Search PubMed⌕ Search

Biomedical subjects

D Emilie

Publications and source records attributed to D Emilie.

At least 73 records · Page 4Linked to original sources
PubMed1997

Interleukin-1 receptor antagonist plasma concentration is specifically increased by alpha-2A-interferon treatment.

BACKGROUND/AIMS: The mechanism of action of recombinant interferon-alpha (rIFN alpha) treatment in chronic hepatitis C is not fully understood, and may include modulation of the immune system as well as a direct antiviral effect. We have therefore evaluated the plasma concentrations of pro- and anti-inflammatory cytokines in patients with chronic hepatitis C before and during treatment with rIFN alpha. METHODS: Twenty-three patients were studied. Plasma concentrations of IL-1 beta, IL-6, TNF, IL-1 receptor antagonist (IL-1RA) and soluble TNF receptors (sTNFRs) type I and type II were determined twice before rIFN alpha treatment (on day -11 and day 1), and on days 11, 32 and 120 of treatment. RESULTS: IL-1 beta, IL-6 and TNF plasma concentrations were rarely increased before treatment (in one, six and seven patients, respectively), and usually declined during treatment. sTNFRs I and II plasma concentrations were not increased either before or during treatment. This was not the case for IL-1RA. In untreated patients, the plasma concentration of IL-1RA was higher than normal in 16 out of 23 patients. When rIFN alpha treatment was initiated, there was a constant and dramatic increase in IL-1RA levels, which reached 8 times the upper limit of the normal range (p < 0.001 as compared to pretreatment values). This increase was sustained up to day 120. CONCLUSIONS: These results indicate that induction of an anti-inflammatory status through modulation of the IL-1/IL-1RA balance may be a key mechanism of action of rIFN alpha treatment in chronic hepatitis C.

Adult↗
PubMed1997

In situ interleukin 5 gene expression in pediatric Crohn's disease.

BACKGROUND: Eosinophils contribute to the intestinal inflammatory infiltrate in Crohn's disease (CD). Eosinophilic infiltration occurs early in Crohn's recurrences, and a release of eosinophil cationic proteins has been observed in active CD. The proliferation, differentiation, and activation of eosinophils are highly dependent on the cytokine interleukin 5 (IL5). In the present study, we used in situ hybridization (ISH) to investigate the expression of the IL5 gene in intestinal specimens from patients with CD. METHODS: We studied 14 intestinal samples from eight children who had undergone ileocolectomy for advanced CD. The samples were examined for the intensity of the inflammatory infiltrate. Normal pediatric intestine specimens served as controls. In situ hybridization was performed on frozen tissue using radiolabeled IL5 mRNA probes. RESULTS: Positive signal with the IL5 antisense probe was observed within numerous cells infiltrating the specimens involved with CD. The number of IL5-expressing cells correlated with the histological grade of inflammation. Most of the labeled cells were eosinophils, characterized by their bilobed nuclei. Rare IL5-positive cells were detected in the control tissues. No positive signal was obtained with the IL5 sense probe. CONCLUSION: These results suggest that IL5 can be produced by eosinophils at the sites of inflammation in active CD and could be involved in the immune response by activating eosinophils, at least in part through an autocrine pathway, and perhaps by interacting with B and T cells.

Adolescent↗
PubMed1997

In situ Rantes and interferon-gamma gene expression in pediatric small bowel Crohn's disease.

BACKGROUND: Rantes (regulated upon activation, normal T cell expressed and secreted) is a chemotactic cytokine for memory T lymphocytes, monocytes, and eosinophils. The cytokine interferon-gamma (IFN-gamma) plays a key in the immune response. Their distributions and possible roles in the selective accumulation of inflammatory cells in Crohn's disease (CD) were examined by determining the expression of Rantes and IFN-gamma genes in patients with CD using in situ hybridization (ISH) on frozen and paraffin-embedded tissue sections. METHODS: Intestinal and mesenteric lymph node samples from 9 children who had undergone ileal resection for CD were examined for the presence of epithelioid-giant cell granulomas (EGCG) and Rantes and IFN-gamma messenger RNA (mRNA). Normal pediatric intestine (n = 5) and lymph nodes (n = 2) served as controls. RESULTS: Many cells in all CD specimens in the epithelial compartment, lamina propria, and the EGCG gave positive signal with the Rantes antisense probe. Labelled cells were identified on paraffin sections as lymphocytes, macrophages, and epithelioid cells. There were Rantes-positive cells in the control intestinal tissues, but many Rantes-positive cells in control lymph nodes that showed follicular hyperplasia. IFN-gamma-positive cells were present in all CD ileal and lymph node specimens, predominantly in close contact with EGCC. No positive signal was obtained with the Rantes and IFN-gamma sense control probes. CONCLUSIONS: These findings suggest that Rantes and IFN-gamma contribute to the selective accumulation of macrophages and memory T helper lymphocytes inside the granulomas and inflammatory infiltrates that are characteristic of CD.

