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1.
Bacillus firmus strongly stimulates Ig synthesis in the cultures of human peripheral blood mononuclear leukocytes. As apparent from the character
of Ig formation and blastic transformation, the stimulation has features of a polyclonal activation of B lymphocytes without
substantial participation of T lymphocytes.B. firmus is a strong B cell polyclonal activator even for human cord blood lymphocytes. The most striking feature is the strong stimulation
of IgA synthesis in both adult and cord blod lymphocytes. Several crude fractions were isolated fromB. firmus. None of them exhibited any remarkable enhancement of activity but the cytoplasmic fraction P-40 was clearly more potent
than the intact bacilli. On the other hand, cell wall peptidoglycan, a well known polyclonal activator of B cells, had a much
lower activity than whole bacteria. The effect ofB. firmus on the stimulation of Ig formation is thus relatively complex; it is not caused mainly by peptidoglycan but rather by some
cytoplasmic constituents of the bacterium.
Dedicated to Professor C. John on the occasion of his 75th birthday 相似文献
2.
Prokesová L Mlcková P Stanková I Ladmanová P Jezková J Chalupná P Novotná O Cechová D Julák J 《Folia microbiologica》2002,47(2):193-197
Bacillus firmus (a Gram-positive nonpathogenic and harmless bacterium), was shown to be a strong polyclonal activator of mouse B lymphocytes
as estimated by ELISA testing of Ig concentrations in culture supernatants after incubation of BALB/c mouse splenocytes with
inactivated bacillus. Synthesis of all main Ig classes and all IgG subclasses was stimulatedin vitro, the considerable effect on IgA formation being the most interesting feature. B cell stimulation was T cell dependent, as
was demonstrated by the effect ofB. firmus on all Ig isotypes and by comparison of lymphocyte response of nu/nu mice and heterozygous nu/+mice. The effect ofB. firmus on splenocyte proliferation was stimulatory or suppressive depending on the dose of the bacterium. Increased synthesis of
IFN-γ and IL-10 (detected by ELISA in splenocyte culture supernatants) showed probable stimulation of Th1 and Th2 subpopulations.
Considering the stimulatory effect on IgA formation and macrophage stimulation,B. firmus seems to be a prospective mucosal adjuvant and/or probiotic. 相似文献
3.
I. Trebichavský M. Mára J. Šinkora I. Šplíchal R. Štěpánková 《Folia microbiologica》1997,42(4):403-408
3-day-old miniature piglets were stimulatedin vivo withBacillus firmus by the intraperitoneal or intragastric route for 1 d. Cells containing IgA and IgG2 were detected in the ileum in all stimulated but not in control animals. The frequency of blood CD3+ cells increased after intraperitoneal administration ofB. firmus, the ratio of polymorphonuclears to lymphocytes increased in all stimulated piglets.B. firmus induced antitumor immunity in rats with transplanted Yoshida sarcoma cells. Granular lymphocytes and dead tumor cells were
found in peritoneal exudate of stimulated animals.B. firmus induced IFN-γ synthesis in human blood lymphocytes stimulatedin vitro for 1 d. The amount of TNF-α produced by these stimulated human peripheral blood mononuclears (PBMC) was lower than that
of PBMC stimulated with some other bacterial immunomodulators. Cells containing TGF-β or IL-8 were not found in human PBMC
stimulated withB. firmus. 相似文献
4.
L Prokesová O Lochman C John 《Journal of hygiene, epidemiology, microbiology, and immunology》1992,36(3):327-336
Alpha, beta and delta toxins of Staphylococcus aureus stimulate human peripheral blood lymphocytes to blastic transformation and formation of IgM, IgG and IgA. The toxins are efficient at concentrations that are not toxic for the cells in culture. A dose of a toxin suitable for stimulation is 100 ng/ml but a stimulation can be observed also at 10 ng/ml, in the case of Ig formation even at a concentration of 1 ng/ml. Toxoids are approximately as effective to elicit blastic transformation as the toxins themselves, their efficiency to stimulate Ig formation being somewhat lower but significant. Alpha and delta toxins and toxoids at the appropriate concentration appear to act as medium-strength polyclonal activators of lymphocytes. Beta toxin and its toxoid are weak polyclonal activators. 相似文献
5.
