RESUMEN

Rotavirus, a dsRNA virus in the Reoviridae family, shows a segmented genome. The VP1 gene encodes the RNA-dependent RNA polymerase (RdRp). This study aims to develop a multiepitope-based vaccine targeting RdRp using immunoinformatic approaches. In this study, 100 available nucleotide sequences of VP1-Rotavirus belonging to different strains across the world were retrieved from NCBI database. The selected sequences were aligned, and a global consensus sequence was developed by using CLC work bench. The study involved immunoinformatic approaches and molecular docking studies to reveal the promiscuous epitopes that can be eventually used as active vaccine candidates for Rotavirus. In total, 27 highly immunogenic, antigenic, and non-allergenic T-cell and B-cell epitopes were predicted for the Multiepitope vaccine (MEV) against rotavirus. It was also observed that MEV can prove to be effective worldwide due to its high population coverage, demonstrating the consistency of this vaccine. Moreover, there is a high docking interaction and immunological response with a binding score of -50.2 kcal/mol, suggesting the vaccine's efficacy. Toll-like receptors (TLRs) also suggest that the vaccine is physiologically and immunologically effective. Collectively, our data point to an effective MEV against rotavirus that can effectively reduce viral infections and improve the health status worldwide.

Asunto(s)

Simulación del Acoplamiento Molecular , Vacunas contra Rotavirus , Rotavirus , Vacunas de Subunidad , Rotavirus/inmunología , Rotavirus/genética , Vacunas de Subunidad/inmunología , Vacunas de Subunidad/genética , Vacunas contra Rotavirus/inmunología , ARN Polimerasa Dependiente del ARN/inmunología , ARN Polimerasa Dependiente del ARN/genética , ARN Polimerasa Dependiente del ARN/química , Biología Computacional , Epítopos de Linfocito T/inmunología , Epítopos de Linfocito T/genética , Humanos , Epítopos/inmunología , Epítopos/genética , Epítopos de Linfocito B/inmunología , Epítopos de Linfocito B/genética , Infecciones por Rotavirus/prevención & control , Infecciones por Rotavirus/inmunología , Inmunoinformática , Vacunas de Subunidades Proteicas

RESUMEN

Salmonella Typhimurium is the most prevalent non-host specific Salmonella serovars and a major concern for both human and animal health systems worldwide contributing to significant economic loss. Type 3 secretion system (T3SS) of Salmonella plays an important role in bacterial adherence and entry into the host epithelial cells. The product of invH gene of Salmonella is an important component of the needle complex of the type 3 secretion system. Hence, the present study was undertaken to clone and express the 15 kDa InvH surface protein of Salmonella Typhimurium in an E. coli host and to evaluate its immune potency in mice. The purified recombinant InvH (r-InvH) protein provoked a significant (p < 0.01) rise in IgG in the inoculated mice. The immunized mice were completely (100%) protected against the challenge dose of 107.5 LD50, while protection against challenge with the same dose of heterologous serovars was 90%. The bacterin-vaccinated group showed homologous protection of 60% against all three serovars. Findings in this study suggest the potential of the r-InvH protein of S. Typhimurium as an effective vaccine candidate against Salmonella infections.

Asunto(s)

Intoxicación Alimentaria por Salmonella , Salmonelosis Animal , Infecciones por Salmonella , Animales , Ratones , Humanos , Salmonella typhimurium/genética , Salmonella typhimurium/metabolismo , Sistemas de Secreción Tipo III/metabolismo , Escherichia coli/genética , Proteínas Bacterianas/metabolismo , Infecciones por Salmonella/prevención & control , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Vacunas de Subunidad/genética , Vacunas de Subunidad/metabolismo , Salmonelosis Animal/microbiología , Vacunas Atenuadas

RESUMEN

The Zika Virus (ZIKV) is an emerging arbovirus of great public health concern, particularly in the Americas after its last outbreak in 2015. There are still major challenges regarding disease control, and there is no ZIKV vaccine currently approved for human use. Among many different vaccine platforms currently under study, the recombinant envelope protein from Zika Virus (rEZIKV) constitutes an alternative option for vaccine development and has great potential for monitoring ZIKV infection and antibody response. This study describes a method to obtain a bioactive and functional rEZIKV using an E. coli expression system, with the aid of a 5-L airlift bioreactor and following an automated fast protein liquid chromatography (FPLC) protocol, capable of obtaining high yields of approximately 20 mg of recombinant protein per liter of bacterium cultures. The purified rEZIKV presented preserved antigenicity and immunogenicity. Our results show that the use of an airlift bioreactor for the production of rEZIKV is ideal for establishing protocols and further research on ZIKV vaccines bioprocess, representing a promising system for the production of a ZIKV envelope recombinant protein-based vaccine candidate.

