C La Bonnardière

University of Maribor, Maribor, Maribor, Slovenia

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Publications (43)78.94 Total impact

  • A Cencic, M Guillomot, S Koren, C La Bonnardière
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    ABSTRACT: Between days 12 and 20 of pregnancy, the trophectoderm of the porcine conceptus secretes two species of interferons (IFN): IFN-gamma (Type II), which is produced in substantial amounts, and IFN-delta (type I), for which secretion peaks at days 15-16 of gestation. The role of these embryonic IFNs is not known. We made the assumption that, in the pig, one possible role of these IFNs may be the remodelling and/or depolarization of the uterine endometrial epithelium, as a prerequisite for implantation and establishment of a functional placenta. A comparative analysis by immunohistochemistry of several cell membrane markers and ECM components of the cyclic and pregnant uterus was performed at day 15 post-oestrus. The markers were those likely to differ between a pregnant and cyclic uterus, or between different stages of pregnancy. A highly specific marker of IFN-gamma activity, namely MHC class II antigens in the uterine mucosa, was also examined. This study provides so far unreported data: in the endometrial epithelium of the pregnant uterus, we observed a partial relocalization of ZO-1, a marker of epithelial tight junctions, thus suggesting significant changes to the endometrial polarity. Heparan-Sulphate Proteoglycan (HSPG) expression did not differ significantly between cyclic and pregnant uteri. In contrast with the accepted rodent model of trophoblast-uterus adhesion, the porcine trophoblast and luminal epithelium were negative for HSPG. Finally, MHC class II antigens were absent from the cyclic uterus, but markedly induced in the day 15 pregnant uterus, particularly in endothelial cells, suggesting that IFN-gamma may indeed cross the maternal epithelium. This hypothesis was supported by the observation of IFN-gamma immunoreactivity associated with clusters of endometrial cells in the pregnant uterus.
    Placenta 01/2003; 24(8-9):862-9. · 3.12 Impact Factor
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    ABSTRACT: Following the demonstration of high levels of interferon-gamma (IFN-gamma) synthesis by the pig trophectoderm around implantation, an adequate experimental system was established so as to study the regulation of endogenous IFN-gamma gene. Several stable cell lines have been isolated from Day 14 and 15 pig trophoblast, that could withstand indefinite growth when cultured on collagen-coated supports. Since no feeder cells were used for culture, and cell lines could be successfully cloned, these lines represent the first pure porcine trophoblastic (TB) cell lines isolated so far. These cells were shown to exhibit most differentiation markers of epithelial cells and in addition to express the porcine trophectoderm-specific antigen SN1-38. The TB cell line A (TBA) was characterized in more details upon culture on microporous filters, where a high apico-basal polarity could be obtained. In those conditions, a transient and acute interferon-gamma secretion was detected only in the apical medium. Moreover, the two trophoblast-specific mRNA of 1.3 and 1.4 kb that have been described in the blastocyst collected in vivo were shown to be synchronously transcribed. This polarized synthesis and secretion of IFN-gamma was correlated with the acquisition of maximal levels of electric resistance of TBA monolayers on filters, and was not observed on the same cells cultured on plastic. This differentiation was maintained over 30 passages, demonstrating that the induction of IFN-gamma secretion by pig conceptus is not maternally controlled. This cellular model will be of prime importance for studies on the developmental regulation of the IFN-gamma gene, and more generally for studies on relationship between secretion and polarity in transporting epithelia.