With a view toward verifying the original classification of alkaliphilic Bacillus firmus OF4, physiological and biochemical characteristics were more extensively catalogued than in original studies, and this catalog
was supplemented with 16S rDNA sequence homology and more extensive DNA–DNA hybridization analyses. Phylogenetic analysis
of this alkaliphile based on the comparison of multiple 16S rDNA sequences from Bacillus species indicated that this strain is most closely related to Bacillus pseudofirmus. Consistently, in the DNA–DNA hybridization analysis of the alkaliphile and Bacillus reference strains, the highest level of DNA–DNA relatedness (96%) was found between the alkaliphile and the B. pseudofirmus type strain (DSM 8715T). The findings support the conclusion that this alkaliphile strain is more closely related to B. pseudofirmus than to B. firmus, and we propose the future use of the designation B. pseudofirmus OF4.
Received: April 20, 1999 / Accepted: August 31, 1999 相似文献
6.
Tadashi Kasahara Hirotomo Harada Kenji Ogata Tadashi Kawai Kohei Shioiri-Nakano 《Microbiology and immunology》1981,25(12):1345-1356
Significant immunoglobulin (Ig) production by human peripheral blood lymphocytes was induced in vitro by stimulating the cells with pokeweed mitogen (PWM) and Staphylococcus aureus Cowan I (SpA CoI). IgG, IgM, and IgA were determined by a combination of the latex fixation test and radioimmunoassay. High levels (1,000 to 5,000 μg/ml) of IgG and IgM and a lesser amount of IgA were constantly produced during 7 to 8 days of incubation with both stimulants. Ig production induced by SpA Col stimulation was independent of the presence of T cells, while Ig production induced by PWM required T cells exclusively. Depletion of monocytes in the culture caused but a slight decrease in Ig production (particularly in the case of IgG). While the addition of a small number of monocytes enhanced IgG induction by both stimulants, coculture with an excess number of monocytes inhibited Ig induction (particularly IgG) by PWM stimulation but not by SpA CoI stimulation. Marked suppression of Ig production (IgG, IgM, and IgA) was observed in cocultures with Con A-activated T cells. The phenomena of suppression were observed in both the SpA Col-stimulated and PWM-stimulated lymphocytes. These data indicate that Ig production from B cells stimulated with a polyclonal B cell activator, SpA CoI, was independent of T cells and relatively of independent of monocytes, but could be subjected to the regulation of the Con A-induced suppressor T cells. 相似文献
7.
Agrobacterium tumefaciens-mediated transformation and transgenic-plant regeneration of onion (Allium cepa L.) 总被引:3,自引:3,他引:0
An Agrobacterium tumefaciens-mediated transformation method has been developed for onions (Allium cepa L.) using immature embryos as the explant source. Transgenic plants were recovered from the open-pollinated onion cultivar
Canterbury Longkeeper at a maximum transformation frequency from immature embryos of 2.7%. The method takes between 3–5 months
from explant to primary regenerant entering the glasshouse. Multiple-shoot formation from primary transgenic material made
possible the clonal multiplication of transformants. The binary vector used carried the nptII antibiotic resistance gene and the m-gfp5-ER reporter gene. Transgenic cultures were initially screened for their ability to fluoresce and to grow in the presence of
geneticin (5–25 mg/l). The transgenic nature of individual plants was confirmed by Southern blot analysis.
Received: 12 October 1998 / Revision received: 17 May 1999 Accepted: 14 June 1999 相似文献
8.
