start-ver=1.4 cd-journal=joma no-vol=299 cd-vols= no-issue=4 article-no= start-page=104587 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=202304 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=ATP and its metabolite adenosine cooperatively upregulate the antigen-presenting molecules on dendritic cells leading to IFN-gamma production by T cells en-subtitle= kn-subtitle= en-abstract= kn-abstract=Dendritic cells (DCs) present foreign antigens to T cells via the major histocompatibility complex (MHC), thereby inducing acquired immune responses. ATP accumulates at sites of inflammation or in tumor tissues, which triggers local inflammatory responses. However, it remains to be clarified how ATP modulates the functions of DCs. In this study, we investigated the effects of extracellular ATP on mouse bone marrow- derived dendritic cells (BMDCs) as well as the potential for subsequent T cell activation. We found that high concentrations of ATP (1 mM) upregulated the cell surface expression levels of MHC-I, MHC-II, and co-stimulatory molecules CD80 and CD86 but not those of co-inhibitory molecules PD-L1 and PD-L2 in BMDCs. Increased surface expression of MHC-I, MHC-II, CD80, and CD86 was inhibited by a pan-P2 receptor antagonist. In addition, the upregulation of MHC-I and MHC-II expression was inhibited by an adenosine P1 receptor antagonist and by inhibitors of CD39 and CD73, which metabolize ATP to adenosine. These results suggest that adenosine is required for the ATP-induced upregulation of MHC-I and MHC-II. In the mixed leukocyte reaction assay, ATP-stimulated BMDCs activated CD4 and CD8T cells and induced interferon-gamma (IFN-gamma) production by these T cells. Collectively, these results suggest that high concentrations of extracellular ATP upregulate the expression of antigenpresenting and co-stimulatory molecules but not that of coinhibitory molecules in BMDCs. Cooperative stimulation of ATP and its metabolite adenosine was required for the upregulation of MHC-I and MHC-II. These ATP-stimulated BMDCs induced the activation of IFN-gamma-producing T cells upon antigen presentation. en-copyright= kn-copyright= en-aut-name=FurutaKazuyuki en-aut-sei=Furuta en-aut-mei=Kazuyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=OnishiHiroka en-aut-sei=Onishi en-aut-mei=Hiroka kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=IkadaYuki en-aut-sei=Ikada en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MasakiKento en-aut-sei=Masaki en-aut-mei=Kento kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=TanakaSatoshi en-aut-sei=Tanaka en-aut-mei=Satoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=KaitoChikara en-aut-sei=Kaito en-aut-mei=Chikara kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=5 en-affil=Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University kn-affil= affil-num=6 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=64 cd-vols= no-issue=9 article-no= start-page=585 end-page=592 dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20200915 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Animal infection models using non‐mammals en-subtitle= kn-subtitle= en-abstract= kn-abstract=The use of non‐human animal models for infection experiments is important for investigating the infectious processes of human pathogenic bacteria at the molecular level. Mammals, such as mice and rabbits, are also utilized as animal infection models, but large numbers of animals are needed for these experiments, which is costly, and fraught with ethical issues. Various non‐mammalian animal infection models have been used to investigate the molecular mechanisms of various human pathogenic bacteria, including Staphylococcus aureus, Streptococcus pyogenes, and Pseudomonas aeruginosa. This review discusses the desirable characteristics of non‐mammalian infection models and describes recent non‐mammalian infection models that utilize Caenorhabditis elegans, silkworm, fruit fly, zebrafish, two‐spotted cricket, hornworm, and waxworm. en-copyright= kn-copyright= en-aut-name=KaitoChikara en-aut-sei=Kaito en-aut-mei=Chikara kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=MurakamiKanade en-aut-sei=Murakami en-aut-mei=Kanade kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=ImaiLina en-aut-sei=Imai en-aut-mei=Lina kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=FurutaKazuyuki en-aut-sei=Furuta en-aut-mei=Kazuyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= en-keyword=infection model kn-keyword=infection model en-keyword=non‐mammals