Adolescent↗
PubMed1997

Early cytokine and chemokine gene expression in lymph nodes of macaques infected with simian immunodeficiency virus is predictive of disease outcome and vaccine efficacy.

Competitive PCR was used to evaluate the expression of cytokine, granzyme B, and chemokine genes in lymph nodes of macaques recently infected with the simian immunodeficiency virus (SIV) pathogenic molecular clone SIVmac239 (n = 16), the nonpathogenic vaccine strain SIVmac239 delta nef (n = 8), and the nonpathogenic molecular clone SIVmac1A11 (n = 8). For both SIVmac239 and its nef-deleted derivative, strong expression was observed as early as 7 days postinfection for interleukin 1beta (IL-1beta), IL-6, tumor necrosis factor alpha, gamma interferon, and IL-13. The levels of gene induction were equally intense for both viruses despite a lower viral load for SIVmac239 deltanef compared with that for SIVmac239. However, the nature of the cytokine network activation varied with the viral inocula. Primary infection with SIVmac239 was characterized by a higher level of IL-4, IL-10, MIP-1alpha, MIP-1beta, MCP-1, and RANTES gene expression and a lower level of IL-12 and granzyme B gene expression compared with infection with SIVmac239 delta nef. Thus, infection with nef-deleted SIV was associated with a preferential Th1 versus Th2 pattern of cytokine production. Infection with SIVmac1A11 was characterized by a delayed immune response for all markers tested. The unique patterns of cytokine and chemokine gene expression in lymph nodes correlated nicely with the pathogenic potential of the SIV strains used as well as with differences in their ability to serve as protective vaccines.

Animals↗
PubMed1997

Production of ovarian cytokines and their role in ovulation in the mammalian ovary.

Cytokines, originally identified as products of immune cells, are synthesized throughout the female reproductive tract. Evidence has accumulated supporting the role of cytokines in reproduction, including gamete and follicle development and steroidogenesis. In these processes, cytokines act either through a paracrine or autocrine mechanism. The present article focuses on the role of cytokines during ovulation, which shares many of the features of the inflammatory reaction. The intraovarian production of cytokines, as well as its regulation by sex steroid and peptide hormones, is considered. The role of cytokines in follicle rupture and remodelling, leukocyte infiltration, angiogenesis, steroid hormone production and oocyte maturation is also described.

Animals↗
PubMed1997

Increased basal production of interleukin-10 by peripheral blood mononuclear cells in human alveolar echinococcosis.

The secretion of IL-10 by peripheral blood mononuclear cells (PBMC) and the expression of IL-10 mRNA in fractionated CD4+ and CD8+ lymphocyte subsets and non-B-non-T cells, with and without stimulation by the mitogen phytohemagglutinin-C (PHA-C) and specific Echinococcus multilocularis (E. multilocularis) antigens, were assessed in 7 patients with alveolar echinococcosis (AE) and 6 healthy subjects. Results of studies on IL-10 were compared to those on IFN-gamma, IL-4 and IL-5 in the same patients and control subjects. IL-10 production was significantly higher in patient PBMC-culture supernatants than in the control group supernatants, both at the basal level and after mitogen or specific E. multilocularis antigen stimulation. Both CD4+ and CD8+ lymphocyte populations and non-B-non-T cells of AE patients and controls expressed IL-10 mRNA. Semi-quantification of IL-10 mRNA revealed a significantly higher transcript level in unstimulated-CD8+ T cells from AE patients in comparison with CD8+ T cells of healthy donors. PBMC from patients produced very low levels of IL-4 but the production of IFN-gamma was not significantly depressed compared to the controls. PBMC, isolated from 4 AE patients and 4 control subjects stimulated with specific E. multilocularis antigens, secreted IL-5; IL-5 mRNA was only detected in the CD4+ lymphocyte subset. The secretion of IL-5 and the expression of IL-5 mRNA in healthy subjects could be due to the presence of non-specific mitogenic parasitic factors. This non-specific mitogenic activity of the parasite, besides inducing a high secretion of IL-10 in patients with evolutive AE, may contribute to the lack of host control of parasite growth and to the persistence of granulomatous lesions, due to the inhibition of an efficient Th1 immune response.