Addition of sonicated dispersions of cholesterol to peptone-salt-vitamin medium resulted in the metabolism of the sterol byHartmanella culbertsoni. Trophozoite multiplication was stimulated at 1–5 mg/litre, but retarded at 10–20 mg/litre. When cholesterol was added to
the medium, incorporation of [1,2-14C] -acetate into neutral lipid, phospholipid, non-saponifiable and cholesterol fractions of the amoebae was significantly
reduced. Cholesterol ester was detected in the medium but phospholipids were not released. Addition of cholesterol stimulated
the activity of lysosomal acid phosphatase, acid deoxyribonuclease and cathepsin B but did not affect 5′-nucleotidase, adenosine
triphosphatase, alkaline phosphatase, glucose-6-phosphatase, succinate dehydrogenase and cytochrome C oxidase.
Communication No.2486 相似文献
9.
H. -S. Wu Y. Wang C. -Y. Zhang M. Gu Y. -X. Liu G. Chen J. -H. Wang Z. Tang Z. -S. Mao Q. -R. Shen 《Folia microbiologica》2009,54(2):115-122
The allelopathic potential of an artificially applied allelochemical, benzoic acid, on in vitro Fusarium oxysporum f.sp. niveum (a soil-borne pathogen causing watermelon wilt) was evaluated. Benzoic acid strongly inhibited its growth, sporulation and
conidia germination, whereas it stimulated virulence factors of this pathogen. The biomass was reduced by 83–96 % and the
conidia germinating rate and conidia production rate were decreased by 100 % at a concentration of >200 mg/L. However, phytopathogenic
enzyme activities and mycotoxin production were stimulated with an increase of 10.2–1250 % for enzyme activities and 610–2630
% for mycotoxin yield. 相似文献
10.
B. Cukrowska J. Šinkora Z. Řeháková I. Šplíchal L. Tučková R. Barot-Ciorbaru A. T. J. Bianchi R. Lodinová-Žádníková H. Tlaskalová-Hogenová 《Folia microbiologica》1995,40(4):421-430
Immunoglobulin (Ig) response to different polyclonal B-cell activators was measured by ELISA in cell culture media of thymocytes,
splenocytes and liver cells isolated from pig fetuses, 8-d-old germ-free piglets and conventionally reared pigs. Both in fetal
and in postnatal life polyclonally stimulated lymphocytes were found to produce predominantly the IgM isotype; the first IgM
formation was detected in 50-d-old fetal liver (gestation in pigs lasts 114 d). Surprisingly, 73-d-old fetal thymic cells
were shown to be induced to Ig synthesis and secretion. In contrast to splenocytes of the same age, which secreted exclusively
IgM, fetal thymocytes produced IgM, IgG and IgA. Polyclonally stimulated splenic cells as compared with thymic cells started
to produce IgA later in fetal ontogeny, whereas the IgG response was not detectable in splenic cell culture media during the
whole embryonal development and appeared only after birth. The earliest and the highest Ig stimulation was found after cultivation
of lymphocytes withNocardia delipidated cell mitogen. Interestingly, the moderate stimulatory effect of 65-kDa heat shock protein (Hsp-65) in polyclonal
IgM response of fetal splenocytes was observed. We showed that thymic B lymphocytes represent probably the first maturing
B cell population detectable in fetal life, which is able to differentiate after polyclonal stimulation into IgM as well as
IgA and IgG producing cells.
Dedicated to Professor J. Šterzl on the occasion of his 70th birthday 相似文献
11.
Timentin as an alternative antibiotic for suppression of Agrobacterium tumefaciens in genetic transformation 总被引:3,自引:0,他引:3
The effects of timentin on shoot regeneration of tobacco (Nicotiana tabaccum) and Siberian elm (Ulmus pumila L.) and its use for the suppression of Agrobacterium tumefaciens in Agrobacterium-mediated genetic transformation were determined. Timentin is a mixture of ticarcillin and clavulanic acid, and at concentrations
of 200–500 mg/l with ratios of ticarcillin:clavulanic acid of 50:1 and 100:1, it had little effect on shoot regeneration of
tobacco or Siberian elm. Timentin was as effective in suppressing A. tumefaciens as carbenicillin and cefatoxime at concentrations commonly used in transformation. The disarmed A. tumefaciens strain LBA4404 in infected tobacco leaf tissues was visually undetectable after three subcultures on medium with 500 mg/l
of timentin and 250 mg/l carbenicillin. Timentin was stable in solid agar medium and remained effective for at least 70 days,
but was unstable when stored as a mixed stock solution or as separate ticarcillin and clavulanic acid stock solutions at –20°C
or –80°C freezer for 4 weeks. Timentin may be an alternative antibiotic for the effective suppression of A. tumefaciens in genetic transformation.
