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G Chaouat

Publications and source records attributed to G Chaouat.

At least 19 recordsLinked to original sources
PubMed2002

Concentration of leukaemia inhibitory factor (LIF) in uterine flushing fluid is highly predictive of embryo implantation.

BACKGROUND: There is strong evidence that locally secreted cytokines control the implantation process and can cause implantation failure. Uterine flushing fluids were analysed to determine their concentrations of leukaemia inhibitory factor (LIF) and tumour necrosis factor (TNF). METHODS AND RESULTS: We began by flushing the uterine cavities of 33 infertile patients on day 26 of two consecutive cycles. The concentrations of LIF (by enzyme-linked immunosorbent assay) and TNF (by bioassay) were significantly correlated during these cycles (r = 0.762, P = 0.0001 and r = 0.822, P = 0.001 respectively) and hence reliable. Then, after a reference flushing of 30 infertile patients, we followed the outcome of their first consecutive cycle of ovarian stimulation, which preceded either IVF or intrauterine insemination. A total of 10 patients became pregnant. The median concentration of LIF was 0 pg/ml (range: 0-177) and of TNF was 0 U/ml (range: 0-6.17) among those who became pregnant, and 203 pg/ml (range: 0-1620) and 2.14 U/ml (range: 0-16) respectively among those who did not. The LIF concentration was significantly lower in the pregnant group (P = 0.0013). CONCLUSION: A low concentration of LIF in the uterine flushing fluid at day 26 was predictive of subsequent implantation. Use of this procedure should increase the number of IVF attempts yielding successful pregnancies and also lead to corrective therapies.

Adult↗
PubMed2002

Combined treatment by pentoxifylline and tocopherol for recipient women with a thin endometrium enrolled in an oocyte donation programme.

BACKGROUND: To evaluate the effect of an antifibrotic treatment by a combination of pentoxifylline (PTX) and tocopherol (vitamin E) in patients with a thin endometrium who were enrolled in an oocyte donation programme. METHODS: Eighteen oocyte recipients who failed to develop a pre-ovulatory endometrial thickness of at least 6 mm after receiving vaginal micronized estradiol were enrolled in the study. The patients received a combination of PTX (800 mg/day) and vitamin E (1000 IU/day) for 6 months. The main outcome measurements were the change in endometrial thickness and the pregnancy and delivery rates after treatment. RESULTS: Endometrial thickness increased significantly (P <0.001), with a mean of (+/-SD) 4.9 +/-0.6 mm before and 6.2 +/- 1.4 mm after treatment, with 72% (13/18) of patients being good responders. Five patients either did not respond to the treatment or responded only slightly. Three patients, of which two had received previous radiotherapy, became spontaneously pregnant, and two became pregnant after embryo transfer. Three patients did not have embryo transfer. A total of four babies were delivered. The pregnancy rate was thus 33% and the delivery rate 27%. CONCLUSION: Treatment by combination of PTX and vitamin E appears to improve the pregnancy rate in patients with a thin endometrium by increasing the endometrial thickness and improving ovarian function. This was especially noticeable in patients who had previously received total body irradiation.

Adult↗
PubMed2001

Plasmodium falciparum induces a Th1/Th2 disequilibrium, favoring the Th1-type pathway, in the human placenta.

During pregnancy, a local and systemic Th2 bias of maternal immunity favors Th1-dependent infections such as malaria. This study measured cytokines secreted in cultures of chorionic villi, placental blood cells (PBC), and serum in term placentas from 88 malaria-infected and -noninfected Cameroon women. Interleukin (IL)--2 and --4 were consistently low; IL-1 beta, IL-6, granulocyte-macrophage colony-stimulating factor, and transforming growth factor (TGF)--beta 2 were highest in villi cultures. Tumor necrosis factor (TNF)--alpha, interferon (IFN)--gamma, and IL-10 were highest in PBC cultures. Malaria placental infection increased Th1-type cytokines, whereas Th2-type cytokines and TGF-beta 2 were unchanged. Addition of lipopolysaccharide or infected erythrocytes to cultures increased TNF-alpha, IL-1 beta, IL-6, and IL-10 secretions but not those of IFN-gamma and IL-4. Overall, Plasmodium falciparum induced a placental immune response involving both Th1- and Th2-type cell activation. Although the Th1 pathway was favored, IL-10 secretion was also increased, and this increase should be effective in protecting the placenta by controlling the negative effects of Th1 cytokines on pregnancy.

