bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential Level in Co‐Down‐Modulation of CD4 and CXCR4 Primed by HIV‐1 gp120 in Response to Phorbol Ester, PMA, among HIV‐1 Isolates
Authors: Tahara‐Hanaoka Satoko , Ushijima Yuki , Tarui Hiroshi , Wada Masayuki , Hara Toshio , Imanishi Shigeo , Yamaguchi Tomoyuki , Hattori Toshio , Nakauchi Hiromitsu , Koito Atsushi 
Published: November 2013

AbstractHIV‐1 enters cells through interacting with cell surface molecules such as CD4 and chemokine receptors. We generated recombinant soluble gp120s derived from T‐cell line‐tropic (T‐tropic) and macrophage‐tropic (M‐tropic) HIV‐1 strains using a baculovirus expression system and investigated the association of CD4‐gp120 complex with the chemokine receptor and/or other surface molecule(s). For monitoring the co‐down‐modulations of the CD4‐gp120 complex, a cytoplasmic domain deletion mutant (tailless CD4), which is not capable of undergoing down‐modulation by itself in response to phorbol ester PMA, was used. Our studies revealed both cell‐type and HIV‐1 strain‐specific differences. We found that T‐tropic gp120s were capable of priming co‐down‐modulation with tailless CD4 by interacting with CXCR4, whereas M‐tropic SF162 gp120 could not after PMA treatment even in the presence of CCR5. Among the T‐tropic HIV‐1 envelopes, IIIB gp120 was the most potent. Furthermore, the ability of gp120 to prime the PMA induced co‐down‐modulation of tailless CD4 appeared to be dependent on the concentration of the principal coreceptor CXCR4. Nevertheless, the observation that IIIB gp120 strongly primed tailless CD4 co‐down‐modulation on human osteosarcoma HOS cells that express undetectable levels of surface CXCR4 raised the possibility that membrane component(s) other than those recently identified can be involved in down‐modulation of the CD4/gp120 complexes.
Development of a Chromosome‐Plasmid Balanced Lethal System for Lactobacillus acidophilus with thyA Gene as Selective Marker
Authors: Fu Xiaoli , Xu Jian‐guo 
Published: November 2013

AbstractA chromosome‐plasmid balanced lethal gene delivery system for Lactobacillus acidophilus based on the thyA gene was developed. The selected L. acidophilus DOM La strain carries a mutated thyA gene and has an obligate requirement for thymidine. This strain can be used as a host for the constructed shuttle vector pFXL03, lacking antibiotic‐resistant markers but having the wild‐type thyA gene from L. casei which complements the thyA chromosomal mutation. The vector also contains the replicon region from plasmid pUC19 and that of the Lactococcus plasmid pWV01, which allows the transfer between Escherichia coli, L. casei and L. acidophilus. Eight unique restriction sites (i.e., PstI, HindIII, SphI, SafI, AccI, XbaI, KpnI and SacI) are available for cloning. After 40‐time transfers in modified MRS medium, no plasmid loss was observed. The vector pFXL03 is potentially useful as a food‐grade vaccine delivery system for L. acidophilus.
Heterogeneous Post‐Translational Modification of Actinobacillus actinomycetemcomitans Fimbrillin
Authors: Inoue Tetsuyoshi , Ohta Hiroyuki , Tanimoto Ichiro , Shingaki Ryuji , Fukui Kazuhiro 
Published: November 2013

AbstractFresh isolates of Actinobacillus actinomycetemcomitans produce bundle‐forming fimbriae. The exact molecular mass of A. actinomycetemcomitans fimbrillin, a structural subunit of fimbriae, was determined by liquid chromatography‐electrospray ionization mass spectrometry. Three major molecular species with 6,226.0, 6,366.0, and 6,513.0 Da were detected in a purified fimbrial fraction from the strain 310‐a. These molecular masses were significantly higher than the molecular weight (5,118 Da) calculated from nucleotide sequence data of the fimbrillin gene, flp, suggesting that the fimbrial peptides were post‐translationally modified. Modification of the fimbrial peptides was also suggested by an N‐terminal amino acid sequence analysis of fimbrillin peptic fragments, with the modified amino acids being due to seven serine or asparagine residues located in the C‐terminal region. A periodate oxidation/biotin‐hydrazide labeling assay of fimbrillin suggested that it might be glycosylated.
Nucleotide Sequencing and Transcriptional Analysis of Two Tandem Genes Encoding Glucosyltransferase (Water‐Soluble‐Glucan Synthetase) in Streptococcus cricetus HS‐6
Authors: Inoue Miho , Inoue Tetsuyoshi , Miyagi Atsushi , Tanimoto Ichiro , Shingaki Ryuji , Ohta Hiroyuki , Fukui Kazuhiro 
Published: November 2013

