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Y Jacques

Publications and source records attributed to Y Jacques.

At least 37 records · Page 2Linked to original sources
PubMed1998

The mannose 6-phosphate/insulin-like growth factor II receptor is a nanomolar affinity receptor for glycosylated human leukemia inhibitory factor.

Comparison of the binding properties of non-glycosylated, glycosylated human leukemia inhibitory factor (LIF) and monoclonal antibodies (mAbs) directed at gp190/LIF-receptor beta subunit showed that most of the low affinity (nanomolar) receptors expressed by a variety of cell lines are not due to gp190. These receptors bind glycosylated LIF produced in Chinese hamster ovary cells (CHO LIF) (Kd = 6.9 nM) but not Escherichia coli-derived LIF or CHO LIF treated with endoglycosidase F. CHO LIF binding to these receptors is neither affected by anti-gp190 mAbs nor by anti-gp130 mAbs and is specifically inhibited by low concentrations of mannose 6-phosphate (Man-6-P) (IC50 = 40 microM), suggesting that they could be related to Man-6-P receptors. The identity of this LIF binding component with the Man-6-P/insulin-like growth factor-II receptor (Man-6-P/IGFII-R) was supported by several findings. (i) It has a molecular mass very similar to that of the Man-6-P/IGFII-R (270 kDa); (ii) the complex of LIF cross-linked to this receptor is immunoprecipitated by a polyclonal anti-Man-6-P/IGFII-R antibody; (iii) this antibody inhibits LIF and IGFII binding to the receptor with comparable efficiencies; (iv) soluble Man-6-P/IGFII-R purified from serum binds glycosylated LIF (Kd = 4.3 nM) but not E. coli LIF. The potential role of Man-6-P/IGFII-R in LIF processing and biological activity is discussed.

Animals↗
PubMed1998

Cotranscription and intergenic splicing of human galactose-1-phosphate uridylyltransferase and interleukin-11 receptor alpha-chain genes generate a fusion mRNA in normal cells. Implication for the production of multidomain proteins during evolution.

In the past 10 years, much attention has been focused on transcription preinitiation complex formation as a target for regulating gene expression, and other targets such as transcription termination complex assemblage have been less intensively investigated. We established the existence of poly(A) site choice and fusion splicing of two adjacent genes, galactose-1-phosphate uridylyltransferase (GALT) and interleukin-11 receptor alpha-chain (IL-11Ralpha), in normal human cells. This 16-kilobase (kb) transcription unit contains two promoters (the first one is constitutive, and the second one, 8 kb downstream, is highly regulated) and two cleavage/polyadenylation signals separated by 12 kb. The promoter from the GALT gene yields two mRNAs, a 1.4-kb mRNA encoding GALT and a 3-kb fusion mRNA when the first poly(A) site is spliced out and the second poly(A) is used. The 3-kb mRNA codes for a fusion protein of unknown function, containing part of the GALT protein and the entire IL-11Ralpha protein. The GALT promoter/IL-11Ralpha poly(A) transcript results from leaky termination and alternative splicing. This feature of RNA polymerase (pol) II transcription, which contrasts with efficient RNA pol I and pol III termination, may be involved, together with chromosome rearrangements, in the generation of fusion proteins with multiple domains and would have major evolutionary implications in terms of natural processes to generate novel proteins with common motifs. Our results, together with accumulation of genomic informations, will stimulate new considerations and experiments in gene expression studies.

Animals↗
PubMed1998

Activation of the signal transducer gp130 by interleukin-11 and interleukin-6 is mediated by similar molecular interactions.