Animals↗
PubMed2001

Expression of beta chemokines in explants and trophoblasts from early and term human placentae.

PROBLEM: Implantation of human embryo requires expression of inflammatory cytokines and local attraction of T cells and natural killer (NK) cells. Chemokines are chemoattractants for these cells in classical inflammation. We speculated that they could also be involved in implantation. METHOD OF STUDY: We assessed by enzyme-linked immunosorbent assay (ELISA), reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry the presence of three classical beta chemokines Macrophage Inflammatory Protein 1 (MIP1)alpha, MIP1beta and Regulated upon activation, normal T cells expressed and secreted (RANTES) in cultures of placental villi or isolated trophoblasts derived from human first trimester and term placenta. RESULTS: Explant culture assays were positive for these three chemokines, with important quantitative variations between individuals. Half of the highly purified trophoblasts cultures were found by ELISA and RT-PCR to secrete in vitro MIP1alpha and MIP1beta. RANTES was never detected by ELISA in trophoblasts cultures, albeit we could detect a low amount of messenger RNA. Immunohistochemistry experiments show that Hofbauer cells and the trophoblast layer are a secretion site of MIP1beta in term placenta, and that cytotrophoblasts are able to secrete this chemokine in early placenta. CONCLUSION: Human placenta is a site of secretion of chemokines that could be involved in establishment of pregnancy.

Chemokine CCL4↗
PubMed2001

Biological activity of the suppressor cells inducer factor secreted by the Jeg-3 choriocarcinoma cell line.

PROBLEM: We wanted to further study the mechanisms of immune suppression and suppression inducing capacities by choriocarcinoma products, e.g. both crude human choriocarcinoma supernatant (HCS) and especially an active fraction obtained by high performance liquid chromatography (HPLC) from the culture supernatant of the Jeg-3 human choriocarcinoma cell line, since it appeared by weight and charge criteria to be a different molecular species than the low molecular weight fraction previously isolated from mouse and human term placenta. It was important to know whether the purified material was active in vivo as it was in vitro. Therefore, we tested the effects of HCS in vivo in three systems: prevention of fetal demise in the CBA/J x DBA/2 abortion prone murine mating combination, where the effects of the HPLC purified fraction were also monitored as well as by a cell transfer system, where the suppression is revealed by a local GVH/HVG assay, and finally enhancement the survival of a mildly immunogenic tumor allograft. METHODS: An active fraction was isolated from HCS by ion exchange HPLC. Female CBA/J were mated with DBA/2 and the influence of 3 intraperitoneal injections of both crude HCS and the active fraction was evaluated by monitoring the percentage of fetal resorptions. Simultaneously, on the day when resorptions were counted, maternal splenocytes from these females were harvested and were injected by the subcutaneous way in C3H/HEJ hind feet. The lymph node reactivity (HVG + GVH) was assessed by [3H]thymidine intake by cells harvested from the draining popliteal lymph nodes. For assessment of influence of HCS on allograft rejection, BALB/b (H-2b) mice received a subcutaneous injection of allogeneic P815 tumor cells (H-2d). The influence of HCS injections on tumor survival was analyzed by regular measurements of the mean tumor diameter. RESULTS: Intraperitoneal injection of HCS reduced fetal resorptions from 24.7 to 13%. Injection of the in vitro active fraction induced the same rate of reduction. The mean intensity of HvG/GvH reaction was 13400 cpm per lymph node when splenocytes from the control group were injected compared to 2900 cpm when splenocytes from treated mice were used. P815 tumor allografts were completely rejected in all cases after 21 days. Weekly subcutaneous injections of HCS prolonged tumor survival in all cases up to at least 30 days. CONCLUSION: The fraction isolated from HCS increased very efficiently the survival of allografts as well as those of allogeneic fetuses in a resorption prone murine mating. The choriocarcinoma cell line might prove to be a useful source of immunosuppressive materials, which could otherwise be important for the fetal-maternal tolerance and a successful pregnancy.

