Search Results (141)

The study evaluated the influence of dietary supplementation with nano-encapsulated cumin oil, B. subtilis, or a combination of both to mitigate the impacts of heat stress on the performance and health of growing rabbits. In the feeding trial, a total of eighty-four growing New Zealand White (35 days, 781.3 ± 1.8 g average body weight) were randomly distributed in a completely randomized design into four groups; each had 21 rabbits arranged in 7 replicates (3 rabbits each). The experiment lasted 42 days (35 days to 77 days). Growing rabbits received a basal diet (first group, CON) without additives, while the other groups were supplemented with nano-encapsulated cumin oil (NECO, 200 mg/kg), B. subtilis (BS, 500 mg/kg), or both (BSNO, 500 mg BS plus 200 mg/kg NECO). Adding BSNO significantly enhanced body weight gain, carcass weight, and feed conversion ratio and reduced mortality rate (p < 0.05). Additionally, the BSNO enhanced digestive system performance by increasing the secretion of trypsin enzymes, as well as nutrient digestibility, especially for protein and fiber (p < 0.05). Supplementing BSNO enhanced oxidative stability and immunity via higher levels of superoxide dismutase (SOD), IgA, IgG, triiodothyronine (T3), thyroxine (T4) and lower malondialdehyde (MDA) levels (p < 0.05), indicating a better ability to adapt to stress. During the examination of gut health, pathogenic bacteria counts decreased, as well as down-regulation of interleukin-6 (IL-6) gene expression and up-regulation of cationic amino acid transporter-1 (CAT-1), interleukin-10 (IL-10), and mucin-2 (MUC-2) gene expression (p < 0.05), supporting gut integrity. This study highlights the potential of mixing nano-encapsulated cumin oil and B. subtilis in growing rabbits’ diets as an effective strategy to counteract the negative effects of heat stress caused by high ambient temperatures. Full article

Nanodiamonds (NDs) are an innovative material in biomedical applications based on their excellent biocompatibility, nanoscale dimensions, and high surface area. In this study, we evaluated the potential of ND-in-oil emulsion to induce potent antibody responses in animals immunized with cobra venom. NDs demonstrated the capacity to bind complex venom proteins as stable conjugates, well dispersed in aqueous solution. Immunization of mice with cobra venom incorporated with ND-in-oil emulsion adjuvant (ND/venom) elicited strong venom-specific antibody responses with titers comparable to those induced by venom formulation with conventional Freund’s adjuvants (FA/venom). IgG subclass analysis revealed that ND- and FA-based formulations induced a Th2-biased immune response in mice. Moreover, antibodies elicited by ND/venom or FA/venom immunization specifically recognized the epitopes of the lethal component of short-chain neurotoxin and conferred full protection against lethal cobra venom challenge (3LD₅₀). Further, ND/venom hyperimmunization was capable of inducing high levels of neutralizing antibodies in larger animals, rabbits, highlighting the potential for antivenom manufacturing. Notably, there were no obvious lesions at the injection sites of animals that received ND/venom, in contrast to those that received FA/venom. These findings indicated NDs as an effective and safe additive in venom formulation for antivenom production. Full article

This study focused on utilizing the double-mutant heat-labile toxin (R192G/L211A) (dmLT) as a backbone protein, into which neutralizing epitopes of ETEC (FaeG, FedF, FanC, FasA, and Fim41a) were embedded. A combination of computational modeling and immunogenicity analysis was conducted to evaluate the dmLT_{(R192G/L211A)} multiepitope fusion antigen (MEFA). Both the computational modeling and experimental results confirmed that all relevant epitopes were clearly exposed on the surface of the MEFA. Subcutaneous immunizations of rabbits with the MEFA protein yielded the development of IgG antibodies that targeted all five fimbriae. Furthermore, these antibodies demonstrated significant inhibition of adhesion for K88+, K99+, 987P+, F18+, and F41+ ETEC strains to porcine small intestinal epithelial cell line IPEC-J2 cells. These results indicated that the dmLT toxoid-based MEFA protein effectively elicits high-titer, functional antibodies capable of neutralizing the attachment of multiple prevalent ETEC fimbrial types, highlighting its potential as a broad-spectrum vaccine candidate. Consequently, it shows promising potential as a broad and effective vaccine against ETEC. Full article

