RESUMEN

Vaccines are one of the most practical means to stop the spreading of Aeromonas veronii in aquaculture. In this study, virulence factor aerolysin mutant NTaer which has lost its hemolytic activity was used as a target antigen. Pichia pastoris constitutive secretory expression NTaer (GS115-NTaer) was used as a potential safe oral vaccine to evaluate its effectiveness on zebrafish immunity. The result shows that vaccination of GS115- NTaer for four weeks did not affect the growth performance of the host, while eliciting an effective immune protective response. Compared with the control group, the GS115-NTaer could significantly up-regulate the relative expression level of the intestinal tight junction protein 1α (TJP1α) gene, and significantly increased the contents of lysozyme (LYZ), complement C3 and C4 in the gut, indicating that the innate immune response of the fish was activated. The relative gene expression levels of macrophage-expressed gene 1 (MPEG1) and T cell receptor (TCR-α) in the gut, and MPEG1, CD4, CD8, TCR-α, GATA3, and T-bet in the spleen were all increased significantly, indicating that the cellular immune response of the fish was activated. Furthermore, the contents of serum IgM and intestinal mucosa IgZ antibodies were significantly increased, which showed that humoral immunity was also activated. Moreover, inoculation with GS115-NTaer significantly changed the structure of gut microbiota. In particular, the relative ratio of (Firmicutes + Fusobacteriota + Bacteroidota)/Proteobacteria was significantly higher than that of the control and GS115 groups. Lastly, the vaccinated fish were challenged with A. veronii, and the relative percent survival of GS115 and the GS115-NTear groups was 14.28% and 33.43%. This improvement of immunity was not only due to the specific immune response but also attributed to the improvement of innate immunity and the gut microbiota which was demonstrated by the germ-free zebrafish model. Collectively, this study provides information on the effectiveness of GS115-NTear as an oral vaccine for the green prevention and control of A. veronii infection in fish aquaculture.

RESUMEN

Conventional oral vaccine delivery in poultry is challenging due to vaccine degradation in the gastrointestinal (GI) environment and the need for cold-chain storage. Microencapsulation offers a solution by protecting vaccines from GI degradation and improving stability. Natural polymers like alginate and cashew gum have mucoadhesive properties, making them promising candidates for oral vaccine delivery. This study developed cashew-alginate microbeads and a powdered dose form for oral vaccine delivery in chickens. The microbeads were created using ionotropic gelation, while the powdered form was obtained via freeze-drying. These formulations were characterized for size, shape, and stability using scanning electron microscopy (SEM), light microscopy, X-ray diffraction (XRD), and Energy Dispersive X-ray (EDX). Peak adhesion time (PAT) was determined using chicken intestinal and esophageal tissues, and antigenicity was assessed with in-vitro hemagglutination (HA) and hemagglutination inhibition (HI) assays. The microbeads exhibited a spherical shape with a porous structure, suggesting enhanced antigen accommodation. Hemagglutination Inhibition tests indicated that the experimental vaccine remained effective without cold-chain storage for three months. These findings suggest that cashew-alginate microbeads are promising for oral vaccine delivery in poultry.

RESUMEN

Vaccination is the most effective method for preventing infectious diseases. Oral vaccinations have attracted much attention due to the ability to boost intestinal and systemic immunity. The focus of this study was to develop a poly (lactide-co-glycolide) acid (PLGA)-based ternary polyelectrolyte complex (PEC) with chitosan, sodium alginate, and transmembrane peptides R8 for the delivery of antigen proteins. In this study, the antigen protein (HBf), consisting of the Mycobacterium avium subspecies paratuberculosis (MAP) antigens HBHA, Ag85B, and Bfra, was combined with R8 to generate self-assembled conjugates. The results showed that PEC presented a cross-linked reticular structure to protect the encapsulated proteins in the simulated gastric fluid. Then, the nanocomposite separated into individual nanoparticles after entering the simulated intestinal fluid. The ternary PEC with R8 promoted the in vivo uptake of antigens by intestinal lymphoid tissue. Moreover, the ternary PEC administered orally to mice promoted the secretion of specific antibodies and intestinal mucosal IgA. In addition, in the mouse models of MAP infection, the ternary PEC enhanced splenic T cell responses, thus reducing bacterial load and liver pathology score. These results suggested that this ternary electrolyte complex could be a promising delivery platform for oral subunit vaccine candidates, not limited to MAP infection.