Received: 8 September 1997 / Revision received: 19 November 1997 / Accepted: 2 December 1997 相似文献
12.
The response of trout and zebrafish embryos to low and high boron concentrations is U-shaped 总被引:2,自引:0,他引:2
Fish in the embryo-larval stage of development have been shown to be sensitive to boron (B) at both ends of the dose-response
curve (1,2). The present study evaluated the health effects of low and high B concentrations on rainbow trout (Oncorhynchus mykiss), a cold water species, and zebrafish (Danio rerio), a warm water species. Rainbow trout embryos were incubated from day 1 until 2 wk posthatch in Type 1 ASTM ultrapure-grade
water (12.5°C) supplemented with only B (0-500 μM) as boric acid, or together with CaCO3 (0–2 mM) to increase water hardness. Embryonic growth was stimulated by B in a dose-dependent manner at all Ca concentrations
(p < 0.001). Chronic exposures below 9 μmol B/L impaired embryonic growth and above 10 mmol B/L caused death (p < 0.001). Thus, the safe range of exposure for the rainbow trout was between the adverse effect concentrations of 9 μmol
B/L and 10 mmol B/L. Zebrafish were maintained for 6 mo in ultrapure water containing <0.2 μmol B/L to determine the effect
of low-level exposure. High-level exposure was assessed by exposing zygotes, derived from parents maintained at 46 μmol B/L,
to graded concentrations of boric acid up to a concentration of 75 mmol B/L from fertilization until they were free feeding
(96 h). Fertilization occurred, but zygotes failed to survive when water contained <0.2 umol B/L (p < 0.001). Death occurred at and above 9.2 mmol B/L. Thus, the safe range of B exposure for zebrafish was between the adverse
effect concentrations of 0.2 μmol B/L and 9.2 mmol B/L. The dose-response for both species was thus U-shaped.
Part of this work was previously published in abstract form and presented at Experimental Biology 97, April 6–9, New Orleans,
LA (Eckhert, C. [1997] Embryonic trout growth and boron exposure,FASEB J.
11, A406 [abstract]). 相似文献
13.
14.
V. Chalupa 《Biologia Plantarum》1989,31(5):400-407
Shoot multiplication of Larixdecidua was achieved using axillary and adventitious buds. The formation of axillary buds was stimulated on shoot tips soaked in
a cytokinin solution (BAP 10-50 mg 1−1 for 2–4 h. Adventitious buds were induced on cotyledons, needles and vegetative buds cultured on WPM or QL medium supplemented
with cytokinin (BAP 1–3 mg 1−1). The shoot formation from induced axillary and adventitious buds was promoted on WPM or QL medium containing a low concentration
of auxin (IBA 0.1 mg 1−1). Shoot multiplication of Pinussylvestris was stimulated on WPM, MS, and QL media supplemented with a low concentration of cytokinin (BAP 0.2 mg 1−1) and auxin (IBA 0.1 mg 1−1). Shoot segments produced 2–5 new axillary shoots within 4–5 weeks. Root initiation was stimulated on larch and pine shoots
cultured first on WPM supplemented with auxins (NAA and IBA) and later transferred to auxin-free medium. 相似文献
15.
