigan/ 45/2015(H1N1)pdm09, A/Singapore/INFIMH-16-0019/2016 (H3N2), B/Colorado/06/2017, B/Phuket/ 3073/2013) between October-December 2018. Hemagglutination inhibition assays measured antibody response to vaccine strains from pre/postvaccination serum samples. Geometric mean titer ratio (GMTR), protection rate (PR) and seroconversion rate (SR) were also calculated. RESULTS: For 108 patients (54.6% males, mean age: 66.7 years) the highest GMTR (61.5-fold) was observed for A/H3N2/, then B/Colorado/06/2017 (10.3-fold), A/H1N1/pdm09 (8.4-fold) and B/Phuket/ 3073/2013 (3.0-fold). Most patients had post-vaccination protection for A/H3N2/ and B/Phuket/3073/ 2013 (64.8% and 70.4%, respectively); lower PRs were observed for A/H1N1/pdm09 (41.8%) and B/Colorado/06/ 2017 (57.4%). The SRs for A/H3N2/, A/H1N1/pdm09, B Victoria and B Yamagata were 64.8%, 38.0%, 46.8%, and 48.2%, respectively. Patients who received QIV vaccination in the previous season presented lower (p < 0.001 and p = 0.03, respectively) response to B Victoria and B Yamagata. CONCLUSIONS: QIV was immunogenic against the additional B lineage strain (B Victoria) without significantly compromising the immunogenicity of the other three vaccine strains, therefore, adding a second B lineage strain in QIV could broaden protection against influenza B infection in this age group. As the QIV immunogenicity differed regarding the four antigens, formulation adjustments to increase the antigen concentration of the serotypes that have lower immunogenicity could increase effectiveness. Prior season vaccination was associated with lower antibody response to a new vaccine, although not consistent through the vaccine strains.


Assuntos
Anticorpos Antivirais/sangue , Vírus da Influenza A Subtipo H1N1/imunologia , Vírus da Influenza A Subtipo H3N2/imunologia , Vírus da Influenza B/imunologia , Vacinas contra Influenza/administração & dosagem , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Subunidades/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Feminino , Testes de Inibição da Hemaglutinação , Humanos , Influenza Humana/prevenção & controle , Masculino , Pessoa de Meia-Idade , Polônia
20.
Fish Shellfish Immunol ; 94: 723-729, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31580933

RESUMO

Photobacteriosis caused by Photobacterium damselae subsp. piscicida (Pdp) remains one of the main infectious diseases affecting cultured fish in Mediterranean countries. Diverse vaccine formulations based in the use of inactivated bacterial cells have been used with unsatisfactory results, especially in newly cultured species like sole (Solea senegalensis). In this work, we describe the use of the outer membrane receptor (FrpA) of the siderophore piscibactin produced by Pdp as a novel subunit vaccine against photobacteriosis. FrpA has been cloned and expressed in Escherichia coli under an arabinose-inducible promoter. A recombinant protein (rFrpA) containing the pelB localization signal and a His tag was constructed to obtain a pure native form of the protein from E. coli outer membranes. The immunogenicity of rFrpA, and its protective effect against photobacteriosis, was tested by i.p. injection of 30  µg of the protein, mixed with Freund's adjuvant, in sole fingerlings with two immunizations separated by 30 days. Results showed that using either pure rFrpA or whole cells as immobilized antigens in ELISA assays, rFrpA induces the production of specific antibodies in sole. An experimental infection using fish vaccinated with rFrpA or formalin-killed whole cells of Pdp showed that both groups were protected against Pdp infection at similar levels, with no significant differences, reaching RPS values of 73% and 79%, respectively. Thus, FrpA constitutes a promising antigen candidate for the development of novel more effective vaccines against fish photobacteriosis.


Assuntos
Proteínas da Membrana Bacteriana Externa/imunologia , Vacinas Bacterianas/administração & dosagem , Doenças dos Peixes/prevenção & controle , Infecções por Bactérias Gram-Negativas/veterinária , Photobacterium/imunologia , Animais , Linguados , Infecções por Bactérias Gram-Negativas/prevenção & controle , Receptores de Superfície Celular/imunologia , Vacinas de Subunidades/administração & dosagem
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