bluuebunny/crossref_metadata_2025 huggingface dataset:
Spontaneous and oxidative stress-induced programmed cell death in lymphocytes from patients with ataxia telangiectasia (AT)
Authors: Schubert R , Reichenbach J , Royer N , Pichler M , Zielen S
Published: March 2003

T cell lymphopenia in the peripheral blood lymphocytes (PBL) of patients with AT is mainly caused by a decrease of naive CD45RA+/CD4+ cells followed by a predominance of memory CD45RO+ lymphocytes. To relate these findings to the regulation of programmed cell death, we investigated the activation state and apoptotic level of PBL in 12 patients and healthy controls by flow cytometry. In accordance with previous investigations, the number of naive CD4+/CD45RA+ cells was significantly decreased in patients compared with healthy controls. This disturbed balance of CD45RA and CD45RO was also reflected in higher amounts of activated HLA-DR and CD95 expressing cells, with a concomitant decrease of Bcl-2 protected lymphocytes in the T cell population. With regard to its role in preventing oxidative-induced cell death, we analysed Bcl-2 expression and apoptosis in the presence of oxidative stress. In culture, cells of patients are more susceptible to spontaneous programmed cell death. However, in our stress-inducing system (hypoxanthine/xanthine oxidase system) the number of cells undergoing apoptosis was lower in patients’ cell populations compared with controls. In addition, preliminary results suggest that Bcl-2 expression and level of spontaneous apoptosis in patients can be modified by IL-2 and interferon-gamma.
Interaction of endothelial cells and neutrophilsin vitro: kinetics of thrombomodulin, intercellular adhesion molecule-1 (ICAM-1), E-selectin, and vascular cell adhesion molecule-1 (VCAM-1): implications for the relevance as serological disease activity markers in vasculitides
Authors: Boehme M W J , Raeth U , Scherbaum W A , Galle P R , Stremmel W
Published: March 2003

Recently markers of endothelial cell activation or injury gained increasing interest as serological parameters of disease activation in vasculitides. Among these, soluble serum thrombomodulin, ICAM-1, VCAM-1 and E-selectin are of particular interest. However, only thrombomodulin showed the expected close correlation. The objective of this study was to investigate in vitro the kinetics of these endothelial cell receptors after interaction of unstimulated or cytokine-activated polymorphonuclear neutrophils (PMN) and endothelial cells in order to find evidence explaining these different clinical findings. Over the time period of up to 48 h of incubation the kinetics of thrombomodulin, ICAM-1, E-selectin, and VCAM-1 levels in the supernatant of endothelial cells in co-culture with neutrophils were determined in vitro by ELISA under basal and partially cytokine-activated (tumour necrosis factor-alpha) conditions. Increased levels of ICAM-1, E-selectin and VCAM-1 were already found due to cytokine activation of endothelial cells alone. This increase was augmented after coincubation with neutrophils. In contrast, a significant increase of thrombomodulin in the supernatant was only found due to cell injury after cell–cell interaction of cytokine-activated endothelial cells with neutrophils. In conclusion, this in vitro model of the kinetics of soluble endothelial cell receptors after cell–cell interaction of cytokine-activated PMN and endothelial cells underlines the advantage of thrombomodulin in contrast to the adhesion molecules as a marker of endothelial damage. Therefore, soluble thrombomodulin seems to be a promising, valuable serological disease activity marker in vasculitides.
Increased levels of circulating soluble CD14 in Kawasaki disease
Authors: Takeshita S , Nakatani K , Tsujimoto H , Kawamura Y , Kawase H , Sekine I
Published: March 2003

