Publications by authors named "Shintaro Seto"

Tuberculosis (TB) pathology involves complex immune responses within granulomatous lesions. Using single-cell RNA sequencing, we characterized the cellular compositions of necrotizing granulomatous lesions that developed in the lungs of -infected C3HeB/FeJ mice. We identified 11 distinct major cell types, including phagocytes such as neutrophils and macrophages, and T cells, natural killer cells, B cells, dendritic cells, and plasmacytoid dendritic cells.

View Article and Find Full Text PDF

Unlabelled: Understanding the functions of human transcriptional regulatory genes and during infection is crucial; in a mouse model, homologous genes and have been shown to negatively regulate inflammatory response genes, including the type I interferon (IFN) response. The reduction of these genes in mice is associated with susceptibility to infection and the development of necrotizing granulomatous lesions. To investigate the involvement of and in human inflammatory response, we analyzed their regulatory manner in THP-1 macrophages infected with .

View Article and Find Full Text PDF

Introduction: It is assumed that host defense systems eliminating the pathogen and regulating tissue damage make a strong impact on the outcome of tuberculosis (TB) disease and that these processes are affected by rifampicin (RIF) resistance-conferring mutations of (Mtb). However, the host responses to the pathogen harboring different mutations have not been studied comprehensively in clinical settings. We analyzed clinico-epidemiological factors and blood transcriptomic signatures associated with major mutations conferring RIF resistance in a cohort study.

View Article and Find Full Text PDF

, v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog B, has been identified as a candidate gene for early tuberculosis (TB) onset in Thai and Japanese populations. Here, we investigated the genome-wide transcriptional profiles of MAFB-knockdown (KD) macrophages infected with () to highlight the potential role of MAFB in host immunity against TB. Gene expression analysis revealed impaired type I and type II interferon (IFN) responses and enhanced oxidative phosphorylation in MAFB-KD macrophages infected with .

View Article and Find Full Text PDF

Infection with leads to the development of tuberculosis (TB) with the formation of granulomatous lesions. Foamy macrophages (FM) are a hallmark of TB granulomas, because they provide the primary platform of proliferation and the main source of caseous necrosis. In this study, we applied spatial multiomic profiling to identify the signatures of FM within the necrotic granulomas developed in a mouse model resembling human TB histopathology.

View Article and Find Full Text PDF

The establishment of animal models reflecting human Mycobacterium avium complex (MAC) lung disease (LD) pathology has the potential to expand our understanding of the disease pathophysiology. However, inducing sustained infection in immunocompetent mice is difficult since MAC generally shows less virulence and higher genetic variability than M. tuberculosis.

View Article and Find Full Text PDF

Mycobacterium tuberculosis (Mtb) has different features depending on different geographic areas. We collected Mtb strains from patients with smear-positive pulmonary tuberculosis in Da Nang, central Vietnam. Using a whole genome sequencing platform, including genome assembly complemented by long-read-sequencing data, genomic characteristics were studied.

View Article and Find Full Text PDF
Article Synopsis
  • Legionella pneumophila uses its type IV secretion system to introduce effector proteins that manipulate the host's secretory pathway, allowing the bacteria to create a specialized compartment called the Legionella-containing vacuole (LCV).
  • The protein Sec22b, a v-SNARE from the endoplasmic reticulum, is recruited to the LCV and interacts with t-SNAREs from the plasma membrane, which is influenced by bacterial proteins.
  • The Legionella deubiquitinase LotB removes K63-linked ubiquitin from Sec22b during infection, affecting its interaction with the t-SNARE syntaxin 3 and demonstrating how the bacteria can control SNARE pairing to enhance their infection process.
View Article and Find Full Text PDF

Background: Lymphopenia has been reported as a risk factor for poor prognosis in various infectious diseases, including Mycobacterium avium complex lung disease (MAC-LD), and recurrence in several infectious diseases. However, the association between lymphopenia and the risk of redeveloping nontuberculous lung disease (NTM-LD) after completed treatment for MAC-LD is unknown.

Methods: We performed a retrospective cohort study with 147 patients with MAC-LD who successfully completed guideline-based therapy.

View Article and Find Full Text PDF

Tuberculosis (TB) and complex lung disease (MAC-LD) are both characterized pathologically by granuloma lesions, which are typically composed of a necrotic caseum at the center surrounded by fibrotic cells and lymphocytes. Although the histological characterization of TB and MAC-LD granulomas has been well-documented, their molecular signatures have not been fully evaluated. In this research we applied mass spectrometry-based proteomics combined with laser microdissection to investigate the unique protein markers in human mycobacterial granulomatous lesions.

View Article and Find Full Text PDF

Hanoi is the capital of Vietnam, one of the 30 countries with a high tuberculosis (TB) burden. Fundamental data on the molecular epidemiology of the disease is required for future TB management. To identify lineages and genotypes of Mycobacterium tuberculosis (Mtb), conventional genotyping data from clinical isolates of the Hanoi area was compared with whole genome sequencing (WGS) analysis from 332 of 470 samples.

View Article and Find Full Text PDF

Drug-resistant tuberculosis (TB) is a serious global problem, and pathogen factors involved in the transmission of isoniazid (INH)-resistant TB have not been fully investigated. We performed whole genome sequencing of 332 clinical Mycobacterium tuberculosis (Mtb) isolates collected from patients newly diagnosed with smear-positive pulmonary TB in Hanoi, Vietnam. Using a bacterial genome-wide approach based on linear mixed models, we investigated the associations between 31-bp k-mers and clustered strains harboring katG-S315T, a major INH-resistance mutation in the present cohort and in the second panel previously published in South Africa.

