scholarly journals Characterization of Chemically-Induced Bacterial Ghosts (BGs) Using Sodium Hydroxide-Induced Vibrio parahaemolyticus Ghosts (VPGs)

Author(s):  
Hyun Jung Park ◽  
Sung Oh ◽  
Nagarajan Vinod ◽  
Seongmi Ji ◽  
Han Byul Noh ◽  
...  

Acellular bacterial ghosts (BGs) are empty non-living bacterial cell envelopes, commonly generated by controlled expression of the cloned lysis gene E of bacteriophage PhiX174. In this study, Vibrio parahaemolyticus ghosts (VPGs) were generated by chemically induced lysis and the method is based on minimum inhibitory concentration (MIC) of sodium hydroxide (NaOH), acetic acid, boric acid, citric acid, maleic acid, hydrochloric acid and sulfuric acid. The MIC values of the respective chemicals were 3.125, 6.25, < 50.0, 25.0, 6.25, 1.56 and 0.781 mg/ml. Except boric acid, the lysis efficiency was reached more than 99.99% at 5 min after treatment of all chemicals. Among those chemicals, NaOH-induced VPGs showed completely DNA-free that was confirmed by quantitative real-time PCR. Besides, lipopolysaccharides (LPS) extracted from the NaOH-induced VPGs showed no distinctive band on SDS-PAGE gel after silver staining. On the other hand, LPS extracted from wild-type bacterial cells as well as the organic acids-induced VPGs showed triple major bands and LPS extracted from the inorganic acids-induced VPGs showed double bands. It suggests that some surface structures in LPS of the NaOH-induced VPGs may be lost, weakened or modified by the MIC of NaOH. Nevertheless, Limulus amoebocyte lysate assay revealed that there is no significant difference in endotoxic activity between the NaOH-induced VPGs and wild-type bacterial cells. Macrophages exposed to the NaOH-induced VPGs at 0.5 × 106 CFU/mL showed cell viability of 97.9%, however the MIC of NaOH did not reduce the cytotoxic effect of wild-type bacterial cells. Like Escherichia coli LPS, the NaOH-induced VPGs are an excellent activator of pro-inflammatory cytokines (IL-1β and iNOS), anti-inflammatory cytokine (IL-10) and dual activities (IL-6) in the stimulated macrophage cells. On the other hand, the induction of TNF-α mRNA was remarkable in the macrophages exposed with wild-type cells. Scanning electron microscopy showed the formation of trans-membrane lysis tunnel structures in the NaOH-induced VPGs. SDS-PAGE and agarose gel electrophoresis also confirmed that cytoplasmic proteins and genomic DNA released from the VPGs to culture medium through the lysis tunnel structures. Taken together, all these results indicated that the NaOH-induced VPGs show the potency of safe, economical and effective inactivated bacterial vaccine candidate.

1976 ◽  
Vol 31 (5-6) ◽  
pp. 285-287 ◽  
Author(s):  
Helmut Rappold ◽  
Adelbert Bacher

Abstract Aerobacter aerogenes mutant 62-1 AC requires high concentrations of 4-aminobenzoate for growth. The mutant accumulates N-glucosyl-4-aminobenzoate and has an intact 4-aminobenzoate synthetase (Bacher, Gilch, Rappold, and Lingens, Z. Naturforsch. 28c, 614 - 617 [1973]). On the other hand the ability of the mutant to synthesize dihydropteroate is markedly reduced. The dihydropteroate synthetase level of mutant 62-1 AC is 1% as compared to the parent strain. Spontaneous revertants of mutant 62-1 AC show wild type levels of dihydropteroate synthetase. We conclude that the requirement for 4-aminobenzoate in mutant 62-1 AC is due to poor utilization of 4-aminobenzoate as a consequence of the low level of dihydropteroate synthetase activity.


Blood ◽  
1999 ◽  
Vol 93 (5) ◽  
pp. 1540-1548 ◽  
Author(s):  
Hirohiko Shibayama ◽  
Naoyuki Anzai ◽  
Stephen E. Braun ◽  
Seiji Fukuda ◽  
Charlie Mantel ◽  
...  