Asunto(s)

Vacunas Virales , Infección por el Virus Zika , Virus Zika , Humanos , Virus Zika/genética , Proteínas del Envoltorio Viral/genética , Anticuerpos Neutralizantes , Escherichia coli , Anticuerpos Antivirales , Vacunas Virales/genética , Vacunas de Subunidad/genética , Proteínas Recombinantes/genética , Reactores Biológicos

RESUMEN

COVID-19 pandemic poses a serious threat to human health; it has completely disrupted global stability, making vaccine development an important goal to achieve. Monoclonal antibodies play an important role in subunit vaccines strategies. In this work, nine murine MAbs against the RBD of the SARS-CoV-2 spike protein were obtained by hybridoma technology. Characterization of purified antibodies demonstrated that five of them have affinities in the order of 108 L/mol. Six MAbs showed specific recognition of different recombinant RBD-S antigens in solution. Studies of the additivity index of anti-RBD antibodies, by using a novel procedure to determine the additivity cut point, showed recognition of at least five different epitopes. The MAbs CBSSRBD-S.11 and CBSSRBD-S.8 revealed significant neutralizing capacity against SARS-CoV-2 in an ACE2-RBD binding inhibition assay (IC50 = 85.5pM and IC50 = 122.7pM, respectively) and in a virus neutralizing test with intact SARS-CoV-2 (VN50 = 0.552 nM and VN50 = 4.854 nM, respectively) when D614G strain was used to infect Vero cells. Also CBSSRBD-S.11 neutralized the SARS-CoV-2 strains Alpha and Beta: VN50 = 0.707 nM and VN50 = 0.132 nM, respectively. The high affinity CBSSRBD-S.8 and CBSSRBD-S.7 recognized different epitopes, so they are suitable for the development of a sandwich ELISA to quantitate RBD-S recombinant antigens in biomanufacturing processes, as well as in pharmacokinetic studies in clinical and preclinical trials.

Asunto(s)

Anticuerpos Monoclonales/metabolismo , Vacunas contra la COVID-19/inmunología , COVID-19/diagnóstico , SARS-CoV-2/fisiología , Enzima Convertidora de Angiotensina 2/metabolismo , Animales , Anticuerpos Monoclonales/genética , COVID-19/inmunología , Vacunas contra la COVID-19/genética , Ensayos Clínicos como Asunto , Femenino , Ingeniería Genética , Humanos , Ratones , Ratones Endogámicos BALB C , Dominios y Motivos de Interacción de Proteínas/genética , Desarrollo de Vacunas , Vacunas de Subunidad/genética

RESUMEN

Haemophilus influenzae is a common organism of the human upper respiratory tract; this bacterium is responsible of a wide spectrum for respiratory infections and can generate invasive diseases such as meningitis and septicemia. These infections are associated with H. influenzae encapsulated serotype b. However, the incidence of invasive disease caused by nontypeable H. influenzae (NTHi) has increased in the post-H. influenzae serotype b (Hib) vaccine era. Currently, an effective vaccine against NTHi is not available; due to this, it is important to find an antigen capable to confer protection against NTHi infection. In this study, 10 linear B cell epitopes and 13 CTL epitopes and a putative plasminogen-binding motif (252FYNKENGMY260) and the presence of enolase on the surface of different strains of H. influenzae were identified in the enolase sequence of H. influenzae. Both in silico and experimental results showed that recombinant enolase from H. influenzae is immunogenic that could induce a humoral immune response; this was observed mediating the generation of specific polyclonal antibodies anti-rNTHiENO that recognize typeable and nontypeable H. influenzae strains. The immunogenic properties and the superficial localization of enolase in H. influenzae, important characteristics to be considered as a new candidate for the development of a vaccine, were demonstrated.

Asunto(s)

Proteínas Bacterianas/inmunología , Infecciones por Haemophilus/prevención & control , Vacunas contra Haemophilus/inmunología , Haemophilus influenzae/inmunología , Fosfopiruvato Hidratasa/inmunología , Infecciones del Sistema Respiratorio/prevención & control , Proteínas Bacterianas/genética , Proteínas Bacterianas/aislamiento & purificación , Clonación Molecular , Biología Computacional , Epítopos/genética , Epítopos/inmunología , Infecciones por Haemophilus/inmunología , Infecciones por Haemophilus/microbiología , Vacunas contra Haemophilus/genética , Vacunas contra Haemophilus/uso terapéutico , Haemophilus influenzae/enzimología , Haemophilus influenzae/genética , Humanos , Fosfopiruvato Hidratasa/genética , Fosfopiruvato Hidratasa/aislamiento & purificación , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/aislamiento & purificación , Infecciones del Sistema Respiratorio/inmunología , Infecciones del Sistema Respiratorio/microbiología , Desarrollo de Vacunas , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología , Vacunas de Subunidad/uso terapéutico