The CD14 molecule, which is known to be a receptor for endotoxin, is expressed on monocytes and neutrophils. It is found as a soluble CD14 (sCD14) in circulation, and the plasma level has been shown to be increased in some infectious diseases, including sepsis. To investigate the potential significance of circulating sCD14 in Kawasaki disease (KD), the plasma level of sCD14 was measured using ELISA in patients with KD, patients with a Gram-negative bacterial infection (GNBI) including sepsis, patients with viral infection (VI), and healthy controls. We also analysed CD14 receptor expression in monocytes and neutrophils using flow cytometry and a semiquantitative reverse transcription-polymerase chain reaction. Although KD patients had significantly lower counts of peripheral neutrophils and monocytes than GNBI patients, KD patients had significantly higher levels of sCD14 than GNBI. No significant correlations were observed between sCD14 levels and clinical laboratory values or the cytokine (interferon-gamma, tumour necrosis factor-alpha) levels in the acute phase. The mean intensity of CD14 receptor expression on neutrophils markedly increased in the acute phases of KD and GNBI compared with that in their convalescent phases, while that on monocytes decreased. The expression of CD14 mRNA in neutrophils increased in the acute phases of KD and GNBI, while that in monocytes did not decrease but instead remained quite abundant. The present findings suggest that the elevated level of circulating sCD14 appears to be an important parameter for KD and that sCD14 shedding is accompanied by different kinetics regarding the expression of CD14 antigen and CD14 gene between monocytes and neutrophils.
Bacteroides fragilisenterotoxin induces the expression of IL-8 and transforming growth factor-beta (TGF-β) by human colonic epithelial cells
Authors: Sanfilippo L , Li C K F , Seth R , Balwin T J , Menozzi M G , Mahida Y R
Published: March 2003

Bacteroides fragilis toxin (BFT) has been shown to be capable of inducing intestinal mucosal inflammation in animals. Such inflammation may be responsible for diarrhoea, which occurs in some, but not all human carriers of enterotoxigenic strains of B. fragilis (ETBF). We have studied responses to BFT by different human intestinal epithelial cell lines and subsequently investigated the expression of IL-8 and TGF-β by T84 cells. The latter were selected because their responses to BFT, characterized by morphological changes and cell death by apoptosis, were similar to those we have recently observed in primary human colonocytes. We show that BFT dose-dependently increased the expression of transcripts and protein of the polymorphonuclear cell chemoattractant IL-8. BFT also dose-dependently induced the release of TGF-β, which has been shown to enhance the repair of the injured intestinal epithelium. However, the secreted TGF-β was almost exclusively in the biologically inactive form, as determined by Mv1Lu bioassay. Our studies therefore suggest that exposure of colonic epithelial cells in vivo to high concentrations of BFT can initiate an inflammatory response via secreted IL-8. BFT-induced release of latent TGF-β may facilitate the subsequent repair of the injured epithelium, following its activation by proteases from neighbouring cells. Variation in cytokine responses by colonic epithelial cells in vivo could be an important determinant in the development of mucosal disease and symptoms in response to ETBF.
Human monoclonal anti-phospholipid antibodies selectively bind to membrane phospholipid andβ2-glycoprotein I (β2-GPI) on apoptotic cells
Authors: Pittoni V , Ravirajan C T , Donohoe S , Machin S J , Lydyard P M , Isenberg D A
Published: March 2003

The ability of an anti-phospholipid (LJ1) and an anti-β2-GPI (RSP-57) human MoAb to bind to apoptotic but not viable cells was demonstrated in this study. Both MoAbs were derived from patients with systemic lupus erythematosus and anti-phospholipid antibody syndrome. The parallel analysis of the specificity and affinity of four anti-phospholipid human MoAbs suggests that the binding of LJ1 MoAb to apoptotic cells is a specific property of this MoAb. RSP-57 MoAb recognizes apoptotic cells through β2-GPI which becomes available for binding after the interaction with negatively charged phospholipids. This observation provides evidence that the binding of human anti-phospholipid antibodies to apoptotic cells occurs in both a β2-GPI-dependent and independent way and involves a restricted group of epitopes. The finding that LJ1 and RSP-57 MoAbs bind apoptotic cells underlines the property of these MoAbs to act as cell membrane markers of apoptosis. Major pathological implications derive from the observation that LJ1 and RSP-57 MoAbs recognize epitopes expressed on ‘early’ apoptotic cells. The interference with the in vivo clearance and processing of apoptotic cells is a potential pathogenic mechanism of these antibodies.
Specificity of anti-phospholipid antibodies in infectious mononucleosis: a role for anti-cofactor protein antibodies
Authors: Sorice M , Pittoni V , Griggi T , Losardo A , Leri O , Magno M S , Misasi R , Valesini G
Published: March 2003

