bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adsorption and Infectivity of Human Immunodeficiency Virus Type 1 Are Modified by the Fluidity of the Plasma Membrane for Multiple‐Site Binding
Authors: Harada Shinji , Akaike Takaaki , Yusa Keisuke , Maeda Yosuke 
Published: November 2013

AbstractBased on the assumption that fluidity of the plasma membrane and viral envelope is necessary for recruiting additional receptors and ligands to the initial attachment site for “multiple‐site binding,” we determined the effect of increased temperature on viral infectivity. Infection of human immunodeficiency virus type 1 (HIV‐1) and a pseudotyped luciferase‐expressing chimeric virus using MAGI and GHOST/CXCR4 cells showed that in 1 hr of viral adsorption the extent of virus infection and the amount of tightly adsorbed viruses depended on temperature; and that membrane fluidity increased according to increased temperature. Augmented infection was observed as post‐attachment enhancement (PAE) when cells were washed and incubated at 40 C for 1 hr after viral adsorption. PAE was completely inhibited by 1 μM of anti‐CXCR4 peptide T140, and addition of T140 at 20 min resulted in a gradual loss of inhibition of PAE, indicating the need for a 30 to 40 min timelag to ensure tight multiple‐site binding. These data suggest that the accumulation of gp120 and receptor complex (multiple‐site binding) was needed to complete the infection. Treatments of cells with 0.05% Tween 20 or 2 μg/ml of anti‐HLA‐II antibody resulted in increases or decreases, respectively, of attached viruses and the infectivity. As well, Tween 20 and anti‐HLA‐II antibody enhanced and suppressed the fluidity of the plasma membrane, respectively. Amounts of adsorbed viruses and degrees of viral infectivity correlated with the intensity of fluidity of the plasma membrane, probably due to the formation of multiple‐site binding.
Heterogeneity of Envelope Molecules Shown by Different Sensitivities to Anti‐V3 Neutralizing Antibody and CXCR4 Antagonist Regulates the Formation of Multiple‐Site Binding of HIV‐1
Authors: Harada Shinji , Yusa Keisuke , Maeda Yosuke 
Published: November 2013

AbstractIncreased temperature enhances the infectivity of human immunodeficiency virus type 1 (HIV‐1), and this enhancement is inhibited by anti‐CXCR4 peptide T140, implying that multiple‐site binding is required to proceed to infection. Here, we tested whether the augmented infectivity induced by increased temperature could account for the heterogeneity of envelope molecules in the effectiveness of anti‐V3 neutralization and anti‐CXCR4 blocking. Pseudoviruses with the X4 envelope which were infectious at room temperature (RT) were more resistant to both anti‐V3 neutralizing antibody 0.5β and T140 than viruses infectious at 37 C and 40 C. Viruses infectious to cells treated with T140 were also resistant to 0.5β. Based on the hypothesis that the HIV‐1 viruses were carrying heterogeneity of functional and nonfunctional gp120 and required the formation of sufficient multiple‐site binding of functional gp120 with receptors to proceed to infection, viruses with many functional gp120 which were infectious at RT and infectious to cells with reduced numbers of CXCR4 by T140 treatment were resistant to 0.5β. Although viruses with many functional gp120 are a minority (less than 5%) of the infectious HIV‐1 fraction, they are regarded as able to escape from neutralizing antibodies and coreceptor antagonists.
Phenotypic Switching and β‐N‐Acetylhexosaminidase Activity of the Pathogenic Yeast Trichosporon asahii
Authors: Ichikawa Tomoe , Sugita Takashi , Wang Li , Yokoyama Koji , Nishimura Kazuko , Nishikawa Akemi 
Published: November 2013

AbstractThe pathogenic yeast Trichosporon asahii is the major causative agent of deep‐seated trichosporonosis in immunocompromised patients. Although infection by this microorganism is becoming increasingly frequent, information related to its pathogenicity and virulence factors is still limited. Therefore, we investigated phenotypic switching in colony morphology, and the production of extracellular enzymes as a virulence factor. Sixty‐one clinical isolates of T. asahii produced four different morphological types on Sabouraud dextrose agar (SDA): 69% WF (white farinose), 18% WP (white pustular), 10% Y (yellowish white), and 3% WC (white cerebriform). Strains of the three major types (WF, WP, and Y) produced two to five colony types when cultured on SDA at 37 C. The frequency of switching between colony types was 10–2 to 10–4, as in Candida albicans and Cryptococcus neoformans. Notably, most of the colonies switched to the smooth (S) type irreversibly, at frequencies of 10–2 to 10–3. No secreted aspartic proteinase or phospholipase activity was detected in T. asahii, while β‐N‐acetylhexosaminidase activity, which catalyzes the hydrolysis of terminal nonreducing N‐acetyl‐D‐hexosamine residues in N‐acetyl‐β‐D‐hexosaminides, was found. Furthermore, enzymatic activity of the S type was significantly greater than that of the parent type in all strains. No other clinically relevant Trichosporon species (T mucoides, T inkin, and T ovoides) produced this enzyme. These results provide basal information for understanding the pathogenic potential of T asahii.
Introduction of 65 kDa Antigen of Mycobacterium tuberculosis to Cancer Cells Enhances Anti‐Tumor Effect of BCG Therapy
Authors: Hara Isao , Sato Noriyuki , Miyake Hideaki , Muramaki Mototsugu , Hikosaka Satoko , Kamidono Sadao 
Published: November 2013