Asunto(s)

Linfocitos T CD8-positivos/inmunología , Infecciones por Virus Sincitial Respiratorio/inmunología , Vacunas contra Virus Sincitial Respiratorio/inmunología , Virus Sincitiales Respiratorios/fisiología , Adenoviridae/genética , Animales , Ensayos Clínicos como Asunto , Humanos , Inmunidad Celular , Inmunidad Humoral , Vacunas Atenuadas , Vacunas de Subunidad/genética , Vacunas Sintéticas/genética , Proteínas Virales de Fusión/genética

RESUMEN

Leptospirosis is a zoonosis of worldwide distribution, caused by infection with pathogenic Leptospira species. The vaccines that are currently available are bacterins, with limited human use, that confer short-term, serovar-specific immunity. Lig proteins are considered to be the best vaccine candidates to date. Here, we aimed to construct a recombinant Lig chimera (LC) comprised of LigAni and LigBrep fragments, and to evaluate it as subunit or DNA vaccine using different administration strategies. Vaccines were formulated with 50 µg of recombinant LC associated with different adjuvants or with 100 µg of pTARGET/LC. Four-week-old hamsters received two doses of vaccine with different strategies and were challenged with 5 × DL50Leptospira interrogans serovar Copenhageni strain Fiocruz L1-130. The immune response generated by Lig chimera conferred 100% protection to hamsters treated with at least one dose of recombinant LC. Despite the high levels of antibodies that vaccinated animals produced, a sterilizing immunity was not achieved. The lack of a sterilizing immunity could indicate the importance of a mixed humoral and cellular immune response. The present study generated insights that will be useful in the future development of improved subunit vaccines against leptospirosis.

Asunto(s)

Antígenos Bacterianos/inmunología , Vacunas Bacterianas/inmunología , Leptospira/inmunología , Leptospirosis/prevención & control , Proteínas Recombinantes de Fusión/inmunología , Vacunas de Subunidad/inmunología , Adyuvantes Inmunológicos , Animales , Anticuerpos Antibacterianos/inmunología , Antígenos Bacterianos/genética , Vacunas Bacterianas/genética , Células CHO , Cricetinae , Cricetulus , Expresión Génica , Humanos , Leptospira/genética , Leptospirosis/inmunología , Leptospirosis/microbiología , Leptospirosis/mortalidad , Proteínas Recombinantes de Fusión/genética , Vacunas de ADN , Vacunas de Subunidad/genética

RESUMEN

Plasmodium vivax Merozoite Surface Protein-9 (PvMSP-9) is a malaria vaccine candidate naturally immunogenic in humans and able to induce high antibody titers in animals when delivered as a recombinant protein. Recently, we identified the sequence EAAPENAEPVHENA (PvMSP9E795-A808) as the main linear B-cell epitope in naturally exposed individuals. However, the potential of PvMSP9E795-A808 as an immunogen in experimental animal models remained unexplored. Here we assess the immunogenicity of PvMSP9E795-A808 using synthetic peptides. The peptides tested in BALB/c mice include two repeats of the sequence EAAPENAEPVHENA tested alone (peptide RII), or linked to an autologous (PvMSP9 peptide pL; pLRII) or heterologous (p2 tetanus toxin universal T cell epitope; TTRII) T cell epitope. Immune responses were evaluated by ELISA, FLUOROSPOT, and indirect immunofluorescence. We show that all of the peptide constructs tested were immunogenic eliciting specific IgG antibodies at different levels, with a prevalence of IgG1 and IgG2. Animals immunized with synthetic peptides containing T cell epitopes (pLRII or TTRII) had more efficient antibody responses that resulted in higher antibody titers able to recognize the native protein by immunofluorescence. Relevantly, the frequency of IFN-γ secreting SFC elicited by immunization with TTRII synthetic peptide was comparable to that reported to the PvMSP9-Nt recombinant protein. Taken together, our study indicates that PvMSP9E795-A808 is highly immunogenic in mice and further studies to evaluate its value as promising vaccine target are warranted. Moreover, our study supports the critical role of CD4 T cell epitopes to enhance humoral responses induced by subunit based vaccines.