View Article and Find Full Text PDF

Background: Digoxin, a cardiac glycoside used for the treatment of heart failure, was reported to inhibit the retinoid-related orphan receptor gamma t (RORγt) and attenuate the severity of experimental autoimmune encephalomyelitis and arthritis in mice. However, the effects of digoxin in a mice model of inflammatory bowel disease have not been elucidated.

Methods: Colitis was induced in severe combined immunodeficiency mice by adoptive transfer of CD45RB CD4 T cells.

View Article and Find Full Text PDF

Bone-marrow-derived macrophages are divided into two phenotypically and functionally distinct subsets, M1 and M2 macrophages. Recently, it was shown that adoptive transfer of M2-polarized peritoneal macrophages reduced the severity of experimental colitis in mice. However, it is still unclear whether peritoneal macrophages possess the same ability to be polarized to cells with functionally different phenotypes and cytokine production patterns as bone-marrow-derived macrophages.

View Article and Find Full Text PDF

Mycobacterium tuberculosis is an intracellular bacterium that can proliferate within phagocytosed macrophages. M. tuberculosis gains this ability by inhibiting phagolysosome biogenesis.

View Article and Find Full Text PDF

We recently have reported on a novel ankylosis gene that is closely linked to the Enpp1 (ectonucleotide pyrophosphatase/phosphodiesterase 1) gene on chromosome 10. Here, we have discovered novel mutant mice in a Jcl:ICR closed colony with ankylosis in the toes of the forelimbs at about 3 weeks of age. The mutant mice exhibited rigidity in almost all joints, including the vertebral column, which increased with age.

View Article and Find Full Text PDF

Mycobacterium tuberculosis is an intracellular pathogen that can survive within phagocytic cells by inhibiting phagolysosome biogenesis. However, host cells can control the intracellular M. tuberculosis burden by the induction of autophagy.

View Article and Find Full Text PDF

Rab39a has pleiotropic functions in phagosome maturation, inflammatory activation and neuritogenesis. Here, we characterized Rab39a function in membrane trafficking of phagocytosis and autophagy induction in macrophages. Rab39a localized to the periphery of LAMP2-positive vesicles and showed the similar kinetics on the phagosome to that of LAMP1.

View Article and Find Full Text PDF

Mycobacterium tuberculosis is an intracellular bacterium that can survive within macrophages. Such survival is potentially associated with Coronin-1a (Coro1a). We investigated the mechanism by which Coro1a promotes the survival of M.

View Article and Find Full Text PDF

Mycobacterium tuberculosis is an intracellular bacterium that can replicate within infected macrophages. The intracellular parasitism by M. tuberculosis results from arresting phagosome maturation and inhibiting phagolysosome biogenesis in infected macrophages.

View Article and Find Full Text PDF

During phagosome maturation, the late endosomal marker Rab7 and the lysosomal marker LAMP1 localize to the phagosomes. We investigated the mobility of Rab7 and LAMP1 on the phagosomes in macrophages by fluorescence recovery after photobleaching (FRAP) analysis. Rab7 was mobile between the phagosomal membrane and the cytosol in macrophages that ingested latex beads during phagosome maturation.

View Article and Find Full Text PDF

Mycobacterium tuberculosis (M. tb) is an intracellular pathogen that can replicate within infected macrophages. The ability of M.

View Article and Find Full Text PDF

Heat shock protein 70 (HSP70) is a member of a highly conserved superfamily of intracellular chaperones called stress proteins that can activate innate and adaptive immune responses. We evaluated the effect of a fusion DNA vaccine that encoded mycobacterial HSP70 and MPT51, a major secreted protein of Mycobacterium tuberculosis. Spleen cells from mice immunized with fusion DNA of full-length HSP70 and MPT51 produced a higher amount of interferon-γ (IFN-γ) in response to the CD4+, but not the CD8+ T-cell epitope peptide on MPT51 than those from mice immunized with MPT51 DNA.

View Article and Find Full Text PDF

M.tb is an intracellular pathogen which survives within the phagosomes of host macrophages by inhibiting their fusion with lysosomes. Here, it has been demonstrated that a lysosomal glycoprotein, CD63, is recruited to the majority of M.

View Article and Find Full Text PDF

We identified a novel HLA-DR4-restricted CD4+ T-cell epitope on a secreted antigen of Mycobacterium tuberculosis, MPT51, in 004149-MM HLA-DR4-transgenic mice which express HLA-DRB1*0401, but not murine MHC class II molecules. The mice were immunized with plasmid DNA encoding MPT51 using gene gun and interferon (IFN)-gamma production from the immune splenocytes was analyzed. In response to overlapping synthetic peptides covering the mature MPT51 sequence, only one peptide, p191-210, stimulated the splenocytes to produce IFN-gamma.

View Article and Find Full Text PDF

Synopsis of recent research by authors named "Shintaro Seto"

  • - Shintaro Seto's research primarily focuses on the molecular mechanisms underlying host-pathogen interactions, specifically in the context of Mycobacterium tuberculosis (Mtb) and other related infections.
  • - His recent studies have identified transcriptional regulators that modulate inflammatory responses in human macrophages and explored how genetic mutations in Mtb influence the host immune response and disease progression, particularly in tuberculosis.
  • - Seto's work employs advanced genomic and proteomic techniques to characterize the cellular and molecular profiles of granulomatous lesions, aiming to provide insights into the pathophysiology of both tuberculosis and nontuberculous lung diseases, contributing to improved treatment strategies.