The antigen specificity of anti-phospholipid antibodies in infectious mononucleosis (IM) was studied using ELISA for the detection of anti-β2-glycoprotein I (β2-GPI), anti-annexin V, anti-protein S and anti-prothrombin antibodies and TLC immunostaining for the detection of anti-phospholipid antibodies. This technique enabled us to look at antibodies reacting to ‘pure’ phospholipid antigens in the absence of protein contamination. Sera from 46 patients with IM, 18 with systemic lupus erythematosus (SLE), 21 with primary anti-phospholipid antibody syndrome (PAPS), 50 with Helicobacter pylori infection and 30 healthy blood donors were tested. This study highlights anti-phospholipid antibodies in patients with IM as specific ‘pure’ anti-cardiolipin antibodies, while in PAPS and SLE patients anti-phosphatidylserine and anti-phosphatidylethanolamine antibodies were also found. This investigation also shows that the anti-cardiolipin antibodies found in IM can be present with anti-cofactor protein antibodies. The higher prevalence of anti-cofactor antibodies found in IM sera than in Helicobacter pylori sera may be due to the immunostimulatory effect and/or the polyclonal activation often observed in course of Epstein–Barr virus infection. However, anti-β2-GPI and, to a lesser extent, anti-prothrombin antibodies occur with a significantly lower prevalence in IM than in PAPS patients. This finding suggests that these antibodies should be regarded as the expression of the broad autoimmune syndrome involving the phospholipid-binding plasma proteins.
Fine specificity of autoantibodies to calreticulin: epitope mapping and characterization
Authors: Eggleton P , Ward F J , Johnson S , Khamashta M A , Hughes G R V , Hajela V A , Michalak M , Corbett E F , Staines N A , Reid K B M
Published: March 2003

Extracellular calreticulin (CRT) as well as anti-CRT antibodies have been reported in patients with various autoimmune disorders and CRT has been implicated in ‘epitope spreading’ to other autoantigens such as the Ro/SS-A complex. In addition, antibodies against parasite forms of the endoplasmic reticulum chaperone, CRT, have been found in patients suffering from onchocerciasis and schistosomiasis. In this study, we screened sera for anti-CRT antibodies from patients with active and inactive systemic lupus ertythematosus (SLE) and primary or secondary Sjögren’s syndrome. Approximately 40% of all SLE patients were positive for anti-CRT antibodies. The antigenic regions of CRT were determined using full length CRT and fragments of CRT prepared in yeast and Escherichia coli, respectively. Synthetic 15mer peptides corresponding to the major autoantigenic region of CRT (amino acids 1–289), each one overlapping by 12 amino acids, were used to map the B cell epitopes on the CRT protein recognized by autoimmune sera. Major antigenic epitopes were found to be associated with the N-terminal half of the protein in 69% of the SLE sera from active disease patients, while the C-domain was not antigenic. Major epitopes were found to be reactive with antibodies in sera from SLE patients with both active and inactive disease, spanning different regions of the N and P-domains. Sera from both healthy and disease controls and primary Sjögren’s syndrome patients were non-reactive to these sequences. Limited proteolysis of CRT with two major leucocyte serine proteases, elastase and cathepsin G, demonstrated that an N-terminal region of CRT is resistant to digestion. Interestingly, some of the epitopes with the highest reactivity belong to the fragments of the protein which bind to C1q and inhibit complement activation. Whether C1q association with CRT is a pathological or protective interaction between these two proteins is currently under investigation.
Up-regulation of human T lymphotropic virus type 1 (HTLV-1)tax/rexmRNA in infected lung tissues
Authors: Seki M , Higashiyama Y , Mizokami A , Kadota J-I , Moriuchi R , Kohno S , Suzuki Y , Takahashi K , Gojobori T , Katamine S
Published: March 2003