Asunto(s)

Epítopos de Linfocito B/inmunología , Inmunogenicidad Vacunal , Vacunas contra la Malaria/inmunología , Proteínas de la Membrana/inmunología , Péptidos/síntesis química , Proteínas Protozoarias/inmunología , Animales , Anticuerpos Antiprotozoarios/inmunología , Formación de Anticuerpos , Ensayo de Inmunoadsorción Enzimática , Femenino , Inmunoglobulina G/inmunología , Vacunas contra la Malaria/genética , Malaria Vivax/prevención & control , Proteínas de la Membrana/genética , Ratones Endogámicos BALB C , Péptidos/inmunología , Plasmodium vivax , Proteínas Protozoarias/genética , Proteínas Recombinantes/síntesis química , Proteínas Recombinantes/inmunología , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología

RESUMEN

Due to an increase in the incidence of leishmaniases worldwide, the development of new strategies such as prophylactic vaccines to prevent infection and decrease the disease have become a high priority. Classic vaccines against leishmaniases were based on live or attenuated parasites or their subunits. Nevertheless, the use of whole parasite or their subunits for vaccine production has numerous disadvantages. Therefore, the use of Leishmania peptides to design more specific vaccines against leishmaniases seems promising. Moreover, peptides have several benefits in comparison with other kinds of antigens, for instance, good stability, absence of potentially damaging materials, antigen low complexity, and low-cost to scale up. By contrast, peptides are poor immunogenic alone, and they need to be delivered correctly. In this context, several approaches described in this review are useful to solve these drawbacks. Approaches, such as, peptides in combination with potent adjuvants, cellular vaccinations, adenovirus, polyepitopes, or DNA vaccines have been used to develop peptide-based vaccines. Recent advancements in peptide vaccine design, chimeric, or polypeptide vaccines and nanovaccines based on particles attached or formulated with antigenic components or peptides have been increasingly employed to drive a specific immune response. In this review, we briefly summarize the old, current, and future stands on peptide-based vaccines, describing the disadvantages and benefits associated with them. We also propose possible approaches to overcome the related weaknesses of synthetic vaccines and suggest future guidelines for their development.

Asunto(s)

Vacunas contra la Leishmaniasis/inmunología , Leishmaniasis/prevención & control , Vacunas de Subunidad/inmunología , Adyuvantes Inmunológicos , Animales , Antígenos de Protozoos/inmunología , Ensayos Clínicos como Asunto , Humanos , Leishmaniasis/inmunología , Vacunas contra la Leishmaniasis/genética , Leishmaniasis Visceral/inmunología , Leishmaniasis Visceral/prevención & control , Ratones , Mapeo Peptídico , Vacunación , Vacunas de Subunidad/genética

RESUMEN

Our group has developed a subunit vaccine candidate against Dengue virus (DENV) based on two different viral regions, the domain III of the envelope protein and the capsid protein. The chimeric proteins for each serotype (DIIIC1-4), aggregated with the oligodeoxynucleotide 39 M, form the tetravalent formulation named Tetra DIIIC. Tetra DIIIC induces a protective immune response in mice when it is inoculated by intraperitoneal route. However, if children are the main targets for a DENV vaccine, then a needle-free route of administration should be attractive and advantageous. In this study, we evaluated for the first time, in vivo, a vaccine candidate against DENV based on recombinant proteins using the intranasal route. After three doses of Tetra DIIIC in mice, we measured the humoral immune response against the four DENV serotypes and the corresponding recombinant proteins. Moreover, the functionality of these antibodies was evaluated through a plaque reduction neutralization test. Finally, to assess the cellular immune response induced, we measured the IFN-γ-levels secreted by spleen cells after in vitro stimulation with DENV. The results presented in this study indicate that the intranasal immunization with Tetra DIIIC favors the generation of DENV-specific cell-mediated immunity. On the other hand, the immunization using intraperitoneal and intranasal routes, simultaneously, generate functional antibodies (anti-DIIIC and anti-DENV) and an in vitro response of IFN-γ secretion.

Asunto(s)

Virus del Dengue/inmunología , Vacunas Virales/administración & dosificación , Vacunas Virales/inmunología , Administración Intranasal , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Proteínas de la Cápside/inmunología , Ensayo de Inmunoadsorción Enzimática , Femenino , Interferón gamma/metabolismo , Leucocitos Mononucleares/inmunología , Ratones Endogámicos BALB C , Pruebas de Neutralización , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunología , Proteínas del Envoltorio Viral/inmunología , Ensayo de Placa Viral , Vacunas Virales/genética

RESUMEN

Streptococcus uberis is one of the most prevalent pathogens causing clinical and subclinical mastitis worldwide. Among bacterial factors involved in intramammary infections caused by this organism, S. uberis adhesion molecule (SUAM) is one of the main virulence factors identified. This molecule is involved in S. uberis internalization to mammary epithelial cells through lactoferrin (Lf) binding. The objective of this study was to evaluate SUAM properties as a potential subunit vaccine component for prevention of S. uberis mastitis. B epitope prediction analysis of SUAM sequence was used to identify potentially immunogenic regions. Since these regions were detected all along the gene, this criterion did not allow selecting a specific region as a potential immunogen. Hence, four fractions of SUAM (-1fr, 2fr, 3fr and 4fr), comprising most of the protein, were cloned and expressed. Every fraction elicited a humoral immune response in mice as predicted by bioinformatics analysis. SUAM-1fr generated antibodies with the highest recognition ability towards SUAM native protein. Moreover, antibodies against SUAM-1fr produced the highest proportion of internalization inhibition of S. uberis to mammary epithelial cells. In conclusion, SUAM immunogenic and functionally relevant regions were identified and allowed to propose SUAM-1fr as a potential candidate for a subunit vaccine for S. uberis mastitis prevention.

