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Y Jacob

Publications and source records attributed to Y Jacob.

16 recordsLinked to original sources
PubMed2006

Rabies: epidemiological tendencies and control tools.

Rabies encephalitis still generates 50,000 human deaths/year. It is due to neuron infection by lyssaviruses. Seven genotypes (GT) are currently distinguished within the Lyssavirus genus which segregate in two phylogroups (PG). This classification is constantly evolving due to isolation of new lyssaviruses within bat populations. Functional differences exist between GTs in term of neurotropism, pathogenesis, induction of apoptosis, immunogenicity, and their molecular basis are starting to be elucidated. Lyssavirus vectors are mammals, preferentially from the Carnivora and Chiroptera orders. Phylogenetic reconstruction strongly supports that lyssaviruses evolved in chiropters long before the emergence of carnivoran rabies which very likely occurred through host-switchings from bats to carnivores. If dog rabies control is possible by vaccination and population control, if oral vaccination demonstrated its potential to eliminate rabies from a terrestrial wildlife reservoir (fox in Western Europe), it is unrealistic today to clear lyssaviruses from bats, while bat rabies is a growing concern for both public and animal health. As bat transmit divergent lyssavirus GTs which are not well prevented by available vaccine strains, there is a need to increase the protection spectrum of vaccines. DNA-based immunization with plasmids expressing chimeric G proteins (fusion of two halves from different GTs) was shown to be effective in inducing a complete immune response and to broaden the spectrum of rabies vaccines toward lyssavirus vaccines. Further, the lyssavirus G protein can carry foreign epitopes/antigens in the perspective of multivalent vaccines against various zoonoses of carnivores.

Animals↗
PubMed2001

Functional interaction map of lyssavirus phosphoprotein: identification of the minimal transcription domains.

Lyssaviruses, the causative agents of rabies encephalitis, are distributed in seven genotypes. The phylogenetically distant rabies virus (PV strain, genotype 1) and Mokola virus (genotype 3) were used to develop a strategy to identify functional homologous interactive domains from two proteins (P and N) which participate in the viral ribonucleoprotein (RNP) transcription-replication complex. This strategy combined two-hybrid and green fluorescent protein-reverse two-hybrid assays in Saccharomyces cerevisiae to analyze protein-protein interactions and a reverse genetic assay in mammalian cells to study the transcriptional activity of the reconstituted RNP complex. Lyssavirus P proteins contain two N-binding domains (N-BDs), a strong one encompassing amino acid (aa) 176 to the C terminus and a weak one in the 189 N-terminal aa. The N-terminal portion of P (aa 52 to 189) also contains a homomultimerization site. Here we demonstrate that N-P interactions, although weaker, are maintained between proteins of the different genotypes. A minimal transcriptional module of the P protein was obtained by fusing the first 60 N-terminal aa containing the L protein binding site to the C-terminal strong N-BD. Random mutation of the strong N-BD on P protein identified three highly conserved K residues crucial for N-P interaction. Their mutagenesis in full-length P induced a transcriptionally defective RNP. The analysis of homologous interactive domains presented here and previously reported dissections of the P protein allowed us to propose a model of the functional interaction network of the lyssavirus P protein. This model underscores the central role of P at the interface between L protein and N-RNA template.

Amino Acid Sequence↗
PubMed2000

Cytoplasmic dynein LC8 interacts with lyssavirus phosphoprotein.