Abstract The proto-oncogene product, p21ras, has been implicated in the cellular mechanism of adhesion, although its precise role has been controversial. Numerous cytokines and growth-factors activate Ras, which is an important component of their growth-promoting signaling pathways. On the other hand, the role of Ras in cytokine-induced adhesion has not been elucidated. We therefore investigated the function of H-Ras in the inside-out signaling pathway of interleukin-3 (IL-3)–induced integrin activation in the murine Baf3 cell line after transfection of cells with either constitutively active, dominant-negative, or wild-type H-Ras cDNAs. Adhesion of Baf3 cells to fibronectin was induced by IL-3 in a dose-dependent manner via very late antigen-4 (VLA-4; 4β1 integrins) and VLA-5 (5β1 integrins) activation. On the other hand, IL-4 did not induce the adhesion of Baf3 cells to fibronectin, although IL-4 did stimulate the cell proliferation of Baf3 cells. Constitutively active H-Ras–transfected Baf3 cells adhered to fibronectin without IL-3 stimulation through VLA-4 and VLA-5, whereas dominant-negative H-Ras–transfected Baf3 cells showed significantly less adhesion induced by IL-3 compared with wild-type and constitutively active H-Ras–transfected Baf3 cells. Anti-β1 integrin antibody (clone; 9EG7), which is known to change integrin conformation and activate integrins, induced the adhesion of dominant-negative H-Ras–transfected Baf3 cells as much as the other types of H-Ras–transfected Baf3 cells. 8-Br-cAMP, Dibutyryl-cAMP, Ras-Raf-1 pathway inhibitors, and PD98059, a MAPK kinase inhibitor, suppressed proliferation and phosphorylation of MAPK detected by Western blotting with anti–phospho-MAPK antibody, but not adhesion of any type of H-Ras–transfected Baf3 cells, whereas U-73122, a phospholipase C (PLC) inhibitor, suppressed adhesion of these cells completely. These data indicate that H-Ras and PLC, but not Raf-1, MAPK kinase, or the MAPK pathway, are involved in the inside-out signaling pathway of IL-3–induced VLA-4 and VLA-5 activation in Baf3 cells.


1994 ◽  
Vol 126 (3) ◽  
pp. 737-745 ◽  
Author(s):  
S Takada ◽  
R Kamiya

The outer dynein arm of Chlamydomonas flagella, when isolated under Mg(2+)-free conditions, tends to dissociate into an 11 to 12S particle (12S dynein) containing the gamma heavy chain and a 21S particle (called 18S dynein) containing the alpha and beta heavy chains. We show here that functional outer arms can be reconstituted by the addition of 12S and 18S dyneins to the axonemes of the outer armless mutants oda1-oda6. A third factor that sediments at integral 7S is required for efficient reconstitution of the outer arms on the axonemes of oda1 and oda3. However, this factor is not necessary for reconstitution on the axonemes of oda2, oda4, oda5, and oda6. SDS-PAGE analysis indicates that the axonemes of the former two mutants lack a integral of 70-kD polypeptide that is present in those of the other mutants as well as in the 7S fraction from the wild-type extract. Furthermore, electron micrographs of axonemal cross sections revealed that the latter four mutants, but not oda1 or oda3, have small pointed structures on the outer doublets, at a position in cross section where outer arms normally occur. We suggest that the 7S factor constitutes the pointed structure on the outer doublets and facilitates attachment of the outer arm. The discovery of this structure raises a new question as to how the attachment site for the outer arm dynein is determined within the axoneme.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Yusei Kawahara ◽  
Miwa Ito ◽  
Tadashi Hoshiyama ◽  
Hisanori Kanazawa ◽  
Kenichi Tsujita