Asunto(s)

Adhesión Bacteriana/inmunología , Vacunas Bacterianas/inmunología , Mastitis/prevención & control , Streptococcus/inmunología , Secuencia de Aminoácidos , Animales , Anticuerpos Antibacterianos/sangre , Adhesión Bacteriana/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/inmunología , Vacunas Bacterianas/genética , Secuencia de Bases , Bovinos , ADN Bacteriano/genética , Células Epiteliales/inmunología , Células Epiteliales/microbiología , Femenino , Inmunoglobulina G/sangre , Lactoferrina/metabolismo , Ratones , Modelos Animales , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Infecciones Estreptocócicas/microbiología , Streptococcus/genética , Vacunas de Subunidad/biosíntesis , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología , Factores de Virulencia/genética

RESUMEN

BACKGROUND: Babesia bovis is a tick-transmitted protozoan hemoparasite and the causative agent of bovine babesiosis, a potential risk to more than 500 million cattle worldwide. The vaccines currently available are based on attenuated parasites, which are difficult to produce, and are only recommended for use in bovines under one year of age. When used in older animals, these vaccines may cause life-threatening clinical symptoms and eventually death. The development of a multi-subunit recombinant vaccine against B. bovis would be attractive from an economic standpoint and, most importantly, could be recommended for animals of any age. In the present study, recombinant ectodomains of MSA-2a1, MSA-2b and MSA-2c antigens were expressed in Pichia pastoris yeast as secreted soluble peptides. RESULTS: The antigens were purified to homogeneity, and biochemically and immunologically characterized. A vaccine formulation was obtained by emulsifying a mixture of the three peptides with the adjuvant Montanide ISA 720, which elicited high IgG antibody titers against each of the above antigens. IgG antibodies generated against each MSA-antigen recognized merozoites and significantly inhibited the invasion of bovine erythrocytes. Cellular immune responses were also detected, which were characterized by splenic and lymph node CD4+ T cells producing IFN-γ and TNF-α upon stimulation with the antigens MSA-2a1 or MSA-2c. CONCLUSIONS: These data strongly suggest the high protective potential of the presented formulation, and we propose that it could be tested in vaccination trials of bovines challenged with B. bovis.

Asunto(s)

Anticuerpos Antiprotozoarios/sangre , Antígenos de Protozoos/inmunología , Antígenos de Superficie/inmunología , Interferón gamma/metabolismo , Leucocitos Mononucleares/inmunología , Proteínas de la Membrana/inmunología , Proteínas Protozoarias/inmunología , Vacunas Antiprotozoos/inmunología , Adyuvantes Inmunológicos/administración & dosificación , Animales , Antígenos de Protozoos/genética , Antígenos de Superficie/genética , Bovinos , Manitol/administración & dosificación , Manitol/análogos & derivados , Proteínas de la Membrana/genética , Ácidos Oléicos/administración & dosificación , Proteínas Protozoarias/genética , Vacunas Antiprotozoos/administración & dosificación , Vacunas Antiprotozoos/genética , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunología

RESUMEN

Zika virus (ZIKV) is a flavivirus that is responsible for the current epidemic in Brazil and the Americas. ZIKV has been causally associated with fetal microcephaly, intrauterine growth restriction, and other birth defects in both humans and mice. The rapid development of a safe and effective ZIKV vaccine is a global health priority, but very little is currently known about ZIKV immunology and mechanisms of immune protection. Here we show that a single immunization with a plasmid DNA vaccine or a purified inactivated virus vaccine provides complete protection in susceptible mice against challenge with a strain of ZIKV involved in the outbreak in northeast Brazil. This ZIKV strain has recently been shown to cross the placenta and to induce fetal microcephaly and other congenital malformations in mice. We produced DNA vaccines expressing ZIKV pre-membrane and envelope (prM-Env), as well as a series of deletion mutants. The prM-Env DNA vaccine, but not the deletion mutants, afforded complete protection against ZIKV, as measured by absence of detectable viraemia following challenge, and protective efficacy correlated with Env-specific antibody titers. Adoptive transfer of purified IgG from vaccinated mice conferred passive protection, and depletion of CD4 and CD8 T lymphocytes in vaccinated mice did not abrogate this protection. These data demonstrate that protection against ZIKV challenge can be achieved by single-shot subunit and inactivated virus vaccines in mice and that Env-specific antibody titers represent key immunologic correlates of protection. Our findings suggest that the development of a ZIKV vaccine for humans is likely to be achievable.