AbstractTwo tandem genes encoding glucosyltransferase synthesizing water‐soluble glucan (GTF‐S) were cloned from the lambda gene library of Streptococcus cricetus HS‐6 (serotype a) using anti‐GTF‐S antibody, and the nucleotide sequences were analyzed. The two genes (ORF1 and ORF2) were identified as streptococcal glucosyltransferases based on the following evidence: [1] the deduced amino acid sequences of their products have an active site for catalytic action and C‐terminal repeated units for dextran binding, and [2] a homology search revealed that the ORF1 and ORF2 products are homologous to the GtfS protein (77.4%) of S. downei Mfe28 and GtfT protein (83.8%) of S. sobrinus OMZ176, respectively, which are both known to have GTF‐S activity. Therefore, ORF1 and ORF2 might be designated gtfS and gtfT of S. cricetus, respectively. A Northern blotting and RNase protection assay suggested that the gtfS and gtfT of S. cricetus are transcribed as a single bicistronic mRNA as well as separate monocistronic mRNAs. Primer extension analysis indicated multiple transcriptional start points for each gene.
Adherence Protects the Binding Sites of Helicobacter pylori Urease from Acid‐Induced Damage
Authors: Icatlo Faustino C. , Yokoyama Hideaki , Kuroki Masahiko , Kobayashi Chizu , Goshima Hideo , Ikemori Yutaka , Kodama Yoshikatsu 
Published: November 2013

AbstractColonization by Helicobacter pylori partly depends on acid‐dependent adherence by urease to gastric mucin. To further verify the relevance of urease adherence to colonization, the influence of acidity on the binding sites of H. pylori urease was investigated. When enzyme‐based in vitro ligand capture assays were used, the effect of acidity on the binding site of H. pylori urease was determined against a backdrop medium consisting of acidic buffers simulating the luminal side of gastric mucus. A high degree of stability was exhibited by adherent urease, suggesting a pivotal role by the denatured enzyme in the persistence of the bacterium within the acidified compartment of gastric mucus.
Metal Content and Biochemical Analyses of a Recombinant Collagenase PrtV from Vibrio parahaemolyticus
Authors: Yu Mei‐shiuan , Yap Mee‐ngan , Lee Chia‐yin 
Published: November 2013

AbstractPrtV is an extracellular metalloprotease of Vibrio parahaemolyticus and regarded as a collagenase. Inductively coupled plasma‐optical emission spectrometry analysis indicated that the recombinant PrtV contains 1 mol of zinc per mol of the native enzyme. On the basis of a kinetic study using 2‐furanacryloyl‐Leu‐Gly‐Pro‐Ala (FALGPA, the specific substrate for bacterial collagenase) as a substrate, it was suggested that metal ions may play a significant role in the binding and catalytic steps of the substrate. PrtV hydrolyzed type I, II, III, and IV collagens; however, it did not hydrolyze type V. In addition, the hydrolysis of native proteins and synthetic substrates revealed that PrtV possesses higher activity toward collagen and collagenlike sequences. The result of the thermal stability study indicated that PrtV was thermostable up to 40 C; at 50 C, stability gradually decreased. In addition, PrtV showed higher storage stability at −20 and 4 C, respectively, than at 25 C. Compared with collagenases from Clostridium histolyticum and Vibrio alginolyticus, PrtV was immunologically different and had no significant effect on the growth of CHO, HeLa, and Vero cells. Taken together, the results of the studies described in this paper advance our knowledge concerning the metal content and biochemical properties of PrtV.
Functional Analysis of the Type III Secretion System in Enteropathogenic Escherichia coli O157: H45
Authors: Abe Akio , Nagano Hideki 
Published: November 2013