HTLV-1 has been implicated in certain pulmonary diseases. We previously demonstrated that expression of HTLV-1 tax/rex mRNA, encoding the transcriptional transactivator Tax, was closely associated with infiltration of activated T lymphocytes into lung tissue. To explore mechanisms of tax/rex expression in the lung, tax/rex mRNA expression and proviral DNA load were compared between peripheral blood mononuclear cells (PBMC) and bronchoalveolar lavage cells (BALC) from four patients with HTLV-1-associated myelopathy (HAM/TSP) and 13 carriers with various pulmonary symptoms. Semiquantitative detection of tax/rex mRNA strongly suggested that the lung was a preferential site for its expression. Proviral DNA loads in non-HAM/TSP carriers were variable but correlated well between PBMC and BALC in each individual, and revealed no relationship with tax/rex mRNA expression. In contrast, both cell groups from four HAM/TSP patients expressed detectable tax/rex mRNA accompanied by high proviral DNA load. The ratio of tax/rex mRNA expression to proviral DNA load was higher in BALC than in PBMC in three of four carriers and in three of four HAM/TSP patients, suggesting up-regulation of tax/rex mRNA in infected lung tissue. To analyse differences in distribution of HTLV-1 quasispecies between the two tissues, phylogenetic analysis was performed for sequence sets of the proviral tax open reading frame (ORF: 1059 bp) derived from PBMC and BALC of two infected individuals. Sequences derived from the two tissues distributed similarly to branches of phylogenetic trees, and there was no evidence of selective distribution of certain quasispecies in the lung. Our results suggest the presence of tissue-specific conditions that activate viral expression in infected cells in the lung. Constitutive exposure of this tissue to foreign antigens leading to up-regulation of basal viral promoter activity is likely to be one such mechanism.
CD8+ cells suppress oil-induced arthritis
Authors: Jansson Å M , Lorentzen J C , Bucht A
Published: March 2003

Oil-induced arthritis is a genetically restricted polyarthritis that develops in the DA rat after injection of the mineral oil Freund's incomplete adjuvant. Here, we investigated the role of the potentially disease-limiting cell populations CD8+ T cells, γδ T cells, natural killer (NK) cells and NK T cells in inguinal lymph nodes for the development of this adjuvant-induced arthritis. Flow cytometry analysis before and at disease onset revealed a higher proportion of lymph node T cells expressing NKR-P1 in the disease-resistant LEW.1AV1 compared with the disease-susceptible DA strain, suggesting that NK T cells might be disease protective. However, prophylactic in vivo administration of an anti-NKR-P1 MoAb (clone 10/78) did not consistently affect the disease course. The proportion of CD8+ T cells and the ratio CD4+/CD8+ T cells in inguinal lymph nodes did not differ significantly between DA and LEW.1AV1 rats before or at disease onset. Nevertheless, prophylactic in vivo depletion of CD8+ cells by the OX8 MoAb in the DA strain resulted in an earlier disease onset compared with the control group, demonstrating that CD8+ cells regulate arthritis development. In vivo depletion of γδ T cells by the V65 MoAb did not alter the disease course, indicating that the disease-suppressive CD8+ cells are αβ T cells or NK cells.
Intravenous immunoglobulin (IVIG) attenuates antibody binding in acute haemorrhagic immunopneumonitis in a rat model of complement-dependent lung injury
Authors: Dantas M , Costa R S , Barbosa J E , Graeff M S Z , Sarti W , De carvalho I F
Published: March 2003

Administration of rabbit anti-rat lung serum (PNTS) to rats produces a fulminant haemorrhagic pneumonitis sensitive to the availability of complement. The present experiments were undertaken to assess whether a high dose of IVIG can affect the development of this kind of cytotoxic reaction. The experimental design included groups of Wistar rats pretreated intravenously with physiologic saline, IVIG or a preparation of human F(ab′)2 fragments. One hour later the animals were challenged with either saline or PNTS. At 30 min after challenge, blood was collected and the lungs were removed. Pulmonary damage was evaluated by light microscopy; C3 deposits and the binding of immunoglobulins to the alveolar septa were assayed by immunofluorescence. The serum complement activity of the classical and alternative pathways was estimated by a kinetic technique. Pretreatment with IVIG decreased binding of rabbit anti-lung antibodies to alveolar septa and prevented the deposition of C3. These results indicate that pretreatment with IVIG inhibits the binding of the pathogenic antibody to lung tissue. Human IgG binding was not detected in any animal. The protection against lung injury afforded by pretreatment with IVIG, in contrast to the pneumotoxic effect of PNTS observed in control animals, was evident despite the administration of F(ab′)2 to the rats. Since pretreatment with F(ab′)2 failed to prevent the acute lung lesion, our results indicate that the attenuation afforded by IVIG in this model of complement-dependent tissue injury seems to be related to the integrity of the IgG molecule.
Ageing, tumour necrosis factor-alpha (TNF-α) and atherosclerosis
Authors: Bruunsgaard H , Skinhøj P , Pedersen A N , Schroll M , Pedersen B K
Published: March 2003

