Publications by authors named "Sangkee Kang"

A new formulation, nanoprebiotics [e.g., phthalyl pullulan nanoparticles (PPNs)], was demonstrated to enhance the antimicrobial activity of probiotics [e.

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Lactic acid bacteria (LAB) have been widely studied as mucosal vaccine delivery carriers against many infectious diseases for heterologous expression of protein antigens. There are three antigen expression strategies for LAB: cytoplasmic expression (CE), cell surface display (SD), and extracellular secretion (ES). Despite the generally higher protein expression level and many observations of antigen-specific immunogenicity in CE, its application as a mucosal vaccine has been overlooked relative to SD and ES because of the antigens enclosed by the LAB cell wall.

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Alpha lipoic acid (LA) and conjugated linoleic acid (CLA) have been well-documented on a variety of functional effects in health foods. The main purpose of this study was focused on the additive anti-inflammatory activity of the combination of LA and CLA in vitro. Raw 264.

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Here, we examined the efficacy of are combinant subunit antigen-based oral vaccine for preventing porcine epidemic diarrhea virus (PEDV). First, we generated a soluble recombinant partial spike S1 protein (aP2) from PEDV in E. coli and then evaluated the utility of aP2 subunit vaccine-loaded hydroxypropyl methylcellulose phthalate microspheres (HPMCP) and RANKL-secreting L.

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Background: Despite the many advantages of recombinant subunit vaccines, they have critical weaknesses that include a low efficacy for promoting cellular and humoral immune responses against antigens because of their poor immunogenicity, and a rapidly cleared properties as a result of proteolytic enzymes in the body. To circumvent these problems, we developed mannan-decorated inulin acetate microparticles (M-IA MPs) that functioned as carriers and adjuvants for immunization with the recombinant foot-and-mouth disease multi-epitope subunit vaccine (M5BT).

Methods: The M5BT-loaded M-IA MPs were obtained by a double-emulsion solvent-evaporation method.

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Article Synopsis
  • The correction addresses errors found in the original publication, DOI: 10.5187/jast.2019.61.2.69.
  • It clarifies specific data points and findings that were misrepresented or inaccurately reported in the initial article.
  • The aim is to ensure the accuracy and integrity of the research presented, contributing to the overall scientific knowledge in the field.
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Recently, probiotics has drawn much attention as an alternative of antibiotics because overuse use of antibiotics has caused widespread bacterial resistance. Given that prebiotics enhance the activity of probiotics, we prepared phthalyl dextran nanoparticles (PDNs) by conjugation of phthalic anhydride with dextran to form a prebiotic and checked its effects on the cellular and antimicrobial properties of the probiotics. First, we found that the internalization of PDNs by probiotics was dependent on temperature, time, and glucose transporters.

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  • Maize, high in omega-6 fatty acids, is commonly used in Hanwoo beef production to enhance marbling, potentially leading to an increased omega-6 to omega-3 ratio in the meat.
  • A study analyzed the fatty acid profiles of 55 Hanwoo steers' muscle, revealing that the n-6/n-3 ratios were much higher in both neutral and phospholipid fractions compared to other breeds.
  • Significant associations were found between three specific SNP markers in genes related to fatty acid metabolism and the omega fatty acid content, indicating genetic influence on the fatty acid profiles of Hanwoo beef.
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Synbiotics, which are the combination of probiotics and prebiotics, have recently attracted attention because of their synergistic net health benefits. Probiotics have been used as alternatives to antibiotics. Among the probiotics, (LP) has shown strong antimicrobial activity against , a major livestock pathogen.

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Probiotics show low cell viability after oral administration because they have difficulty surviving in the stomach due to low pH and enzymes. For the oral delivery of probiotics, developing a formula that protects the probiotic bacteria from gastric acidity while providing living cells is mandatory. In this study, we developed tablets using a new pH-sensitive phthalyl inulin (PI) to protect probiotics from gastric conditions and investigated the effects of different compression forces on cell survival.

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The intestinal microbiota affect various physiological traits of host animals such as brain development, obesity, age, and the immune system. In the swine industry, understanding the relationship between intestinal microbiota and growth stage is essential because growth stage is directly related to the feeding system of pigs, thus we studied the intestinal microbiota of 32 healthy pigs across five sows at 10, 21, 63, 93, and 147 d of ages. The intestinal microbiota were altered with growth of pigs and were separated into three distinct clusters.

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One of the most challenging aspects of probiotics as a replacement for antibiotics is to enhance their antimicrobial activity against pathogens. Given that prebiotics stimulate the growth and/or activity of probiotics, we developed phthalyl inulin nanoparticles (PINs) as prebiotics and observed their effects on the cellular and antimicrobial activities of Pediococcus acidilactici (PA). First, we assessed the internalization of PINs into PA.

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Synbiotics are a combination of probiotics and prebiotics, which lead to synergistic benefits in host welfare. Probiotics have been used as an alternative to antibiotics. Among the probiotics, (PA) has shown excellent antimicrobial activity against Gallinarum (SG) as a major poultry pathogen and has improved the production performances of animals.

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After the introduction of a ban on the use of antibiotic growth promoters (AGPs) for livestock, the feeding environment, including the composition of animal intestinal microbiota, has changed rapidly. We hypothesized that the microbial genomes have also been affected by this legal prohibition, and investigated an important member of the swine gut microbiota, Lactobacillus salivarius, with a pan-genomic approach. Here, we isolated 21 L.