AbstractA mass outbreak of Escherichia coli O157:H45 was first reported in Japan in 1998. This pathogen was classified as an enteropathogenic E. coli (EPEC) O157 because it was characterized by the Shiga toxin gene (stx)‐negative and bundle‐forming pilus (bfp) gene‐positive genotypes. In this study, we investigated the type III secretion system in EPEC O157. Although no type III secreted proteins, Esps (E. coli‐secreted proteins), in EPEC O157:H45 were detectable in culture supernatant, secreted proteins were induced by the introduction of an EPEC plasmid‐encoded regulator, per. In further contrast to EHEC O157:H7, EPEC O157:H45 triggered the accumulation of tyrosine phosphorylated proteins beneath the adherent bacteria. These results suggest that regulation of the type III secretion apparatus and host signal transduction events between E. coli O157:H45 and O157:H7 are completely different.
Molecular Analysis of the folC Gene of Pseudomonas aeruginosa
Authors: Murata Takahiro , Bognar Andrew L. , Hayashi Tetsuya , Ohnishi Makoto , Nakayama Keisuke , Terawaki Yoshiro 
Published: November 2013

AbstractWe have cloned the Pseudomonas aeruginosa folC gene coding for folylpolyglutamate synthetase‐dihydrofolate synthetase, which was located between the trpF and purF loci, and determined the nucleotide sequence of the folC gene and its flanking region. The deduced amino acid sequence of P. aeruginosa FolC was highly homologous to that of Escherichia coli FolC. The cloned gene complemented E. coli folC mutations and was found to encode both folylpolyglutamate synthetase and dihydrofolate synthetase activities. The gene organization around the folC gene in P. aeruginosa was completely conserved with that in E. coli; the accD gene was located upstream of the folC gene, and dedD, cvpA and purF genes followed the folC gene in this order. The gene arrangement and the result of the promoter activity assay suggested that the P. aeruginosa accD and folC genes were co‐transcribed.
Decline in the HIV‐1 Isolation Rate in Japan: A 12‐Year Observation
Authors: Nakasone Tadashi , Takamatsu Junki , Watanabe Kuhomi , Naganawa Satoshi , Someya Kenji , Yoshino Naoto , Kaizu Masahiko , Ohsu Takeaki , Takizawa Mari , Izumi Yasuyuki , Kawahara Mamoru , Hara Takashi , Fujimura Yoshihiro , Yamada Kaneo , Nagai Yoshiyuki , Yamazaki Shudo , Honda Mitsuo 
Published: November 2013

AbstractSince 1988, we have isolated HIV‐1 from 614 HIV‐1‐infected persons (total sample = 2,785) in Japan. During the past 12 years, we have found a decline in the HIV‐1 isolation rate in Japan, with two identifiable turning points, 1991–1992 and 1996–1997. The two turning points correspond to shifts in anti‐HIV‐1 therapy. These findings suggest that HIV‐1 in Japan is currently biologically well controlled, probably due to anti‐HIV‐1 therapy. On the other hand, this decline is inconsistent with the recent increase of genetic drug‐resistant HIV‐1 in Japan. Further studies are needed to clarify mechanisms that might explain the discrepancy.
Characterization of a Novel Vibrio parahaemolyticus Phage, KVP241, and Its Relatives Frequently Isolated from Seawater
Authors: Matsuzaki Shigenobu , Inoue Tetsuyoshi , Tanaka Shuji , Koga Tetsuro , Kuroda Masayuki , Kimura Susumu , Imai Shosuke 
Published: November 2013