Ageing is associated with increased inflammatory activity in the blood. The purpose of this study was to investigate if age-related increased plasma levels of TNF-α were associated with atherosclerosis in a cohort of 130 humans aged 81 years. The elderly cohort had increased circulating levels of TNF-α, C-reactive protein (CRP), total cholesterol (TC), low-density lipoproteins (LDL) and a low high-density lipoprotein (HDL)/TC ratio compared with a young control group (n = 44). The elderly cohort was divided by tertiles into three subgroups with low, intermediate, and high levels of TNF-α, respectively. In the group with high TNF-α concentrations a significantly larger proportion had clinical diagnoses of atherosclerosis. Furthermore, weak correlations were found between TNF-α on one hand and blood concentrations of triglycerides, leucocytes, CRP and a low HDL/TC ratio on the other which are known as risk factors of atherogenesis and thromboembolic complications. No correlations were found between TNF-α, TC, LDL, or the body mass index. In conclusion, the present study shows that in a cohort of 81-year-old humans, high levels of TNF-α in the blood were associated with a high prevalence of atherosclerosis.
Different regulation of factor H and FHL-1/reconectin by inflammatory mediators and expression of the two proteins in rheumatoid arthritis (RA)
Authors: Friese M A , Hellwage J , Jokiranta T S , Meri S , Müller-Quernheim H J , Peter H H , Eibel H , Zipfel P F
Published: March 2003

Factor H and the FHL-1/reconectin protein are two human plasma proteins that act as important regulators of the alternative complement pathway. Each protein is encoded by a unique transcript, but both mRNAs are derived from the factor H gene by means of alternative processing. In order to address potential functional differences between the two proteins we analysed their expression in hepatic and non-hepatic cells and studied their regulation by inflammatory mediators. We demonstrate that factor H and FHL-1/reconectin transcripts which are regulated by the same gene promoter and are initiated at the same transcription start site are differently expressed. Expression of the molecules is induced and regulated by the inflammatory mediators interferon-gamma (IFN-γ) and the anti-inflammatory glucocorticoid dexamethasone. Both factor H and FHL-1/reconectin are expressed and secreted by synovial fibroblasts and are present in synovial fluid derived from patients suffering from rheumatoid or reactive arthritis. The local synthesis in synovial fibroblasts and their induction by IFN-γ and dexamethasone, but not by tumour necrosis factor-alpha, suggests for each of the two complement regulators a protective role in RA.
Immunotherapy of a human papillomavirus (HPV) type 16 E7-expressing tumour by administration of fusion protein comprisingMycobacterium bovisbacille Calmette–Guérin (BCG) hsp65 and HPV16 E7
Authors: Chu N R , Wu H B , Wu T-C , Boux L J , Siegel M I , Mizzen L A
Published: March 2003

Human papillomavirus type 16 (HPV16) infection has been linked to the development of cervical and anal dysplasia and cancer. One hallmark of persistent infection is the synthesis of the viral E7 protein in cervical epithelial cells. The expression of E7 in dysplastic and transformed cells and its recognition by the immune system as a foreign antigen make it an ideal target for immunotherapy. Utilizing the E7-expressing murine tumour cell line, TC-1, as a model of cervical carcinoma, an immunotherapy based on the administration of an adjuvant-free fusion protein comprising Mycobacterium bovis BCG heat shock protein (hsp)65 linked to HPV16 E7 (hspE7) has been developed. The data show that prophylactic immunization with hspE7 protects mice against challenge with TC-1 cells and that these tumour-free animals are also protected against re-challenge with TC-1 cells. In addition, therapeutic immunization with hspE7 induces regression of palpable tumours, confers protection against tumour re-challenge and is associated with long-term survival (> 253 days). In vitro analyses indicated that immunization with hspE7 leads to the induction of a Th1-like cell-mediated immune response based on the pattern of secreted cytokines and the presence of cytolytic activity following antigenic recall. In vivo studies using mice with targeted mutations in CD8 or MHC class II or depleted of CD8 or CD4 lymphocyte subsets demonstrate that tumour regression following therapeutic hspE7 immunization is CD8-dependent and CD4-independent. These studies extend previous observations on the induction of cytotoxic T lymphocytes by hsp fusion proteins and are consistent with the clinical application of hspE7 as an immunotherapy for human cervical and anal dysplasia and cancer.
Analysis of the autoimmune epitopes on human testicular NASP using recombinant and synthetic peptides
Authors: Batova I N , Richardson R T , Widgren E E , O'Rand M G
Published: March 2003