High-efficiency transformation of the diploid strawberry (Fragaria vesca) for functional genomics 总被引:2,自引:0,他引:2
Oosumi T Gruszewski HA Blischak LA Baxter AJ Wadl PA Shuman JL Veilleux RE Shulaev V 《Planta》2006,223(6):1219-1230
Fragaria vesca L., a diploid (2n=2x=14) relative of the commercial octoploid strawberry, is an attractive model for functional genomics research in Rosaceae. Its small genome size, short reproductive cycle, and facile vegetative and seed propagation make F. vesca a promising candidate for forward and reverse genetics experiments. However, the lack of a high-efficiency transformation protocol required for systematic production of thousands of T-DNA insertional mutant lines and high-throughput gene validation is a major bottleneck. We describe a new transformation procedure that uses leaf explants from newly unfolded trifoliate leaves obtained from stock plants 6–7 weeks after seed germination, co-cultivation with Agrobacterium strain GV3101, and stringent selection on MS medium containing 4 mg l−1 hygromycin. Using this protocol we achieved 100% transformation efficiency for 6 of 14 F. vesca accessions tested. Accession PI 551572 was determined to be the best candidate for a model in F. vesca functional genomics research, as it showed the greatest propensity for callus formation, transformation, shoot regeneration, ex vitro establishment, and plant growth, requiring only 14–15 weeks to complete its life cycle in different seasons in the greenhouse. 相似文献
16.
Andrzej K. Siwicki Zdzisław Zakęś Elżbieta Terech-Majewska Krzysztof Kazuń Agnieszka Lepa Edward Głąbski 《Reviews in Fish Biology and Fisheries》2010,20(3):435-439
Influence of beta-1.3/1.6-glucan (Macrogard) on the innate immunity and protection against Aeromonas hydrophila in tench (Tinca tinca (L.)) was assessed. Macrogard was fed at doses of 0, 0.5, 1 and 2 g kg−1 of pellets for 1 month. The blood, spleen and head kidney from 10 fish of each group were separated and analysed for immunity
parameters. Twenty tench from each group were infected with A. hydrophila. Macrogard at doses 1 and 2 g kg−1 of feed significantly (P < 0.05) increased the phagocytic activity of macrophages and proliferative response of mitogens stimulated lymphocytes. The
same doses significantly (P < 0.05) increased lysozyme activity and Ig level in serum, compared to the control and dose 0.5 g kg−1 of feed. The challenge test showed that Macrogard reduced mortality of tench after experimental infection (5–35%). 相似文献
17.
Studies were carried out to evaluate the colour removal capacity of a moderately halotolerant bacterium, Bacillus firmus, in synthetic saline wastewater medium (SSWM) under static condition. The bacterial strain effectively decolourized Polar red B (an azo dye) in a wide range of sodium chloride (1-6%, w/v), dye (5-100 mg/L) and SDS (0.1-5.0 mg/L) concentrations and at pH range of 6-10 after 24 h of incubation. Cell immobilization studies indicated that colour removal was significantly higher (p < 0.05) in immobilized halotolerant cell systems than with free cells of B. firmus especially at salt concentrations higher than 4%. Results suggest the potential of using the immobilized halotolerant cell system for effective treatment of dye-contaminated saline wastewaters. 相似文献
18.
Chloroplast transformation of rapeseed (Brassica napus) by particle bombardment of cotyledons 总被引:1,自引:0,他引:1
Lin Cheng He-Ping Li Bo Qu Tao Huang Jin-Xing Tu Ting-Dong Fu Yu-Cai Liao 《Plant cell reports》2010,29(4):371-381
A protocol for chloroplast transformation of an elite rapeseed cultivar (Brassica napus L.) was developed based on optimized conditions for callus induction and regeneration from cotyledonary tissues. Comparison
of six different media with three elite cultivars showed that B5 medium plus 3 mg/l AgNO3 supplemented with 0.6 mg/l 2,4-dichlorophenoxyacetic acid and 0.2 mg/l 6-furfurylaminopurine was optimal for callus formation
and maintenance without differentiation, while the medium suitable for regeneration was B5 medium supplemented with 1 mg/l
6-benzylaminopurine, 1 mg/l 6-furfurylaminopurine and 0.5 mg/l α-naphthaleneacetic acid. A rapeseed-specific chloroplast transformation
vector was constructed with the trnI and trnA sequences amplified from the rapeseed chloroplast genome using two primers designed according to Arabidopsis homologs. The aadA gene was used as a selection marker regulated by the ribosome-binding site from the bacteriophage T7 gene 10L, the tobacco
16S rRNA promoter and the psbA terminator. After bombardment, cotyledonary segments were cultured for callus formation on media containing 10 mg/l spectinomycin
and regeneration was carried out on medium with 20 mg/l spectinomycin. Heteroplasmic plastid transformants were isolated.