Asunto(s)

Alginatos , Quitosano , Inmunidad Mucosa , Quitosano/química , Alginatos/química , Animales , Inmunidad Mucosa/efectos de los fármacos , Ratones , Administración Oral , Polielectrolitos/química , Femenino , Ratones Endogámicos BALB C , Antígenos Bacterianos/inmunología , Antígenos Bacterianos/química , Vacunas Bacterianas/inmunología , Vacunas Bacterianas/administración & dosificación , Vacunas Bacterianas/química

RESUMEN

Avian influenza virus subtype H9N2 has the ability to infect birds and humans, further causing significant losses to the poultry industry and even posing a great threat to human health. Oral vaccine received particular interest for preventing majority infection due to its ability to elicit both mucosal and systemic immune responses, but their development is limited by the bad gastrointestinal (GI) environment, compact epithelium and mucus barrier, and the lack of effective mucosal adjuvants. Herein, we developed the dendritic fibrous nano-silica (DFNS) grafted with Cistanche deserticola polysaccharide (CDP) nanoparticles (CDP-DFNS) as an adjuvant for H9N2 vaccine. Encouragingly, CDP-DFNS facilitated the proliferation of T and B cells, and further induced the activation of T lymphocytes in vitro. Moreover, CDP-DFNS/H9N2 significantly promoted the antigen-specific antibodies levels in serum and intestinal mucosal of chickens, indicating the good ability to elicit both systemic and mucosal immunity. Additional, CDP-DFNS facilitate the activation of CD4 + and CD8 + T cells both in spleen and intestinal mucosal, and the indexes of immune organs. This study suggested that CDP-DFNS may be a new avenue for development of oral vaccine against pathogens that are transmitted via mucosal route.

Asunto(s)

Adyuvantes Inmunológicos , Pollos , Inmunidad Mucosa , Subtipo H9N2 del Virus de la Influenza A , Vacunas contra la Influenza , Gripe Aviar , Nanopartículas , Polisacáridos , Dióxido de Silicio , Animales , Subtipo H9N2 del Virus de la Influenza A/inmunología , Subtipo H9N2 del Virus de la Influenza A/efectos de los fármacos , Polisacáridos/administración & dosificación , Polisacáridos/farmacología , Polisacáridos/química , Polisacáridos/inmunología , Dióxido de Silicio/administración & dosificación , Dióxido de Silicio/química , Nanopartículas/administración & dosificación , Vacunas contra la Influenza/administración & dosificación , Vacunas contra la Influenza/inmunología , Inmunidad Mucosa/efectos de los fármacos , Gripe Aviar/prevención & control , Gripe Aviar/inmunología , Adyuvantes Inmunológicos/administración & dosificación , Adyuvantes Inmunológicos/farmacología , Administración Oral , Mucosa Intestinal/inmunología , Mucosa Intestinal/efectos de los fármacos , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología

RESUMEN

In the field of aquaculture, the enhancement of animal health and disease prevention is progressively being tackled using alternatives to antibiotics, including vaccines and probiotics. This study was designed to evaluate the potential of a recombinant Bacillus methylotrophicus, engineered to express the outer membrane channel protein TolC of Aeromonas hydrophila AH3 and the green fluorescent protein GFP, as an oral vaccine. Initially, the genes encoding tolC and GFP were cloned into a prokaryotic expression system, and anti-TolC mouse antiserum was generated. Subsequently, the tolC gene was subcloned into a modified pMDGFP plasmid, which was transformed into B. methylotrophicus WM-1 for protein expression. The recombinant B. methylotrophicus BmT was then administered to grass carp via co-feeding, and its efficacy as an oral vaccine was assessed. Our findings demonstrated successful expression of the 55 kDa TolC and 28 kDa GFP proteins, and the preparation of polyclonal antibodies with high specificity. The BmT exhibited stable expression of the GFP-TolC fusion protein and excellent genetic stability. Following oral immunization, significant elevations were observed in serum-specific IgM levels and the activities of acid phosphatase (ACP), alkaline phosphatase (AKP), superoxide dismutase (SOD), and lysozyme (LZM) in grass carp. Concurrently, significant upregulation of immune-related genes, including IFN-I, IL-10, IL-1ß, TNF-α, and IgT, was noted in the intestines, head kidney, and spleen of the grass carp. Colonization tests further revealed that the BmT persisted in the gut of immunized fish even after a fasting period of 7 days. Notably, oral administration of BmT enhanced the survival rate of grass carp following A. hydrophila infection. These results suggest that the oral BmT vaccine developed in this study holds promise for future applications in aquaculture.