Animals↗
PubMed2001

Localization of pro-inflammatory (IL-12, IL-15) and anti-inflammatory (IL-11, IL-13) cytokines at the foetomaternal interface during murine pregnancy.

The involvement of some interleukins (ILs) in early and established pregnancy has been convincingly demonstrated, but little is known about the potential role of the more recently discovered ones. However, since many of these have positive or negative regulatory effects on both NK and T cells, it is highly probable that they also have regulatory functions in both implantation and placental development. Therefore, as a first step in tackling this problem, we have investigated whether several recently described pro- (IL-12, IL-15) and anti-inflammatory (IL-11, IL-13) cytokines were expressed at the uteroplacental interface by use of immunohistochemistry at different stages of gestation in mice. Each of these molecules was found at the foetomaternal interface, with specific distributions and patterns of expression depending on both the cytokine itself and the stage of pregnancy. The significance of these data is discussed.

Animals↗
PubMed2001

Placental cytokine and chemokine production in HIV-1-infected women: trophoblast cells show a different pattern compared to cells from HIV-negative women.

In utero transmission of HIV-1 has been demonstrated and may account for around 10-20% of all materno-fetal HIV-1 transmission. The possible routes for such transmission are transannexial or transplacental. In both cases, the microenvironment (cytokines and chemokines) at the placental interface could be an important regulatory factor in viral transmission. We therefore performed explant cultures of placental villi, and isolated purified trophoblasts, from term placentae obtained from HIV-1-seropositive and HIV-1-seronegative women in order to assess and compare the cytokine and chemokine secretion profiles using ELISA and semiquantitative RT-PCR. No major differences could be seen in the secretions of cytokines and chemokines at the level of whole placental tissue in HIV-1-positive and HIV-1-negative women. However, variations were observed in the expression of inflammatory cytokines and chemokines from trophoblastic cells, depending on the status of HIV-1 infection of the mothers but not the babies, all of which remained uninfected. The significance of these data is discussed.

Cytokines↗
PubMed2001

Arthroscopic treatment of pigmented villonodular synovitis of the shoulder.

Pigmented villonodular synovitis (PVNS) rarely affects the shoulder. Fewer than 30 cases have been reported in the English and French language literature. In those patients, PVNS was treated by open surgery involving total or local synovectomy, sometimes associated with total shoulder replacement, cuff tear repair, or arthroplastic head resection. The authors report 2 cases of PVNS of the shoulder treated arthroscopically and discuss the advantages and limitations of this technique in the treatment of shoulder PVNS.

Adult↗
PubMed2001

Follicular fluid concentration of leukaemia inhibitory factor is decreased among women with polycystic ovarian syndrome during assisted reproduction cycles.

BACKGROUND: The possibility that a specific cytokine profile could be detected in the ovaries of patients with polycystic ovarian syndrome (PCOS) was investigated. METHOD: Enzyme-linked immunosorbent assay (ELISA) or bioassays were used to assess the concentrations of leukaemia inhibitory factor (LIF), tumour necrosis factor, interleukin 11, gamma interferon, progesterone and oestradiol in follicular fluids from preovulatory follicles collected after ovarian stimulation from 15 PCOS patients, 15 infertile control patients with regular cycles, and 8 oocyte donors. RESULTS: LIF and progesterone concentrations were significantly lower in the follicular fluid of PCOS patients (LIF median: 265 pg/ml) compared with controls (LIF median: 816 pg/ml); LIF and progesterone follicular fluid concentrations were correlated (r = 0.720, P = 0.0001). The LH/FSH ratio was negatively correlated with LIF concentrations (r = - 0.714, P = 0.0075). Although the PCOS and control patients did not differ significantly in age, ovarian reserve or IVF indication, the implantation rate was significantly lower among the women with PCOS (IR = 9 versus 21%, P = < 0.01). CONCLUSION: The specific cytokine profile of the PCOS patients is probably related to the lower implantation rate since follicular fluid LIF appears to function as an embryotrophic agent.

