Expression of the filarial nematode phosphorylcholine-containing glycoprotein, ES62, is stage specific

Parasitology ◽  
2002 ◽  
Vol 125 (2) ◽  
pp. 155-164 ◽  
Author(s):  
G. STEPEK ◽  
M. AUCHIE ◽  
R. TATE ◽  
K. WATSON ◽  
D. G. RUSSELL ◽  
...  
Keyword(s):  
Transcriptional Control ◽  
Close Relation ◽  
Onchocerca Volvulus ◽  
Filarial Nematode ◽  
Cdna Libraries ◽  
Homologous Sequences ◽  
Acanthocheilonema Viteae ◽  
Filarial Nematodes ◽  
Species Specific ◽  
Control Of Expression

ES62, an immunomodulatory phosphorylcholine-containing glycoprotein secreted by the rodent filarial nematode Acanthocheilonema viteae, has previously been shown to be produced by L4 larvae and adult worms only. However, homologous sequences to ES62 have recently been found in L1 and L3 cDNA libraries of certain human filarial nematodes. Therefore, the various stages of A. viteae were re-examined and it was again found that only the post-L3 stages secreted ES62. Synthesis but not secretion by earlier stages was ruled out by examination of the protein content of whole worm extracts and by immunoelectron microscopy. However, examination by PCR of the mRNA for ES62 revealed that it was found in the L1 and L3 larvae. This may explain why homologous sequences to ES62 have been found in Brugia malayi and Onchocerca volvulus larval cDNA libraries. It also suggests that filarial nematodes, in general, may secrete ES62. To obtain evidence for this, we investigated production by Brugia pahangi, a close relation of B. malayi. We found that ES62 was indeed secreted but, as with A. viteae, only by the post-L3 stages, although again the mRNA for ES62 could be detected in the earlier stages. Overall our results suggest that production of ES62 is not species specific, that it is indeed stage specific, and that this may be due to post-transcriptional control of expression.

scholarly journals Essential Role of Chitinase in the Development of the Filarial Nematode Acanthocheilonema viteae

2007 ◽  
Vol 76 (1) ◽  
pp. 221-228 ◽  
Author(s):  
Babila Tachu ◽  
Smitha Pillai ◽  
Richard Lucius ◽  
Thomas Pogonka
Keyword(s):  
Essential Role ◽  
Model Organism ◽  
Filarial Nematode ◽  
Developmental Expression ◽  
Phage Library ◽  
Modular Organization ◽  
Transcript Levels ◽  
Acanthocheilonema Viteae ◽  
Filarial Nematodes

ABSTRACT Chitinases of pathogens have been proposed as potential targets of vaccines or specific inhibitors. We studied the genomic organization, transcript levels, developmental expression, and biological function of chitinases in the rodent filarial nematode Acanthocheilonema viteae, a model organism for human-pathogenic filarial worms. Characterization of nine genomic clones from an A. viteae phage library and Southern blot experiments revealed the existence of three different chitinase genes, two of which could theoretically yield functional transcripts. The deduced proteins of these genes had the common modular organization of family 18 chitinases. Northern blot experiments and rapid amplification of cDNA ends-PCR with adult worms and larval stages showed that only one gene is expressed, with high variation in transcript levels, as determined by real-time PCR. Chitinase transcript levels were lowest in the late male stage 4 larva (L4) and peaked in the stage 3 larva (L3), which was corroborated by Western blotting. RNA interference (RNAi) experiments showed that treatment of L3 and adult female worms with double-stranded RNA of chitinase inhibited molting of L3 worms and hatching of microfilariae. RNAi also led to the death of 50% of female worms, revealing the essential role of chitinase in the life cycle of filarial nematodes.

Stage-specific and species-specific differences in the production of the mRNA and protein for the filarial nematode secreted product, ES-62

Parasitology ◽  
2004 ◽  
Vol 128 (1) ◽  
pp. 91-98 ◽  
Author(s):  
G. STEPEK ◽  
K. M. HOUSTON ◽  
H. S. GOODRIDGE ◽  
E. DEVANEY ◽  
W. HARNETT
Keyword(s):  
Life Cycle ◽  
Protein Production ◽  
Mrna Abundance ◽  
Filarial Nematode ◽  
Mrna Levels ◽  
Nematode Parasites ◽  
Life Cycle Stages ◽  
Significant Difference ◽  
Filarial Nematodes ◽  
Species Specific

Previous studies have shown that the secreted phosphorylcholine-containing glycoprotein of filarial nematodes, ES-62, is only present in the post-infective life-cycle stages, but that the mRNA is transcribed throughout the worm's life-cycle. The aim of this current study was to investigate whether the presence or absence of protein expression simply reflects differences in mRNA abundance. To this end, we investigated the relative abundance of ES-62 using TaqMan real time RT-PCR, in different life-cycle stages of 2 model filarial nematode parasites,Acanthocheilonema viteaeandBrugia pahangi. ForB. pahangi, microfilariae, infective larvae and adult worms were each found to have approximately similar levels of ES-62 mRNA. However, the corresponding stages ofA. viteaediffered greatly from each other with a pattern of increased mRNA production with maturation. As a ruleA. viteaehad higher levels of ES-62 mRNA thanB. pahangi, and this was particularly noticeable in the adult stage where the difference was approximately 3500-fold higher. However, this significant difference in mRNA abundance was not reflected in the quantity of ES-62 protein secreted by the adult worms of each species, asA. viteaeonly secreted ~3 times as much ES-62 asB. pahangi. Thus, overall, the results obtained from this study indicate that ES-62 protein production does not solely reflect mRNA levels, and also suggest that the 2 nematodes may employ different mechanisms for regulating protein production.