AbstractBacillus Calmette Guerin (BCG) immunotherapy has anti‐tumorigenic effects against bladder cancer. To improve the efficacy of BCG therapy, we introduced the gene encoding the 65 kDa heat shock protein (hsp) of Mycobacterium tuberculosis into a mouse malignant melanoma cell line (B16). An expression vector harboring the 65 kDa antigen gene was transfected into B16 using Lipofectamine, then expression of the antigen was confirmed by RT‐PCR and Western blotting. Several cell lines expressing 65 kDa antigen were established (B16/65kDa). We also established a control cell line transfected with the vector alone (B16/con). All cell lines (B16, B16/con, B16/65kDa) were injected intraperitoneally into syngeneic mice with or without BCG prior immunization and the development of tumor ascites was examined. To analyze the mechanism of the anti‐tumor effect, CD4 T cells or CD8 T cells were depleted in vivo by administering the corresponding monoclonal antibody. B16/65kDa expressed the 65 kDa hsp of M. tuberculosis. The tumor growth of B16/65kDa was slightly retarded in naive mice, but significantly inhibited by BCG. The anti‐tumor effect was totally abrogated in mice deficient in CD4 T cells, suggesting that CD4 T cells are involved in this process. The 65 kDa hsp of M. tuberculosis was expressed after gene transduction in a malignant melanoma cell line and significantly enhanced the anti‐tumor effect of BCG immunotherapy. CD4 T cells play an important role in this anti‐tumor effect.
Complex Formation of CD23/Surface Immunoglobulin and CD23/CD81/MHC Class II on an EBV‐Transformed Human B Cell Line and Inferable Role of Tetraspanin
Authors: Kijimoto‐Ochiai Shigeko , Noguchi Atsutaka , Ohnishi Toshiyuki , Araki Yoshio 
Published: November 2013

AbstractCD23, a low‐affinity IgE receptor, is a type II transmembrane protein having a C‐type lectin domain and it associates noncovalently with MHC class II on B cells. The results of our immunoprecipitation analysis suggest that CD23 co‐exists with at least two additional molecules, surface immunoglobulin (sIg) and CD81 (and/or CD9), on the cell surface of L‐KT9 cells (an Epstein‐Barr virus (EBV)‐transformed human B cell line). When both CD23 and sIg molecules were stimulated simultaneously by the corresponding antibodies, a large increase in CD81 in the immunoprecipitation was observed as compared with the case of stimulation by only one antibody. Simultaneous stimulation by anti‐CD23 and anti‐Ig may mimic the situation of B cells stimulated by an antigen/IgE complex. In addition, a large increase in MHC class II in the immunoprecipitation was also observed by cross‐linking of CD23 with anti‐CD23 and its second antibody as compared with the case of stimulation by anti‐CD23 alone. The cross‐linking of CD23 with anti‐CD23 and its antibody may mimic the situation of B cells stimulated by an IgE/antigen/IgE complex. Therefore, the complex formation among CD23, sIg, MHC class II, and CD81 on the cell surface of L‐KT9 cells by the antigen/IgE or IgE/antigen/IgE complex is most likely to be closely related to B cell regulatory events by signaling through sIg or MHC class II. Tetraspanins such as CD81 and CD9 are thought to be involved in the formation and the preservation of various different membrane complexes consisting of several functional proteins.
IL‐7‐Dependent Homeostatic Proliferation in the Presence of a Large Number of T Cells in Gld Mice
Authors: Aranami Toshimasa , Iclozan Cristina , Iwabuchi Kazuya , Onoé Kazunori 
Published: November 2013

