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D Emilie

Publications and source records attributed to D Emilie.

At least 109 records · Page 6Linked to original sources
PubMed1994

Interleukin-6 biosynthesis in human preovulatory follicles: some of its potential roles at ovulation.

In the present work we explored cellular sites of interleukin-6 (IL-6) biosynthesis in human follicular aspirates from patients undergoing in vitro fertilization therapy and the effects of this cytokine on oocyte fertilization and granulosa cell (GC) steroidogenesis. Biological IL-6 activity from 20-40 IU/mL was present in follicular fluids from 22 patients; it was also detected in 10 of 22 supernatants of cultured oocyte-cumulus complexes and in cumulus cell and GC cultures. Biological IL-6 activity in oocyte-cumulus complex cultures was not related to fertilization rates. Total ribonucleic acid was isolated from follicular aspirates and GC-enriched preparations. After reverse transcriptase and polymerase chain reaction cycles using oligonucleotide primers corresponding to known cDNA sequences for IL-6, a 126-basepair band characterized the amplification product of IL-6 transcripts on gel electrophoresis. To localize IL-6 messenger ribonucleic acid, in situ hybridization analysis was performed using a [35S]IL-6 riboprobe. The distribution of transcripts was more dense (15% vs. 3% stained cells) in GC-enriched preparations, which contained more than 95% GCs, than in original follicular preparations, which contained 20-40% viable GCs; it was not significantly modified by the presence of macrophage contaminants. The expression of IL-6 protein was assessed by positive immunohistological stainings. Biological IL-6 activity was higher, and in situ hybridization signals were more dense and more intense in 24-h GC cultures than in 72-h GC cultures, suggesting that IL-6 biosynthesis was transiently induced. Under experimental conditions of low IL-6 endogenous levels in cultures, adding recombinant human IL-6 from 10-200 IU/mL had no effect on progesterone production or aromatase activity in GC cultures free of macrophages, whereas in GC cultures including macrophage contaminants, stimulatory effects on basal and hCG-stimulated progesterone production and on basal and FSH-stimulated aromatase activities were observed. The present study provides strong support for the view that IL-6 is produced by GCs in the preovulatory follicle at the time of ovulation. In addition, we showed that IL-6 might be an intraovarian regulatory factor concerned with steroidogenesis.

Adult↗
PubMed1994

In situ detection of activated cytotoxic cells in follicular lymphomas.

The presence of cytotoxic cells and their activation status were analyzed in tissue sections of 26 follicular lymphomas. To this end, expression of the perforin and granzyme B genes was studied by in situ hybridization experiments, and expression of the TIA-1 antigen was analyzed by immunohistochemistry. Cells expressing the granzyme B gene and the perforin gene were detected in all cases. Their density was, however, highly heterogeneous from case to case, ranging from 160 to 7,040 positive cells/cm2 of tissue sections. TIA-1-positive cells were also evidenced in the 10 follicular lymphomas tested. Virtually all cytotoxic cells were located in interfollicular areas. Double labeling immunochemical experiments showed that most cytotoxic cells belonged to the CD8+ T lymphocyte population, although few CD4+ T lymphocytes and CD56+ natural killer cells also expressed the TIA-1 antigen. These findings show that development of a malignant B lymphocyte proliferation is associated with a host-derived immune response involving intratumoral cytotoxic T lymphocytes. Further studies comparing the density of such cells with the final outcome are required to determine whether the intensity of this immune response has a prognostic value.

Adult↗
PubMed1994

[Immunopathology of cytomegalovirus pneumonia and allograft rejection in lung transplantation. Group of Pulmonary Transplantation of the University Paris-Sud].