    Placenta 12/2002; 23(10):716-26. · 3.12 Impact Factor
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    ABSTRACT: At the time of implantation in the maternal uterus, the trophectoderm of the pig blastocyst is the source of a massive secretion of interferon-gamma (IFN-gamma), together with lesser amounts of IFN-delta, a unique species of type I IFN. This trophoblastic IFN-gamma (TrIFN-gamma) is an unprecedented example of IFN-gamma being produced spontaneously by an epithelium. We therefore studied some of its structural and biochemical properties, by comparison with pig IFN-gamma from other sources, either natural LeIFN-gamma (from adult leucocytes), or recombinant. Biologically active TrIFN-gamma is a dimeric molecule, of which monomers are mainly composed of a truncated polypeptide chain with two glycotypes, unlike LeIFN-gamma which is formed of at least two polypeptide chains and four glycotypes. TrIFN-gamma collected in the uterus lumen was enzymatically deglycosylated and analysed by mass spectrometry (MALDI-TOF). The data revealed that the more abundant polypeptide has a mass of 14.74 kDa, corresponding to a C-terminal cleavage of 17 residues from the expected 143-residue long mature sequence. A minor polypeptide, with a mass of 12.63 kDa, corresponds to a C-terminal truncation of 36 amino acids. MALDI-TOF analysis of tryptic peptides from the glycosylated molecule(s) identifies a single branched carbohydrate motif, with six N-acetylgalactosamines, and no sialic acid. The only glycan microheterogeneity seems to reside in the number of l-fucose residues (one to three). The lack of the C-terminal cluster of basic residues, and the presence of nonsialylated glycans, result in a very low net charge of TrIFN-gamma molecule. However, the 17-residue truncation does not affect the antiproliferative activity of TrIFN-gamma on different cells, among which is a porcine uterine epithelial cell line. It is suggested that these specific properties might confer on TrIFN-gamma a particular ability to invade the uterine mucosa and exert biological functions beyond the endometrial epithelium.
    European Journal of Biochemistry 07/2002; 269(11):2772-81. · 3.58 Impact Factor
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    Avrelija Cencic, Claude La Bonnardière
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    ABSTRACT: In the pig as in ruminant species, the implantation of the elongated conceptus - the embryo with its associated membranes - onto the maternal uterus is accompanied by an intense secretion of interferon (IFN), which culminates at day 15 of development. It has been shown that in fact the pig trophectoderm - the polarized epithelium which lines the conceptus - simultaneously secretes two types of interferons: IFN-gamma (IFN-gamma), which is the more abundant species, is produced in very substantial amounts. Another IFN is also secreted, which happens to be a novel type I IFN, now named IFN-delta. It was previously shown that the uterus is the most probable target of the pig trophoblastic IFNs, since no autocrine effect was found on the trophoblast. It has also been shown that, unlike for the ruminant species, the pig trophoblastic IFNs do not play an apparent role in the so-called maternal recognition of pregnancy. We have focused this review on IFN-gamma, because first, it is the major species secreted and secondly, IFN-gamma has various regulatory effects on different tissues, including lymphoid cells. We particularly address the question of the possible role of trophoblastic IFN-gamma in early pregnancy, in the light of the known biological functions of human and mouse IFN-gamma.
    Veterinary Research 03/2002; 33(2):139-57. · 3.43 Impact Factor
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    M Moudjou, Y Frobert, J Grassi, C La Bonnardière
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    ABSTRACT: Expression of the cellular prion protein PrP(C) is sine qua none for the development of transmissible spongiform encephalopathy and thus for the accumulation of the illness-associated conformer PrP(Sc). Therefore, the tissue distribution of PrP(C) at the protein level in both quantitative and qualitative terms was investigated. PrP(C) was quantified using a two-site enzyme immunometric assay which was calibrated with purified ovine recombinant prion protein (rPrP). The most PrP(C)-rich tissue was the brain, followed by the lungs, skeletal muscle, heart, uterus, thymus and tongue, which contained between 20- and 50-fold less PrP(C) than the brain. The PrP(C) content of these tissues seems to be comparable between sheep. Other organs, however, showed different, but low, levels of the protein depending on the animal examined. This was also the case for tissues from the gastrointestinal tract. The tissue containing the lowest concentration of PrP(C) was shown to be the liver, where PrP(C) was found to be between 564- and 16000-fold less abundant than in the brain. PrP(C) was concentrated from crude cellular extracts by immunoprecipitation using several monoclonal and polyclonal anti-ovine PrP antibodies. Interestingly, it was observed that the isoform profile of PrP(C) was tissue-specific. The most atypical electrophoretic profile of PrP(C) was found in the skeletal muscle, where two polypeptides of 32 and 35 kDa were detected.