The transmembrane glycoprotein gp130 is involved in many cytokine-mediated cellular responses and acts therein as the signal transducing receptor subunit. Interleukin-6 (IL-6) and interleukin-11 (IL-11), in complex with their specific alpha-receptors, homodimerize gp130 and, as a consequence, activate the Janus kinase (Jak)/signal transducer and activator of transcription (STAT) signalling pathway in their target cells. So far, it is not clear whether gp130 is bound to these cytokines and their specific alpha-receptor subunits through identical or different epitopes. In order to study the interaction of IL-11 and IL-11R with human gp130 the soluble form of the recently cloned human IL-11R was expressed in baculovirus-infected insect cells. By a coprecipitation binding-assay it is demonstrated that IL-11 and IL-6 compete for binding to gp130. Using deletion and point mutants of gp130 it is shown that IL-11-IL-11R and IL-6-IL-6R recognize overlapping binding motifs on gp130. Moreover, using well-established Jak-deficient cell lines we demonstrate that STAT activation by IL-11 requires Jak1. Taken together, our data support the concept that IL-6 and IL-11 activate gp130 by very similar molecular mechanisms.

Animals↗
PubMed1997

G alpha16 protein expression is up- and down-regulated following T-cell activation: disruption of this regulation impairs activation-induced cell responses.

The role of heterotrimeric G proteins in T-cell activation is poorly understood. Here we show that in normal, mature human T-cells, expression of G alpha16, the 43 kDa alpha subunit of G16, varies widely, depending on T-cell activation status. Quiescent blood lymphocytes strongly up-regulate G alpha16 after Leuco A stimulation: protein expression of G alpha16 is maximal at day 4, then decreases. Consistently, in human T-cell clones, expression of G alpha16 is high in the first week following activation and decreases rapidly within the second week. In addition, permanent disruption of regulated G alpha16 expression in Jurkat T-cells by stable overexpression of 43 kDa G alpha16 inhibited Leuco A-induced interleukin-2 production, CD69 up-regulation and cell apoptosis (by 58%, 46% and 74%, respectively), suggesting that coordinate regulation of G alpha16 expression is necessary for optimal activation-induced T-cell responses, and that G alpha16 proteins may be involved in the negative regulation of TCR signalling.

Antigens, CD↗
PubMed1997

Production and characterization of monoclonal antibodies against the leukemia inhibitory factor low affinity receptor, gp190.

Leukemia inhibitory factor (LIF), oncostatin-M (OSM), ciliary neurotrophic factor (CNTF) and cardiotrophin-1 (CT1) act through transmembrane receptors which share the gp190 glycoprotein chain. The understanding of its involvement in the biology of these cytokines is of importance since these systems have recently been shown to participate in major inflammatory and neoplastic processes such as myelomatosis (Rose-John, S., Heinrich, P.C., 1994. Soluble receptors for cytokines and growth factors: generation and biological function. Biochem. J. 300, 281). In addition, this family of receptors also shares the gp130 transducing chain, with the IL6 and IL11 receptors. Because IL6 and gp130 were the first members to be discovered, most of the available reagents are directed at them. In this respect, monoclonal antibodies have played a major role in elucidating these receptor/ligand interactions and exploring the pathophysiological aspects of their biology. So far, no such reagents have been described for the gp190. We now report the production and characterization of 16 monoclonal antibodies directed against human gp190. They were obtained using recombinant chimeric or truncated proteins produced in a eukaryotic CHO cell line. One was able to block the biological activity of LIF. Because gp190 comprises two hematopoietin binding domains, crude epitope mapping was possible using the same reagents. While more of these antibodies are required, the present set validate the technological approach used for their preparation and should improve our understanding of this class of cytokines.

Animals↗
PubMed1997

Close phenotypic and functional similarities between human and murine alphabeta T cells expressing invariant TCR alpha-chains.