kn-keyword=non‐mammals en-keyword=pathogenic bacteria kn-keyword=pathogenic bacteria END start-ver=1.4 cd-journal=joma no-vol=30 cd-vols= no-issue= article-no= start-page=105388 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=202006 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Dataset for de novo transcriptome assembly of the African bullfrog Pyxicephalus adspersus en-subtitle= kn-subtitle= en-abstract= kn-abstract=In this article, we report the first de novo transcriptome assembly of the African bullfrog Pyxicephalus adspersus. In this data, 75,320,390 raw reads were acquired from African bullfrog mRNA using Illumina paired-end sequencing platform. De novo assembly resulted in a total of 136,958 unigenes. In the obtained unigenes, 30,039 open reading frames (ORFs) were detected. This dataset provides basic information for molecular level analysis of this species, which undergoes a state of dormancy under dry conditions at ordinary temperatures called estivation. en-copyright= kn-copyright= en-aut-name=YoshidaNaoki en-aut-sei=Yoshida en-aut-mei=Naoki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KaitoChikara en-aut-sei=Kaito en-aut-mei=Chikara kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= en-keyword=RNA-Seq kn-keyword=RNA-Seq en-keyword=de novo assembly kn-keyword=de novo assembly en-keyword=Transcriptome kn-keyword=Transcriptome en-keyword=African bullfrog kn-keyword=African bullfrog en-keyword=Pyxicephalus adspersus kn-keyword=Pyxicephalus adspersus END start-ver=1.4 cd-journal=joma no-vol=371 cd-vols= no-issue= article-no= start-page=fnae007 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2024 dt-pub=20240201 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Knockout of adenylosuccinate synthase purA increases susceptibility to colistin in Escherichia coli en-subtitle= kn-subtitle= en-abstract= kn-abstract=Colistin is a cationic cyclic antimicrobial peptide used as a last resort against multidrug-resistant gram-negative bacteria. To understand the factors involved in colistin susceptibility, we screened colistin-sensitive mutants from an E. coli gene-knockout library (Keio collection). The knockout of purA, whose product catalyzes the synthesis of adenylosuccinate from IMP in the de novo purine synthesis pathway, resulted in increased sensitivity to colistin. Adenylosuccinate is subsequently converted to AMP, which is phosphorylated to produce ADP, a substrate for ATP synthesis. The amount of ATP was lower in the purA-knockout mutant than that in the wild-type strain. ATP synthesis is coupled with proton transfer, and it contributes to the membrane potential. Using the membrane potential probe, 3,3′-diethyloxacarbocyanine iodide [DiOC2(3)], we found that the membrane was hyperpolarized in the purA-knockout mutant compared to that in the wild-type strain. Treatment with the proton uncoupler, carbonyl cyanide m-chlorophenyl hydrazone (CCCP), abolished the hyperpolarization and colistin sensitivity in the mutant. The purA-knockout mutant exhibited increased sensitivity to aminoglycosides, kanamycin, and gentamicin; their uptake requires a membrane potential. Therefore, the knockout of purA, an adenylosuccinate synthase, decreases ATP synthesis concurrently with membrane hyperpolarization, resulting in increased sensitivity to colistin. en-copyright= kn-copyright= en-aut-name=KanoTomonori en-aut-sei=Kano en-aut-mei=Tomonori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=IshikawaKazuya en-aut-sei=Ishikawa en-aut-mei=Kazuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FurutaKazuyuki en-aut-sei=Furuta en-aut-mei=Kazuyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KaitoChikara en-aut-sei=Kaito en-aut-mei=Chikara kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= en-keyword=colistin kn-keyword=colistin en-keyword=adenylosuccinate synthase kn-keyword=adenylosuccinate synthase en-keyword=de novo purine synthesis kn-keyword=de novo purine synthesis en-keyword=membrane potential kn-keyword=membrane potential en-keyword=ATP synthesis kn-keyword=ATP synthesis END start-ver=1.4 cd-journal=joma no-vol=18 cd-vols= no-issue=3 article-no= start-page= end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=20230324 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Knockout of ribosomal protein RpmJ leads to zinc resistance in Escherichia coli en-subtitle= kn-subtitle= en-abstract= kn-abstract=Zinc is an essential metal for cells, but excess amounts are toxic. Other than by regulating the intracellular zinc concentration by zinc uptake or efflux, the