Adult↗
PubMed2001

FAS/FAS ligand interaction at the placental interface is not required for the success of allogeneic pregnancy in anti-paternal MHC preimmunized mice.

PROBLEM: FAS ligand (FASL) induces apoptosis in FAS+ T cells. FAS-FASL interaction can explain tolerance of some types of allografts. Do similar interactions prevent rejection of the fetal allograft and transplacental passage of maternal T cells capable of causing GvH leading to runting? METHOD OF STUDY: We examined growth of subcutaneous EL-4 (H-2b) tumor cells in syngeneic MRL.lpr/lpr mice mated with syngeneic MRL.lpr/lpr or allogeneic C57/B1/6.lpr/lpr males. Lpr/lpr mice lack FAS and their T cells should remain effective at the fetomaternal interface. In some studies, the mice were preimmunized against C57B1/6 to enhance the likelihood of fetal rejection and/or runting. Cytotoxic lymphocyte (CTL) activity in the spleens was assessed using a 51Cr-release assay. Birth weights and weights at weaning were measured. RESULTS: Tumor rejection was delayed by about 3 days in allopregnant lpr/lpr females compared to syngeneic pregnant females occurred, but tumors were rejected and in a secondary fashion with minimal delay allopregnant females preimmunized to H-2b. CTL activity was present more in decidua than in spleen in preimmunized mice, and allopregnancy failed to reduce this activity. No neonates born to preimmunized or control lpr/lpr mothers developed runt disease. Indeed, the birth weight was greater for immunized females, but at 10 weeks, the difference compared to non-immunized females disappeared. CONCLUSIONS: FAS/FASL interaction between FAS+ T cells and FASL+ fetal trophoblasts at the fetomaternal interface is not mandatory for successful allopregnancy. The potential roles of other apoptosis-induction mechanisms at the fetomaternal interface, such as TNF/TRAIL, require critical testing before enthusiasm is merited. It maybe necessary to eliminate all such mechanisms to show a deleterious effect on pregnancy. Spontaneous deletion of all pathways seems a priori unlikely to occur, and hence, of dubious relevance to fetal loss.

Animals↗
PubMed2001

Cell-to-cell contact results in a selective translocation of maternal human immunodeficiency virus type 1 quasispecies across a trophoblastic barrier by both transcytosis and infection.

Mother-to-child transmission can occur in utero, mainly intrapartum and postpartum in case of breastfeeding. In utero transmission is highly restricted and results in selection of viral variant from the mother to the child. We have developed an in vitro system that mimics the interaction between viruses, infected cells present in maternal blood, and the trophoblast, the first barrier protecting the fetus. Trophoblastic BeWo cells were grown as a tight polarized monolayer in a two-chamber system. Cell-free virions applied to the apical pole neither crossed the barrier nor productively infected BeWo cells. In contrast, apical contact with human immunodeficiency virus (HIV)-infected peripheral blood mononuclear cells (PBMCs) resulted in transcytosis of infectious virus across the trophoblastic monolayer and in productive infection correlating with the fusion of HIV-infected PBMCs with trophoblasts. We showed that viral variants are selected during these two steps and that in one case of in utero transmission, the predominant maternal viral variant characterized after transcytosis was phylogenetically indistinguishable from the predominant child's virus. Hence, the first steps of transmission of HIV-1 in utero appear to involve the interaction between HIV type 1-infected cells and the trophoblastic layer, resulting in the passage of infectious HIV by transcytosis and by fusion/infection, both leading to a selection of virus quasispecies.

Cell Communication↗
PubMed2001

[Contribution of diagnostic ultrasonography in cases of repeated embryonic implantation failure in fertilization in vitro].