The human nuclear autoantigenic sperm protein, NASP, is a testicular histone-binding protein of 787 amino acids to which most vasectomized men develop autoantibodies. In this study to define the boundaries of antigenic regions and epitope recognition pattern, recombinant deletion mutants spanning the entire protein coding sequence and a human NASP cDNA sublibrary were screened with vasectomy patients' sera. Employing panel sera from 21 vasectomy patients with anti-sperm antibodies, a heterogeneous pattern of autoantibody binding to the recombinant polypeptides was detected in ELISA and immunoblotting. The majority of sera (20/21) had antibodies to one or more of the NASP fusion proteins. Antigenic sites preferentially recognized by the individual patients' sera were located within aa 32–352 and aa 572–787. Using a patient's serum selected for its reactivity to the whole recombinant protein in Western blots, cDNA clones positive for the C-terminal domain of the molecule were identified. The number and location of linear epitopes in this region were determined by synthetic peptide mapping and inhibition studies. The epitope-containing segment was delimited to the sequence aa 619–692 and analysis of a series of 74 concurrent overlapping 9mer synthetic peptides encompassing this region revealed four linear epitopes: amino acid residues IREKIEDAK (aa 648–656), KESQRSGNV (aa 656–664), AELALKATL (aa 665–673) and GFTPGGGGS (aa 680–688). All individual patients' sera reacted with epitopes within the sequence IRE….GGS (aa 648–688). The strongest reactivity was displayed by peptides corresponding to the sequence AELALKATL (aa 665–673). Thus, multiple continuous autoimmune epitopes in NASP involving sequences in the conserved C-terminal domain as well as in the less conserved testis-specific N-terminal region comprising the histone-binding sites, as predicted for an antigen-driven immune response, may be a target of autoantibodies in vasectomized men and may provide a relevant laboratory variable to describe more accurately the spectrum of autoantibody specificities associated with the clinical manifestation of vasectomy.
Cytokine-mediated up-regulation of CD55 and CD59 protects human hepatoma cells from complement attack
Authors: Spiller O B , Criado-García O , Rodríguez De Córdoba S , Morgan B P
Published: March 2003

Hepatic parenchymal cells respond in many different ways to acute-phase cytokines. Some responses may protect against damage by liver-derived inflammatory mediators. Previous investigations have shown that cytokines cause increased secretion by hepatoma cells of soluble complement regulatory proteins, perhaps providing protection from complement attack. More important to cell protection are the membrane complement regulators. Here we examine, using flow cytometry and Northern blotting, the effects of different cytokines, singly or in combination, on expression of membrane-bound complement regulators by a hepatoma cell line. The combination of tumour necrosis factor-alpha, IL-1β, and IL-6 caused increased expression of CD55 (three-fold) and CD59 (two-fold) and decreased expression of CD46 at day 3 post-exposure. Interferon-gamma reduced expression of CD59 and strongly antagonized the up-regulatory effects on CD59 mediated by the other cytokines. Complement attack on antibody-sensitized hepatoma cells following a 3-day incubation with the optimum combination of acute-phase cytokines revealed increased resistance to complement-mediated lysis and decreased C3b deposition. During the acute-phase response there is an increased hepatic synthesis of the majority of complement effector proteins. Simultaneous up-regulation of expression of CD55 and CD59 may serve to protect hepatocytes from high local concentrations of complement generated during the acute-phase response.
Resistance/susceptibility to Echinococcus multilocularis infection and cytokine profile in humans. I. Comparison of patients with progressive and abortive lesions
Authors: Godot V , Harraga S , Beurton I , Deschaseaux M , Sarciron E , Gottstein B , Vuitton D A
Published: March 2003