Using a yeast two-hybrid human brain cDNA library screen, the cytoplasmic dynein light chain (LC8), a 10-kDa protein, was found to interact strongly with the phosphoprotein (P) of two lyssaviruses: rabies virus (genotype 1) and Mokola virus (genotype 3). The high degree of sequence divergence between these P proteins (only 46% amino acid identity) favors the hypothesis that this interaction is a common property shared by all lyssaviruses. The P protein-dynein LC8 interaction was confirmed by colocalization with laser confocal microscopy in infected cells and by coimmunoprecipitation. The dynein-interacting P protein domain was mapped to the 186 amino acid residues of the N-terminal half of the protein. Dynein LC8 is a component of both cytoplasmic dynein and myosin V, which are involved in a wide range of intracellular motile events, such as microtubule minus-end directed organelle transport in axon "retrograde transport" and actin-based vesicle transport, respectively. Our results provide support for a model of viral nucleocapsid axoplasmic transport. Furthermore, the role of LC8 in cellular mechanisms other than transport, e.g., inhibition of neuronal nitric oxide synthase, suggests that the P protein interactions could be involved in physiopathological mechanisms of rabies virus-induced pathogenesis.

Animals↗
PubMed2000

DNA-based immunization against Lyssaviruses.

Rabies is a fatal encephalomyelitis. Most cases occur in developing countries and are transmitted by dogs. Because of their high cost, cell culture vaccines have not totally replaced the unsafe brain-derived vaccines which are still used in many developing countries. Moreover, there will be a need for vaccines against rabies-related viruses against which classical vaccines are not always effective. DNA vaccines would, therefore, be a valuable alternative for the production of cheaper rabies vaccines against a larger spectrum of viruses. In this review we report published data on DNA-based immunization with sequences encoding rabies and rabies-related virus antigens.

Animals↗
PubMed2000

DNA-based immunisation against rabies and rabies-related viruses: towards multivalent vaccines.

Prototypes of multivalent DNA vaccines against lyssaviruses (LV: rabies and rabies-related viruses) and other viruses were developed using chimaeric LV glycoprotein (cLVG) DNA and cLVG DNA carrying foreign epitopes. cLVG is composed of the N-terminal half of an LV genotype (GT) containing antigenic site II, the C-terminal half of GT containing antigenic site III, as well as the transmembrane and cytoplasmic domains of the same or a different GT. Both antigenic sites induced virus neutralizing antibodies (VNAb). Foreign B and T cell epitopes inserted between the two halves of cLVG correspond to the B cell C3 neutralisation epitope of poliovirus VP1 protein and to the H2d CMH I restricted T cell epitope of the nucleoprotein of the lymphocytic choriomeningitis virus (LCMV). In mice and dogs homogenous rabies virus G DNA induced protection against wild-type rabies virus whereas cLVG protected against lyssaviruses. cLVG DNA carrying foreign epitopes induced VNAb against LV and poliovirus and protection against LCMV. The results obtained clearly demonstrate the potential usefulness of cLVG for the development of multivalent vaccines against viral diseases, including rabies and zoonoses.

Animals↗
PubMed1999

Immunization of dogs with a DNA vaccine induces protection against rabies virus.

Rabies is a fatal encephalomyelitis which is transmitted to man, mostly by dogs in developing countries. This zoonosis can be prevented by vaccination of humans before or after exposure. However, a more radical approach is possible, involving the elimination of the principal vector/reservoir by vaccinating dogs. The vaccine must be effective, safe and inexpensive. Mass production of plasmids is possible and DNA-based immunization with a plasmid encoding the antigen responsible for inducing protection seems to be more cost-effective than classical techniques involving cell culture. Beagles were immunized by intramuscular (i.m.) injection with a plasmid encoding the rabies virus (PV strain) glycoprotein. Neutralizing antibodies against both wild-type rabies virus and European Bat Lyssaviruses (EBL1 and EBL2) were detected after a single injection and a boost, but levels of neutralizing antibodies against EBL1 were low. Moreover, all vaccinated dogs were protected against a lethal challenge with a wild-type dog rabies strain. This is one of the first studies to demonstrate that dogs can be protected by DNA vaccines, and opens important perspectives for rabies control.

Animals↗
PubMed1999

Chimeric lyssavirus glycoproteins with increased immunological potential.