Argasid ticks Ornithodoros erraticus and Ornithodoros moubata are major vectors of zoonotic pathogens, including the African swine fever virus and relapsing fever Borrelia spp., and their control is essential to reduce disease transmission. In this study, we evaluated the immunogenicity and protective efficacy of four Ornithodoros tick antigens formulated as mRNA–lipid nanoparticles (mRNA-LNPs): OeSOD, OeTSP1, OmPLA2, and Om86. Rabbits were immunised with three doses of each mRNA-LNP construct, and immune responses and tick biological parameters were assessed following infestation with both tick species. All mRNA-LNP constructs induced antigen-specific IgG responses that recognised native proteins in tick saliva and midgut extracts. Vaccination resulted in significant reductions in female oviposition and fertility, which correlated with antibody levels, and yielded protective efficacies of 21.9–41.6% against O. moubata and 23.1–41.6% against O. erraticus. Notably, the mRNA-LNPs of OeSOD and OeTSP1 outperformed their recombinant counterparts against O. moubata, and Om86 mRNA-LNP conferred markedly improved protection against both O. moubata and O. erraticus. These findings highlight the potential of mRNA-LNP vaccines to induce effective anti-argasid tick immunity and provide a promising platform for the development of sustainable strategies to control argasid ticks and associated pathogens. Full article

This study aims to investigate the effects of dietary supplementation with different concentrations of oligofructose (FOS) on growth performance, antioxidant capacity, immunity, and intestinal microbial composition in growing rabbits. One hundred female Dehua black rabbits (34 d of age) were randomly assigned to four groups (CON, FOS-1, FOS-2, and FOS-3), with twenty-five rabbits in each group. The CON group received only a basal diet, while the FOS-1/FOS-2/FOS-3 group received the diet supplemented with 0.3%/0.6%/0.9% FOS, respectively. The trial period lasted for 72 days. Our results revealed that FOS supplementation could improve the growing performance of rabbits and decrease the feed/gain ratio. FOS significantly enhanced serum antioxidant enzyme (SOD) and total antioxidant capacity (T-AOC) while reducing malondialdehyde (MDA). The levels of plasmic immunoglobulin (IgG, IgA, and IgM) and intestinal immune factors (IL-1α, IL-2, and sIgA) were significantly improved with the FOS supplement. Additionally, FOS can improve intestinal morphology and enhance the activity of intestinal enzymes, including cellulase, lipase, and protease. Furthermore, FOS supplementation influenced the composition of intestinal microflora by increasing the abundance of Lachnospiraceae_NK4A136_group (barrier-enhancing) and Monoglobus (fiber-degrading). In conclusion, the addition of FOS has a positive impact on the growth performance, antioxidant capacity, immunity, and intestinal health of growing rabbits. The optimal dietary addition for rabbits was identified as 0.6% oligofructose. Full article

Background/Objectives: Group B Streptococcus (GBS) is a significant cause of perinatal infection in neonates and infants. Complications could include neonatal sepsis and meningitis, preterm birth, stillbirth, or death. Though no GBS vaccine is currently licensed, maternal immunization is expected to be a highly effective strategy to address invasive GBS disease—particularly in low- and middle-income countries (LMICs), where the disease burden is the greatest and access to existing interventions is limited. In this study, we present a novel hexavalent GBS vaccine candidate with a unique combination of serotypes (ST)—Ia, Ib, II, III, V, and VII—that could be an efficacious and cost-effective intervention, with the broadest coverage of 99% against circulating serotypes globally. Methods: The 6-valent conjugate vaccine candidate, GBS-06, is developed using a novel approach by linking the six polysaccharides (PS) to recombinant cross-reactive material 197 (rCRM197) carrier protein derivatized with a hydrazide-polyethylene glycol-hydrazide (HZ-PEG-HZ) linker. A repeat-dose GLP toxicology study with GBS-06 was conducted at the highest clinical dose of 20 µg in rabbits with saline as the placebo control. Results: The results reveal induction of robust anti-capsular polysaccharide-specific IgG responses against each of the six serotypes after each dose with the highest antibody GMCs at Day 49 following the third dose. Conclusions: Hence, this work is the first demonstration of strong immunogenicity achieved using a linker (HZ-PEG-HZ) for GBS glycoconjugate vaccine development. The positive data from the study have strong implications in the advancement of the candidate for evaluation in clinical trials and provide a licensure pathway for maternal immunization. Full article