AbstractA vibriophage, KVP241, and six of its relatives were isolated independently from seawater using Vibrio parahaemolyticus as the host. All of the phages had the same morphology (a hexagonal head and a tail with a contractile sheath) and the same host range (specific for some V. parahaemolyticus strains). DNA‐DNA hybridization experiments elucidated that their genomes are highly homologous to each other. Analyses of amino acid sequences of putative major capsid proteins indicated that KVP241 may be weakly related to T4‐type phages having a more elongated head.
IL‐4 Is Required for Defense against Mycobacterial Infection
Authors: Sugawara Isamu , Yamada Hiroyuki , Mizuno Satoru , Iwakura Yoichiro 
Published: November 2013

AbstractAlthough the involvement of T helper (Th1) cells is central to protection against intracellular bacteria, including Mycobacterium tuberculosis, the involvement of Th2 cells, characterized by potent interleukin (IL)‐4 secretion in mycobacterial infection is still unclear. In order to clarify the role of IL‐4 in murine tuberculosis, IL‐4‐deficient mutant mice, IL‐4 knockout (IL‐4 KO) mice, were utilized. The mice were infected with H37Rv, Kurono or BCG Pasteur via an airborne infection route by placing them in the exposure chamber of a Middlebrook airborne infection apparatus. Their capacity to control mycobacterial growth, granuloma formation, cytokine secretion, and nitric oxide (NO) production were examined. These mice developed large granulomas, but not necrotic lesions in the lungs, liver or spleen (P < 0.05). This was consistent with a significant increase in lung colony‐forming units (CFU). Compared with levels in wild‐type mice, upon stimulation with mycobacteria, splenic IL‐10 levels were low and IL‐6 levels were intermediate, but interferon (IFN)‐γ and IL‐12 levels were significantly higher. IL‐18 levels were within the normal range. The level of NO production by alveolar macrophages of the IL‐4 KO mice was similar to that of the wild‐type mice. Granulomatous lesion development by IL‐4 KO mice was inhibited significantly by treatment with exogenous recombinant IL‐4. These findings were not specific to the IL‐4 KO mice used. Our data show that IL‐4 may play a protective role in defense against mycobacteria, although IFN‐γ and TNF‐α play major roles in it. Our data do not rule out an IFN‐γ‐independent function of IL‐4 in controlling tuberculosis.
Salmonella typhimurium Induces Apoptosis in Human Monocyte‐Derived Macrophages
Authors: Zhou Xin , Mantis Nicholas , Zhang Xiao‐ru , Potoka Douglas A. , Watkins Simon C. , Ford Henri R. 
Published: November 2013

AbstractSalmonella species represent a leading cause of gastroenteritis worldwide. More recently, they have been proposed as putative vaccine delivery vehicles in humans. Oral infection with Salmonella leads to invasion of the intestinal epithelial barrier and subsequent interaction with mucosal macrophages. In this study, we investigated the fate of Salmonella typhimurium‐infected human macrophages differentiated from blood monocytes by GM‐CSF. Wild type S. typhimurium strain SL1344 induced macrophage surface blebbing and caused the release of host cytoplasmic lactate dehydrogenase beginning 30 min post‐infection. Three hours later more than 80% of the macrophages in the culture were killed. In contrast, during the same period, macrophages infected with the non‐invasive S. typhimurium strain BJ66 remained viable. Chromatin fragmentation is a hallmark of cells undergoing apoptosis. Using TUNEL analysis, we observed chromatin fragmentation in macrophages infected with SL1344 but not in BJ66 infected cells. Consistent with this observation, we found that pretreatment of human macrophages with an inhibitor of caspase‐3, a member of the pro‐apoptotic enzyme family shown to be involved in S. typhimurium‐induced killing of mouse macrophages, reduced SL1344‐mediated cytotoxicity by 40%. Our study provides the first evidence that invasive S. typhimurium induces apoptosis in human macrophages that were differentiated from blood monocytes by GM‐CSF, and that cell death is a caspase‐dependent phenomenon.
Circulating Soluble CD4 Directly Prevents Host Resistance and Delayed‐Type Hypersensitivity Response to Cryptococcus neoformans in Mice
Authors: Kawakami Kazuyoshi , Koguchi Yoshinobu , Qureshi Mahboob Hossain , Yara Satomi , Kinjo Yuki , Miyazato Akiko , Nishizawa Akio , Nariuchi Hideo , Saito Atsushi 
Published: November 2013