Asunto(s)

Aeromonas hydrophila , Vacunas Bacterianas , Carpas , Enfermedades de los Peces , Infecciones por Bacterias Gramnegativas , Animales , Enfermedades de los Peces/inmunología , Enfermedades de los Peces/prevención & control , Carpas/inmunología , Vacunas Bacterianas/inmunología , Vacunas Bacterianas/administración & dosificación , Infecciones por Bacterias Gramnegativas/veterinaria , Infecciones por Bacterias Gramnegativas/prevención & control , Infecciones por Bacterias Gramnegativas/inmunología , Aeromonas hydrophila/inmunología , Administración Oral , Vacunación/veterinaria , Bacillus , Proteínas de la Membrana Bacteriana Externa/inmunología , Proteínas de la Membrana Bacteriana Externa/genética

RESUMEN

Functional M cells are differentiated by receptor activator of NF-κB ligand (RANKL) and capture of luminal antigens to initiate immune responses. We aimed to use postbiotic-based recombinant chicken RANKL (cRANKL) to promote M cell differentiation and test the efficacy of oral vaccines. Chicks were divided into three groups that were administered phosphate-buffered saline (PBS), cell extracts of wild-type Lactococcus lactis subsp. lactis IL1403 (WT_CE), or cell extracts of recombinant L. lactis expressing cRANKL (cRANKL_CE). The expression of the M cell marker was measured, and the gut microbiome was profiled. The efficiency of the infectious bursal disease (IBD) vaccine was tested after 12 consecutive days of administering cRANKL_CE. The chickens that were administered cRANKL_CE (p = 0.038) had significantly higher Annexin A5 (ANXA5) mRNA expression levels than those in the PBS group (PBS vs. WT_CE, p = 0.657). In the gut microbiome analysis, no significant changes were observed. However, the relative abundance of Escherichia-Shigella was negatively correlated (r = - 0.43, p = 0.019) with ANXA5 mRNA expression in Peyer's patches. cRANKL_CE/IBD (p = 0.018) had significantly higher IBD-specific faecal IgA levels than PBS/IBD (PBS/IBD vs. WT_CE/IBD, p = 0.217). Postbiotic-based recombinant cRANKL effectively improved the expression of M cell markers and the efficiency of oral vaccines. No significant changes were observed in the gut microbiome after administration of postbiotic-based recombinant cRANKL. This strategy can be used for the development of feed additives and adjuvants. KEY POINTS: • Postbiotic-based recombinant cRANKL enhanced the expression of ANXA5 in chicken. • The relative abundance of Escherichia-Shigella was negatively correlated with ANXA5 expression. • Postbiotic-based recombinant cRANKL effectively improved the efficiency of oral vaccine.

Asunto(s)

Pollos , Microbioma Gastrointestinal , Lactococcus lactis , Ligando RANK , Proteínas Recombinantes , Animales , Pollos/inmunología , Administración Oral , Lactococcus lactis/genética , Lactococcus lactis/metabolismo , Lactococcus lactis/inmunología , Ligando RANK/inmunología , Ligando RANK/genética , Ligando RANK/metabolismo , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/genética , Proteínas Recombinantes/administración & dosificación , Infecciones por Birnaviridae/prevención & control , Infecciones por Birnaviridae/inmunología , Infecciones por Birnaviridae/veterinaria , Enfermedades de las Aves de Corral/prevención & control , Enfermedades de las Aves de Corral/inmunología , Enfermedades de las Aves de Corral/microbiología , Virus de la Enfermedad Infecciosa de la Bolsa/inmunología , Virus de la Enfermedad Infecciosa de la Bolsa/genética , Diferenciación Celular , Ganglios Linfáticos Agregados/inmunología