In order to better understand the immunopathology of acute complications of lung transplantation we have analysed the different parameters of cytotoxic cell and macrophage activation during the course of pulmonary allograft rejection and cytomegalovirus pneumonia. In transplanted patients presenting with an acute pulmonary allograft rejection, a cytomegalovirus pneumonia or no complication (control group), we have studied, first serum markers of immune activation: interleukin-2 soluble receptor (IL-2sR), neopterin, IL-6, TNF soluble receptors (TNF-sR55 and TNF-sR75). Secondly the intrapulmonary compartmentalisation of allogenic and antiviral responses were evaluated by studying bronchoalveolar lavage fluid (BAL). The level of IL-6 was measured in BAL supernatants and the gene expression of two cytokines (IL-1 beta and IL-6) and two markers of activated cytotoxic cells (granzyme B and perforin) were studied by in situ hybridisation on the alveolar cells. Acute pulmonary allograft rejection was characterised by the paucity of systemic stigmata of immune activation and by the intrapulmonary compartmentalisation of the inflammatory response principally expressed by an increase in alveolar concentration of IL-6, TNF-sR55 and TNF-sR75, and an increased expression of the IL-1 beta gene. Cytomegalovirus pneumonia is accompanied by an intense local and systemic inflammatory activity as evidenced by the serum level of IL-2sR, neopterin, TNF-sR55 and TNF-sR75, the alveolar concentration of IL-6, TNF-sR55 and TNF-sR75, and the expression of monokine (IL-1 beta, IL-6) and of cytotoxic mediator (granzyme b, perforin) genes by BAL cells. These mediators could participate in the elaboration of an acute or chronic inflammatory response which would be potentially deleterious for the graft.

Biopterins↗
PubMed1994

[Interleukins and HIV disease].

We characterised the effects of HIV infection on the production of Interleukins in lymphoid organs by studying the expression of the genes for two TH1 type Interleukins, IL2 and Interferon gamma, of two TH2 type Interleukins, IL4 and IL10, and of two proinflammatory Interleukins, IL6 and IL1 beta. Our results show, in benign hyperplastic lymph nodes, a hyperexpression of Interferon gamma by cytotoxic T8 cells, without increased expression of TH2 type or of proinflammatory Interleukins. In contrast lymphomatous lymph nodes are characterised by a paracrine hyperproduction of IL6 and an autocrine hyperproduction of IL10.

B-Lymphocytes↗
PubMed1993

[Cytokines and AIDS].

HIV infection is associated with abnormalities of cytokine production. A number of cytokines (IL-1, IL-6, TNF-alpha, interferons-alpha and -gamma) are produced at an increased level in vivo, whereas the production of IL-2 is decreased. This latter abnormality certainly plays an important role in the immunodeficiency of AIDS patients. Monokines (IL-1, IL-6, TNF-alpha) stimulate HIV replication in vitro, whereas the interferons decrease it. Cytokine effects on the in vivo spreading of HIV remain however to be determined. Cytokines may also be mediators of the clinical manifestations of AIDS. IL-1, IL-6 and TNF-alpha may induce tissue lesions of opportunistic infections and HIV encephalopathy. Cytokines, and mainly IL-6, may stimulate the growth of malignant cells in Kaposi sarcomas and in lymphomas. A better knowledge of the roles of cytokines in HIV infection may allow new therapeutic approaches using either recombinant cytokines or specific antagonists, with the aim of inhibiting both HIV spreading and the clinical manifestations of the infection.

Acquired Immunodeficiency Syndrome↗
PubMed1993

[Cytokine assay: value and limitations].

Cytokines are proteins with multiple functions indispensable to body homeostasis. They are also good indicators of certain diseases which they are sometimes suspected to induce (e.g. septic shock, allograft rejection). Making cytokine assay methods available to scientists and clinicians has been a notable step forward in the understanding of numerous illnesses. However, these quantitative assays create more problems than they solve, and although reliable and easy tests exist we cannot recommend their use in routine clinical practice. In 1992, cytokine assays must be reserved for research studies where their results in patient populations are meaningful and where they can usefully be completed by other detection methods, such as amplification by polymerase chain reaction or hybridization in situ. Nevertheless, the constant improvement of assay kits, the ever increasing number of cytokines that can be quantified by simple laboratory tests and a better study of interactions between cytokines, their soluble receptors and their natural inhibitors will perhaps make it possible, in the near future, to analyse finely the immune response in not very invasive samplings. Moreover, there are hopes that modern molecular biology tools will soon be available in daily clinical practice. For instance, the development of automated methods for amplification by polymerase chain reaction will provide useful information on the activation of the immune system in various clinical situations. Such techniques, combined with measurements of local or circulating cytokine concentrations are undoubtedly promising tools. Finally, cytokine assays are essential to research workers who can study, within well-defined systems, the kinetics of production and the respective role played by these mediators.