AbstractIn gld mice, CD4 and 8‐double‐negative (DN) T cells as well as naive and memory‐phenotype T cells accumulate in the peripheral lymphoid organs. Although Fas ligand (L) defect accounts for the progressive accumulation of abnormal DN T cells, the existence of other mechanisms which may be involved in the defective homeostasis in gld mice has been unclear. In this study, we analyze T‐cell homeostasis in gld mice using adoptive transfer systems. It was shown that a gld, but not C57BL/6 (B6), environment led to augmented proliferation of B6 T cells transferred without up‐regulation of CD69. Thus, the augmented T‐cell proliferation seemed to result from mal‐homeostatic proliferation even in the presence of a large number of recipient T cells. T cells from lpr mice showed no significant proliferation in the B6 environment, suggesting that the absence of Fas‐Fas L interaction was not responsible for the mal‐homeostatic proliferation. Although similar levels of IL‐7 mRNA were detected in gld and B6 spleens, the intensity of CD127 and the proportion of CD127+ cells in the T cells were significantly lower in gld mice than in B6 mice, suggesting that IL‐7 excess in a gld environment is responsible for the abnormal proliferation of transferred T cells. The administration of anti‐CD127 antibody inhibited the proliferation of transferred lymphocytes. Thus, IL‐7‐dependent proliferation seems to be involved in the abnormal proliferation of lymphocytes in gld recipients.
Reliability of the Detection of Meningococcal γ‐Glutamyl Transpeptidase as an Identification Marker for Neisseria meningitidis
Authors: Takahashi Hideyuki , Kuroki Toshiro , Watanabe Yuko , Dejsirilert Surang , Saengsuk Leelaowadee , Yamai Shiro , Watanabe Haruo 
Published: November 2013

AbstractDetection of γ‐glutamyl transpeptidase (GGT; ggt) activity is one of the useful methods for a specific identification of Neisseria meningitidis. However, we previously happened to isolate a ggt‐deficient N. meningitidis strain (NIID113) from a healthy carrier. In this study, in order to re‐examine the reliability of the marker, we again investigated the GGT activity of 245 N. meningitidis human isolates and identified two other GGT‐defective N. meningitidis isolates besides NIID113. The isolation frequency (1.2%) of ggt mutants among human isolates strongly confirmed the 98.8% reliability of GGT activity as the identification marker for N. meningitidis.
Effect of Silver‐Carrying Photocatalyst “Hikari‐Gintech” on Mycobacterial Growth In Vitro
Authors: Matsui Yoshifumi , Otomo Koji , Ishida Shinichiro , Yanagihara Kazuo , Kawanobe Yasutaka , Kida Shoji , Taruoka Eiichi , Sugawara Isamu 
Published: November 2013

AbstractThe antimycobacterial activity of “Hikari‐Gintech” powder, which has photocatalytic activity, was examined in vitro. Both powder dissolved in liquid and Hikari‐Gintech‐coated cloths showed strong antimycobacterial activity against Mycobacterium tuberculosis H37Rv, M. bovis BCG Pasteur, multi‐drug‐resistant M. tuberculosis (a clinical isolate) and M. avium. Hikari‐Gintech powder appeared to affect mycobacterial cell wall metabolism rather than mycobacterial DNA because no damage to mycobacterial DNA was detected after spraying with Hikari‐Gintech solution.
Antibody Reactive to a Hepatitis C Virus (HCV)‐Derived Peptide Capable of Inducing HLA‐A2 Restricted Cytotoxic T Lymphocytes Is Detectable in a Majority of HCV‐Infected Individuals without HLA‐A2 Restriction
Authors: Takao Yukari , Yamada Akira , Yutani Shigeru , Sata Michio , Itoh Kyogo 
Published: November 2013

AbstractHepatitis C virus (HCV) is a single‐strand RNA virus. Approximately 170 million people around the world are persistently infected and are at risk of liver cirrhosis or cancer. There is an urgent need to develop both therapeutic and diagnostic modalities of HCV. One approach to achieve these goals would be to determine highly immunodominant HCV peptides which are recognized by both cellular and humoral immunities. This study reports one such peptide, HCV‐core protein at positions 35–44, having HLA‐A2 binding motifs. IgG specific to this CTL‐epitope peptide is consistently detectable in a majority of the patients with HCV infection regardless of the different HLA types, different disease conditions, and different HCV‐genotypes tested. The sequence LPRR at positions 37–40 is considered to be the fine epitope recognized by the IgG. These results may provide new insights for the development of both therapeutic and diagnostic modalities of HCV at lower costs.
Ultrastructure of a Japanese Rickettsial Strain Genetically Identified as Rickettsia helvetica Which Was Originally Found in Europe
Authors: Yano Yasuhiro , Fujita Hiromi , Takada Nobuhiro 
Published: November 2013

