Publications by authors named "Byoung Jun Kim"

Introduction: Skin vaccination using dissolving microneedle patch (MNP) technology for transdermal delivery is a promising vaccine delivery strategy to overcome the limitations of the existing vaccine administration strategies using syringes. To improve the traditional microneedle mold fabrication technique, we introduced droplet extension (DEN) to reduce drug loss. Tuberculosis remains a major public health problem worldwide, and BCG revaccination had failed to increase the protective efficacy against tuberculosis.

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Our recent genome-based study indicated that Mycobacterium paragordonae (Mpg) has evolved to become more adapted to an intracellular lifestyle within free-living environmental amoeba and its enhanced intracellular survival within Acanthamoeba castellanii was also proved. Here, we sought to investigate potential use of Mpg for antimycobacterial drug screening systems. Our data showed that Mpg is more susceptible to various antibiotics compared to the close species M.

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At present, concerns that the recent global emergence of SARS-CoV-2 variants could compromise the current vaccines have been raised, highlighting the urgent demand for new vaccines capable of eliciting T cell-mediated immune responses, as well as B cell-mediated neutralizing antibody production. In this study, we developed a novel recombinant expressing the SARS-CoV-2 receptor-binding domain (RBD) (rMpg-RBD-7) that is capable of eliciting RBD-specific immune responses in vaccinated mice. The potential use of rMpg-RBD-7 as a vaccine for SARS-CoV-2 infections was evaluated in using mouse models of two different modules, one for single-dose vaccination and the other for two-dose vaccination.

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Serological tests offer the potential in order to improve the diagnosis of tuberculosis (TB). Macrophage migration inhibitory factor (MIF) plays a protective role in infection control in TB; however, to date, no studies on antibody responses to MIF have been reported. We measured immunoglobulin (Ig)A and IgG responses to MIF in individuals with either active tuberculosis (ATB; = 65), latent tuberculosis (LTBI; = 53), or in non-infected individuals (NI; = 62).

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Article Synopsis
  • Human cytomegalovirus (HCMV) uses the interleukin-10 (IL-10) pathway to weaken the host's immune response, making it easier for other infections to occur alongside HCMV.
  • Research demonstrated that HCMV infection increases IL-10 production in macrophages, which in turn aids the growth of non-tuberculous mycobacteria (NTM).
  • Transcriptomic analysis indicated that HCMV infection suppresses key immune regulatory pathways, hindering the body's response to co-infection with NTM by lowering levels of interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), and interleukin-1 (IL-1).
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Tuberculosis remains a major public health problem. Conventional tests are inadequate to distinguish between active tuberculosis (ATB) and latent tuberculosis infection (LTBI). We measured antibody responses to antigens ( chorismate mutase (TBCM), antigen 85B (Ag85B), early secreted antigen-6 (ESAT-6), and culture filtrate protein-10 (CFP-10) in ATB, LTBI, and non-infected (NI) individuals.

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Article Synopsis
  • Mycobacterium abscessus (MAB) is a rapidly growing pathogen with increasing global infections, particularly the rough type (MAB-R) and its enhanced virulence compared to the smooth type (MAB-S) due to its ability to escape from phagosomes.
  • Research focused on how MAB-R strains affect mitochondrial oxidative stress in murine macrophages, showing that live MAB-R heightened mitochondrial reactive oxygen species (mtROS) levels, leading to greater IL-1β and IFN-I production compared to MAB-S.
  • Treatments that modulate mtROS significantly reduced cytosolic oxidized mitochondrial DNA, which led to decreased inflammation and growth of MAB-R, highlighting how MAB-R manipulates host cell responses
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Recombinant Mycobacterium strains such as recombinant BCG (rBCG) have received considerable attention for the HIV-1 vaccine development. Recently, we described a temperature-sensitive Mycobacterium paragordonae (Mpg) strain as a novel live tuberculosis vaccine that is safer and showed an enhanced protective effect against mycobacterial infection compared to BCG. We studied the possibility of developing a vaccine against HIV-1 infection using rMpg strain expressing the p24 antigen (rMpg-p24).

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Article Synopsis
  • - The study investigates the prevalence of lateral gene transfer (LGT) in Mycobacteroides abscessus strains, focusing on the hsp65 gene, which is commonly used for bacterial identification but shows resistance to LGT.
  • - Researchers analyzed 100 clinical strains from Korea using various genetic typing methods, revealing discrepancies between hsp65 and rpoB analyses, specifically identifying two rough strains as M. abscessus subsp. massiliense.
  • - Findings suggest that the hsp65 genes of these strains may have been laterally transferred from M. abscessus subsp. abscessus, highlighting possible misidentifications in mycobacterial detection using hsp65-based methods.
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(Mpg) is a temperature-sensitive species that can grow at permissive temperatures but fails to grow above 37°C. Due to this unique growth trait, Mpg has recently been proposed as a novel live vaccine candidate for the prevention of mycobacterial infections. Furthermore, the increasing frequency of the isolation of Mpg from water supply systems led us to hypothesize that the free-living amoeba system is the natural reservoir of Mpg.

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complex (MAB) is a rapidly growing mycobacterium(RGM) whose clinical significance as an emerging human pathogen has been increasing worldwide. It has two types of colony morphology, a smooth (S) type, producing high glycopeptidolipid (GPL) content, and a rough (R) type, which produces low levels of GPLs and is associated with increased virulence. However, the mechanism responsible for their difference in virulence is poorly known.