The rabies virus glycoprotein molecule (G) can be divided into two parts separated by a flexible hinge: the NH2 half (site II part) containing antigenic site II up to the linear region (amino acids [aa] 253 to 275 encompassing epitope VI [aa 264]) and the COOH half (site III part) containing antigenic site III and the transmembrane and cytoplasmic domains. The structural and immunological roles of each part were investigated by cell transfection and mouse DNA-based immunization with homogeneous and chimeric G genes formed by fusion of the site II part of one genotype (GT) with the site III part of the same or another GT. Various site II-site III combinations between G genes of PV (Pasteur virus strain) rabies (GT1), Mokola (GT3), and EBL1 (European bat lyssavirus 1 [GT5]) viruses were tested. Plasmids pGPV-PV, pGMok-Mok, pGMok-PV, and pGEBL1-PV induced transient expression of correctly transported and folded antigens in neuroblastoma cells and virus-neutralizing antibodies against parental viruses in mice, whereas, pG-PVIII (site III part only) and pGPV-Mok did not. The site III part of PV (GT1) was a strong inducer of T helper cells and was very effective at presenting the site II part of various GTs. Both parts are required for correct folding and transport of chimeric G proteins which have a strong potential value for immunological studies and development of multivalent vaccines. Chimeric plasmid pGEBL1-PV broadens the spectrum of protection against European lyssavirus genotypes (GT1, GT5, and GT6).

Amino Acid Sequence↗
PubMed1998

DNA-based immunization for exploring the enlargement of immunological cross-reactivity against the lyssaviruses.

DNA-based immunization was used for studying the cross-reactivity of lyssavirus neutralizing antibodies and for exploring the induction of a wider range of protection against lyssaviruses. In order to immunize mice with homogeneous and chimeric genes of glycoproteins (G) from two divergent lyssaviruses, we used for the first time a new plasmid (pCI-neo) known to be a highly efficient vector for in vitro expression. The homogeneous plasmids pGPV and pGMok encoded the Pasteur virus (PV: genotype 1-GT-) and Mokola virus (Mok: GT 3) G, respectively. The chimeric pGMokPV encoded the NH2 part of GMok and the COOH part of GPV. These plasmids elicited full protection against intracerebral challenges with various lyssaviruses and a range of antigen-specific and non-specific immune responses. Virus neutralizing antibody (VNAb) levels were dose dependent and a single intramuscular (i.m.) injection of plasmids was sufficient to induce continuous high levels of VNAb. Production of antigen-specific T helper (Th), cytotoxic T cells (Tc) and non-specific natural killer cells was observed. Cross-reactivity studies showed that VNAb are obtained by immunizing with: (i) pGPV against GT 1 (classical rabies), GT 4 (Duvenhage: Duv), GT 5 (European Bat Lyssavirus: EBL-1) and GT 6 (European Bat Lyssavirus: EBL-2); (ii) pGMok against GT 2 (Lagos Bat: LB) and GT 3 (Mokola: Mok); (iii) pGMokPV against all GTs except GT 4 which is weakly neutralized. Therefore, the DNA-based immunization with the chimeric pGMokPV, could be very interesting to enlarge protection to all the lyssaviruses. According to the cross-reactivity of VNAb induced by the G genes, the lyssavirus GTs could be classified into two groups: the first including GT 1, 4, 5 and 6; the second including GT 2 and 3.

Animals↗
PubMed1997

The complete Mokola virus genome sequence: structure of the RNA-dependent RNA polymerase.

The genome sequence of the rabies-related virus Mokola virus (genus Lyssavirus) has been completed by sequencing the L gene, which consists of 6384 nucleotides encoding a 2127 amino acid polymerase. Alignment of the Mokola virus L protein with other polymerases from the virus order Mononegavirales defined three domains: a divergent NH2-terminal domain, a highly conserved central domain carrying most of the functional motifs and a COOH-terminal domain with alternating conserved and divergent regions. A statistical study outlined the stringency of conservation of glycine, acidic (D, E) and basic (K, R, H) amino acids in polymerases, particularly as key residues of the conserved motifs.