AbstractIn the present study, we examined the effect of soluble CD4 (sCD4) on host resistance and delayed‐type hypersensitivity (DTH) response to Cryptococcus neoformans using a novel mutant mouse that exhibits a defect in the expression of membrane‐bound CD4 but secretes high levels of sCD4 in the serum. In these mice, host resistance to this pathogen was impaired as indicated by an increased number of live pathogens in the lung. To elucidate the mechanism of immunodeficiency, three different sets of experiments were conducted. First, administration of anti‐CD4 mAb restored the attenuated host defense. Second, in CD4 gene‐disrupted (CD4KO) mice, host resistance was not attenuated compared to control mice. Third, implantation of sCD4 gene‐transfected myeloma cells rendered the CD4KO mice susceptible to this infection, while similar treatment with mock‐transfected cells did not show such an effect. These results indicated that immunodeficiency in the mutant mice was attributed to the circulating sCD4 rather than to the lack of CD4+ T cells. In addition, DTH response to C. neoformans evaluated by footpad swelling was reduced in the mutant mice compared to that in the control, and the reduced response was restored by the administration of anti‐CD4 mAb. Finally, serum levels of IFN‐γ, IL‐12 and IL‐18 in the mutant mice were significantly reduced, while there was no difference in Th2 cytokines, such as IL‐4 and IL‐10. Considered collectively, our results demonstrated that sCD4 could directly prevent host resistance and DTH response to C. neoformans through interference with the production of Th1‐type cytokines.
Molecular Cloning of Rat NK Target Structure —The Possibility of CD44 Involvement in NK Cell‐Mediated Lysis
Authors: Kanki Kazushige , Torigoe Toshihiko , Hirai Itaru , Sahara Hiroeki , Kamiguchi Kenjiro , Tamura Yasuaki , Yagihashi Atsuhito , Sato Noriyuki 
Published: November 2013

AbstractThe nature of target molecules of natural killer (NK) cell‐mediated lysis remains to be elucidated. As we previously reported, mAb 109 recognizes one of the tumor‐associated antigens, designated as 109 antigen (Ag), expressed on the cell surface of rat fibrosarcomas W31 and W14, which are transformants of WFB (rat fetal fibroblast cell line) with H‐ras oncogene. 109Ag was thought to be a target structure of NK cells since mAb 109 inhibited NK cell‐mediated lysis against W31 and W14. Here, we demonstrate by molecular cloning that 109Ag is identical to rat CD44. Immunoprecipitation and immunoblotting studies also showed that mAb 109 and anti‐rat CD44 mAb OX‐50 recognize the same protein of W31 cell lysates with an 86 kDa molecular size. CD44 was suggested to be a target structure of NK cell‐mediated lysis; however, rat CD44 cDNA transfection alone into CD44 null cell lines did not result in up‐regulation of target cell susceptibility to NK cell‐mediated lysis. Our results therefore indicated that CD44 may play a crucial role as one of the target structures in our rat fibrosarcoma system though the cell surface expression of CD44 alone does not affect NK susceptibility of the target cells.
A Simple and Rapid Method for Purifying Staphylococcal Exfoliative Toxin A
Authors: Yamazaki Taisuke , Sakurai Susumu , Matsuo Naruto , Machida Katsuhiko , Kohno Minoru 
Published: November 2013

AbstractA rapid and efficient method of purification of staphylococcal exfoliative toxin A, the causative agent of staphylococcal scalded skin syndrome (SSSS), has been developed. It is based on ammonium sulfate precipitation of the culture supernatant and hydrophobic interaction chromatography on Phenyl‐Sepharose CL‐4B. This procedure results in 87‐fold purification of this toxin, which appears as a single band in sodium dodecyl sulfate‐polyacrylamide gels.
A Role for Lipid Rafts in Immune Cell Signaling
Authors: Katagiri Yohko U. , Kiyokawa Nobutaka , Fujimoto Junichiro 
Published: November 2013