    Journal of General Virology 09/2001; 82(Pt 8):2017-24. · 3.13 Impact Factor
  • A Cencic, F LeFèvre, S Koren, C La Bonnardière
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    ABSTRACT: Tetracycline-controlled expression plasmids that allow inducible expression of proteins in mammalian cells (Gossen & Bujard, 1992), have been used to express porcine interferon-gamma in the RK-13 rabbit kidney cell line. Following neomycin selection, stable clones produced recombinant, glycosylated porcine interferon-gamma (rGPoIFN-gamma) only after removal of tetracycline (Tc). Southern blot analysis of one clone showed that approximately 50 copies of IFN-gamma cDNA were present in the cell genome. In the absence of Tc, stable clones secreted large amounts of rGPoIFN-gamma (up to 16 microg/ml) into the medium supplemented with 10% FCS and high glucose concentration. Molecular weight comparison of 35S-Methionine, labelled rGPoIFN-gamma with natural leukocytic IFN-gamma after immunoprecipitation, revealed 4 major glycoforms with apparent Mr of 27,000; 25,000; 20,000 and 18,500, that are almost identical in both IFN-gamma species. In both cases, all 4 glycoforms resolved into 2 polypeptide monomers with apparent Mr of 16,500 and 14,500 upon deglycosylation with N-glycosydase F. The biological activity of rGPoIFN-gamma was in the same range as that of natural leukocytic PoIFN-gamma (2 x 10(6) U/mg). Eventually, this recombinant mammalian IFN-gamma should constitute a very useful substitute for leukocyte PoIFN-gamma in in vitro or in vivo experiments.
    Animal Biotechnology 02/1999; 10(1-2):63-79. · 0.88 Impact Factor
  • Sabine D'andréa, Claude La Bonnardière
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    ABSTRACT: In early gestation, trophoblastic cells of porcine preimplanting conceptuses transiently and massively secrete two distinct interferons (IFNs), one of which is IFN-gamma. In order to localize possible cellular target(s) for this IFN-gamma, the expression of the porcine IFN-gamma receptor and its developmental regulation have been investigated on the maternal endometrium and on the embryonic tissues. A cDNA encoding the porcine IFN-gamma binding-chain (pIFNGR1) was isolated. When expressed in COS-7 cells, it displayed a specific binding to radiolabelled pIFN-gamma and was shown to be a glycosylated membrane protein with an apparent molecular mass of 92 kDa. Porcine IFNGR1 mRNA was detected by RT-PCR not only in uterine epithelial cells but also in embryonic tissues from at least as early as day 10 of gestation. Moreover, membrane expression of the pIFN-gamma receptor quantified by binding and crosslinking of 32P-pIFN-gamma was demonstrated in uterine epithelium and in the trophoblast. In the trophoblast, expression of the receptor was found to be developmentally regulated: although expression was weak on days 12 and 15 of gestation, it reached a level similar to that found on some IFN-gamma-sensitive cells on day 16. This study shows that maternal endometrium is not the only possible target for trophoblastic IFN-gamma: the induction of pIFN-gamma receptor expression in the trophoblast around day 16 of gestation could suggest the appearance of responsiveness to pIFN-gamma in this implanted tissue and therefore a possible delayed autocrine effect of trophoblastic pIFN-gamma.
    Molecular Reproduction and Development 12/1998; 51(3):225-34. · 2.81 Impact Factor
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    I Vancová, C La Bonnardiere, P Kontsek
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    ABSTRACT: The soluble vaccinia virus-encoded protein B18R inhibits the antiviral activity and cellular binding of the type I interferons (IFN)-alpha, -beta and -omega of different mammalian species. Recently, a novel type I IFN was detected in pigs and classified as a member of a distinct IFN family designated IFN-delta. Our study aimed to determine if the structural properties of this shortest (149 residues long) type I IFN allow its interaction with the type I IFN-binding protein B18R. Experiments using bovine (MDBK) cells demonstrated that B18R neutralized the antiviral activity of porcine IFN-delta with high efficiency. Preincubation of B18R with radiolabelled IFN-delta specifically inhibited binding of IFN to bovine cells. These data indicate that the overall conformation of the novel IFN-delta might be similar to that of other type I IFNs.