Background and Objectives: It has been shown that cardiac conduction disorders can be seen in patients with wild-type amyloidogenic transthyretin (ATTRwt) and variant ATTR (ATTRv) cardiac amyloidosis. However, its appropriate timing of pacemaker implantation has not been clarified yet. Methods and Results: The consecutive 100 patients with ATTRwt cardiac amyloidosis who diagnosed by myocardium biopsy and/or technetium-99m-pyrophosphate scintigraphy and 62 patients with ATTRv cardiac amyloidosis who diagnosed by means of genetic screening were included in this study. In patients with ATTRwt cardiac amyloidosis, 21 patients have normal conduction at the time of diagnosis. However, conduction disorder had seen in only 5 patient (first degree atrioventricular block (AVB); 4 patients, complete AVB; 1 patients) and only one patient underwent cardiac implantable electric device (CIED) implantation during follow-up period. On the other hand, in patients with ATTRv cardiac amyloidosis, 36 patients have normal conduction at the time of diagnosis. However, conduction disorder had seen in 13 patient (first degree AVB; 8 patients, second degree AVB; 3 patients, trifascicular block; 1 patients, complete AVB; 1 patients) (5/21 vs 13/36, p=0.335) and 6 patients underwent CIED implantation during follow-up period (1/21 vs 6/36, p=0.186). Furthermore, in ATTRwt cardiac amyloidosis, 10 patients (first degree AVB; 2 patients, second degree AVB; 1 patient, trifascicular block; 7 patients) had underwent CIED implantation because of cardiac conduction disorders and/or prevention of sudden cardiac death. However, only 4 patients with trifascicular block progressed to complete AVB.On the other hand, In ATTRv cardiac amyloidosis, 14 patients (first degree AVB; 2 patients, second degree AVB; 4 patient, trifascicular block; 8 patients) had underwent CIED implantation for same reason. However, only 3 patients with trifascicular block progressed to complete AVB. Conclusions: Patients with ATTRv cardiac amyloidosis were more likely to progress conduction disorders than those with ATTRwt cardiac amyloidosis. However, prophylactic pacemaker implantation might had not need in both ATTRwt and ATTRv patients with first or second degree AVB.


2007 ◽  
Vol 81 (20) ◽  
pp. 11106-11115 ◽  
Author(s):  
Kahori Minami ◽  
Yukihiro Tambe ◽  
Ryosuke Watanabe ◽  
Takahiro Isono ◽  
Masataka Haneda ◽  
...  

ABSTRACT GADD34 is a protein that is induced by a variety of stressors, including DNA damage, heat shock, nutrient deprivation, energy depletion, and endoplasmic reticulum stress. Here, we demonstrated that GADD34 induced by vesicular stomatitis virus (VSV) infection suppressed viral replication in wild-type (WT) mouse embryo fibroblasts (MEFs), whereas replication was enhanced in GADD34-deficient (GADD34-KO) MEFs. Enhanced viral replication in GADD34-KO MEFs was reduced by retroviral gene rescue of GADD34. The level of VSV protein expression in GADD34-KO MEFs was significantly higher than that in WT MEFs. Neither phosphorylation of eIF2α nor cellular protein synthesis was correlated with viral replication in GADD34-KO MEFs. On the other hand, phosphorylation of S6 and 4EBP1, proteins downstream of mTOR, was suppressed by VSV infection in WT MEFs but not in GADD34-KO MEFs. GADD34 was able to associate with TSC1/2 and dephosphorylate TSC2 at Thr1462. VSV replication was higher in TSC2-null cells than in TSC2-expressing cells, and constitutively active Akt enhanced VSV replication. On the other hand, rapamycin, an mTOR inhibitor, significantly suppressed VSV replication in GADD34-KO MEFs. These findings demonstrate that GADD34 induced by VSV infection suppresses viral replication via mTOR pathway inhibition, indicating that cross talk between stress-inducible GADD34 and the mTOR signaling pathway plays a critical role in antiviral defense.


Amylase ◽  
2018 ◽  
Vol 2 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Takashi Tonozuka ◽  
Takanori Nihira ◽  
Masahiro Mizuno ◽  
Atsushi Nishikawa ◽  
Shigehiro Kamitori

Abstract An α-amylase from Thermoactinomyces vulgaris, TVA I, hydrolyzes both α-1,4- and α-1,6-glucosidic linkages. Two variants of TVA I have been previously constructed, one containing a substitution of three residues, Ala357- Gln359-Tyr360, with Val-Asn-Glu (AQY/VNE), and the other bearing a deletion of 11 residues from Ala363 to Asn373 (Del11). The activities of both AQY/VNE and Del11 for the α-1,4-glucosidic linkage of maltotriose were decreased compared to that of wild-type TVA I, while the activities of the two variants for the α-1,6-glucosidic linkage of a trisaccharide, isopanose, were less significantly altered. Here, we determined the crystal structures of AQY/VNE and Del11. The structure of AQY/VNE was almost isomorphous with that of wild-type TVA I. On the other hand, the structure of Del11 showed that a conformational change in domain B was induced by the 11-residue deletion, causing narrowing of the catalytic cleft. Taken together with the results of kinetic analysis, this narrower catalytic cleft is likely responsible for the preference of the TVA I enzyme for the α-1,6-glucosidic linkage.