AbstractA rickettsial strain IO‐1 has been isolated from a tick, Ixodes ovatus, in Japan and genetically identified as Rickettsia helvetica, a member of the spotted fever group rickettsiae. Ultrastructural observations were made on the microorganism. The ultrastructure of R. helvetica IO‐1 appeared to be generally the same as that previously shown for other rickettsiae of the spotted fever and typhus groups. The rickettsiae were primarily found free in the cytoplasm of L929 cultured cells. Occasionally, the rickettsiae may also invade the host cell nucleus; however, the frequency of the nuclear localization was very low.
Autolysis of Porphyromonas gingivalis Is Accompanied by an Increase in Several Periodontal Pathogenic Factors in the Supernatant
Authors: Kamaguchi Arihide , Nakano Miyo , Shoji Mikio , Nakamura Reiko , Sagane Yoshimasa , Okamoto Masaaki , Watanabe Toshihiro , Ohyama Tohru , Ohta Michio , Nakayama Koji 
Published: November 2013

AbstractPorphyromonas gingivalis autolyzes in the culture media. To examine in more detail the molecular components of the autolysate, two‐dimensional gel electrophoresis was performed. Many protein spots varied both in number and volume. One of these spots included Arg‐gingipain (Rgp) as determined by N‐terminal amino acid sequencing. Corresponding to the increase in spot volume, Rgp activity also increased during autolysis. The results of this study suggested that Rgp and other proteins in the P. gingivalis autolysate may be involved with the prolongation of periodontal disease, even after the death of P. gingivalis cells.
A Plasmid Encoding Japanese Encephalitis Virus PrM and E Proteins Elicits Protective Immunity in Suckling Mice
Authors: Wu Yushui , Zhang Fuquan , Ma Wenyu , Song Jianhua , Huang Qingsheng , Zhang Hongyi 
Published: November 2013

AbstractA plasmid encoding Japanese encephalitis virus (JEV) prM and E proteins was constructed, and its efficacy as a candidate vaccine against JEV was evaluated in suckling mice. Groups of 10 BALB/c mice (5–7 days old) were immunized twice via muscular injection with this DNA vaccine, an empty vector or PBS at an interval of 3 weeks, and were challenged with a lethal dose of JEV 3 weeks after the second inoculation. Both cellular and humoral immune responses were examined before the challenge. Two animals from each group were sacrificed to detect the JEV‐specific cytotoxic T lymphocyte activity. JEV‐specific lactate dehydrogenase release in the DNA vaccine, empty vector and PBS groups was 37.5%, 18% and 8.5% respectively. JEV‐specific antibody was detected in 8 of 10 animals in DNA vaccine group with a geometrical mean titer of 1:28.3. The pooled serum from the same group also showed a neutralizing activity. Six of 8 mice in the DNA vaccine group survived the challenge, with a protection rate of 75%, but all the mice died in the two control groups. These results show that this JEV prM and E DNA vaccine is immunogenic and protective against JEV infection in the mouse model.
The Role of IFN‐γ and Toll‐Like Receptors in Nephropathy Induced by Toxoplasma gondii Infection
Authors: Kudo Masamichi , Aosai Fumie , Mun Hye‐Seong , Norose Kazumi , Akira Shizuo , Iwakura Yoichiro , Yano Akihiko 
Published: November 2013

AbstractThe pathologic links between Toxoplasma gondii infections and renal diseases have not yet been established. Gamma interferon (IFN‐γ) and Toll‐like receptors (TLRs) are involved in the host defense mechanism against T. gondii infection. The role of IFN‐γ and TLRs in renal function of T. gondii‐infected mice was studied using wild type (WT), TLR2‐deficient and TLR4‐deficient mice perorally infected with cysts of an avirulent cyst‐forming Fukaya strain of T. gondii. T. gondii was abundant in kidneys in IFN‐γ KO (GKO) mice as determined by a quantitative competitive‐polymerase chain reaction (QC‐PCR). But, T. gondii was not detected in kidneys in WT, TLR2‐deficient and TLR4‐deficient mice. Interestingly, renal function of TLR2‐deficient and TLR4‐deficient mice was damaged as evaluated by serum creatinine, serum blood urea nitrogen (BUN), and urine albumin/creatinine ratio (ACR), whereas renal function of GKO and WT mice was not damaged. Histopathology of TLR2‐deficient mice exhibited glomerular and extracellular matrix swelling with advancing glomerular tissue proliferation, thickened Bowman's capsules and vacuolization of tubules. Renal immunofluorescence study of T. gondii‐infected TLR2‐deficient mice displayed positive staining of the glomerular basement membrane, mesangial areas and peritubular capillaries. The damage of kidney from TLR4‐deficient mice was less severe compared to TLR2‐deficient mice, and histopathological damage of kidney was not observed in WT and GKO mice. These results indicate that TLR2, but not IFN‐γ, plays a role in the protection of the renal function against T. gondii infection.
Amino‐Acid Residues Involved in the Expression of the Activity of Escherichia coli TolC
Authors: Yamanaka Hiroyasu , Morisada Naoyuki , Miyano Masaya , Tsuge Hideaki , Shinoda Sumio , Takahashi Eizo , Okamoto Keinosuke 
Published: November 2013