Spinal cord ischemia–reperfusion (SCI/R) injury remains a major clinical challenge with limited therapeutic options. High-mobility group box 1 (HMGB1), a proinflammatory mediator released during cellular stress, has been implicated in the pathogenesis of ischemia–reperfusion-induced neural damage. In this study, we investigated the neuroprotective potential of the anti-HMGB1 monoclonal antibody (mAb) in a rabbit model of SCI/R injury. Male New Zealand White rabbits were anesthetized and subjected to 11 min of abdominal aortic occlusion using a micro-bulldog clamp following heparinization. Anti-HMGB1 mAb or control IgG was administered intravenously immediately after reperfusion and again at 6 h post-reperfusion. Neurological function was assessed at 6, 24, and 48 h after reperfusion using the modified Tarlov scoring system. The rabbits were euthanized 48 h after reperfusion for spinal cord and blood sampling. Treatment with anti-HMGB1 mAb significantly improved neurological outcomes, reduced the extent of spinal cord infarction, preserved motor neuron viability, and decreased the presence of activated microglia and infiltrating neutrophils. Furthermore, it attenuated apoptosis, oxidative stress, and inflammatory responses in the spinal cord, and helped maintain the integrity of the blood–spinal cord barrier. These findings suggest that anti-HMGB1 mAb may serve as a promising therapeutic agent for SCI/R injury. Full article

The purpose of this experiment was to study the effects of heat stress on the performance and protein metabolism of skeletal muscle in meat rabbits. A total of 160 New Zealand White rabbits aged 80 days with mean initial body weights of 2359 ± 200 g were randomly divided into a control group and a heat stress group. The experiment duration was 20 days. Heat stress treatment reduced the growth performance and slaughter performance of the rabbits (p < 0.05) and increased muscle yellowness (b*, p < 0.05). In addition, heat stress treatment increased the concentrations of leptin, cholesterol, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol in serum (p < 0.05), and decreased the serum total protein and immunoglobulin (IgG, IgM, and IgA) contents of rabbits. Under the criteria fold-change ≥ 1.20 or ≤0.84 and p-value ≤ 0.05, 7 up-regulated proteins and 122 down-regulated proteins were screened. A gene ontology (GO) enrichment analysis of the differentially expressed proteins was performed. The most enriched specific GO terms among the differential proteins were response to stress, extracellular region, and protein binding in the biological process (BP), cellular component (CC), and molecular function (MF) categories, respectively, and the most enriched pathway was the PI3K/Akt signalling pathway. In conclusion, heat stress could reduce the carcass yield of meat rabbits, change the physical characteristics of the skeletal muscle, and influence protein metabolism by changing blood indices, potentially through the PI3K/Akt signalling pathway. Full article

Danshen polysaccharide (DSPS) is the main natural compound extracted from the traditional Chinese herb Danshen. Although DSPS is well-known for its antioxidant and anti-inflammatory properties, its impact on aflatoxin B1 (AFB1)-induced damage has not been explored. This study aims to investigate the potential protective mechanisms of DSPS against AFB1-induced liver damage and immune disorders. The experiment lasted a total of three weeks, during which 120 rabbits were randomly assigned to six groups (n = 20). AFB1 and DSPS were incorporated into the diets of each group. We found that DSPS significantly inhibited AFB1-induced hepatocyte edema, inflammatory cell infiltration, and increased serum aspartate aminotransferase (AST)/ alanine aminotransferase (ALT) levels (p < 0.05). DSPS alleviated oxidative damage by downregulating CYP1A1/A2 mRNA, enhancing liver total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and glutathione (GSH) levels, and reducing the production of reactive oxygen species (ROS) and malondialdehyde (MDA) (p < 0.05). DSPS inhibits the expression of cytochrome c (cyt.c), caspase 9, and caspase 3, significantly reducing the apoptosis rate of hepatocytes (p < 0.05). Additionally, DSPS elevates the levels of immunoglobulins (IgA, IgG, IgM) and interferon-gamma (IFN-γ), while decreasing the concentration of IL-4 (p < 0.05). This study demonstrates that DSPS can alleviate AFB1-induced damage, with the underlying mechanisms likely related to enhanced antioxidant capacity, inhibition of oxidative stress, and intrinsic apoptotic pathways, as well as improved immune responses. Full article