RESUMEN

We previously established the selection-marker-free rice-based oral cholera vaccine (MucoRice-CTB) line 51A for human use by Agrobacterium-mediated co-transformation and conducted a double-blind, randomized, placebo-controlled phase I trial in Japan and the United States. Although MucoRice-CTB 51A was acceptably safe and well tolerated by healthy Japanese and U.S. subjects and induced CTB-specific antibodies neutralizing cholera toxin secreted by Vibrio cholerae, we were limited to a 6-g cohort in the U.S. trial because of insufficient production of MucoRice-CTB. Since MucoRice-CTB 51A did not grow in sunlight, we re-examined the previously established marker-free lines and selected MucoRice-CTB line 19A. Southern blot analysis of line 19A showed a single copy of the CTB gene. We resequenced the whole genome and detected the transgene in an intergenic region in chromosome 1. After establishing a master seed bank of MucoRice-CTB line 19A, we established a hydroponic production facility with LED lighting to reduce electricity consumption and to increase production capacity for clinical trials. Shotgun MS/MS proteomics analysis of MucoRice-CTB 19A showed low levels of α-amylase/trypsin inhibitor-like proteins (major rice allergens), which was consistent with the data for line 51A. We also demonstrated that MucoRice-CTB 19A had high oral immunogenicity and induced protective immunity against cholera toxin challenge in mice. These results indicate that MucoRice-CTB 19A is a suitable oral cholera vaccine candidate for Phase I and II clinical trials in humans, including a V. cholerae challenge study.

RESUMEN

Oral delivery of cells, such as probiotics and vaccines, has proved to be inefficient since cells are generally damaged in an acidic stomach prior to arrival at the intestine to exert their health benefits. In addition, short retention in the intestine is another obstacle which affects inefficiency. To overcome these obstacles, a cell-in-shell structure was designed with pH-responsive and mucoadhesive properties. The pH-responsive shell consisting of three cationic layers of chitosan and three anionic layers of trans-cinnamic acid (t-CA) was made via layer-by-layer (LbL) assembly. t-CA layers are hydrophobic and impermeable to protons in acid, thus enhancing cell gastric resistance in the stomach, while chitosan layers endow strong interaction between the cell surface and the mucosal wall which facilitates cell mucoadhesion in the intestine. Two model cells, probiotic L. rhamnosus GG and dead Streptococcus iniae, which serve as inactivated whole-cell vaccine were chosen to test the design. Increased survival and retention during oral administration were observed for coated cells as compared with naked cells. Partial removal of the coating (20-60% removal) after acid treatment indicates that the coated vaccine can expose its surface immunogenic protein after passage through the stomach, thus facilitating vaccine immune stimulation in the intestine. As a smart oral delivery platform, this design can be extended to various macromolecules, thus providing a promising strategy to formulate oral macromolecules in the prevention and treatment of diseases at a cellular level.

Asunto(s)

Quitosano , Animales , Administración Oral , Concentración de Iones de Hidrógeno , Quitosano/química , Probióticos/administración & dosificación , Probióticos/farmacología , Humanos , Ratones , Lacticaseibacillus rhamnosus , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efectos de los fármacos , Intestinos/efectos de los fármacos

RESUMEN

Porcine epidemic diarrhea (PED) caused by porcine epidemic diarrhea virus (PEDV), is an acute and highly infectious disease, resulting in substantial economic losses in the pig industry. Given that PEDV primarily infects the mucosal surfaces of the intestinal tract, it is crucial to improve the mucosal immunity to prevent viral invasion. Lactic acid bacteria (LAB) oral vaccines offer unique advantages and potential applications in combatting mucosal infectious diseases, making them an ideal approach for controlling PED outbreaks. However, traditional LAB oral vaccines use plasmids for exogenous protein expression and antibiotic genes as selection markers. Antibiotic genes can be diffused through transposition, transfer, or homologous recombination, resulting in the generation of drug-resistant strains. To overcome these issues, genome-editing technology has been developed to achieve gene expression in LAB genomes. In this study, we used the CRISPR-NCas9 system to integrate the PEDV S1 gene into the genome of alanine racemase-deficient Lactobacillus paracasei △Alr HLJ-27 (L. paracasei △Alr HLJ-27) at the thymidylate synthase (thyA) site, generating a strain, S1/△Alr HLJ-27. We conducted immunization assays in mice and piglets to evaluate the level of immune response and evaluated its protective effect against PEDV through challenge tests in piglets. Oral administration of the strain S1/△Alr HLJ-27 in mice and piglets elicited mucosal, humoral, and cellular immune responses. The strain also exhibited a certain level of resistance against PEDV infection in piglets. These results demonstrate the potential of S1/△Alr HLJ-27 as an oral vaccine candidate for PEDV control. KEY POINTS: • A strain S1/△Alr HLJ-27 was constructed as the candidate for an oral vaccine. • Immunogenicity response and challenge test was carried out to analyze the ability of the strain. • The strain S1/△Alr HLJ-27 could provide protection for piglets to a certain extent.