Several studies have demonstrated the existence of a murine NK1.1+ alphabeta T cell subset expressing V alpha14+ TCR alpha-chains with highly conserved invariant junctional sequences and able to secrete Th2 cytokines when exposed to CD1+ stimulator cells. In humans, alphabeta T cells carrying invariant V alpha24+ TCR alpha-chains highly homologous to those expressed by murine NK1.1 cells have been recently described. Here we show that these cells (referred to as V alpha24inv T cells) and murine NK1.1+ alphabeta T cells resemble each other in several ways. First, like their murine counterparts, T cells expressing high levels of V alpha24inv TCRs can be either CD4- CD8- double negative (DN) or CD4+, but they never express heterodimeric CD8 molecules. Second, most V alpha24inv T cells are brightly stained by NKRP1-specific mAb but not by mAb directed against other type II transmembrane proteins of the NK complex. Third, DN and particularly CD4+ V alpha24inv T cells are greatly enriched for IL-4 producers. The concomitant expression of highly conserved TCRs of a particular set of NK markers and of Th2 cytokines in human and murine alphabeta T cells suggests a coordinate acquisition of these phenotypic and functional properties. Furthermore, the relatively high frequency of human V alpha24inv T cells, which are presently shown to represent on average 1/500 PBL, and the high interindividual variations of the size of this cell subset under physiologic conditions go for a major role played by alphabeta T cells carrying invariant TCR in a large array of immune responses.

Animals↗
PubMed1997

Chromosome mapping and expression of the human interleukin-13 receptor.

Interleukin-13 (IL-13) is a cytokine secreted by activated T cells and shares most but not all biological activities with interleukin-4 (IL-4). Both cytokines play an important role as a switch factor directing synthesis of IgE; they act on monocytes and endothelial cells, but unlike IL-4, IL-13 does not act on T cells. These cytokines have both common and distinct components in their respective receptors. Based on sequence similarity shared by cytokine receptor family members, we have identified a cDNA encoding the human IL-13 receptor (IL-13R). This cDNA was used to examine the pattern of IL-13R mRNA expression by Northern blot analyses of poly(A)+ RNA purified from different human tissues and cell lines. Among several myeloma cell lines analyzed, the U266 cell line was the only one found to express IL-13R transcripts. This cell line is also the only one described as producing IgE. The IL-13R gene was mapped to chromosome Xq24 by in situ hybridization. Interestingly, this locus is near that of the CD40 ligand gene, the product of which is also involved, like IL-13, in proliferation and IgE isotype switching of human B cells. The human IL-13R gene maps between two cytokine receptor genes located on the chromosome arm Xq region: the interleukin-2 receptor gamma chain gene (Xq13.1) and the interleukin-9 receptor gene (Xq28). The lack of nucleotide sequence similarity suggests unrelated evolutionary pathways between these receptor genes.

Amino Acid Sequence↗
PubMed1997

Reconstitution of two isoforms of the human interleukin-11 receptor and comparison of their functional properties.

Long-term stable Ba/F3 transfectants (B13R alpha1 and B13R alpha2) expressing two isoforms of the human IL-IIR alpha receptor (alpha1 full length or alpha2 lacking the cytoplasmic domain) in combination with human gp130 were established. IL-11R alpha1 and IL-11R alpha2 were each expressed and detected as three bands upon Western blot analysis, with apparent molecular masses in agreement with those of the polypeptide backbone (47 and 44 kDa, respectively) with no, one or two N-linked sugars. B13R alpha1 and B13R alpha2 bound IL-11-thioredoxin with similar efficiencies and proliferated with superimposable dose-response curves to IL-11, demonstrating that the intracellular domain of IL-11R alpha has no significant contribution on ligand binding and signaling. Analysis of a set of anti-human gp130 mAbs confirmed the similar responsiveness of B13R alpha1 and B13R alpha2 transfectants.

Animals↗
PubMed1997

An investigation of the physical behaviour of moisture-activated mucoadhesive hydrogels upon contact with biological and non-biological substrates.

The physical behaviour of moisture-activated mucoadhesive hydrogels in contact with a Plexiglas plate or artificial mucin gels was investigated using an adapted tensile tester fitted with force and displacement transducers. Our study of the 'Plexiglas-hydrogel' interface showed that the intrinsic mechanical response of most poly(acrylic acid) polymers is quite different from that exhibited by cellulose derivatives. The former exert an attractive interaction towards the substrate in contrast to the latter where the interaction is essentially repulsive. The interfacial forces developed by pure mucin were closely related to those of poly(acrylic acid) polymers. Similar results were observed when the Plexiglas was replaced by artificial mucin gels. A correlation was found between the attractive force developed by poly(acrylic acid) hydrogels towards the inert substrate and their in vitro mucoadhesive joint strength. Therefore, a non-specific physical interaction occurs during the initial adhesive process, whatever the nature of the substrate. Besides the water absorption capacity and swelling properties of the candidate materials, it seems that their initial mucoadhesiveness depends more on their mechanical response to hydration and less on the extent of molecular interactions at the adhesive interface.