To clarify the role of Th1- and Th2-type cytokines in the various outcomes of human alveolar echinococcosis (AE), the cytokine immune response of self-cured patients was studied and compared with those of progressive AE patients and healthy subjects. Self-cured patients were divided into two groups according to the following clinical features: subjects who had positive Echinococcus multilocularis serologies and hepatic calcifications typical of AE were classified as ‘abortive AE’ patients, and those who had positive E. multilocularis serologies but no hepatic lesions or calcifications detectable by ultrasonography were classified as ‘positive serology’ subjects. Secretions of IL-5, IL-10 and interferon-gamma, and expression of IL-5 mRNA were evaluated in peripheral blood mononuclear cells (PBMC) stimulated in vitro with the mitogen phytohaemagglutinin-C or specific E. multilocularis antigenic preparations. The cytokine profile of abortive AE patients was the opposite of that observed in progressive AE patients. An intermediate profile was observed in positive serology subjects. PBMC from abortive AE patients, whether non-stimulated or stimulated with PHA and antigenic preparations, secreted significantly lower levels of IL-10 than those isolated from progressive AE patients. Our observations seem to confirm the regulatory role of IL-10 in the immunopathology of human AE.
Angiotensin-converting enzyme inhibitor captopril prevents activation-induced apoptosis by interfering with T cell activation signals
Authors: Odaka C , Mizuochi T
Published: March 2003

Captopril is an orally active inhibitor of angiotensin-converting enzyme (ACE) which is widely used as an anti-hypertensive agent. In addition to its ability to reduce blood pressure, captopril has a number of other biological activities. Recently the drug was shown to inhibit Fas-induced apoptosis in human activated peripheral T cells and human lung epithelial cells. In this study, we investigated whether captopril blocks activation-induced apoptosis in murine T cell hybridomas, and found that captopril inhibited IL-2 synthesis and apoptotic cell death upon activation with anti-CD3 antibody. In addition, captopril inhibited an inducible caspase-3-like activity during activation-induced apoptosis. On the other hand, captopril did not interfere with Fas signalling, since anti-Fas antibody-induced apoptosis in Fas+ Jurkat cells was unaffected by the drug. Furthermore, we examined whether captopril blocks activation-induced apoptosis by interfering with expression of Fas, Fas ligand (FasL), or both on T cell hybridomas. FasL expression on activated T cells was significantly inhibited by captopril, whereas up-expression of Fas was partially inhibited, as assessed by cell surface staining. Taking all data together, we conclude that captopril prevents activation-induced apoptosis in T cell hybridomas by interfering with T cell activation signals. Captopril has been reported to induce systemic lupus erythematosus syndrome, and our findings may be useful for elucidating the mechanism of captopril-induced autoimmunity.
Pathogenic roles of eosinophils in guinea-pig contact sensitivity: regulation of dermal eosinophilia with remotely administered IL-5
Authors: Satoh T , Yokozeki H , Nishioka K
Published: March 2003

Eosinophils have a variety of functions. Although increasing evidence links the presence of eosinophils to airway damage, studies have not examined in detail if, and how, eosinophils affect skin inflammation. The purpose of this study was to determine whether eosinophil infiltration augments the contact sensitivity reaction in vivo. Guinea-pigs were sensitized with 2, 4-dinitrochlorobenzene and challenged on the dorsal skin or on the right ear lobe. The number of eosinophils and macroscopic changes of the skin lesion in the presence or absence of human recombinant IL-5 (rIL-5) administered at the remote site was assessed. The reaction on the dorsal skin was acutely eczematous with considerable basophil infiltration. In contrast, eosinophils had extensively infiltrated the right ear lobe and major basic protein was deposited in the dermis. A subcutaneous injection of rIL-5 (10 pmol/kg) at the remote site (left ear lobe) 12 h after challenge induced transient blood eosinophilia and enhanced eosinophil accumulation in the challenged ear lobe. These changes were accompanied by increased ear swelling and severe erythema. In contrast, eosinophil infiltration was significantly inhibited by rIL-5 administered at the time of challenge. Ear thickness, as well as the erythema and oedema, were also reduced. These data suggest that marked eosinophil infiltration enhances skin inflammation in allergic contact dermatitis. Moreover, locally administered IL-5 functions remotely by controlling eosinophil recruitment into the skin. The guinea-pig model of contact sensitivity may be useful for evaluating therapies and pharmaceuticals targeted at eosinophil infiltration.
Th1 cytokine pattern in sarcoidosis is expressed by bronchoalveolar CD4+ and CD8+ T cells
Authors: Prasse A , Georges C G , Biller H , Hamm H , Matthys H , Luttmann W , Virchow Jr J C
Published: March 2003