INTRODUCTION: To assess ultrasonic data in the context of repeated failure of implantation in assisted reproduction medicine. MATERIALS AND METHODS: We reviewed ultrasonic data (uterine score at follicular and luteal phase). The same ultrasound exploration was repeated for two consecutive cycles to assess the changes in abnormalities observed and compare findings in 16 patients with repeated failure of implantation and in 14 controls. The controls were women who became pregnant within the three months following the exploration. We then introduced acetylsalicylic acid and prednisolone as first line treatment and nitroglycerin as second line treatment to measure the effects induced in 14 pathological uterine scores. RESULTS: The score obtained under hormonal treatment was representative of other cycles (r = 0.812, p < 0.0014). The score was significantly lower and the luteal uterine artery pulsatility index was significantly higher in the repeated failure group than in the control group (p < 0.0001 and p = 0.008 respectively). For the 14 patients, treatment improved the uterine score in 8 with acetylsalicylic acid and prednisolone and in 4 with nitroglycerin. Two patients did not respond to treatment. Concerning the effect of therapy, of 14 patients, 8 had an improved uterine score with A + P, and with T; 2 patients did not respond to any treatment. CONCLUSION: The uterine score and luteal artery pulsatility index may be valuable tools for patients with implantation failure who all do not respond to the same therapy.

Arteries↗
PubMed2000

Coreceptor usage of HIV-1 isolates representing different genetic subtypes obtained from pregnant Cameroonian women. European Network for In Utero Transmission of HIV-1.

In this study, coreceptor usage of HIV-1 other than subtype B in relation to HIV-1 transmission from mother to child was investigated. Repeated sampling of 42 HIV-1-seropositive, asymptomatic women in Cameroon during the second and third trimesters of pregnancy, at delivery, and 6 months postpartum were performed. Env subtyping was carried out from uncultured peripheral blood mononuclear cells (PBMCs) by heteroduplex mobility assay and, whenever necessary, by DNA sequencing. Virus isolates were tested for coreceptor usage on human cell lines-U87.CD4 and GHOST(3)-engineered to express stably CD4 and the chemokine receptors CCR1, CCR2b, CCR3, CCR5, or CXCR4, or the orphan receptors BOB/gpr15 or Bonzo/STRL33/TYMSTR. Transmission rate was 11.9%. Viruses were predominantly envelope subtype A and used CCR5 as coreceptor and, surprisingly, 4 of 28 (14.2%) isolates from mothers and 1 of 3 isolates from children used the orphan receptor Bonzo as well. In 2 transmitting mothers from whom sequential HIV-1 isolates were available, viral coreceptor usage evolved from CCR5 monotropic to CCR5/Bonzo dual tropic during pregnancy, and in 1 case transmission of this virus could be documented. Our data suggest that evolution of HIV-1 coreceptor usage to dual (or multi-) tropism may occur during pregnancy.

Cameroon↗
PubMed2000

Comparative reactivity of different HLA-G monoclonal antibodies to soluble HLA-G molecules.

Different HLA-G monoclonal antibodies (mAbs) were first evaluated for their capability to identify soluble HLA-G (sHLA-G) in ELISA. Three of them, namely 87G, BFL.1 and MEM-G/9, when used as coating mAbs together with W6/32 capture mAb, identified beta2-microglobulin (beta2m)-associated-sHLA-G but not soluble HLA-B7 (sHLA-B7) in cell culture supernatants from transfected cells. By comparison, the anti-HLA class I mAb 90 did recognize both sHLA-G and sHLA-B7. By using these HLA-G mAbs, sHLA-G was identified in amniotic fluids as well as in culture supernatants of first trimester and term placental explants but not in cord blood. Intron 4-retaining sHLA-G isoforms were identified in some amniotic fluids by the use of an intron 4-specific mAb (16G1). Reactivity of these different HLA-G mAbs was then compared to determine their respective binding sites on soluble and membrane-bound HLA-G. Using both ELISA and flow cytometry analysis, we showed that they did not compete with each other, which suggested that they did not recognize the same determinants. Finally, we report that two mAbs directed against the alpha1 domain of HLA class I heavy chain (mAb 90 and YTH 862) did compete with 87G, therefore demonstrating that this latter mAb recognized an epitope localized on this external domain of HLA-G.

Antibodies, Monoclonal↗
PubMed2000

HIV-1 co-receptor expression on trophoblastic cells from early placentas and permissivity to infection by several HIV-1 primary isolates.