An overall efficiency for the chloroplast transformation was one transplastomic plant per four bombarded plates. Southern
blot analyses demonstrated proper integration of the target sequence into the rapeseed chloroplast genome via homologous recombination.
The expression of the aadA gene was confirmed by Northern blot analysis. Analysis of T1 transplastomic plants revealed that the transgenes integrated
into the chloroplast were inheritable with a ratio of about 8%. These results suggest that rapeseed may be a suitable crop
for chloroplast transformation with cotyledons as explants under appropriate conditions. 相似文献
19.
Costa C Vecherskaya M Dijkema C Stams AJ 《Journal of industrial microbiology & biotechnology》2001,26(1-2):9-14
13C NMR was used to study the effect of oxygen on methanol oxidation by a type II methanotrophic bacterium isolated from a bioreactor
in which methane was used as electron donor for denitrification. Under high (35–25%) oxygen conditions the first step of methanol
oxidation to formaldehyde was much faster than the following conversions to formate and carbon dioxide. Due to this the accumulation
of formaldehyde led to a poisoning of the cells. A more balanced conversion of 13C-labelled methanol to carbon dioxide was observed at low (1–5%) oxygen concentrations. In this case, formaldehyde was slowly
converted to formate and carbon dioxide. Formaldehyde did not accumulate to inhibitory levels. The oxygen-dependent formation
of formaldehyde and formate from methanol is discussed kinetically and thermodynamically. Journal of Industrial Microbiology & Biotechnology (2001) 26, 9–14.
Received 04 March 2000/ Accepted in revised form 07 November 2000 相似文献
20.
Basement membrane proteins are targeted in a variety of pathologic autoimmune responses, yet little is known regarding the
origins and regulation of this subset of pathogenic lymphocytes. To examine the generation and fate of B cells reactive with
a matrix autoantigen, nonautoimmune C57BL/6 mice were rendered transgenic for a nephrotropic lupus anti-laminin immunoglobulin
(Ig) H chain, termed LamH-Cμ. We previously reported recovery of two distinct phenotypes among LamH-Cμ-transgenic mice: progeny
of founders M6 and M29 contained abundant transgene-expressing B cells but little anti-laminin Ig, whereas spontaneous autoreactivity
was readily recovered from the M7 lineage that expressed minimal B-cell mIgM. To explore the spectrum of autoreactivity generated
in vivo by different LamH-Cμ-endogenous L-chain combinations, we determined in vitro and in vivo antigen reactivity and L-chain
V-region sequences of 17 LamH-Cμ-transgenic anti-laminin Igs. The results reveal a heterogeneous population of anti-laminin
Igs with different fine specificities encoded by diverse endogenous L chains, encompassing nine different Vk gene families, 11 Vk genes, and three Jk genes. Many of the L chains are identical to known or putative unmutated germline Vk genes used to encode Igs reactive with self and foreign antigens in nonautoimmune and genetically autoimmune-prone mouse
strains. These observations confirm that the LamH-Cμ H chain plays a dominant role in determining anti-laminin reactivity,
and indicate that nonautoimmune B6 mice are fully capable of generating a diverse pool of basement-membrane-reactive B cells
using unmutated Ig genes. When interpreted in the context of the divergent M6/M29 and M7 transgenic mouse phenotypes, our findings further suggest
that these matrix-reactive lymphocytes are not spontaneously activated in vivo under normal circumstances.
Received: 1 July 1999 / Revised: 28 July 1999 相似文献