Asunto(s)

Vacunas Virales/inmunología , Infección por el Virus Zika/prevención & control , Infección por el Virus Zika/virología , Virus Zika/inmunología , Traslado Adoptivo , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Especificidad de Anticuerpos , Brasil , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Femenino , Eliminación de Gen , Humanos , Inmunoglobulina G/inmunología , Inmunoglobulina G/aislamiento & purificación , Ratones , Microcefalia/complicaciones , Microcefalia/virología , Vacunas de ADN/química , Vacunas de ADN/genética , Vacunas de ADN/inmunología , Vacunas de Productos Inactivados/química , Vacunas de Productos Inactivados/genética , Vacunas de Productos Inactivados/inmunología , Vacunas de Subunidad/química , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología , Proteínas del Envoltorio Viral/química , Proteínas del Envoltorio Viral/genética , Proteínas del Envoltorio Viral/inmunología , Vacunas Virales/química , Vacunas Virales/genética , Virus Zika/química , Virus Zika/genética , Infección por el Virus Zika/complicaciones , Infección por el Virus Zika/inmunología

RESUMEN

Dengue is the most important arbovirus disease throughout the world and it is responsible for more than 500,000 dengue hemorrhagic cases and 22,000 deaths every year. One vaccine was recently licensed for human use in Brazil, Mexico and Philippines and although at least seven candidates have been in clinical trials the results of the most developed CYD vaccine have demonstrated immunization problems, such as uneven protection and interference between serotypes. We constructed a vaccine candidate based on vesicular stomatitis virus (VSV) expression of pre-membrane (prM) and envelope (E) proteins of dengue-2 virus (DENV-2) and tested it in mice to evaluate immunogenicity and protection against DENV-2 infection. VSV has been successfully used as vaccine vectors for several viruses to induce strong humoral and cellular immune responses. The VSV-DENV-2 recombinant was constructed by inserting the DENV-2 structural proteins into a VSV plasmid DNA for recombinant VSV-DENV-2 recovery. Infectious recombinant VSV viruses were plaque purified and prM and E expression were confirmed by immunofluorescence and radiolabeling of proteins of infected cells. Forty Balb/C mice were inoculated through subcutaneous (s.c.) route with VSV-DENV-2 vaccine in a two doses schedule 15 d apart and 29 d after first inoculation, sera were collected and the mice were challenged with 50 lethal doses (LD50) of a neurovirulent DENV-2. The VSV-DENV-2 induced anti-DENV-2 antibodies and protected animals in the challenge experiment comparable to DENV-2 immunization control group. We conclude that VSV is a promising platform to test as a DENV vaccine and perhaps against others Flaviviridae.

Asunto(s)

Vacunas contra el Dengue/inmunología , Virus del Dengue/inmunología , Dengue/prevención & control , Portadores de Fármacos , Vectores Genéticos , Vesiculovirus/genética , Animales , Anticuerpos Antivirales/sangre , Vacunas contra el Dengue/administración & dosificación , Vacunas contra el Dengue/genética , Virus del Dengue/genética , Modelos Animales de Enfermedad , Leucocitos Mononucleares/inmunología , Ratones Endogámicos BALB C , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunología , Proteínas Estructurales Virales/genética , Proteínas Estructurales Virales/inmunología

RESUMEN

Leptospirosis is a global zoonotic disease caused by different Leptospira species, such as Leptospira interrogans, that colonize the renal tubules of wild and domestic animals. Thus far, attempts to develop effective leptospirosis vaccines, both for humans and animals, have failed to induce immune responses capable of conferring protection and simultaneously preventing renal colonization. In this study, we evaluated the protective immunity induced by subunit vaccines containing seven different recombinant Leptospira interrogans outer membrane proteins, including the carboxy-terminal portion of the immunoglobulinlike protein A (LigA(C)) and six novel antigens, combined with aluminum hydroxide (alum) or Salmonella flagellin (FliC) as adjuvants. Hamsters vaccinated with the different formulations elicited high antigen-specific antibody titers. Immunization with LigA(C), either with alum or flagellin, conferred protective immunity but did not prevent renal colonization. Similarly, animals immunized with LigA(C) or LigA(C) coadministered with six leptospiral proteins with alum adjuvant conferred protection but did not reduce renal colonization. In contrast, immunizing animals with the pool of seven antigens in combination with flagellin conferred protection and significantly reduced renal colonization by the pathogen. The present study emphasizes the relevance of antigen composition and added adjuvant in the efficacy of antileptospirosis subunit vaccines and shows the complex relationship between immune responses and renal colonization by the pathogen.