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Three rapidly growing mycobacterial strains, MOTTH4W, MOTT36W and MOTT68W, were isolated from the sputa of three independent Korean patients co-infected with Mycobacterium yongonense Type II strains. The 16S rRNA gene sequences of all three strains were unique, which were closest to that of Mycobacterium chelonae subsp. bovis KCTC 39630 (99.

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Even though the rate of new human immunodeficiency virus type 1 (HIV-1) infections is gradually decreasing worldwide, an effective preventive vaccine for HIV-1 is still urgently needed. The recombinant BCG (rBCG) is promising for the development of an HIV-1 vaccine. Recently, we showed that a recombinant expressing HIV-1 gag in a pMyong2 vector system (rSmeg-pMyong2-p24) increased the efficacy of a vaccine against HIV-1 in mice.

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We recently showed that could be divided into two genotypes: Type I, in which the gene has been transferred from , and Type II, in which the gene has not been transferred. Comparative genome analysis of three Type I, two Type II and type strains were performed in this study to gain insight into gene transfer from into Type I strains. We found two genome regions transferred from : one contained 3 consecutive genes, including the operon, and the other contained 57 consecutive genes that had been transferred into Type I genomes via homologous recombination.

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Recently, we introduced a temperature sensitive Mycobacterium spp., Mycobacterium paragordonae (Mpg). Here, we checked its potential as a candidate for live vaccination against Mycobacterium tuberculosis and Mycobacterium abscessus.

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Three rapidly growing mycobacterial strains, QIA-37, QIA-40 and QIA-41, were isolated from the lymph nodes of three separate Korean native cattle, Hanwoo (Bos taurus coreanae). These strains were previously shown to be phylogenetically distinct but closely related to Mycobacterium chelonae ATCC 35752 by taxonomic approaches targeting three genes (16S rRNA, hsp6 and rpoB) and were further characterized using a polyphasic approach in this study. The 16S rRNA gene sequences of all three strains showed 99.

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Cultivation of the smooth colony Mycobacterium abscessus at the sub-minimum inhibitory concentration (MIC) of amikacin changed its growth pattern including its colony morphology (smooth to rough) and cell arrangement (dispersed to cord formation). In addition, reduced sliding motility and biofilm formation were observed. The amount of glycogpetidolipid (GPL) and mRNA expression of key genes involved in GPL synthesis were decreased in the amikacin-treated M.

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Recent multi locus sequence typing (MLST) and genome based studies indicate that lateral gene transfer (LGT) events in the rpoB gene are prevalent between Mycobacterium abscessus complex strains. To check the prevalence of the M. massiliense strains subject to rpoB LGT (Rec-mas), we applied rpoB typing (711 bp) to 106 Korean strains of M.

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Recently, we have developed a novel Mycobacterium-Escherichia coli shuttle vector system using pMyong2, which can provide an enhanced expression of heterologous genes in recombinant Mycobacterium smegmatis (rSmeg). To investigate the usefulness of rSmeg using pMyong2 in vaccine application, we vaccinated M. smegmatis with pMyong2 system expressing Human Immunodeficiency Virus Type I (HIV-1) Gag p24 antigen (rSmeg-pMyong2-p24) into mice and examined its cellular and humoral immune responses against HIV gag protein.

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Three mycobacterial strains, isolated from independent Korean patients with pulmonary infections, belonging to the Mycobacterium intracellulare genotype 1 (INT-1) were characterized using a polyphasic approach. The sequences of the 16S rRNA gene and internal transcribed spacer 1 (ITS1) of the INT-1 strains were identical to those of Mycobacterium intracellulare ATCC 13950T. However, multilocus sequence typing (MLST) analysis targeting five housekeeping genes (hsp65, rpoB, argG, gnd and pgm) revealed the phylogenetic separation of these strains from M.

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Recently, we introduced a distinct Mycobacterium intracellulare INT-5 genotype, distantly related to other genotypes of M. intracellulare (INT-1 to -4). The aim of this study is to determine the exact taxonomic status of the M.

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Background: Mycobacterium yongonense, as a novel member of the M. avium complex (MAC), was recently reported to be isolated from human specimens in South Korea and Italy. Due to its close relatedness to other MAC members, particularly M.

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Recently, we introduced a novel Mycobacterium massiliense Type II genotype from Korean patients, in which all isolates showed only a rough (R) colony morphotype. In this study, we sought to compare clinical factors and virulence potentials of two genotypes of M. massiliense, Type I and Type II.

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Background: Recently, we introduced a novel peptide nucleic acid (PNA) multi-probe real time PCR method targeting the hsp65 gene (hsp65 PNA RT-PCR) to distinguish Mycobacterium abscessus groups.

Methods: Here, we evaluated the usefulness of the hsp65 PNA RT-PCR for the direct identification of the M. abscessus group at the subspecies and genotype levels from sputa samples.

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From the whole blood of Korean native cattle, Hanwoo (Bos taurus coreanae), a previously undescribed, rapidly growing, scotochromogenic isolate of the genus Mycobacterium is reported. Its 16S rRNA gene sequence, and the sequences of three other genes (hsp65, recA and rpoB) were unique and phylogenetic analysis based on 16S rRNA gene sequence (1420 bp) placed the organism into the rapidly growing Mycobacterium group close to Mycobacterium smegmatis (98.5% sequence similarity).

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