Biological Assay↗
PubMed1993

In vitro production of IL-6, IL-1 beta, and tumor necrosis factor-alpha by human embryonic microglial and neural cells.

The abilities of the different cells from human central nervous system (CNS) to produce IL-6, IL-1 beta, and TNF-alpha were tested in vitro using either cultures enriched in human embryonic microglial cells or primary cultures of human embryonic CNS cells. High amounts of IL-6, low amounts of IL-1 beta but no TNF-alpha were detected in supernatants of microglial cells, kept either in FCS-free conditions or in FCS-containing medium. Moreover, IL-6 mRNA was also present in 45 to 55% of microglial cells cultured in the presence of FCS as visualized by in situ hybridization, whereas IL-1 beta mRNA remained undetectable. After prestimulation of microglial cells with LPS or IL-1 alpha, the percentage of cells labeled with an antisense IL-6 mRNA probe increased to 70% and hybridization with an antisense IL-1 beta mRNA probe became detectable. In contrast to this dyscoordinate production of cytokines by microglial cells, human monocytes, freshly isolated from blood and kept in the same culture conditions, produced high levels of the three cytokines tested. In primary cultures of human embryonic CNS cells, IL-6, IL-1 beta, and TNF-alpha were produced mostly or only by microglial cells because no IL-1 beta mRNA or IL-6 mRNA were detected in astrocytes, even after prestimulation with LPS or IL-1 alpha. Finally, IL-1 was the main inducer of IL-6 production because IL-1 alpha, but not LPS, induced a significant increase in IL-6 synthesis in cultures kept in FCS-free medium. However, in presence of FCS, LPS appeared to initiate a cascade reaction involving the production of IL-1 by microglial cells, acting as an autocrine loop to trigger IL-6 synthesis.

Astrocytes↗
PubMed1993

In situ production of interleukin-6 within human lung allografts displaying rejection or cytomegalovirus pneumonia.

Interleukin-6 (IL-6) is a pleiotropic cytokine that is a regulator of inflammation and immunity. As production of IL-6 may be an important mechanism by which local and systemic inflammatory processes are regulated during lung transplantation, we measured this cytokine concentration in the serum and bronchoalveolar lavage fluid (BALF) collected in 27 lung recipients. IL-6 bioactivity was analyzed using a B cell hybridoma proliferation assay (B9 cell line). Three groups of clinical situations were analyzed: control lung recipients, rejections, and CMV pneumonia. Serum IL-6 concentrations (mean +/- SEM) were 24.2 +/- 3.3 U/ml in the 26 control samples. In 20 allograft rejection episodes, the serum IL-6 concentration was higher than in control samples but the difference was not significant (59.3 +/- 20.5 U/ml, P > 0.05). IL-6 serum levels were significantly increased during the 14 CMV pneumonias (61.2 +/- 11.5 U/ml, P < 0.01). In BALF, IL-6 levels were increased during CMV pneumonia (52.4 +/- 21.9 U/ml BALF), and to a lesser extent during rejection events (14.1 +/- 3.7 U/ml BALF), as compared with controls (5.6 +/- 1.6 U/ml BALF, P < 0.005, and P < 0.05, respectively). Similar results were observed when IL-6/albumin and IL-6/urea ratios were determined so as to compensate for possible dilution effects in BALF. IL-6 in BALF was produced in situ during CMV pneumonia as shown by in situ hybridization experiments that revealed a significant number of IL-6 gene-expressing alveolar cells in this condition. IL-6 concentrations in the serum and in the BALF were compared. There was no correlation between serum and BALF IL-6 concentrations, showing that serum IL-6 levels do not accurately reflect intrapulmonary IL-6 levels do not accurately reflect intrapulmonary IL-6 production. Thus IL-6 is produced within lung transplants during CMV pneumonia, and to a lesser extent during allograft rejection.