Adult↗
PubMed1996

Intrapulmonary production of RANTES during rejection and CMV pneumonitis after lung transplantation.

RANTES (regulated upon activation, normally T expressed and secreted) is a chemoattractant for macrophages, memory T lymphocytes, and eosinophils. We investigated whether intrapulmonary production of the chemokine RANTES contributes to the recruitment of immune cells during lung transplantation complications. RANTES concentration was measured in bronchoalveolar lavage (BAL) fluids using an ELISA assay. It was significantly higher during CMV pneumonitis (36.2 +/- l6 pg/ml, n=12, P=0.031) and allograft rejection (31.1 +/- 8.5 pg/ml, n=27, P=0.013) than in patients without complications (9.1 +/- 2.3 pg/ml, n=22). At least some of the RANTES was produced by lung macrophages: BAL macrophages cultured for 24 hr spontaneously released larger amount of RANTES during CMV pneumonitis (140 +/- 53 pg/ml, n=8, P=0.002) and allograft rejection (84 +/- 44 pg/ml, n=11, P=0.037) than in control patients (15.2 +/- 6.5 pg/ml, n=21). Moreover, macrophages in transbronchial biopsies were labeled by an anti-RANTES mAb. RANTES production by BAL macrophages was followed in 2 patients with CMV pneumonitis. It remained high as long as CMV-induced cytopathic effects or clinical symptoms were present, but it returned to baseline as the infection was controlled. These results suggest that the intrapulmonary production of the chemokine RANTES by activated macrophages contributes to the intrapulmonary accumulation of immune cells during complications of lung transplantation.

Antiviral Agents↗
PubMed1996

Interleukin-13 and interleukin-4 act as interleukin-6 inducers in human microglial cells.

The effect of interleukin 4 (IL-4) and IL-13 on IL-6 and IL-1 beta production by human embryonic microglial cells and human peripheral blood monocyte cells (PBMC) was compared. IL-4 or IL-13 increase intra-cellular IL-6 mRNA and IL-6 titres in supernatants of microglial cells whereas they decreased IL-6 production by PBMC tested in the same conditions. IL-4 and IL-13 increased also IL-1 beta production by human microglial cells. Stimulations associating IL-4 or IL-13 and IL-1 beta had an additive effect on IL-6 production by microglial cells, whereas, in the same conditions, an inhibitory effect was observed in PBMC. In contrast, dexamethasone downregulated IL-6 production by microglial cells and PBMC. Finally, IL-1 receptor (IL-1r) type 1 and IL-1r type 2 were detected on human microglial cells but it was demonstrated that IL-13 and IL-4 acted as IL-6 inducers in human microglial cells independently of the IL-1/IL-1r pathway.

Cells, Cultured↗
PubMed1996

Contrasting effects of IL-4, IL-10 and corticosteroids on RANTES production by human monocytes.

RANTES is a chemokine produced in delayed-type hypersensitivity (DTH) and allergic reactions, in which it may contribute to the recruitment of immune cells. Macrophages participate in the cellular infiltration in both conditions and they represent a potent source of RANTES. To understand the regulation of RANTES production by human monocytes, we analyzed the effect of cytokines and of corticosteroids on this production. We showed that IFN-gamma and tumor necrosis factor (TNF)-alpha cooperated to induce RANTES production by monocytes. N-acetylcysteine inhibited this effect, indicating that reactive oxygen intermediates are required for RANTES production. Both IL-10 and corticosteroids antagonized the stimulating effect of IFN-gamma and TNF-alpha on RANTES production. In contrast, IL-4 had no effect on IFN-gamma-induced RANTES production and it potentiated the positive effect of TNF-alpha on this production. Thus, the deactivating properties of IL-10 and corticosteroids on macrophage functions include RANTES production, and this may contribute to the immunosuppressive effect of both compounds in DTH and allergic reactions. In contrast, IL-4 has an opposite effect on RANTES production and this property may contribute to cell recruitment in allergic reactions. Therefore, although IL-10 and IL-4 belong to the Th2 family of cytokines, they can display distinct functions in immune reactions.

Acetylcysteine↗
PubMed1996

Enterovirus in sudden unexpected deaths in infants.