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Several barriers such as gastric pH, enzymatic degradation and rapid transit should be overcome to orally deliver antigens for taking up by epithelial microfold cells in Peyer's patches of small intestine. To solve the above mentioned problems, we designed pH-sensitive and mucoadhesive polymeric microparticles (MPs) prepared by double emulsion technique using cellulose acetate phthalate (CAP) to enhance immune response of foot-and-mouth disease (FMD) virus (FMDV) subunit vaccine. Thiolation of CAP improved mucoadhesive property of CAP to prolong the MPs transit time through the gastrointestinal tract.

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Article Synopsis
  • The study focused on enhancing the antimicrobial properties of the probiotic Pediococcus acidilactici against the poultry pathogen Salmonella enterica serovar Gallinarum through UV mutagenesis and genome shuffling.
  • Five UV mutants were initially created, leading to the identification of four improved strains after further genome shuffling, with GS1 showing the highest antimicrobial activity tied to protein-based substances such as bacteriocins.
  • In broiler feeding experiments, GS1 significantly reduced harmful coliform bacteria and modified the cecal microbiota compared to untreated and avilamycin-treated groups, indicating its potential as a safe probiotic alternative to antibiotics in poultry farming.
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After the introduction of a ban on the use of antibiotic growth promoters (AGPs) for livestock, reuterin-producing Lactobacillus reuteri is getting attention as an alternative to AGPs. In this study, we investigated genetic features of L. reuteri associated with host specificity and antipathogenic effect.

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Article Synopsis
  • - Concerns have emerged about the safety of traditional inactivated foot-and-mouth disease (FMD) vaccines, leading to research on a safer alternative using recombinant protein technology.
  • - The study developed a chimeric recombinant protein called 5BT, which includes multiple B cell and T cell epitopes to enhance immunogenicity, and was further improved for stability by conjugating it with a membrane protein (BmpB).
  • - Immunization of mice with either 5BT or its conjugate B5BT produced strong immune responses, comparable to conventional vaccines, suggesting that this recombinant protein could serve as an effective alternative for FMD vaccination.
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As alternatives to antibiotics in livestocks, probiotics have been used, although most of them in the form of liquid or semisolid formulations, which show low cell viability after oral administration. Therefore, suitable dry dosage forms should be developed for livestocks to protect probiotics against the low pH in the stomach such that the products have higher probiotics survivability. Here, in order to develop a dry dosage forms of probiotics for poultry, we used hydroxypropyl methylcellulose phthalate 55 (HPMCP 55) as a tablet-forming matrix to develop probiotics in a tablet form for poultry.

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The emergence of highly pathogenic variant porcine epidemic diarrhea virus (PEDV) strains, from 2013 to 2014, in North American and Asian countries have greatly threatened global swine industry. Therefore, development of effective vaccines against PEDV variant strains is urgently needed. Recently, it has been reported that the N-terminal domain (NTD) of S1 domain of PEDV spike protein is responsible for binding to the 5-N-acetylneuraminic acid (Neu5Ac), a possible sugar co-receptor.

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The development of subunit mucosal vaccines requires an appropriate delivery system or an immune modulator such as an adjuvant to improve antigen immunogenicity. The nasal route for vaccine delivery by microparticles has attracted considerable interest, although challenges such as the rapid mucociliary clearance in the respiratory mucosa and the low immunogenicity of subunit vaccine still remain. Here, we aimed to develop mannan-decorated mucoadhesive thiolated hydroxypropylmethyl cellulose phthalate (HPMCP) microspheres (Man-THM) that contain ApxIIA subunit vaccine - an exotoxin fragment as a candidate for a subunit nasal vaccine against Actinobacillus pleuropneumoniae.

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Article Synopsis
  • Scientists are working on a vaccine to protect pigs from a virus called PEDV, which makes them very sick.
  • They found a way to produce two parts of a key virus protein that could help the immune system fight off the virus.
  • By using special helper proteins, they were able to make more of these important parts and tested them on mice, showing promising results for a future vaccine.
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A successful delivery of antigen through oral route requires to overcome several barriers, such as enzymatic barrier of gastrointestinal tract and epithelial barrier that constitutes of microfold cells (M cells) for antigen uptake. Although each barrier represents a critical step in determining the final efficiency of antigen delivery, the transcytosis of antigen by M cells in the follicle-associated epithelium (FAE) to Peyer's patches appears to be a major bottleneck. Considering the systemic administration of receptor activator of nuclear factor (NF)-ĸB ligand (RANKL) induces differentiation of receptor activator of nuclear factor (NF)-ĸB (RANK)-expressing enterocytes into M cells, here, we illustrated a promising approach of antigen delivery using full length transmembrane RANKL (mRANKL).

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Although there have been many attempts to produce ω-3 fatty acid-rich eggs using alpha-linolenic acid (ALA) that is a popular fatty acid in the poultry feed industry, only limited knowledge about the effects of ALA-enriched diets on chicken fecal microbiota is currently available. Herein we examined the changes in the fecal microbiota composition, egg quality traits and fatty acid composition of the egg yolks of laying hens fed ALA-rich flaxseed oil for 8 weeks. The animals fed the experimental diets that contained 0 % (group C), 0.

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Article Synopsis
  • The study investigates how soluble RANKL (sRANKL) can enhance the differentiation of M cells, which are crucial for initiating mucosal immune responses by transporting antigens in the intestine.
  • Researchers engineered a strain of Lactococcus lactis to produce sRANKL and confirmed its effectiveness in promoting M cell development and immune responses in mice when administered orally.
  • The findings suggest that oral delivery of sRANKL could be a novel adjuvant strategy to improve the efficacy of oral vaccines by boosting the immune response at mucosal sites.
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