Amino Acid Sequence↗
PubMed1991

Analysis of Krüppel control elements reveals that localized expression results from the interaction of multiple subelements.

The Drosophila gap gene Krüppel (Kr) displays a complex spatiotemporal pattern of expression during embryogenesis. Using P-element transformation experiments, we demonstrate that control elements guiding Kr expression in the central or in the anterior domain at the blastoderm stage are each composed of multiple subelements that interact synergistically. We provide evidence that bicoid (bcd) and hunch-back (hb) gene products, as well as at least one other activator, are needed to activate Kr expression in the central domain. We localize and describe regulatory elements within the 4.1-kilobase region proximal to the Kr promoter that are responsible for expression in the ectoderm, mesoderm, amnioserosa, and nervous system. Finally, a protein instability motif encoded in the second exon appears to be important for resetting the dynamic Kr pattern.

Animals↗
PubMed1987

Cloning and sequencing of a rat CuZn superoxide dismutase cDNA. Correlation between CuZn superoxide dismutase mRNA level and enzyme activity in rat and mouse tissues.

The molecular cloning and nucleotide sequence of a cDNA clone (pR SOD) for rat CuZn superoxide dismutase (CuZnSOD) is reported. Nucleotide sequence homology with human superoxide dismutase is 86% for the coding region and 71% for the 3' untranslated region. The deduced amino acid sequence is given and the homologies with the sequences reported for other species are presented. Northern blot analysis of total RNA from various rat and mouse tissues and from two mouse cell lines show that pR SOD hybridizes with one mRNA species of about 0.7 kb. The amount of CuZnSOD mRNA in each tissue, measured by densitometry of the Northern blot autoradiograms, correlates with the enzymatic activity based on protein content. These results indicate that the control of CuZnSOD activity in mammalian tissues is largely dependent on the regulation of CuZnSOD mRNA levels. In human liver, fibroblasts and FG2 hepatoma cells, two CuZnSOD mRNAs (0.7 kb and 0.9 kb) are observed. The level of CuZnSOD mRNA in FG2 is 25% that of the liver and four times more abundant than in fibroblasts.

Amino Acid Sequence↗
PubMed1983

[Lateral calcaneal flaps].

The authors have studied the cutaneous vascularization of the lateral side of the ankle. Different technics of vascular injection have identified a cutaneous flap based on the lateral calcaneal artery, a collateral branch of the posterior peroneal artery. This flap can be used to cover the chronic ulceration of the achilleen region.

Calcaneus↗
PubMed1983

[The Chinese anti-brachial radial flap: anatomic study].

Concerning twenty forearms of fresh cadavers, the authors describe a cutaneous flap irrigated by a radial artery whose ligature is without consequence on the vascularization of the hand. They specify the margins of the flap, its vascularization and innervation. They also specify the anatomical sacrifices necessary to its dissection and the different bony and tendinous elements which it is possible to include to form a complex osteo-musculo-cutaneous flap.

Brachial Artery↗
PubMed1980

[Sternal cleft. Correction by silastic prosthesis (author's transl)].

After observing a sternal failure of closure, the authors indicate how rare this anastomic defect is, and explain its embryo-genic formation. Besides the use of early postnatal operations they emphasize the benefit of a delayed operation and the use of a silactic plate. This method is easy, its functional and anesthetic results are stressed.

Follow-Up Studies↗
PubMed1980

[Right congenital diaphragmatic hernia with systemic artery (author's transl)].

Concerning a congenital diaphragmatic hernia with abnormal systemic artery, the authors point out the classification of Pryce concerning pulmonary sequestrations and also the new classification proposed by M. Merlier and his collaborators. Their opinion is that in the case of sequestration of type I cutting and stitching of the artery must be carried out as a matter of course in order to prevent accidents which can be serious.

Bronchopulmonary Sequestration↗