BACKGROUND: Conventional approaches to virus detection failed to provide convincing evidence of a viral etiology in sudden unexplained deaths in infants (SUDI). Many viruses may not have been detected by the routinely used methods; among them enteroviruses (EV) have seldom been found in SUDI. METHODS: In this study EV were sought directly in stools, in pharyngeal and tracheal samples and in myocardial and lung tissues, by using a nested PCR; they were also sought indirectly by detecting IgM antibodies with a new capture immunoassay. Twenty-four SUDI cases were divided into two groups: Group I, certainly associated with; or Group II, not associated with clinical, biologic or histologic signs of viral infection. RESULTS: EV were found in stools but their prevalence was not significantly different between Group I and Group II (20 and 22.2%, respectively). On the contrary EV were detected in respiratory tract and/or lung samples in 53.8% of infants of Group I and in none of Group II. Anti-EV IgM antibodies were detected in 55.5% of infants of Group I and in none of Group II. CONCLUSIONS: These results indicate that EV infection may be specifically associated with the subgroup of SUDI with viral signs, raising the question of its role in this condition.

Base Sequence↗
PubMed1996

Mechanisms of lysis by activated cytotoxic cells expressing perforin and granzyme-B genes and the protein TIA-1 in muscle biopsies of myositis.

OBJECTIVE: Polymyositis (PM) and cermatomyositis (DM) are inflammatory muscle diseases of autoimmune origin. A chronic mononuclear cell infiltrate is always present around PM and DM muscle damage. In PM, the predominant cells are activated cytotoxic cells, natural killer, and CD8+ T lymphocytes. Cytotoxic cells can kill the target cells via 2 mechanisms. Both pathways induce target cell death by releasing the molecules (granule exocytosis) perforin (PF), which attacks the target cell membrane and causes cell death by necrosis, and TIA-1 protein and granzyme-B (GZB), possibly responsible for apoptosis. We studied the mechanisms of lysis in muscle biopsies of myositis. METHODS: We used a panel of monoclonal antibodies to determine the phenotypes of reactive lymphocyte subsets, in situ hybridization to study the expression of PF and GZB genes, and immunohistochemistry to evaluate TIA-1 protein production in muscle biopsies from 14 patients with myositis (11 PM/3 DM). Results were compared to those obtained from muscle biopsies of 12 control patients with muscle weakness, including patients with muscle dystrophy and vasculitis, but without myositis. RESULTS: Abundant CD8+ cells, especially in endomysial sites in PM, formed the predominant phenotype. The predominant mononuclear cells observed in DM were CD4+ T cells and CD22+ B lymphocytes, in perivascular sites. The GZB and PF genes and the TIA-1 protein were expressed simultaneously in muscle samples from patients with myositis. GZB, PF, and TIA-1 positive cells were predominantly located in endomysial sites of PM, in the nonnecrotic muscle fibers. In DM, these positive cells were rare. CONCLUSION: In myositis, especially PM, cytotoxic cells may cause muscle damage and muscle cell necrosis and/or apoptosis by releasing several proteins (PF, GZB, and TIA-1 proteins) responsible for the lysis of these stimulating target cells. Some drugs (prednisone and cyclosporine) inhibit the release of GZB and PF. Their efficacy may be due in part to this inhibitory effect.

Adult↗
PubMed1996

Serum interleukin-10 in acquired immunodeficiency syndrome lymphoma patients. Seroco-Hemoco Study Group.

Interleukin-10 (IL-10) has multiple effects on lymphoid development, particularly as a stimulant of activated B-cell proliferation and differentiation. It is thought that IL-10 might play a role in the development of B lymphoid malignancies based on the observation that lymphomatous tissues from HIV+ patients contain numerous cells containing IL-10 mRNA as well as IL-10 protein. The aim of this study using an Elisa test was to analyze IL-10 in the serum of 18 HIV+ patients with non Hodgkin's B lymphoma (NHL) and compared the presence of this cytokine in the serum of 18 HIV+ patients without NHL. In this comparative study we also considered the different parameters such as the mode of contamination, sex, age and number of CD4 cells. 44% of the patients with HIV-related NHL had significant levels of IL-10 (> or = 12 pg/ml) in their serum, in comparison to the patients without NHL who did not show detectable serum IL-10.

Adult↗
PubMed1996

[Cytomegalovirus infection and allograft rejection].

Allograft rejection and human cytomegalovirus (HCMV) infections are two major complications of allotransplantation. HCMV infection could promote allograft rejection through different mechanisms including the production of several proinflammatory cytokines, increased expression of major histocompatibility complex and adhesion molecules, and molecular mimicry. Similarly immune activation occurring during allograft rejection, its treatment and its prevention budget increases rates of HCMV disease. A better understanding of the links between allograft rejection and HCMV infection is necessary to develop new preventative or curative therapeutic approaches which could improve allotransplantation results in humans.