Background/Objectives: Opioid use disorder (OUD) remains a severe health problem globally, resulting in substantial social and economic challenges. While existing medications for managing OUD are proven to be effective, they also present certain challenges. A vaccine offers a promising therapeutic strategy to combat OUD and potentially reduce the risk of overdose death. The TT-6-AmHap heroin conjugate vaccine has effectively reduced heroin-induced pharmacological effects in behavioral assays as well as demonstrated the induction of high titer and high affinity antibody responses in mice and rats. In this GLP study conducted in rabbits, the potential local and systemic toxicity of the TT-6-AmHap heroin vaccine in combination with or without adjuvants ALF43 and Alhydrogel^® (ALFA) was investigated. Methods: Male and female New Zealand White rabbits were administered with vaccines or a saline control intramuscularly at two-week intervals over a 57-day study period. The presence, persistence or reversibility of any toxic effects of the vaccine was determined over a four-week recovery period. Results: Administration of TT-6-AmHap with or without the adjuvants induced high antibody-specific IgG in treatment groups compared to the controls. The study found no TT-6-AmHap-related effects on mortality, physical examinations, dermal Draize observations, body weights, body weight changes, food consumption, ophthalmology, clinical pathology (hematology, coagulation, clinical chemistry, and urinalysis), macroscopic pathology, or organ weights. Conclusions: Under the conditions of this study, these results demonstrate that the TT-6-AmHap vaccine with or without adjuvants was well tolerated, immunogenic, and the effects were not considered adverse in both male and female rabbits. Full article

Background/Objectives: Porcine circovirus type 2d (PCV2d) is the predominant genotype associated with porcine circovirus-associated disease (PCVAD), leading to significant economic losses. In South Korea, current vaccine lot-release testing relies on a T/C-ratio-based guinea pig assay, which lacks scientific justification and methodological robustness. This study aimed to develop and validate a statistically defined in-house ELISA using rabbit-derived polyclonal antibodies against PCV2d for the standardized evaluation of immunogenicity. Methods: Polyclonal IgG was generated by immunizing a rabbit with inactivated PCV2d, and it was purified through Protein A chromatography. Guinea pigs (n = 18) were immunized with IMMUNIS^® DMVac, an inactivated PCV2d vaccine candidate developed by WOOGENE B&G, at different doses. In-house ELISA parameters were optimized (antigen coating, blocking agent, and substrate incubation), and analytical performance was evaluated by ROC, linearity, reproducibility, and specificity. Sera from guinea pigs and pigs were analyzed under validated conditions. Results: The optimal performance was achieved using 10⁵ genomic copies/mL of the antigen coating and a 5% BSA blocking agent. The assay showed strong diagnostic accuracy (AUC = 0.97), reproducibility (CVs < 5%), and linearity (R² = 0.9890). Specificity tests with PCV2a, PCV2b, and PRRSV showed minimal cross-reactivity (<7%). The cross-species comparison revealed a positive correlation (R² = 0.1815) and acceptable agreement (bias = −0.21) between guinea pig and porcine sera. The validated cut-off (S/P = 0.4) enabled accurate classification across both species and aligned well with commercial kits. Conclusions: The in-house ELISA offers a robust, reproducible, and scientifically validated platform for immunogenicity verification, supporting its application in Korea’s national lot-release system. Homologous competition assays with PCV2d are planned to further confirm antigen specificity. Full article

Objectives: This study aims to assess the adjuvant effects of lentinan and its combination with Mn(J), a manganese-based colloidal adjuvant, on the BG (fusion protein BfrB-GrpE of Mycobacterium tuberculosis) subunit vaccine. Methods: A rabbit skin infection model was established to evaluate the immune protection conferred by the BG–lentinan vaccine, the BG–lentinan/Mn(J) vaccine, and the Bacillus Calmette-Guérin (BCG) vaccine against tuberculosis. Rabbits were vaccinated at weeks 0, 2, and 4. Six weeks post-vaccination, antigen-specific IgG levels were measured, followed by a BCG skin challenge. Results: Both the BG–lentinan and BG–lentinan/Mn(J) vaccines significantly increased antigen-specific IgG levels against BfrB and GrpE in rabbits (p < 0.05). Furthermore, these vaccines accelerated the pathological process following BCG infection. The bacterial load in nodules was notably reduced, with the BG–lentinan vaccine group exhibiting the lowest levels (p < 0.01). Conclusions: Lentinan and its combined adjuvant, lentinan/Mn(J), significantly enhance the immune response elicited by the BG tuberculosis subunit vaccine, providing effective protection. Full article