Asunto(s)

Virus de la Diarrea Epidémica Porcina , Vacunas Virales , Animales , Porcinos , Ratones , Anticuerpos Antivirales , Virus de la Diarrea Epidémica Porcina/genética , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Antibacterianos

RESUMEN

Enterotoxigenic Escherichia coli (ETEC) causes severe diarrhea in piglets. The current primary approach for ETEC prevention and control relies on antibiotics, as few effective vaccines are available. Consequently, an urgent clinical demand exists for developing an effective vaccine to combat this disease. Here, we utilized food-grade Lactococcus lactis NZ3900 and expression plasmid pNZ8149 as live vectors, together with the secreted expression peptide Usp45 and the cell wall non-covalent linking motif LysM, to effectively present the mutant LTA subunit, the LTB subunit of heat-labile enterotoxin, and the FaeG of F4 pilus on the surface of recombinant lactic acid bacteria (LAB). Combining three recombinant LAB as a live vector oral vaccine, we assessed its efficacy in preventing F4+ ETEC infection. The results demonstrate that oral immunization conferred effective protection against F4+ ETEC infection in mice and piglets lacking maternal antibodies during weaning. Sow immunization during late pregnancy generated significantly elevated antibodies in colostrum, which protected piglets against F4+ ETEC infection during lactation. Moreover, booster immunization on piglets during lactation significantly enhanced their resistance to F4+ ETEC infection during the weaning stage. This study highlights the efficacy of an oral LAB vaccine in preventing F4+ ETEC infection in piglets by combining the sow immunization and booster immunization of piglets, providing a promising vaccination strategy for future prevention and control of ETEC-induced diarrhea in piglets.

RESUMEN

Oral vaccines are a safe and convenient alternative to injected vaccines and have great potential to prevent major infectious diseases. However, the harsh gastrointestinal (GI) environment, mucus barriers, low immunogenicity, and lack of effective and safe mucosal adjuvants are the major challenges for oral vaccine delivery. In recent years, nanoparticle-based strategies have become attractive for improving oral vaccine delivery. Here, the dendritic fibrous nano-silica (DFNS) grafted with Cistanche deserticola polysaccharide (CDP) nanoparticles (CDP-DFNS) were prepared and investigated how to impact the immune responses. CDP-DFNS facilitated the antigen uptake in mouse bone marrow-derived dendritic cells (BMDCs), and induce the activation of DCs in vitro. Furthermore, in vivo experiments, the result showed that the uptake efficiency by Peyer's patches (PPs) of CDP-DFNS/BSA was the best. And CDP-DFNS/BSA then significantly activated the DCs in lamina propria (LP), and T/B cells in PPs and mesenteric lymph nodes (MLNs). Moreover, the memory T cell responses in later period of vaccination was stronger than other groups. In addition, CDP-DFNS/BSA enhanced BSA-specific antibody IgG, IgA production, and SIgA secretion, was effective at inducing a strong mixed Th1/Th2 response and mucosal antibody responses. These results indicated that CDP-DFNS deserves further consideration as an oral vaccine adjuvant delivery system.