Adhesiveness↗
PubMed1997

Epitope-function relationships of human leukemia inhibitory factor receptors using a novel set of anti-gp190 mAB.

The binding and functional properties of a set of six mAb directed against the human gp190 [leukemia inhibitory factor (LIF) receptor] signal transducing molecule were determined. Each of the antibodies reacted with a distinct epitope on gp190 expressed either by gp190-transfected Chinese hamster ovary cells or by the LIF receptor-positive choriocarcinoma JAR cell line. Two of the antibodies (1B4 and 6E6) had binding stoichiometries that were approximately 2-fold lower than those of other mAb (10B2, 12D9 and 7G7), suggesting either that gp190 is present as a pre-associated homodimer in the cell membrane or that part of gp190 is pre-associated with another component. Two mAb (1C7 and 1B4) were found to inhibit LIF binding on the two cell types studied. On JAR cells, this inhibition was, however, restricted to the high-affinity LIF component, suggesting different modes of LIF engagement with the low- and high-affinity receptor species. mAb 1C7 and 1B4 were also found to synergize for inhibiting LIF high-affinity binding. This synergy also extended to the inhibition of LIF- or oncostatin M (OSM)-induced proliferation of a Ba/F3 cell line co-transfected with human gp130 and gp190. However, this mAb combination inhibited LIF- but not OSM-induced haptoglobin secretion by HepG2 cells, suggesting that whereas haptoglobin secretion induced by LIF involves gp130/gp190 common LIF/OSM type I receptors, that induced by OSM mainly involves type II OSM receptors.

Animals↗
PubMed1996

The human interleukin-11 receptor alpha gene (IL11RA): genomic organization and chromosome mapping.

The high-affinity receptor for interleukin-11 (IL-11) is composed of two subunits, IL-11 receptor alpha chain (IL-11R alpha) and gp130, the common subunit of the interleukin-6 (IL-6), ciliary neurotrophic factor (CNTF), leukemia inhibitory factor, and oncostatin M receptors. The IL-11 receptor-specific alpha chain shares homologies with the alpha chain of the CNTF and IL-6 receptors. We isolated and characterized genomic DNA clones encompassing the entire coding sequence of the IL-11R alpha cDNA. The exon-intron organization of the IL-11R gene (HGMW-approved symbol IL11RA) is consistent with the predicted structure of the different domains of the IL-11R alpha protein, confirming evolutionary conservation at the level of gene organization among the hematopoietic cytokine receptor family. The IL-11R gene has been assigned to chromosome 9 band p13 by in situ hybridization using human IL-11R alpha cDNA as a probe. The fact that the ciliary neurotrophic factor (CNTFR) gene has recently been localized on this same band and the conserved genomic structure between IL-11R and CNTFR suggest that they may have evolved from a common ancestor.

Base Sequence↗
PubMed1996

Lack of intermediate-affinity interleukin-2 receptor in mice leads to dependence on interleukin-2 receptor alpha, beta and gamma chain expression for T cell growth.