    Journal of General Virology 08/1998; 79 ( Pt 7):1647-9. · 3.13 Impact Factor
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    ABSTRACT: In the pig species, the preimplanting trophoblast is known to synthesize and secrete high amounts of interferon during early development. Previous experiments in cyclic gilts using total conceptus secretory proteins suggested that porcine trophoblastic interferons, unlike those of ruminants, exert no effect on the luteal cycle. In the present experiment, cyclic Meishan gilts were divided into two groups, cannulated on both uterine horns, and given daily injections of either a placebo or increasing doses of a mixture of recombinant interferon-gamma and interferon-delta, on Days 11-14 of the estrous cycle. In treated gilts, the injected doses were much higher than those previously found in uterine perfusates from pregnant gilts. However, no significant differences could be found between the control (n = 4) and the treated (n = 5) group concerning the days of the estrous cycle for mid-decrease of progesterone (control: Day 14.5+/-0.57 [mean+/-SD]; treated: Day 15+/-1.25), the day of estrus (control: Day 19+/-0.96; treated: Day 19.6+/-0.55), and the subsequent ovulation rate (control: 14+/-2.2 corpora lutea; treated: 13.1+/-1.1 corpora lutea). These data confirm that pig trophoblastic interferons, unlike those of ruminants, do not themselves exert an antiluteolytic effect. A possible synergistic effect of embryonic estrogens on the luteal functions of nonpregnant sows remains to be determined.
    Biology of Reproduction 04/1998; 58(4):1026-31. · 4.03 Impact Factor
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    ABSTRACT: We have recently described a novel type I interferon (IFN) co-expressed with IFN-gamma by the trophectoderm of the pig conceptus between day 12 and day 18 of gestation, a development stage that corresponds to implantation in the uterus. This IFN, now officially named IFN-delta, is recognized as the first member of a novel type I IFN family. This paper reviews the main published data on IFN-delta, together with some new data, showing that IFN-delta, while being a true type I IFN, has some very specific structural and biological properties. Sequences related to IFN-delta coding sequence were found in the genome of man and other ungulates but the only other potentially functional gene was found, so far, in the horse. The pig IFN-delta mature protein, with 149 amino acids, is the smallest of all known type I IFNs. It is unusually rich in cysteines (seven residues), and has a very basic isoelectric point. Recombinant IFN-delta expressed in insect cells is glycosylated and has a high antiviral activity on porcine cells, but not on human cells. It has high antiproliferative activity, which is significantly enhanced in the presence of IFN-gamma. This new IFN was shown to bind on pig cells to the same type I receptor as IFN-alpha. IFN-delta and IFN-gamma genes are co-regulated in the pig trophectoderm, whose cells on day 14-16 of development simultaneously secrete both IFN proteins. The biological role of porcine IFN-delta in early pregnancy has been found unrelated to the known antiluteolytic effect of trophoblastic IFN-tau in ruminants.
    Biochimie 01/1998; 80(8-9):779-88. · 3.14 Impact Factor
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    M Guillomot, P Reinaud, C La Bonnardière, G Charpigny
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    ABSTRACT: Two proteins (17 and 22-24 kDa) produced by day 17 goat conceptuses were purified from in vitro culture media. Analysis of their N-terminal amino acid sequences and of their antiviral activity confirmed that both proteins belonged to the interferon tau family characteristic of ruminant conceptuses. The two molecules were glycosylated (22-24 kDa) or nonglycosylated (17 kDa) isoforms of the same protein. The time course of secretion was plotted and immunoblotting of the protein contents of uterine flushings from day 13 to day 21 of pregnancy was performed. The nonglycosylated isoform (17 kDa) was first detected on day 16; both isoforms were present at day 17 and, thereafter during pregnancy, the two proteins were not present in uterine flushings. Immunohistochemistry was used to show that the goat interferon tau was present in the trophoblastic cells as early as day 14 and until day 17. However, immunostaining was not uniform along the conceptus; labelling was greater at the abembryonic pole than at the embryonic pole. By day 18, as implantation proceeded, goat interferon tau was no longer detected. These results confirmed that the goat conceptus secretes interferon tau during the period of maternal recognition of pregnancy but its rapid decrease suggests that other factors need to be present by day 18 to take over its role in the maintenance of luteal function.
    J Reprod Fertil 01/1998; 112(1):149-56.