Asunto(s)

Cistanche , Vacunas , Animales , Ratones , Adyuvantes de Vacunas , Dióxido de Silicio , Membrana Mucosa , Adyuvantes Inmunológicos/farmacología , Adyuvantes Farmacéuticos , Polisacáridos/farmacología , Inmunidad Mucosa

RESUMEN

BACKGROUND: This study aimed to evaluate the immunogenicity and safety of different types of poliovirus vaccines. METHODS: A randomized, blinded, single-center, parallel-controlled design was employed, and 360 infants aged ≥ 2 months were selected as study subjects. They were randomly assigned to bOPV group (oral Sabin vaccine) and sIPV group (Sabin strain inactivated polio vaccine), with 180 infants in each group. Adverse reaction events in the vaccinated subjects were recorded. The micro-neutralization test using cell culture was conducted to determine the geometric mean titer (GMT) of neutralizing antibodies against poliovirus types I, II, and III in different groups, and the seroconversion rates were calculated. RESULTS: Both groups exhibited a 100% seropositivity rate after booster immunization. The titers of neutralizing antibodies for the three types were predominantly distributed within the range of 1:128 to 1:512. The fold increase of type I antibodies differed markedly between the two groups (P < 0.05). Moreover, the fold increase of type II and type III antibodies for poliovirus differed slightly between the two groups (P > 0.05). The fourfold increase rate in sIPV group was drastically superior to that in bOPV group (P < 0.05). When comparing the post-immunization GMT levels of type I antibodies in individuals who completed the full course of spinal muscular atrophy vaccination, bOPV group showed greatly inferior levels to sIPV group (P < 0.05). For type II and type III antibodies, individuals in bOPV group demonstrated drastically superior post-immunization GMT levels to those in sIPV group (P < 0.05). The incidence of adverse reactions between the bOPV and sIPV groups differed slightly (P > 0.05). CONCLUSION: These findings indicated that both the oral vaccine and inactivated vaccine had good safety and immunogenicity in infants aged ≥ 2 months. The sIPV group generated higher levels of neutralizing antibodies in serum, particularly evident in the post-immunization GMT levels for types II and III.

Asunto(s)

Poliomielitis , Poliovirus , Humanos , Lactante , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Esquemas de Inmunización , Poliomielitis/prevención & control , Poliomielitis/inducido químicamente , Vacuna Antipolio Oral/efectos adversos , Observación

RESUMEN

Micropterus salmoides rhabdovirus (MSRV) is one of the main pathogens of largemouth bass, leading to serious economic losses. The G protein, as the only envelope protein present on the surface of MSRV virion, contains immune-related antigenic determinants, thereby becoming the primary target for the design of MSRV vaccines. Here, we displayed the G protein on the surface of yeast cells (named EBY100/pYD1-G) and conducted a preliminary assessment of the protective efficacy of the recombinant yeast vaccine. Upon oral vaccination, a robust immune response was observed in systemic and mucosal tissue. Remarkably, following the MSRV challenge, the relative percent survival of EBY100/pYD1-G treated largemouth bass significantly increased to 66.7 %. In addition, oral administration inhibited viral replication and alleviated the pathological symptoms of MSRV-infected largemouth bass. These results suggest that EBY100/pYD1-G could be used as a potential oral vaccine against MSRV infection.

Asunto(s)

Lubina , Enfermedades de los Peces , Rhabdoviridae , Animales , Saccharomyces cerevisiae , Vacunación , Proteínas Fúngicas , Vacunas Sintéticas

RESUMEN

Brucellosis is regarded as one of the world's most severe zoonotic diseases. This study aimed to investigate the possibility of using recombinant Lactococcus lactis (L. lactis) as a live vector to produce recombinant Brucella abortus (B. abortus) Omp10. The gene sequences were obtained from GenBank. The proteins' immunogenicity was assessed using Vaxijen. After confirming the cloning of the Omp10 gene in the pNZ8148 vector by enzymatic digestion and PCR, transformation into L. lactis was done. SDS-PAGE and western blot methods evaluated omp10 protein expression. Mice received oral recombinant L. lactis vaccines. IgG antibodies against Omp10 were tested using ELISA. Real-time PCR and ELISA were used to analyze cytokine responses. Survival rate and histopathological changes were evaluated after the challenge. Omp10 was chosen for its 1.5524 antigenicity score. Enzymatic digestion and PCR identified a 381-bp gene fragment. A 10 kDa band indicated the success of L. lactis transformation. Mice administered the L. lactis-pNZ8148-Omp10-Usp45 vaccination 14 days after priming showed significantly higher Omp10-specific total IgG and IgG1 (P < 0.001) than the PBS control group. The mice who received the L. lactis-pNZ8148-Omp10-Usp45 and IRBA vaccines had significantly elevated levels of IFN-γ, TNFα, IL-4, and IL-10 in samples collected on days 14 and 28 (P < 0.001). Inflammatory response, morphological damage, alveolar edema, and lymphocyte infiltration were reduced in the target group. A recombinant L. lactis expressing the Omp10 protein was constructed as an oral Lactococcus-based vaccine and compared to live attenuated vaccines for future brucellosis investigations.