An interleukin (IL)-4 dependent mouse T cell clone 8.2 derived from an IL-2-dependent T cell line was characterized. As measured by flow cytometric analysis and Northern blotting, it expresses IL-2 receptor beta (IL-2R beta) and gamma (IL-2R gamma) chains, but has lost expression of IL-2 receptor alpha chain (IL-2R alpha). To investigate the properties of the mouse IL-2R beta gamma complex and the role of IL-2R alpha gene expression, this clone was further studied. T cell clone 8.2 has lost the capacity to bind 125I-labeled human IL-2 under experimental conditions able to detect intermediate-affinity IL-2R in human cells. Mouse IL-2 is unable to block the binding of mAb TM beta 1 to 8.2 cells. Under the same experimental conditions, mouse IL-2 blocks the binding of TM beta 1 to C30-1 cells expressing the IL-2 alpha beta gamma complex. Since TM beta 1 recognizes an epitope related to the IL-2 binding site of IL-2R beta, these results can be taken as a demonstration that mouse IL-2R beta gamma does not bind mouse IL-2. Furthermore, T cell clone 8.2 does not proliferate in response to recombinant mouse or human IL-2. On the other hand, T cell transfectant lines expressing heterospecific receptors made of the human IL-2R beta and mouse IL-2R gamma chains bind 125I-labeled human IL-2 and proliferate in response to IL-2. This establishes the difference between mouse and human IL-2R beta chains. Transfection of T cell clone 8.2 with human IL-2R alpha genes restores their capacity to proliferate in response to IL-2. In addition, all transfectants grown in IL-2 express the endogeneous mouse IL-2R alpha chain. When grown in IL-4, the endogeneous mouse IL-2R alpha gene remains silent in all these transfectants. These results show that, contrary to the human, the mouse does not express an intermediate-affinity IL-2R. Expression of the IL-2R alpha gene is therefore required for the formation of the functional IL-2R in mice.

Animals↗
PubMed1996

Leukemia inhibitory factor (LIF) and oncastsin M (OSM) high affinity binding require additional receptor subunits besides GP130 and GP190.

The structure of Leukaemia Inhibitory Factor (LIF) and Oncostatin M (OSM) receptors is not completely resolved. Heterodimerization of gp190 and gp130 has been proposed to form a high affinity receptor (type I) shared by LIF and OSM, while heterodimerization of gp130 with an as yet unidentified subunit is proposed to form a high affinity OSM receptor (type II) not shared by LIF. We have analysed the binding stoichiometries, cross-competition properties and cross-linking patterns of LIF and OSM to the choriocarcinoma JAR cell line. The data obtained are not fully accounted for by the model proposed above. They indicate rather that third chains of 140-150 kDa molecular mass, in addition to the gp130 and gp190 subunits, enter in the structure of LIF and OSM high affinity receptors. These results were strongly supported by transfection experiments in CHO cells. CHO cells co-transfected with the human gp190 and gp130 cDNAs expressed high affinity LIF receptors but no high-affinity OSM receptors, indicating that an additional component is required for high affinity OSM binding. High-affinity LIF cross-linking on these cells also showed the association of LIF with a 150 kDa component in addition to the gp130 and gp190 subunits.

Animals↗
PubMed1996

Antibodies directed at mouse IL-2-R alpha and beta chains act in synergy to abolish T-cell proliferation in vitro and delayed type hypersensitivity reaction in vivo.

The anti-mouse IL-2-R beta chain mAb TM-beta 1 which, by itself, does not affect IL-2-dependent proliferation through the high affinity mouse IL-2 receptor, was shown to cooperate in a synergistic way with a set of anti-IL-2-R alpha chain mAbs both in vitro and in vivo. In vitro, when associated at equimolar concentrations, the TM-beta 1/anti-alpha mAb association was four to ten times more efficient at inhibiting the proliferation of the CTL-L2 cell line than was a similar concentration of anti-alpha mAb alone. In addition, a bispecific antibody in which a Fab' fragment of TM-beta 1 was covalently linked to a Fab' fragment of one of the anti-alpha mAb (5A2) was shown to be as efficient as the TM-beta 1/5A2 association. The association of TM-beta 1 with 5A2 was also tested in vivo in a sheep red blood cell-induced delayed type hypersensitivity (DTH) model. TM-beta 1 which, by itself, had no effect on DTH, induced a two- to threefold decrease in the doses of 5A2 required to suppress this cell-mediated immune reaction.

Animals↗
PubMed1995

Molecular cloning of two isoforms of a receptor for the human hematopoietic cytokine interleukin-11.