AbstractThe Escherichia coli TolC, composed of 471 amino‐acid residues, functions as a channel tunnel in the transport of various molecules across the outer membrane. We found previously that Leu‐412, the 60th amino‐acid residue from the carboxy terminal end, was crucial to the transport activity of TolC. Leu‐412 is located in a domain which protrudes from the main body of TolC into the periplasm. Subsequent study indicated that the hydrophobicity generated by Leu‐412 played an important role in the activity of TolC (H. Yamanaka, T. Nomura, N. Morisada, S. Shinoda, and K. Okamoto, Microb. Pathog. 33: 81–89, 2002). We predicted that other hydrophobic amino‐acid residues around Leu‐412 were also involved in the expression of the activity of TolC. To test this possibility, we substituted several hydrophobic residues around Leu‐412, (Leu‐3, Val‐6, Leu‐212, Leu‐213, Leu‐223, and Leu‐224), with serine and examined the activity of these mutant TolCs. The result showed that Leu‐3 is involved in the activity of TolC, but the other residues are not. The involvement of Leu‐3 was confirmed by the residue deletion experiment. A subsequent point‐mutational analysis of the residue showed that a hydrophobic side chain is required at position 3 for TolC to express its activity. As the distance between the α‐carbons of Leu‐3 and Leu‐412 is just 7.45 Å, hydrophobic interaction between the two leucine residues might be involved in the activity of TolC.
Consideration of Cysteine Protease Activity for Serological M‐Typing of Clinical Streptococcus pyogenes Isolates
Authors: Morita Masatomo , Ikebe Tadayoshi , Watanabe Haruo 
Published: November 2013

AbstractClinical isolates of Streptococcus pyogenes were classified by serological typing of their surface M protein. Non‐M typeable strains with the emm1 gene were characterized as the degradation of M protein caused by overproduction of the extracellular cysteine protease, SpeB. These events are dependent on the growth phase. M protein produced prior to expression of SpeB is degraded in the stationary phase when the active form of SpeB is detected. The proteolytic degradation of M protein should be considered for precise M typing analysis.
Studies on the Conditions Required for Structural and Functional Maturation of Rabies Virus Glycoprotein (G) in G cDNA‐Transfected Cells
Authors: Sakai Mai , Kankanamge Pushpa J. , Shoji Jun'ichi , Kawata Sanae , Tochikura Tadafumi S. , Kawai Akihiko 
Published: November 2013

AbstractWhen the rabies virus G cDNA was expressed with the help of T7 RNA polymerase provided by a recombinant vaccinia virus (RVV‐T7), functional G proteins were produced in terms of their ability to induce low pH‐dependent syncytium formation and the formation of conformational epitopes, including the acid‐sensitive epitope recognized by mAb #1‐30‐44. Such an ability and the 1‐30‐44 epitope formation, however, were not associated with the G gene products when G cDNA was expressed without the help of RVV‐T7 using a tetracycline‐regulated expression vector (pTet‐G), although they were normally transported to the surface of established G protein‐producing BHK‐21 (G‐BHK) cells. But, when the G‐BHK cells were treated with 2.5 MM sodium butyrate (NaB) after the removal of tetracycline, we could observe not only a much increased frequency of G protein‐producing cells, but also the greatly enhanced maturation of the protein. Another short acylate, sodium propionate (NaP), similarly induced increased G protein synthesis at a concentration of 2.5 MM as NaB; however, such proteins were mostly not endowed with the fusion activity nor the 1‐30‐44 epitope, while NaP at a higher concentration as 5.0 MM did induce similarly the increased production and enhanced maturation of G protein, including the 1‐30‐44 epitope formation. From these results, we conclude that functional maturation of G protein to acquire fusogenic activity is correlated with 1‐30‐44 epitope formation, and 2.5 MM NaB not only stimulates G protein production, but also provides such cellular conditions as are required for the structural and functional maturation of the protein.