AbstractCross‐linking of surface receptors in hematopoietic cells results in the enrichment of these receptors in the rafts along with other downstream signaling molecules. A possible explanation how signal is transduced through the plasma membrane has arisen from the concept of raft. From the study of cellular responses in the plasma membrane which enrich members of the Src‐family tyrosine kinase, rafts can function as centers of signal transduction by forming patches. Under physiological conditions, these elements synergize to transduce successfully a signal at the plasma membrane. Rafts are suggested to be important in controlling appropriate protein interactions in hematopoietic cells, and aggregation of rafts following receptor ligation may be a general mechanism for promoting immune cell signaling.
Effect of Constitutively Expressed phoP Gene on the Localization of Salmonella typhimurium within Mac‐1 Positive Phagocytes
Authors: Matsui Hidenori , Eguchi Masahiro , Kikuchi Yuji 
Published: November 2013

AbstractIntracellular localization of the wild‐type (Spv+), the phoP‐constitutively expressed strain (PhoPc), and the spv‐deleted strain (Spv–) of Salmonella typhimurium was examined by the use of confocal laser scanning microscopy analysis of immunostained sections of mouse spleens after oral or subcutaneous inoculation. Only 40% of salmonellae of both the PhoPc and the Spv– strains were detected intracellularly within Mac‐1 positive cells at day five after oral or day four after subcutaneous inoculation. In contrast, over 85% of salmonellae of the Spv+ strain were detected inside Mac‐1 positive cells. In both inoculation trials, the splenic colony‐forming unit values for the PhoPc and Spv– strains were significantly lower than the corresponding value for the Spv+ strain. These findings suggest that the constitutively expressed phoP gene of S. typhimurium attenuated virulence by limiting intracellular proliferation within mouse spleen phagocytes, and that the lack of spv genes had the same effect.
A Nested PCR Assay to Detect DNA in Sera for the Diagnosis of Deep‐Seated Trichosporonosis
Authors: Sugita Takashi , Nakajima Masamitsu , Ikeda Reiko , Niki Yoshihito , Matsushima Toshiharu , Shinoda Takako 
Published: November 2013

AbstractDeep‐seated trichosporonosis caused by Trichosporon asahii has a high mortality rate and a very poor prognosis. New species‐specific oligonucleotide primers for T. asahii were developed from a sequence analysis of rRNA genes that included the internal transcribed spacer regions. A nested PCR assay with specific primers was used to examine 11 serum samples from 7 patients, who were diagnosed with deep‐seated trichosporonosis histologically at autopsy. In addition, Trichosporon cell wall polysaccharide (PS) was detected by a latex agglutination (LA) test. Of 11 samples, seven had a positive LA test, and T. asahii DNA was also detected with the nested PCR assay. Of the four samples in which PS antigen was not detected, the nested PCR of two samples was positive. Our new nested PCR assay may be used as an adjunct to conventional methods for diagnosing T. asahii infection.
Chemotaxis of Oral Treponemes toward Sera and Albumin of Rabbit
Authors: Umemoto Toshihiko , Jinno Takayashi , Taiji Yasuhiro , Ogawa Tomohiko 
Published: November 2013

AbstractThe motility and chemotaxis of human oral spirochetes Treponema denticola ATCC 35404, T. medium ATCC 700293, and T. vincentii ATCC 35580 were examined by a capillary assay method. Of five sera three human oral treponemes were dominantly chemoattractant to the rabbit serum. The checkerboard analysis of chemotaxis toward rabbit serum clearly showed that the motile T. denticola cells swam toward the culture media containing higher concentrations of the rabbit serum. T. denticola chemotaxis to the rabbit serum was clearly reduced by heating serum, and rabbit albumin contributed by 60 to 70% to its chemotaxis to the rabbit serum. Western blotting analysis demonstrated that these treponemes possessed rabbit albumin‐binding polypeptides with approximate molecular sizes of 65 kDa and 70 kDa. Immunoelectron microscopy demonstrated that a 65 kDa rabbit albumin‐binding polypeptide was located on the outer envelopes, suggesting that the rabbit albumin‐binding polypeptide is responsible for chemotaxis toward rabbit serum.