Cell Adhesion Molecules↗
PubMed1996

[Cytokines and lupus].

Lymphocyte B hyperactivity and cell-mediated immune deficiency are characteristic features of systemic lupus erythematosus. This imbalance is seen in cytokine production. T lymphocyte production of interleukin-2 is defective while proinflammatory cytokines such as IL1 beta, IL6 and TNF alpha increase spontaneously during flare-ups. However, the capacity of the monocytes in these patients to produce cytokines is reduced after stimulation by exterior agents such as LPS. Moreover, production of interleukin 10 is increased in lupus patients. Most likely, it is this increase in interleukin 10 production which causes the disrupted immunity in this disease.

Animals↗
PubMed1995

T helper type 1/T helper type 2 cytokines and T cell death: preventive effect of interleukin 12 on activation-induced and CD95 (FAS/APO-1)-mediated apoptosis of CD4+ T cells from human immunodeficiency virus-infected persons.

Human immunodeficiency virus (HIV) infection leads to a progressive loss of CD4+ T helper (Th) type 1 cell-mediated immunity that is associated with defective in vitro CD4+ T cell proliferation and abnormal T cell death by apoptosis in response to T cell receptor (TCR) stimulation. Quantification of interleukin (IL)-2, interferon gamma, IL-4, IL-5, and IL-10 secretion by immunoassays, and of interferon gamma, IL-4 and IL-10 messenger RNA expression by competitive reverse transcriptase polymerase chain reaction after in vitro stimulation of the TCR revealed a similar Th1 cytokine profile in T cells from HIV-infected persons and from controls. These data indicated that the loss of CD4+ Th1 cell function in HIV-infected persons is not related to a Th1 to Th2 cytokine switch as previously proposed, but to a process of activation-induced death of CD4+ Th1 cells. Despite the absence of elevated levels of Th2 cytokines, apoptosis of CD4+ T cells, but not of CD8+ T cells, was prevented in vitro by antibodies to IL-10 or IL-4, two Th2 cytokines that downregulate Th1 cell responses, or by the addition of recombinant IL-12, a cytokine that upregulates Th1 functions. TCR-induced apoptosis of T cell hybridomas and preactivated T cells has been shown to involve the CD95 (Fas/Apo-1) molecule. CD4+ and CD8+ T cells from HIV-infected persons expressed high levels of the CD95 molecule, and, in contrast to T cells from controls, were highly sensitive to antibody-mediated CD95 ligation, which induced apoptosis in a percentage of T cells similar to that induced by TCR stimulation. As TCR-induced apoptosis, CD95-mediated apoptosis of CD4+ T cells, but not of CD8+ T cells, was prevented by the addition of recombinant IL-12. Together, these findings suggest that apoptosis of CD4+ T cells from HIV-infected persons involves an abnormal sensitivity to CD95 ligation, and to TCR stimulation in the presence of normal levels of Th2 cytokines. The preventive effect of IL-12 on both mechanisms has potential implications for the design of immunotherapy strategies aimed at the upregulation of CD4+ Th1 cell functions in AIDS.

Apoptosis↗
PubMed1995

Role of interleukin 10 in the B lymphocyte hyperactivity and autoantibody production of human systemic lupus erythematosus.

Interleukin-10 (IL-10) is produced at a high level by B lymphocytes and monocytes of patients with systemic lupus erythematosus (SLE). In the present work, we analyzed whether this increased production of IL-10 contributed to the abnormal production of immunoglobulins (Ig) and of autoantibodies in SLE. The role of IL-10 was compared with that of IL-6, another cytokine suspected to play a role in these abnormalities. The spontaneous in vitro production of IgM, IgG, and IgA by peripheral blood mononuclear cells from SLE patients was weakly increased by recombinant IL (rIL)-6, but strongly by rIL-10. This production was not significantly affected by an anti-IL-6 mAb but was decreased by an anti-IL-10 mAb. We then tested the in vivo effect of these antibodies in severe combined immunodeficiency mice injected with PBMC from SLE patients. The anti-IL-6 mAb did not significantly affect the serum concentration of total human IgG and of anti-double-stranded DNA IgG in the mice. In contrast, the anti-IL-10 mAb strongly inhibited the production of autoantibodies, and, to a lesser extent, that of total human IgG. These results indicate that the Ig production by SLE B lymphocytes is largely IL-10 dependent, and that the increased production of IL-10 by SLE B lymphocytes and monocytes may represent a critical mechanism in the emergence of the autoimmune manifestations of the disease.

Adult↗