RESUMEN

Rabies has been with humans for a long time, and its special transmission route and almost 100 % lethality rate made it once a nightmare for humans. In this study, by predicting the rabies virus glycoprotein outer membrane region and nucleoprotein B-cell antigenic epitopes, the coding sequence of the predicted highly antigenic polypeptide region obtained was assembled using the eukaryotic expression vector pcDNA3.1(-), and then E. coli was used as the delivery vector. The immunogenicity and protective properties of the vaccine were verified by in vivo and in vitro experiments, which demonstrated that the vaccine could produce antibodies in mice and prolong the survival time of mice exposed to the strong virus without any side effects. This study demonstrated that the preparation of an oral rabies DNA vaccine using food-borne microorganisms as a transport vehicle is feasible and could be a new strategy to eradicate rabies starting with wild animals.

Asunto(s)

Vacunas Antirrábicas , Virus de la Rabia , Rabia , Vacunas de ADN , Humanos , Animales , Ratones , Rabia/prevención & control , Escherichia coli , Anticuerpos Antivirales , Vacunas Antirrábicas/genética , Virus de la Rabia/genética , Epítopos de Linfocito B/genética

RESUMEN

Vaccines continue to play an enormous role in the progression of aquaculture industries worldwide. Though preventable diseases cause massive economic losses, injection-based vaccine delivery is cost-prohibitive or otherwise impractical for many producers. Most oral vaccines, which are much cheaper to administer, do not provide adequate protection relative to traditional injection or even immersion formulas. Research has focused on determining why there appears to be a lack of protection afforded by oral vaccines. Here, we review the basic immunological principles associated with oral vaccination before discussing the recent progress and current status of oral vaccine research. This knowledge is critical for the development and advancement of efficacious oral vaccines for the aquaculture industry.

RESUMEN

Oral vaccines are highly envisaged for veterinary applications due to their convenience and ability to induce protective mucosal immunity as the first line of defense. The present investigation harnessed live-attenuated Salmonella Typhimurium to orally deliver novel expression vector systems containing the Cap and Rep genes from porcine circovirus type 2 (PCV2), a significant swine pathogen. The antigen expression by the vaccine candidates JOL2885 and JOL2886, comprising eukaryotic pJHL204 and pro-eukaryotic expression pJHL270 plasmids, respectively, was confirmed by Western blot and IFA. We evaluated their immunogenicity and protective efficacy through oral vaccination in a mouse model. This approach elicited both mucosal and systemic immunity against PCV2d. Oral administration of the candidates induced PCV2-specific sIgA, serum IgG antibodies, and neutralizing antibodies, resulting in reduced viral loads in the livers and lungs of PCV2d-challenged mice. T-lymphocyte proliferation and flow-cytometry assays confirmed enhanced cellular immune responses after oral inoculation. The synchronized elicitation of both Th1 and Th2 responses was also confirmed by enhanced expression of TNF-α, IFN-γ, IL-4, MHC-I, and MHC-II. Our findings highlight the effectiveness and safety of the constructs with an engineered-attenuated S. Typhimurium, suggesting its potential application as an oral PCV2 vaccine candidate.