Mechanisms underlying the transfer of phosphorylcholine to filarial nematode glycoproteins – a possible role for choline kinase

Parasitology ◽  
1999 ◽  
Vol 118 (3) ◽  
pp. 311-318 ◽  
Author(s):  
K. M. HOUSTON ◽  
W. HARNETT
Keyword(s):  
Immune Responses ◽  
Filarial Nematode ◽  
Choline Kinase ◽  
Kennedy Pathway ◽  
Acanthocheilonema Viteae ◽  
Filarial Nematodes ◽  
Eukaryotic Organisms

Phosphorylcholine (PC) is a common constituent of proteins secreted by filarial nematodes. As this substance has been shown to interfere with immune responses, we are interested in designing strategies for blocking its attachment. Towards this end, we are investigating the mechanism of incorporation of PC into filarial molecules and in the present manuscript we describe experiments relating to elucidating the source of PC for attachment. Synthesis of phosphatidylcholine in eukaryotic organisms can occur by a mechanism involving the transfer of PC from CDP-choline to diacylglycerol (the Kennedy pathway). By (i) measuring transfer of radio-isotope labelled PC from CDP-choline to parasite molecules and (ii) employing inhibitors of CDP-choline synthesis, we have investigated whether CDP-choline can act as a source of PC for transfer to ES–62, a major secreted glycoprotein of the rodent filarial nematode Acanthocheilonema viteae. Although we can find no evidence of this, we show that attachment of PC is blocked by hemicholinium-3, an inhibitor of choline kinase, the first enzyme in the Kennedy pathway. Thus, at least the first step in this pathway – phosphorylation of choline, would appear to be necessary for attachment of PC to ES-62.

scholarly journals Embryo-induced transcriptome changes in bovine endometrium reveal species-specific and common molecular markers of uterine receptivity

Reproduction ◽  
2006 ◽  
Vol 132 (2) ◽  
pp. 319-331 ◽  
Author(s):  
Stefan Bauersachs ◽  
Susanne E Ulbrich ◽  
Karin Gross ◽  
Susanne E M Schmidt ◽  
Heinrich H D Meyer ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Molecular Mechanisms ◽  
Cdna Array ◽  
Early Embryo ◽  
Cdna Libraries ◽  
Control Group ◽  
Regulation Of Transcription ◽  
Uterine Receptivity ◽  
Subtracted Cdna Libraries ◽  
Species Specific

The endometrium plays a central role among the reproductive tissues in the context of early embryo–maternal communication and pregnancy. This study investigated transcriptome profiles of endometrium samples from day 18 pregnant vs non-pregnant heifers to get insight into the molecular mechanisms involved in conditioning the endometrium for embryo attachment and implantation. Using a combination of subtracted cDNA libraries and cDNA array hybridisation, 109 mRNAs with at least twofold higher abundance in endometrium of pregnant animals and 70 mRNAs with higher levels in the control group were identified. Among the mRNAs with higher abundance in pregnant animals, at least 41 are already described as induced by interferons. In addition, transcript levels of many new candidate genes involved in the regulation of transcription, cell adhesion, modulation of the maternal immune system and endometrial remodelling were found to be increased. The different expression level was confirmed with real-time PCR for nine genes. Localisation of mRNA expression in the endometrium was shown byin situhybridisation forAGRN,LGALS3BP,LGALS9,USP18,PARP12andBST2. A comparison with similar studies in humans, mice, and revealed species-specific and common molecular markers of uterine receptivity.

Experimental analysis of the control of expression of the homeobox-gene Msx-1 in the developing limb and face

Development ◽  
1993 ◽  
Vol 119 (1) ◽  
pp. 41-48 ◽  
Author(s):  
J.M. Brown ◽  
S.E. Wedden ◽  
G.H. Millburn ◽  
L.G. Robson ◽  
R.E. Hill ◽  
...  
Keyword(s):  
Homeobox Gene ◽  
Host Tissue ◽  
Face To Face ◽  
Limb Mesenchyme ◽  
The Face ◽  
Mesenchyme Cells ◽  
Species Specific ◽  
Signalling Systems ◽  
Control Of Expression