Adolescent↗
PubMed1993

Serum neopterin after lung transplantation.

OBJECTIVE: Neopterin (N), a marker for activated cell-mediated immunity, was assayed in the sera of 44 lung recipients early and late after transplantation. The study was a prospective, blind clinical trial designed to evaluate the following: (1) the daily dynamics of the serum neopterin/creatinine (N/C) ratio during the first 3 weeks after transplantation; (2) the correlation between changes in the serum N/C ratio and episodes of rejection or infection; (3) the correlation between the serum N/C ratio and the concentration of serum soluble interleukin 2 receptor (sIL-2R), a marker of T-cell activation; and (4) the potential value of monitoring the serum N/C ratio during noninvasive long-term follow-up of lung recipients. METHODS: Sera from lung recipients were collected every day or every 2 days for the first 3 weeks after transplantation (22 patients) and before fiberoptic bronchoscopy and routine consultation (44 patients). The N concentrations were determined by radioimmunoassay and sIL-2R levels were measured using a sandwich enzyme immunoassay. RESULTS: Serum N/C is an early and sensitive marker of immune activation in the 21 days following transplantation. The N/C ratios during early rejections (815 +/- 182 mumol/mol) and infections (677 +/- 75 mumol/mol) were higher than those in patients with no complications (160 +/- 32 mumol/mol). In contrast, the N/C ratio did not increase during rejection later after transplantation. More than 3 weeks after transplantation, an increase in the N/C ratio was specifically correlated with infections, mainly those due to cytomegalovirus (CMV) (control subjects, 132 +/- 12 mumol/mol; rejections, 163 +/- 25 mumol/mol; CMV pneumonia, 786 +/- 103 mumol/mol, p < 0.001). The N/C ratio correlated with sIL-2R serum levels (r = 0.625, p < 0.001). CONCLUSIONS: Our results indicate that more than 3 weeks after transplantation, the serum N/C ratio increases only in cases of infection, mostly CMV pneumonia. In contrast, both rejection and infectious complications are associated with an increased N production in the early postoperative period.

Adolescent↗
PubMed1993

Intratumoral production of IL-6 in B cell chronic lymphocytic leukemia and B lymphomas.

Interleukin-6 is a major B lymphocyte growth factor, and may play a role in the proliferation of malignant B lymphocytes. In order to provide arguments supporting such a role, the intratumoral production of IL-6 was studied by in situ hybridization and immunohistochemistry in 53 neoplastic tissues from B cell chronic lymphocytic leukemia or B lymphomas. IL-6-producing cells were detected in all samples but 5. However, the number of IL-6 producing cells was variable amongst the different cases. Increased density of IL-6-producing cells was highly dependent on the presence of malignant immunoblasts within the neoplastic clone. IL-6 was produced in a paracrine way, macrophages and endothelial cells being the main producers of the cytokine while malignant immunoblasts expressed the IL-6 receptor. Taken together, these results suggest that IL-6 may indeed act as a growth factor for malignant cells in some B lymphoproliferations and that this paracrine loop could be the target of new therapeutic approaches.

Gene Expression↗
PubMed1993

[Immunohistochemical study of lesions of temporal arteritis in Horton's disease].