mechanisms underlying bacterial resistance to excess zinc are unknown. In the present study, we searched for zinc-resistant mutant strains from the Keio collection, a gene knockout library of Escherichia coli, a model gram-negative bacteria. We found that knockout mutant of RpmJ (L36), a 50S ribosomal protein, exhibited zinc resistance. The rpmJ mutant was sensitive to protein synthesis inhibitors and had altered translation fidelity, indicating ribosomal dysfunction. In the rpmJ mutant, the intracellular zinc concentration was decreased under excess zinc conditions. Knockout of ZntA, a zinc efflux pump, abolished the zinc-resistant phenotype of the rpmJ mutant. RNA sequence analysis revealed that the rpmJ mutant exhibited altered gene expression of diverse functional categories, including translation, energy metabolism, and stress response. These findings suggest that knocking out RpmJ alters gene expression patterns and causes zinc resistance by lowering the intracellular zinc concentration. Knockouts of other ribosomal proteins, including RplA, RpmE, RpmI, and RpsT, also led to a zinc-resistant phenotype, suggesting that deletion of ribosomal proteins is closely related to zinc resistance. en-copyright= kn-copyright= en-aut-name=ShirakawaRiko en-aut-sei=Shirakawa en-aut-mei=Riko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=IshikawaKazuya en-aut-sei=Ishikawa en-aut-mei=Kazuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FurutaKazuyuki en-aut-sei=Furuta en-aut-mei=Kazuyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KaitoChikara en-aut-sei=Kaito en-aut-mei=Chikara kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=16 cd-vols= no-issue=4 article-no= start-page=e1008469 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2020 dt-pub=20200423 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Non-pathogenic Escherichia coli acquires virulence by mutating a growth-essential LPS transporter en-subtitle= kn-subtitle= en-abstract= kn-abstract=The molecular mechanisms that allow pathogenic bacteria to infect animals have been intensively studied. On the other hand, the molecular mechanisms by which bacteria acquire virulence functions are not fully understood. In the present study, we experimentally evaluated the evolution of a non-pathogenic strain of Escherichia coli in a silkworm infection model and obtained pathogenic mutant strains. As one cause of the high virulence properties of E. coli mutants, we identified amino acid substitutions in LptD (G580S) and LptE (T95I) constituting the lipopolysaccharide (LPS) transporter, which translocates LPS from the inner to the outer membrane and is essential for E. coli growth. The growth of the LptD and LptE mutants obtained in this study was indistinguishable from that of the parent strain. The LptD and LptE mutants exhibited increased secretion of outer membrane vesicles containing LPS and resistance against various antibiotics, antimicrobial peptides, and host complement. In vivo cross-linking studies revealed that the conformation of the LptD-LptE complex was altered in the LptD and LptE mutants. Furthermore, several clinical isolates of E. coli carried amino acid substitutions of LptD and LptE that conferred resistance against antimicrobial substances. This study demonstrated an experimental evolution of bacterial virulence properties in an animal infection model and identified functional alterations of the growth-essential LPS transporter that led to high bacterial virulence by conferring resistance against antimicrobial substances. These findings suggest that non-pathogenic bacteria can gain virulence traits by changing the functions of essential genes, and provide new insight to bacterial evolution in a host environment. Author summary Pathogenic bacteria developed their virulence properties by changing the functions of various genes after the emergence of the host animals on earth. The types of gene function alterations that confer bacterial virulence properties, however, have remained unclear. We utilized a silkworm infection model to perform an experimental evolution of bacterial virulence activity. From a non-pathogenic strain of Escherichia coli, we obtained a mutant strain that exhibited 500-fold higher virulence than the original strain and identified mutations of the lipopolysaccharide (LPS) transporter, which translocates LPS onto the bacterial surface, as one cause of the high virulence. The mutations changed the structure of the LPS transporter, increased the secretion of outer membrane vesicles, and