  • Sabine D'andréa, Claude La Bonnardière
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    ABSTRACT: In early gestation, trophoblastic cells of porcine preimplanting conceptuses transiently and massively secrete two distinct interferons (IFNs), one of which is IFN-γ. In order to localize possible cellular target(s) for this IFN-γ, the expression of the porcine IFN-γ receptor and its developmental regulation have been investigated on the maternal endometrium and on the embryonic tissues. A cDNA encoding the porcine IFN-γ binding-chain (pIFNGR1) was isolated. When expressed in COS-7 cells, it displayed a specific binding to radiolabelled pIFN-γ and was shown to be a glycosylated membrane protein with an apparent molecular mass of 92 kDa. Porcine IFNGR1 mRNA was detected by RT-PCR not only in uterine epithelial cells but also in embryonic tissues from at least as early as day 10 of gestation. Moreover, membrane expression of the pIFN-γ receptor quantified by binding and crosslinking of 32P-pIFN-γ was demonstrated in uterine epithelium and in the trophoblast. In the trophoblast, expression of the receptor was found to be developmentally regulated: although expression was weak on days 12 and 15 of gestation, it reached a level similar to that found on some IFN-γ–sensitive cells on day 16. This study shows that maternal endometrium is not the only possible target for trophoblastic IFN-γ: the induction of pIFN-γ receptor expression in the trophoblast around day 16 of gestation could suggest the appearance of responsiveness to pIFN-γ in this implanted tissue and therefore a possible delayed autocrine effect of trophoblastic pIFN-γ. Mol. Reprod. Dev. 51:225–234, 1998.© 1998 Wiley-Liss, Inc.
    Molecular Reproduction and Development 01/1998; 51(3):225-234. · 2.81 Impact Factor
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    S Riffault, C Carrat, L Besnardeau, C La Bonnardière, B Charley
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    ABSTRACT: A low frequency peripheral blood mononuclear cell (PBMC) subpopulation, referred to as natural interferon-producing (NIP) cells, is described as producing interferon-alpha (IFN-alpha) following contact with non-infectious viral structures, namely viral glycoproteins. These cells are characterized in vitro as non-T, non-B, MHC class II+ and CD4+ cells. In this study, NIP cells were analysed in vivo after an intravenous injection of UV-inactivated transmissible gastroenteritis virus in newborn piglets, which resulted in strong serum IFN-alpha production. Splenocytes, but not PBMC, were the IFN-alpha producers in vivo. Using double immunohistochemical labelling for both IFN-alpha and leukocyte markers, we established that splenic NIP cells were not T or B cells. The majority were MHC class II+ and only a minority expressed a macrophage marker. NIP cells were localized in contact with MHC class II-expressing cells and T cells, which suggested that NIP cells might modulate the antiviral immune response.
    Journal of General Virology 11/1997; 78 ( Pt 10):2483-7. · 3.13 Impact Factor
  • P D Niu, FRANÇOIS LEFEVRE, CLAUDE LA BONNARDIERE
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    ABSTRACT: The short porcine type I interferon (spI IFN), encoded by a gene physiologically expressed by the pig embryonic trophoblast during implantation, represents the first member of a novel family type I IFN. Binding and cross-linking experiments were carried out to characterize its cellular receptor. On porcine kidney cells, specific binding of 125I-spI IFN could be displaced significantly by spI IFN, rpIFN-alpha 1, and rhIFN-alpha 1, but not by rhIFN-alpha 2a or by rpIFN-gamma. On the other hand, all these type I IFNs but not rpIFN-gamma were capable of displacing bound 32P-hIFN-alpha A-P1 on these cells. Cross-linking data show that the specific 120 kD complex formed with these two radiolabeled ligands was displaceable by an excess of both spI IFN and rpIFN-alpha 1. These results provide primary evidence that spI IFN shares at least the major binding subunit of type I IFN receptor on porcine cells. On human WISH cells, 125I-spI IFN did not form any complex, nor did spI IFN affect cross-linking complexes of 32P-hIFN-alpha A-P1 on these cells, unlike rpIFN-alpha 1. The lack of antiviral and antiproliferative effects of spI IFN on human cells is primarily a result of its inability to recognize human type I IFN receptor.