Mouse mesenchyme was grafted into chick embryos to investigate the control of mesenchymal expression of Msx-1 in the developing limb and face. In situ hybridization, using species-specific probes, allows a comparison between Msx-1 expression in the graft and the host tissue. The results show that Msx-1 expression in both limb-to-limb and face-to-face grafts corresponds closely with the level of Msx-1 expression in the surrounding chick mesenchyme. Cells in grafts that end up within the host domain of Msx-1 express the gene irrespective of whether they were from normally expressing, or non-expressing, regions. Therefore Msx-1 expression in both the developing limb and the developing face appears to be position-dependent. Mesenchyme from each of the three major facial primordia behaved in the same way when grafted to the chick maxillary primordium. Reciprocal grafts between face and limb gave a different result: Msx-1 expression was activated when facial mesenchyme was grafted to the limb but not when limb mesenchyme was grafted to the face. This suggests either that there are quantitative or qualitative differences in two local signalling systems or that additional factors determine the responsiveness of the mesenchyme cells.

scholarly journals Species-specific rDNA transcription is due to promoter-specific binding factors.

1984 ◽  
Vol 4 (2) ◽  
pp. 221-227 ◽  
Author(s):  
R Miesfeld ◽  
N Arnheim
Keyword(s):  
Rna Polymerase ◽  
Transcriptional Control ◽  
Specific Binding ◽  
Rna Polymerase I ◽  
Rdna Transcription ◽  
Nucleolar Dominance ◽  
Cell Extracts ◽  
Species Specific ◽  
Polymerase I

RNA polymerase I transcription factors were purified from HeLa and mouse L cell extracts by phosphocellulose chromatography. Three fractions from each species were found to be required for transcription. One of these fractions, virtually devoid of RNA polymerase I activity, was found to form a stable preinitiation complex with small DNA fragments containing promoter sequences from the homologous but not the heterologous species. These species-specific DNA-binding factors can explain nucleolar dominance in vivo in mouse-human hybrid somatic cells and species specificity in cell-free, RNA polymerase I-dependent transcription systems. The evolution of species-specific transcriptional control signals may be the natural outcome of a special relationship that exists between the RNA polymerase I transcription machinery and the multigene family coding for rRNA.

Localization, turnover and conservation of gp15/400 in different stages ofBrugia malayi

Parasitology ◽  
1993 ◽  
Vol 107 (4) ◽  
pp. 449-457 ◽  
Author(s):  
M. E. Selkirk ◽  
W. F. Gregory ◽  
R. E. Jenkins ◽  
R. M. Maizels
Keyword(s):  
Protein Complex ◽  
Cdna Probe ◽  
The Body ◽  
Mammalian Host ◽  
Major Protein ◽  
Homologous Genes ◽  
Acanthocheilonema Viteae ◽  
Filarial Nematodes ◽  
The Matrix

SUMMARYThe expression of a protein complex designated gp15/400, previously identified via extrinsic iodination of adultBrugia malayi, was examined by labelling all stages found in the mammalian host and immunoprecipitation with a specific antibody raised to a recombinant protein. In this way, gp15/400 could be detected in L3, L4, adult worms and microfilariae recovered from jirds and labelled with Bolton–Hunter reagent. Metabolic labelling indicated that gp15/400 was released into culture medium when adult worms were maintainedin vitro, but at a rate slower than that of gp29, the major soluble cuticular glycoprotein. Immuno-electron microscopy showed that the protein complex was broadly distributed in different tissues, although it was not detectable in the cuticle of adult worms. Dense labelling was observed in the matrix of the basal laminae bordering the hypodermis, somatic musculature and oesophagus, and lower but significant labelling was seen in the cells overlying these extracellular matrices. Hybridization of genomic DNA with a cDNA probe encoding gp15/400 indicated that homologous genes were present inDirofilaria immitisandAcanthocheilonema viteae. The failure to detect related genes in non-filarial nematodes was presumed to be due to divergence beyond the practical limits of detection by nucleic acid probes, as antibody reagents showed that the protein cross-reacted immunologically with ABA-1, a major protein allergen from the body fluid ofAscaris.

Subversion of immune cell signal transduction pathways by the secreted filarial nematode product, ES-62

Parasitology ◽  
2005 ◽  
Vol 130 (S1) ◽  
pp. S63-S68 ◽  
Author(s):  
W. HARNETT ◽  
H. S. GOODRIDGE ◽  
M. M. HARNETT
Keyword(s):  
Signal Transduction ◽  
B Lymphocytes ◽  
Immune Cell ◽  
Filarial Nematode ◽  
Signal Transduction Pathways ◽  
Immunomodulatory Effects ◽  
Filarial Nematodes ◽  
Intracellular Signal ◽  
Cell Signal Transduction ◽  
Immunomodulatory Properties

Filarial nematodes achieve longevity within the infected host by suppressing and modulating the host immune response. To do this, the worms actively secrete products that have been demonstrated to possess immunomodulatory properties. In this article we discuss the immunomodulatory effects of the phosphorylcholine-containing filarial nematode secreted glycoprotein ES-62. In particular we describe how it modulates intracellular signal transduction pathways in a number of different cells of the immune system, in particular B-lymphocytes, T-lymphocytes, macrophages and dendritic cells.

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