We examined CD4 and major HIV-1 co-receptor expression by trophoblast cells (TC) from early placentas, and the permissiveness of TC for infection by several natural HIV-1 isolates in vitro. Ten early placentas (4-6 weeks of gestation) from HIV- women were obtained after elective abortion. CD4 and HIV-1 co-receptor expression by TC was examined in terms of both mRNA and protein. The same TC were then challenged with three clinical HIV isolates of known phenotype, two originating from mothers who transmitted the virus to their child and one from a vertically infected newborn. TC infection was detected by polymerase chain reaction. CD4 expression was detected in five of the 10 placentas, while membrane protein expression of CCR3, CXCR4 and CCR5 was detected in every case, despite quantitative differences among individuals. Bonzo, GPR1 and ChemR23 mRNAs were detected in all TC preparations. TC from seven out of eight placentas were permissive to HIV entry, but no productive viral replication was detected (reverse transcriptase activity in culture supernatants). Interestingly, the addition of chemokine(s) or a CD4-blocking antibody to the cultures failed to inhibit TC virus entry. These data point to marked interindividual variability in HIV co-receptor expression by trophoblast cells and show that TC from early placentas can be infected in vitro by clinical HIV-1 isolates. They also suggest that viral entry in vitro might occur through a mechanism independent of both CD4 and chemokine receptors.

Acquired Immunodeficiency Syndrome↗
PubMed1999

An unusual HIV type 1 env sequence embedded in a mosaic virus from Cameroon: identification of a new env clade. European Network on the study of in utero transmission of HIV-1.

An atypical HIV-1 strain (CAM001) was identified in a pregnant Cameroonian woman in 1995. HMA subtyping of the env region was unsuccessful, and sequence analyses were performed. Unique sequence motifs were found at the V3 tip (GAGRALHA and GAGRAWIHA), and phylogenetic studies showed that the env C2-V5 sequence branched within group M but remained distinct from all known HIV-1 subtypes, while p17 gag branched with the subtype F sequences. Four other HIV group M viruses, undetermined by HMA, of African origin were found to cluster with CAM001 in the C2-V5 sequences. With the BLAST method, we found in databases three strains whose V3 sequences also clustered with CAM001. These unusual env sequences from eight HIV-1 strains derived from Cameroon formed a separate cluster in HIV-1 group M, which we designated k.

Amino Acid Sequence↗
PubMed1999

Stromal cell-derived factor 1 (SDF-1) and antenatal human B cell lymphopoiesis: expression of SDF-1 by mesothelial cells and biliary ductal plate epithelial cells.

The chemokine stromal cell-derived factor 1 (SDF-1) stimulates the growth of pre-B cells in vitro, and mice with a disrupted SDF-1 gene have abnormal fetal liver B cell lymphopoiesis. The origin of SDF-1 production has not been determined yet. Using an anti-SDF-1 mAb, we performed immunohistochemical studies in four human embryos and five fetuses to define which cells express the SDF-1 protein at sites of antenatal B cell lymphopoiesis. All mesothelial cells contained SDF-1 at all stages of development, including in the intraembryonic splanchnopleuric mesoderm early into gestation. In fetal lungs and kidneys, SDF-1 was expressed by epithelial cells, and a few B lymphoid precursors, expressing V pre-B chains, were also detected. In the fetal liver, in addition to mesothelial cells, biliary epithelial cells were the only cells to contain SDF-1. Pre-B cells expressing V chains were abundant and exclusively located around the edge of portal spaces, in close contact with biliary ductal plate epithelial cells. They did not colocalize with biliary collecting ducts. Biliary ductal plate epithelial cells and liver B cell lymphopoiesis display a parallel development and disappearance during fetal life. These results indicate that early B cell lymphopoiesis in the splanchnopleura may be triggered by mesothelial cells producing SDF-1. Later into gestation, biliary ductal plate epithelial cells may support B cell lymphopoiesis, thus playing a role similar to that of epithelial cells in the avian bursa of Fabricius, and of thymic epithelial cells for T cell lymphopoiesis.

Amino Acid Sequence↗