Interleukin-11 (IL-11) is a stromal cell-derived cytokine with multiple biologic activities on lymphohematopoietic cells. It belongs to a family of pleiotropic and redundant cytokines that use the gp 130 transducing subunit in their high affinity receptors. By amplifying human cDNA libraries with oligonucleotide primers corresponding to the conserved WSXWS motif found in the hematopoietic cytokine receptor family, a novel cytokine receptor cDNA was identified that, based on high (82%) sequence homology with the recently cloned murine IL-11 receptor, appears to encode the human IL-11 receptor. This receptor is a 422-amino acid protein containing a signal peptide followed by extracellular, transmembrane, and cytoplasmic domains. The extracellular region has a two-domain structure homologous to those of the IL-6 and ciliary neurotrophic factor (CNTF) receptors: an immunoglobulin-like domain and a cytokine receptor-like domain. In addition, an isoform of the human IL-11 receptor that lacks the cytoplasmic domain was also identified. In agreement with the pleiotropic effects of IL-11 on different hematopoietic lineages and bone cells, IL-11 receptor transcripts were found to be expressed by the myelogenous leukemia cell line K562, the megakaryocytic leukemia cell line Mo7E, the erythroleukemia cell line TF1, and the osteosarcoma cell lines MG-63 and Saos-2.

Amino Acid Sequence↗
PubMed1995

Culturing of cells from giant cell tumour of bone on natural and synthetic calcified substrata: the effect of leukaemia inhibitory factor and vitamin D3 on the resorbing activity of osteoclast-like cells.

Osteoclastic cells from giant cell tumour of bone (GCT) of bone provide a rich source for investigation of cellular mechanisms leading to formation of multinucleated cells, the resorption process and involvement of hormones and cytokines in these events. In the present study we investigated the effect of 1,25-dihydroxyvitamin D3 (VD3) and leukaemia inhibitory factor (LIF) on the resorbing potential of osteoclast of GCT origin using quantitative image-analysis of resorption lacunae in an in vitro dentine model. While VD3 unsignificantly increased the number of resorption pits and implicated surface after 7 days of GCT cell culturing, the stimulative effect of LIF was statistically significant. In cultures supplemented with LIF (5000 U/ml) the number of lacunae and resorption surface increased by 38% and 55%, respectively, when compared with control cultures. We suggest that both osteotropic agents increased osteoclastic activity, as the number of multinucleated cells was similar in control and experimental cultures. Seeding of GCT cells on biphasic calcium phosphate substratum revealed the relative inability of osteoclastic cells to resorb this synthetic material.

Adult↗
PubMed1995

Chimeric interleukin 2 receptor alpha chain antibody derivatives with fused mu and gamma chains permit improved recruitment of effector functions.

In order to investigate the feasibility of shuffling effector functions of monoclonal antibodies, we constructed chimeric antibodies with fused heavy chains. The derivatives studied are based on a monoclonal antibody directed against the alpha chain of the human Il2-R. Derivatives studied were the IgG1 and IgM isotypes; IgM delta, lacking the ability of multimerization due to a deletion; IgMc gamma 1 and IgGlc mu, with fused mu and gamma 1 chains and vice versa. IgG1, IgM delta and IgMc gamma 1 were secreted as monomers, IgM and IgG1c mu as polymers. The Ki values for competition with radio-iodinated Il2 with respect to binding to the Il2-R were markedly lower for polymeric than for monomeric derivatives (300-400 pM versus 2500-6500 pM). Recruitment of complement mediated by the deposition of C3 fragments, either of heterologous (rabbit) or homologous (human) origin, was mediated only by the polymeric derivatives IgM and IgG1c mu. ADCC was mediated by monomeric IgG1 and polymeric IgG1c mu, the latter derivative being active at concentrations 100-fold lower than the former. Together, the results demonstrate that both CDC and ADCC effector functions can be combined on a polymeric antibody derivative with fused gamma 1 and mu chains. In addition, such a derivative, due to its polymeric nature, has a high binding affinity. These properties may be important for the elimination of target cells in vivo.

Amino Acid Sequence↗