    Journal of Interferon & Cytokine Research 10/1995; 15(9):769-75. · 3.30 Impact Factor
  • P D Niu, F Lefevre, D Mege, C La Bonnardiere
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    ABSTRACT: A recombinant baculovirus was designed to express short porcine type I interferon (spI interferon), a novel and atypical type I interferon that was recently described as the product of a gene transcribed in pig trophoblast at the time of implantation in the uterus [Lefèvre, F. & Boulay, V.C. (1993) J. Biol. Chem. 268, 19,760-19,768]. The recombinant protein, secreted into the culture medium of Sf9 cells at 3 days post infection (60,000 IU/ml), was purified by ion-exchange and reverse-phase HPLC. N-terminal sequencing confirmed the predicted signal peptide cleavage site and therefore the size of the mature protein (149 amino acids), the shortest of all reported type I interferons. Purified spI interferon, with a specific antiviral activity using Madin-Darby bovine kidney cells of 3.7 x 10(7) IU/mg, is an N-glycosylated monomer of 19 kDa that possesses several physicochemical characteristics of interferons: (a) disulfide bonds are necessary for bioactivity; spI interferon is thermolabile, stable at pH 2, and able to renature after complete denaturation (1% 2-mercaptoethanol, 1% SDS, and 5 M urea); (b) the carbohydrate chain is not essential for bioactivity since no loss of antiviral activity is observed following complete deglycosylation. In this study, antiviral and anti-proliferation activities of spI interferon in cell culture were compared with those of other interferons, especially with porcine type 1 interferon-alpha. A major difference with porcine type 1 interferon-alpha was that spI interferon was not active on human cells in either test, and it was relatively more active on pig cells compared to bovine cells than porcine type 1 interferon-alpha. Serological cross-neutralization results obtained with anti-(spI interferon) serum confirmed that several members of interferon families are not antigenically related to spI interferon, in agreement with previous observations; this provides further evidence that spI interferon could represent a new family of type I interferon.
    European Journal of Biochemistry 06/1995; 230(1):200-6. · 3.58 Impact Factor
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    ABSTRACT: A recombinant baculovirus was designed to express short porcine type I interferon (spI interferon), a novel and atypical type I interferon that was recently described as the product of a gene transcribed in pig trophoblast at the time of implantation in the uterus [Lefèvre, F. & Boulay, V. C. (1993) J. Biol. Chem. 268, 19760–19768]. The recombinant protein, secreted into the culture medium of Sf9 cells at 3 days post infection (60000 IU/ml), was purified by ion-exchange and reverse-phase HPLC. N-terminal sequencing confirmed the predicted signal peptide cleavage site and therefore the size of the mature protein (149 amino acids), the shortest of all reported type I interferons. Purified spI interferon, with a specific antiviral activity using Madin-Darby bovine kidney cells of 3.7×107IU/mg, is an N-glycosylated monomer of 19kDa that possesses several physicochemical characteristics of interferons: (a) disulfide bonds are necessary for bioactivity; spI interferon is thermolabile, stable at pH 2, and able to renature after complete denaturation (1% 2-mercaptoethanol, 1 % SDS, and 5 M urea); (b) the carbohydrate chain is not essential for bioactivity since no loss of antiviral activity is observed following complete deglycosylation. In this study, antiviral and anti-proliferation activities of spI interferon in cell culture were compared with those of other interferons, especially with porcine type 1 interferon-α. A major difference with porcine type 1 interferon-α was that spI interferon was not active on human cells in either test, and it was relatively more active on pig cells compared to bovine cells than porcine type 1 interferon-α. Serological cross-neutralization results obtained with anti-(spI interferon) serum confirmed that several members of interferon families are not antigenically related to spI interferon, in agreement with previous observations; this provides further evidence that spI interferon could represent a new family of type I interferon.
    European Journal of Biochemistry. 05/1995; 230(1).
  • C La Bonnardière, F Lefèvre, B Charley
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    ABSTRACT: This paper reviews the current state of knowledge on porcine interferons (IFN). Three type I IFN subfamilies (IFN alpha, beta and omega) and one type II IFN (IFN gamma) have been identified in the porcine species. A list of the known porcine IFN genes and already produced recombinant proteins, as compiled from the literature, was included. Two major aspects of porcine IFN were discussed: (1) IFNs as host responses to infections, and (2) IFNs in pregnancy. The first part mainly focusses on the IFN production by virus-infected pigs and the nature of IFN alpha secreting leukocytes. The second part reviews recent data showing the secretion of two different IFNs by the pig embryo at the time of implantation. One striking finding was that a non-lymphoid tissue, namely the porcine trophoblast, was able to secrete high levels of IFN gamma. In addition, the expression of another, newly described, IFN gene was also shown in pig trophectoderm. This novel trophoblastic type I IFN differs from the others in size and sequence. Several hypotheses are discussed on the possible role(s) of porcine embryonic IFNs at the initial stages of gestation.