The creation of surface relief gratings using hydrogels for label-free biomolecule detection represents a significant advance in the development of versatile, cutting-edge biosensors. Central to this innovation is the formulation of materials with enhanced mechanical properties, especially for applications in soft, wearable technologies. In this work, we have developed novel biofunctional hydrogels that incorporate slide-ring supramolecular structures into their network, enabling the production of surface relief gratings with superior mechanical characteristics for biomolecule detection without the need for labels. These hydrogels, functionalized with bovine serum albumin and goat anti-rabbit antibodies, demonstrated excellent selectivity and sensitivity toward anti-bovine serum albumin and rabbit IgGs in blood serum, evaluated using a label-free format. Remarkably, the new materials matched the analytical performance of conventional hydrogels based on static networks while offering dramatically improved toughness and elasticity, with a compressive modulus comparable to human skin. This demonstrates the potential of slide-ring hydrogels for fabricating robust, label-free biosensing platforms. Furthermore, the flexibility of this system allows for the incorporation of various recognition elements tailored to specific applications. Full article

Background/Objectives: In the past, FhSAP-2, an 11.5 kDa recombinant protein belonging to the Fasciola hepatica saposin-like/NK-lysin family, has been shown to induce over 60% partial protection in immunized rabbits and mice when challenged with F. hepatica metacercariae. However, despite FhSAP-2 being a promising vaccine candidate, its hydrophobic nature has made its purification a challenging process. The present study aimed to determine whether a modified 9.8 kDa variant of protein (mFhSAP-2), lacking a string of 16 hydrophobic amino acids at the amino terminus and a dominant Th1 epitope, could retain its immunogenic and Th1-inducing properties. Methods: RAW264.7 cells were stimulated with mFhSAP-2, and TNFα levels were determined. C57BL/6 mice were immunized with mFhSAP-2 alone or emulsified with Montanide ISA50. Total anti-mFhSAP-2 IgG subtypes, along with their avidity and titers, were measured using ELISA. The T cell proliferation index and levels of CD4+/CD8+ and IFNγ/IL-4 ratios were determined. Results: In vitro, mFhSAP-2 induced dose-dependent TNFα production in RAW264.7 cells. In vivo, mice immunized with mFhSAP-2 or mFhSAP-2+ISA50 developed high-avidity IgG2a and IgG2c antibodies at levels that were significantly higher than IgG1 antibody levels. However, the mFhSAP-2+ISA50 formulation induced higher and more homogenous antibody titers than mFhSAP-2, suggesting that an adjuvant may be required to enhance mFhSAP-2 immunogenicity. Immunization with mFhSAP-2+ISA50 also induced significantly higher activated CD4+/CD8+ T cell ratios and IFNγ/IL-4 ratios compared to naïve mice. Conclusions: Our results demonstrate that mFhSAP-2 retained its immunogenicity and Th1-polarizing properties, which were enhanced by the Montanide ISA50 adjuvant. The present study highlights the feasibility of inducing Th1-associated immune responses in mice using mFhSAP-2 as an antigen. Further studies are required to assess the potential application of the mFhSAP-2+ISA50 formulation as a vaccine against F. hepatica in natural hosts such as cattle and sheep, which could contribute to improved control and aid in the prevention and eradication of F. hepatica infection. Full article

A partial sequence of an human coronavirus (HCoV)-OC43 S2 subunit that cross-reacts with the S2 subunit of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was fused with a nasal immuno-inducible sequence (NAIS), and the resulting complex was used for intranasal immunization of rabbits. Crude serum from rabbits immunized with three doses showed an IgG titer > 1000 against the S2 subunits of HCoV-OC43 and SARS-CoV-2 and inhibited OC43 viral replication as a neutralizing antibody in vitro. Full article