Fourteen monoclonal antibodies were used to immunohistochemically label 22 temporal artery biopsy specimens taken from patients with temporal arteritis before treatment (n = 10), after 1.3 days of corticotherapy (n = 6) and after 12-30 days of steroids (n = 6). Histological sections from untreated patients revealed an inflammatory infiltrate comprised of approximately equal proportions of macrophages and T lymphocytes; the majority of the latter belonged to the CD4+ subset (the CD4+/CD8+ ratio varied from 2/1 to 4/1, depending upon the biopsy). These cells expressed high levels of HLA DR and low levels of interleukin-2 (IL2) receptors. A few B lymphocytes and plasmocytes were seen, mainly in the adventitia. Antigen-presenting cells (APC) were always found in the damaged media and natural killer cells (few in number) were sometimes present. Some macrophages were positively immunolabeled for IL6. A short, 1-to-3-day course of corticosteroids did not appreciably modify the lesions: cells remained highly activated, APC were seen in half the biopsies and IL6 immunolabeling persisted. The findings were essentially the same in treated but poorly controlled patients. Biopsies from 2 patients in clinical and biological remission revealed the persistence of an active immunological process. These observations indicate that the immunological process is poorly controlled by corticosteroid therapy.

Aged↗
PubMed1992

Antagonistic effect of interferon-gamma on tat-induced transactivation of HIV long terminal repeat.

Interferon-gamma (IFN-gamma) has been shown to inhibit human immunodeficiency virus (HIV) replication in macrophages. However, the site of its effect on the HIV infectious cycle is unknown. We show here that IFN-gamma inhibits the transactivation of HIV long terminal repeat (LTR) during viral infection and that it antagonizes tat effect in HT4LacZ-1 cells. HT4LacZ-1 is an indicator CD4+ HeLa cell line for HIV infectivity, because it harbors a HIV LTR-LacZ gene susceptible to transactivation by tat. It was used in combination with a computer-assisted image analyzer to quantify: (i) the number of transactivated foci following HIV infection, (ii) their individual level of transactivation, and (iii) the fusion potency of infected cells. IFN-gamma induced a 75% decrease of the number of transactivated foci following infection of HT4LacZ-1 cells by HIV. The remaining 25% foci still susceptible to transactivation were transactivated at a lower level than in control cultures, and the fusion potency of infected cells was strongly decreased. IFN-gamma acted after HIV entry into the cell and independently of reverse transcription. IFN-gamma antagonized tat-induced LTR transactivation: it inhibited transactivation of HT4LacZ-1 cells when tat was provided either from a SV40-based expression vector of tat or by polyethylene glycol-induced cell fusion with HeLa-tat-III cells. These results suggest that IFN-gamma affects the expression or the activity of cellular factors interacting with tat and that the high level of IFN-gamma production associated with HIV infection plays a role in the establishment of HIV latency.

Genes, tat↗
PubMed1992

Interleukin-6 production in high-grade B lymphomas: correlation with the presence of malignant immunoblasts in acquired immunodeficiency syndrome and in human immunodeficiency virus-seronegative patients.

The mechanisms leading to malignant cell proliferation may differ between the different histologic forms of high-grade non-Hodgkin's lymphomas. To analyze the potential role of interleukin-6 (IL-6) as a growth factor for lymphomatous cells in these different forms, the in situ production of this cytokine was analyzed in lymphomatous samples taken from 24 patients, 18 of whom were human immunodeficiency virus (HIV) infected. Eleven Burkitt's lymphomas (BLs), seven diffuse large-cell lymphomas, and six immunoblastic lymphomas were studied. In situ hybridization experiments showed that the IL-6 gene was expressed in all tissues. The number of IL-6 gene-expressing cells was 7 times higher in the non-BLs than in the BLs, and it was 17 times higher than that of 14 control lymph nodes displaying a benign follicular hyperplasia. Analysis of individual cases indicated that the level of IL-6 gene expression was strongly correlated with the presence of immunoblasts within the malignant clone. In contrast, this level was not correlated with the presence of Epstein-Barr virus genome in the lymphoma or with the HIV status of patients. Immunohistochemical studies with an anti-IL-6 monoclonal antibody showed that IL-6 was produced in non-BLs, but not in BLs. In the former, IL-6 mainly originated from reactive, nonmalignant cells. Immunohistochemical analyses of non-BLs also showed that malignant cells produced the 80-Kd chain of the IL-6 receptor. Taken together, these results suggest that IL-6 may act as a growth factor in some forms of high-grade B lymphomas. The presence of immunoblasts may be an indicator of such forms.

Acquired Immunodeficiency Syndrome↗