enabled bacterial survival in the presence of host antimicrobial substances. This mechanism to gain high virulence occurs naturally, as several E. coli clinical isolates carried mutations of the LPS transporter that confer resistance against antimicrobial substances. Our study unveiled a novel mechanism by which bacteria increase their virulence through modifying their gene function. en-copyright= kn-copyright= en-aut-name=KaitoChikara en-aut-sei=Kaito en-aut-mei=Chikara kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=YoshikaiHirono en-aut-sei=Yoshikai en-aut-mei=Hirono kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=WakamatsuAi en-aut-sei=Wakamatsu en-aut-mei=Ai kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=MiyashitaAtsushi en-aut-sei=Miyashita en-aut-mei=Atsushi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=MatsumotoYasuhiko en-aut-sei=Matsumoto en-aut-mei=Yasuhiko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=FujiyukiTomoko en-aut-sei=Fujiyuki en-aut-mei=Tomoko kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=KatoMasaru en-aut-sei=Kato en-aut-mei=Masaru kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=OguraYoshitoshi en-aut-sei=Ogura en-aut-mei=Yoshitoshi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=HayashiTetsuya en-aut-sei=Hayashi en-aut-mei=Tetsuya kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= en-aut-name=IsogaiTakao en-aut-sei=Isogai en-aut-mei=Takao kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=10 ORCID= en-aut-name=SekimizuKazuhisa en-aut-sei=Sekimizu en-aut-mei=Kazuhisa kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=11 ORCID= affil-num=1 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Pharmaceutical Sciences, The University of Tokyo kn-affil= affil-num=3 en-affil=Japan Biological Informatics Consortium (JBIC) kn-affil= affil-num=4 en-affil=Graduate School of Pharmaceutical Sciences, The University of Tokyo kn-affil= affil-num=5 en-affil=Department of Microbiology, Meiji Pharmaceutical University kn-affil= affil-num=6 en-affil=The Institute of Medical Science, The University of Tokyo kn-affil= affil-num=7 en-affil=Devision of Bioanalytical Chemistry, School of Pharmacy,Showa University kn-affil= affil-num=8 en-affil=Department of Bacteriology, Faculty of Medical Sciences,Kyushu University kn-affil= affil-num=9 en-affil=Department of Bacteriology, Faculty of Medical Sciences,Kyushu University kn-affil= affil-num=10 en-affil=Translational Research Center, Fukushima Medical University kn-affil= affil-num=11 en-affil=Institute of Medical Mycology, Teikyo University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=14 cd-vols= no-issue=5 article-no= start-page=e0217517 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2019 dt-pub=20190530 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Staphylococcus aureus aggregation in the plasma fraction of silkworm hemolymph en-subtitle= kn-subtitle= en-abstract= kn-abstract= Staphylococcus aureus formed bacterial aggregates in the plasma fraction of the hemolymph of silkworm, the larva of Bombyx mori, in a growth-dependent manner. The addition of arabinose or galactose inhibited the formation of S. aureus aggregates in the silkworm plasma. Formation of the bacterial aggregates depended on S. aureus genes required for the synthesis of bacterial surface polysaccharides-ypfP and ltaA, which are involved in lipoteichoic acid synthesis, and the tagO gene, which is involved in wall teichoic acid synthesis. These findings suggest that S. aureus forms bacterial aggregates in the silkworm plasma via bacterial surface teichoic acids. en-copyright= kn-copyright= en-aut-name=RyunoHiroki en-aut-sei=Ryuno en-aut-mei=Hiroki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NigoFuki en-aut-sei=Nigo en-aut-mei=Fuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NaguroIsao en-aut-sei=Naguro en-aut-mei=Isao kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=SekimizuKazuhisa en-aut-sei=Sekimizu en-aut-mei=Kazuhisa kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KaitoChikara en-aut-sei=Kaito en-aut-mei=Chikara kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil=Graduate School of Pharmaceutical Sciences, The University of Tokyo kn-affil= affil-num=2 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Pharmaceutical Sciences, The University of Tokyo kn-affil= affil-num=4 en-affil=Institute of Medical Mycology, Teikyo University kn-affil= affil-num=5 en-affil=Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University kn-affil= END