    Veterinary Immunology and Immunopathology 11/1994; 43(1-3):29-36. · 1.88 Impact Factor
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    S D'Andrea, S Chousterman, J E Flechon, C La Bonnardière
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    ABSTRACT: Interferon-gamma (IFN-gamma) and a type I IFN (spI IFN) are transiently coexpressed by trophoblastic cells of pig conceptuses at implantation between day 12 and day 20 of gestation. The local effects of these trophoblastic IFNs were examined on endometrial cells and on trophoblast by measuring antiviral activity and the induction of (2',5')-oligoadenylate synthetase activity. Trophoblastic vesicles were shown to be susceptible to infection by vesicular stomatitis virus and transmissible gastroenteritis virus. Vesicular stomatitis virus multiplied by about 1000 times in trophoblastic vesicles, and endogenous trophoblastic IFNs or exogenous recombinant IFN-gamma or spI IFN had no effect on virus production. No (2',5')-oligoadenylate synthetase activity could be measured on the trophoblast, even after treatment with IFN-gamma or spI IFN. These results clearly show that trophoblastic IFNs cannot induce antiviral resistance or (2',5')-oligoadenylate synthetase activity in the trophoblast, suggesting that these IFNs have no autocrine function. Endometrial epithelial and stromal cells in primary cultures displayed distinct sensitivity to the antiviral effect of IFN-gamma and spI IFN. Stromal fibroblasts were highly sensitive to spI IFN but weakly sensitive to IFN-gamma; epithelial cells were sensitive to both IFNs. The same sensitivity pattern was obtained when measuring the (2',5')-oligoadenylate synthetase activity. Flushing fluid, containing IFN-gamma and type I IFN, was a potent inducer of antiviral effect and (2',5')-oligoadenylate synthetase activity. It is therefore postulated that the endometrial epithelium is the most likely target of trophoblastic IFNs. It is possible that these IFNs play a role in the viral protection of conceptuses.
    J Reprod Fertil 10/1994; 102(1):185-94.
  • C L Bonnardiere
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    ABSTRACT: Interferons (IFN) have been shown to be secreted by the trophectoderm of implanting embryos in different species, in particular ungulates. In the pig, a clear-cut IFN-gamma production, the role of which is unknown, was found in the trophoblast at implantation. A murine counterpart to these IFNs has not yet been identified. Two sets of experiments were conducted to test the presence of IFN-gamma in the mouse conceptus. First, day 4 blastocysts were collected from Swiss mice and their antiviral activity measured in a microassay using mouse L 929 cells and vesicular stomatitis virus (VSV) in the presence or absence of anti-IFN-gamma antibodies. In a second set of experiments, uteri from Swiss mice on days 5.5 and 6.5 of pregnancy were flushed and the resulting fluids assayed in a specific and sensitive ELISA test. In the antiviral assay, no consistent IFN-like activity was found. The viral challenge also revealed a high susceptibility of mouse blastocysts to VSV infection. By ELISA, all but two samples (N = 75), whether on 5.5 or 6.5, were found negative. We conclude that in this rodent species IFN-gamma is most probably not involved in early maternal-fetal interactions.
    American journal of reproductive immunology (New York, N.Y.: 1989) 09/1993; 30(1):26-31. · 3.32 Impact Factor
  • W Nowacki, B Cederblad, C Renard, C La Bonnardière, B Charley
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    ABSTRACT: Porcine blood mononuclear cells (PBMC) were shown to secrete interferon alpha (IFN-alpha) after induction by a coronavirus, the transmissible gastroenteritis virus (TGEV). IFN-alpha producing cells, referred to as natural interferon alpha producing (NIP) cells, were detected by an ELISPOT assay using anti-porcine IFN-alpha monoclonal antibodies. The frequency of NIP cells among blood cells is low, at most 40-110 per 10(5) PBMC and each NIP cell was found to produce several units of IFN. We have shown that NIP cell frequency and IFN yield per cell gradually increased with the age of the donor animals, from the neonatal period to the adult age, with a significant increase around puberty. Our present results also indicate that NIP cells may be influenced by physiological and genetic factors; thus (1) NIP cell frequency and IFN yield per cell were decreased during lactation; (2) Chinese (Meishan) pigs were found to have higher NIP cell frequency and IFN yield per cell than European (Large White) animals.
    Veterinary Immunology and Immunopathology 08/1993; 37(2):113-22. · 1.88 Impact Factor