2000 ◽  
Vol 76 (2) ◽  
pp. 125-133 ◽  
Author(s):  
ATSUSHI MATSUDA ◽  
YOSHIRO SAIMI ◽  
MIHOKO TAKAHASHI

A non-excitable behavioural mutant, d4-662, was previously characterized as the fourth pawn locus mutant pwD in Paramecium tetraurelia. We now provide data demonstrating that d4-662 is in fact controlled by a pwB allele that has the unusual feature of complementing other pwB alleles in heterozygous F1 progeny. Neither the cytoplasm nor the nucleoplasm of d4-662 cured the mutational defects of pwB and in the reverse combination of d4-662 and pwB, the result was the same. On the other hand, pwA, another non-excitable mutant, was cured upon cross-injection with d4-662 and mutants carrying trichocyst non-discharge marker genes were also cured. This evidence suggests that d4-662 is a new mutant belonging to pwB, and would be better designated as pwB662. Extensive crossbreeding analyses, however, showed an unusual genetic relationship between d4-662 and pwB (pwB95 or pwB96). When d4-662 was crossed with pwB mutants, many progeny expressing wild-type phenotype or mixed clones of wild-type and pawn cells were obtained in the F1. Less than 12·5% expressed the pawn phenotype. The appearance of wild-type progeny in this F1 strongly suggests that an inter-allelic interaction between pwB662 and other pwB alleles may occur during development of the macronucleus.


2021 ◽  
Vol 25 (4) ◽  
pp. 561-566
Author(s):  
F.E. Otitigbe

Maintaining the pH of drilling fluid with suitable additives is one of the important operation for efficient drilling operations.  However, commercial hydroxides are mostly used to control the pH of the drilling fluid. This paper evaluates locally sourced pH additives of burnt plantain heads (BPH), burnt ripe burnt ripe plantain peels (BRPP), and burnt banana plantain peels (BBPP) in comparison with conventional potassium hydroxide (KOH) and sodium hydroxide (NaOH) as suitable agents to control pH of drilling fluid. The drilling fluid as prepared with bentonite and local clay in different concentrations of KOH, NaOH, BPH, BRPP and BBRPP including Traona. The result of the study showed that pH of the drilling improved with respective use of conventional KOH, NaOH, BPH, BRPP and BBRPP as additives. In addition, KOH showed the maximum percentage of degree (%) of improvement on the drilling fluid with 38.46-45.45% compared with 27.2-40% for NaOH. On the other hand, BRPP achieved 27.2-41.2%, followed with 20-33% and 20-29.4% for BPH and BBPP respectively. Thus, the locally sourced additives could be used to enhance the pH and properties of drilling fluid.


2009 ◽  
Vol 3 (2) ◽  
pp. 29-40
Author(s):  
Wasan Abbood ◽  
Alice Krekor

The Hydrophobicity of the seven isolates of L.acidophilus were detected by applying BATH test (Bacterial Adherence To Hydrocarbons) using xylene. The percentage of Hydrophobicity of the isolates ranged between 28-88% and the differences between the rates were significant (P<0.05). There was three hydrophobic isolates. The autoaggregation ability of the three isolates was tested by using the supernatant of MRS and LAPTg media in which the bacteria was cultivated for 24 hr. The results revealed that the three isolates were more aggregative in LAPTg supernatant. The percentage of the aggregation ranged between 70- 83.3% .On the other hand the percentage of the autoaggregation using MRS supernatant ranged between 30-70%. The nature of the surface and secreted factors which are responsible for the autoaggregation were determined by treatment of the bacterial cells and their LAPTg supernatants by proteinase K, lipase and sodium periodate. Results obtained indicated that the two types of these factors were proteins because of the inhibition of the aggregation after either the treatment of cells or the supernatants by proteinase K, and it's resistance to treatment with lipase or sodium periodate.


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