Asunto(s)

Adyuvantes Inmunológicos/administración & dosificación , Proteínas de la Membrana Bacteriana Externa/inmunología , Vacunas Bacterianas/inmunología , Flagelina/administración & dosificación , Leptospira interrogans/inmunología , Leptospirosis/prevención & control , Hidróxido de Aluminio/administración & dosificación , Animales , Anticuerpos Antibacterianos/sangre , Proteínas de la Membrana Bacteriana Externa/genética , Vacunas Bacterianas/administración & dosificación , Vacunas Bacterianas/genética , Inmunoglobulina G/sangre , Riñón/microbiología , Leptospira interrogans/genética , Leptospirosis/inmunología , Masculino , Mesocricetus , Análisis de Supervivencia , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunología

RESUMEN

This review provides an outlook of the medical applications of immunomodulatory compounds taken from Pleurotus and proposes this fungus as a convenient host for the development of innovative vaccines. Although some fungal species, such as Saccharomyces and Pichia, occupy a relevant position in the biopharmaceutical field, these systems are essentially limited to the production of conventional expensive vaccines. Formulations made with minimally processed biomass constitute the ideal approach for developing low cost vaccines, which are urgently needed by low-income populations. The use of edible fungi has not been explored for the production and delivery of low cost vaccines, despite these organisms' attractive features. These include the fact that edible biomass can be produced at low costs in a short period of time, its high biosynthetic capacity, its production of immunomodulatory compounds, and the availability of genetic transformation methods. Perspectives associated to this biotechnological application are identified and discussed.

Asunto(s)

Biotecnología/métodos , Pleurotus/metabolismo , Tecnología Farmacéutica/métodos , Vacunas Comestibles/metabolismo , Vacunas de Subunidad/metabolismo , Vacunas Sintéticas/metabolismo , Humanos , Pleurotus/genética , Vacunas Comestibles/genética , Vacunas de Subunidad/genética , Vacunas Sintéticas/genética

RESUMEN

Subunit recombinant vaccines against classical swine fever virus (CSFV) are a promising alternative to overcome practical and biosafety issues with inactivated vaccines. One of the strategies in evaluation under field conditions is the use of a new marker E2-based vaccine produced in the milk of adenovirally transduced goats. Previously we had demonstrated the efficacy of this antigen, which conferred early protection and long-lasting immunity in swine against CSFV infection. Here, we have used a simpler downstream process to obtain and formulate the recombinant E2 glycoprotein expressed in the mammary gland. The expression levels reached approximately 1.7 mg/ml, and instead of chromatographic separation of the antigen, we utilized a clarification process that eliminates the fat content, retains a minor amount of caseins, and includes an adenoviral inactivation step that improves the biosafety of the final formulation. In a vaccination and challenge experiment in swine, different doses of the E2 antigen contained within the clarified whey generated an effective immune response of neutralizing antibodies that protected all of the animals against a lethal challenge with CSFV. During the immunization and after challenge, the swine were monitored for adverse reactions related to the vaccine or symptoms of CSF, respectively. No adverse reactions or clinical signs of disease were observed in vaccinated animals, in which no replication of CSFV could be detected after challenge. Overall, we consider that the simplicity of the procedures proposed here is a further step toward the introduction and implementation of a commercial subunit vaccine against CSF.

Asunto(s)

Anticuerpos Antivirales/inmunología , Virus de la Fiebre Porcina Clásica/inmunología , Peste Porcina Clásica/prevención & control , Proteínas del Envoltorio Viral/inmunología , Vacunas Virales/inmunología , Animales , Anticuerpos Neutralizantes/inmunología , Femenino , Cabras , Porcinos , Vacunación , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunología , Proteínas del Envoltorio Viral/genética , Vacunas Virales/genética , Proteína de Suero de Leche

RESUMEN

Chagas disease is a leading cause of heart disease affecting approximately 10 million people in Latin America and elsewhere worldwide. The two major drugs available for the treatment of Chagas disease have limited efficacy in Trypanosoma cruzi-infected adults with indeterminate (patients who have seroconverted but do not yet show signs or symptoms) and determinate (patients who have both seroconverted and have clinical disease) status; they require prolonged treatment courses and are poorly tolerated and expensive. As an alternative to chemotherapy, an injectable therapeutic Chagas disease vaccine is under development to prevent or delay Chagasic cardiomyopathy in patients with indeterminate or determinate status. The bivalent vaccine will be comprised of two recombinant T. cruzi antigens, Tc24 and TSA-1, formulated on alum together with the Toll-like receptor 4 agonist, E6020. Proof-of-concept for the efficacy of these antigens was obtained in preclinical testing at the Autonomous University of Yucatan. Here the authors discuss the potential for a therapeutic Chagas vaccine as well as the progress made towards such a vaccine, and the authors articulate a roadmap for the development of the vaccine as planned by the nonprofit Sabin Vaccine Institute Product Development Partnership and Texas Children's Hospital Center for Vaccine Development in collaboration with an international consortium of academic and industrial partners in Mexico, Germany, Japan, and the USA.