RESUMEN

Classical swine fever (CSF) re-emerged in Gifu Prefecture, central Japan, in September 2018 and is currently widespread in wild boar populations. Due to its widespread in wild boars, an oral mass vaccination strategy was initiated in March 2019, employing a commercial bait vaccine that is a live attenuated vaccine. To enhance the effectiveness of oral vaccination, it is crucial to determine the vaccine's effective spatial range. This understanding is essential for devising a comprehensive vaccination strategy, which should also include a preliminary investigation of wild boar habitats before vaccination. This study aimed to estimate the effective range of oral vaccination for wild boars against CSF by analyzing the geographical relationship between immune wild boars and vaccination points within the vaccination areas in Gifu Prefecture. This study utilized oral vaccination data from April 2021 to March 2022. The prevalence of CSF infections in wild boars remained below 5% in this period, suggesting limited disease transmission and immune wild boars were considered to be induced by the effect of vaccination. Two vaccination campaigns were conducted during this period, with almost 2000 vaccination points each. To investigate the factors associated with the intensity (i.e., density) of immune wild boar, the nearest distances to a vaccination point and to a susceptible wild boar were evaluated as explanatory variables. The Rhohat procedure and point process model were utilized to analyze the relationship between the intensity of immune wild boars and the explanatory variables. The point process model revealed a significant decrease in the intensity of immune wild boars when the distance from the nearest vaccination point exceeded 500 m, indicating that the effective spatial range of bait vaccination is within 500 m of the vaccination point. Although the distance to the nearest susceptible animal did not show significance in the model, Rhohat plots indicated that the intensity of immune wild boars decreased at distances greater than 1200 m from the nearest susceptible wild boar. This finding highlights the importance of investigating susceptible wild boar populations within a range of at least 1200 m from a vaccination point before implementation. The present study revealed the effective range of oral vaccination for wild boars against CSF and indicated the importance of investigating susceptible wild boar habitats around vaccination points before the implementation of vaccination. These findings may help improve the effectiveness of oral vaccinations.

Asunto(s)

Virus de la Fiebre Porcina Clásica , Peste Porcina Clásica , Enfermedades de los Porcinos , Vacunas Virales , Porcinos , Animales , Sus scrofa , Peste Porcina Clásica/epidemiología , Peste Porcina Clásica/prevención & control , Vacunación/veterinaria , Vacunación/métodos , Vacunas Atenuadas , Susceptibilidad a Enfermedades/veterinaria , Animales Salvajes

RESUMEN

Yeast surface display (YSD) is a technology that fuses the exogenous target protein gene sequence with a specific vector gene sequence, followed by introduction into yeast cells. Subsequently, the target protein is expressed and localized on the yeast cell surface by using the intracellular protein transport mechanism of yeast cells, whereas the most widely used YSD system is the α-agglutinin expression system. Yeast cells possess the eukaryotic post-translational modification mechanism, which helps the target protein fold correctly. This mechanism could be used to display various eukaryotic proteins, including antibodies, receptors, enzymes, and antigenic peptides. YSD has become a powerful protein engineering tool in biotechnology and biomedicine, and has been used to improve a broad range of protein properties including affinity, specificity, enzymatic function, and stability. This review summarized recent advances in the application of YSD technology from the aspects of library construction and screening, antibody engineering, protein engineering, enzyme engineering and vaccine development.

Asunto(s)

Ingeniería de Proteínas , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Biotecnología , Anticuerpos/metabolismo , Secuencia de Aminoácidos

RESUMEN

Bovine respiratory disease (BRD) affects feedlot cattle across North America, resulting in economic losses due to animal treatment and reduced performance. In an effort to develop a vaccine candidate targeting a primary bacterial agent contributing to BRD, we produced a tripartite antigen consisting of segments of the virulence factor Leukotoxin A (LktA) and lipoprotein PlpE from Mannheimia haemolytica, fused to a cholera toxin mucosal adjuvant (CTB). This recombinant subunit vaccine candidate was expressed in the leaves of Nicotiana benthamiana plants, with accumulation tested in five subcellular compartments. The recombinant protein was found to accumulate highest in the endoplasmic reticulum, but targeting to the chloroplast was employed for scaling up production due the absence of post-translational modification while still producing feasible levels. Leaves were freeze dried, then orally administered to mice to determine its immunogenicity. Sera from mice immunized with leaf tissue expressing the recombinant antigen contained IgG antibodies, specifically recognizing both LktA and PlpE. These mice also had a mucosal immune response to the CTB+LktA+PlpE protein as measured by the presence of LktA- and PlpE-specific IgA antibodies in lung and fecal material. Moreover, the antigen remained stable at room temperature with limited deterioration for up to one year when stored as lyophilized plant material. This study demonstrated that a recombinant antigen expressed in plant tissue elicited both humoral and mucosal immune responses when fed to mice, and warrants evaluation in cattle.