Asunto(s)

Enfermedad de Chagas/inmunología , Enfermedad de Chagas/terapia , Vacunas Antiprotozoos/inmunología , Adyuvantes Inmunológicos/administración & dosificación , Compuestos de Alumbre/administración & dosificación , Animales , Humanos , Vacunas Antiprotozoos/administración & dosificación , Vacunas Antiprotozoos/genética , Vacunación/métodos , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunología

RESUMEN

Histophilus somni is an economically important pathogen of cattle and other ruminants and is considered one of the key components of the bovine respiratory disease (BRD) complex, the leading cause of economic loss in the livestock industry. BRD is a multifactorial syndrome, in which a triad of agents, including bacteria, viruses, and predisposing factors or "stressors," combines to induce disease. Although vaccines against H. somni have been used for many decades, traditional bacterins have failed to demonstrate effective protection in vaccinated animals. Hence, the BRD complex continues to produce strong adverse effects on the health and well-being of stock and feeder cattle. The generation of recombinant proteins may facilitate the development of more effective vaccines against H. somni, which could confer better protection against BRD. In the present study, primers were designed to amplify, clone, express, and purify two recombinant lipoproteins from H. somni, p31 (Plp4) and p40 (LppB), which are structural proteins of the outer bacterial membrane. The results presented here demonstrate, to our knowledge for the first time, that when formulated, an experimental vaccine enriched with these two recombinant lipoproteins generates high antibody titers in rabbits and sheep and exerts a protective effect in mice against septicemia induced by H. somni bacterial challenge.

Asunto(s)

Proteínas de la Membrana Bacteriana Externa/inmunología , Vacunas Bacterianas/inmunología , Lipoproteínas/inmunología , Infecciones por Pasteurellaceae/veterinaria , Pasteurellaceae/inmunología , Sepsis/veterinaria , Animales , Anticuerpos Antibacterianos/sangre , Proteínas de la Membrana Bacteriana Externa/genética , Proteínas de la Membrana Bacteriana Externa/aislamiento & purificación , Vacunas Bacterianas/administración & dosificación , Vacunas Bacterianas/genética , Bovinos , Clonación Molecular , Modelos Animales de Enfermedad , Expresión Génica , Lipoproteínas/genética , Lipoproteínas/aislamiento & purificación , Ratones , Infecciones por Pasteurellaceae/inmunología , Infecciones por Pasteurellaceae/prevención & control , Reacción en Cadena de la Polimerasa , Conejos , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/aislamiento & purificación , Sepsis/inmunología , Sepsis/prevención & control , Ovinos , Análisis de Supervivencia , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunología

RESUMEN

Pneumococcal surface protein A (PspA) is an important candidate for a vaccine against pneumococcal infections. DNA vaccines expressing PspA were shown to protect mice against intraperitoneal and colonization challenge models in mice. We now show that a DNA vaccine expressing PspA from clade 4 (pSec-pspA4Pro) is also able to elicit protection against an intranasal lethal challenge model at levels similar to the recombinant protein PspA4Pro adjuvanted with alum. PspA4Pro + alum induced an IgG response characterized by a high IgG1/IgG2a ratio, leading to a lack of binding of anti-PspA IgG2a antibodies to intact pneumococci in vitro, which is in contrast to the response elicited by pSec-pspA4Pro. Epitopes recognized by the sera were mapped and antibodies induced by immunization with PspA4Pro + alum showed positive reaction with several synthetic peptides, mostly located in the first half of the protein. On the other hand, antibodies induced by the DNA vaccine showed reactivity with only two peptides. Though both strategies were protective against the intranasal lethal challenge model, the elicited humoral responses differ significantly, with the detection of important differences in the Fc (IgG1/IgG2a ratios) and Fab (recognized epitopes) regions of the induced antibodies.

Asunto(s)

Anticuerpos Antibacterianos/sangre , Proteínas Bacterianas/inmunología , Infecciones Neumocócicas/prevención & control , Vacunas Neumococicas/inmunología , Vacunación/métodos , Vacunas de ADN/inmunología , Adyuvantes Inmunológicos/administración & dosificación , Compuestos de Alumbre/administración & dosificación , Animales , Proteínas Bacterianas/genética , Modelos Animales de Enfermedad , Mapeo Epitopo , Femenino , Inmunoglobulina G/sangre , Ratones , Ratones Endogámicos BALB C , Infecciones Neumocócicas/inmunología , Vacunas Neumococicas/administración & dosificación , Vacunas Neumococicas/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Análisis de Supervivencia , Vacunas de ADN/administración & dosificación , Vacunas de ADN/genética , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/genética , Vacunas Sintéticas/inmunología