The pathogenesis of pulmonary sarcoidosis has been related to an increased production of Th1-like cytokines. However, cytokine expression in sarcoidosis has not been systematically studied at a single-cell level. We therefore investigated the expression of IL-2, IL-4, IL-13, tumour necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) intracellularly in bronchoalveolar lavage (BAL) and peripheral blood CD3+ T lymphocytes from patients with pulmonary sarcoidosis (radiologic stage II–III, n = 8) and normal controls (n = 9) by flow cytometry. In contrast to IL-4 and IL-13, the percentage of T lymphocytes expressing intracellular IL-2 (49·3 ± 21·3% versus 14·5 ± 15·6%), IFN-γ (75·5 ± 14·9% versus 32·6 ± 18·7%) and TNF-α (68·3 ± 18·7% versus 36·8 ± 20·8%) was significantly higher in patients with sarcoidosis than in normal controls (each P < 0·005). In contrast to BAL lymphocytes, expression of these cytokines in peripheral blood lymphocytes did not differ between patients with sarcoidosis and normal controls. Close correlations were observed between the percentages of BAL lymphocytes expressing intracellular IL-2, IFN-γ and TNF-α, but not for IL-4 or IL-13. Analysis of the expression of these cytokines in T lymphocyte subsets revealed IL-2, IFN-γ, and TNF-α in CD4+ as well as CD8+ T lymphocytes, suggesting a contribution of TC1 cells to the production of proinflammatory cytokines in sarcoidosis. We conclude that a Th1-like cytokine pattern can be observed in CD4+ as well as in CD8+ BAL T lymphocytes in patients with pulmonary sarcoidosis.
TheLeishmania infantumacidic ribosomal protein LiP2a induces a prominent humoral responsein vivoand stimulates cell proliferationin vitroand interferon-gamma (IFN-γ) production by murine splenocytes
Authors: Soto M , Alonso C , Requena J M
Published: March 2003

The acidic ribosomal proteins of the protozoan parasite Leishmania infantum have been described as prominent antigens during both human and canine visceral leishmaniasis. In this study we present data showing that the intraperitoneal administration in BALB/c mice of the Leishmania LiP2a protein, in the absence of any added adjuvants, elicited a strong humoral response as an indication that the protein is a potent immunogen. Despite the evolutionary conservation of the acidic ribosomal proteins, the antibody response was found to be specific for the Leishmania protein. Another remarkable finding was the observation that the LiP2a protein stimulates the in vitro proliferation of splenocytes from either LiP2a-immunized or naive BALB/c mice. Since similar proliferative indices were observed in T cell-enriched cultures, it is likely that the LiP2a stimulating activity is due mainly to T lymphocyte expansion. Also, the stimulatory effect was demonstrated to be antigen-specific, since the proliferation was abrogated by the presence of anti-LiP2a antibodies. Interestingly, the LiP2a protein stimulated the production of substantial amounts of IFN-γ in cultured splenocytes from LiP2a-immunized mice. Our data indicate therefore that the immunostimulatory properties shown by this antigen should be taken into account when developing therapeutic and prophylactic vaccines against leishmaniasis.
Identification of structural variations in the carboxyl terminus of Alzheimer's disease-associated βA4[1–42] amyloid using a monoclonal antibody
Authors: Jayasena U L H R , Gribble S K , Mckenzie A , Beyreuther K , Masters C L , Underwood J R
Published: March 2003

The accumulation of amyloid plaques and amyloid congophilic angiopathy (ACA) in the brains of affected individuals is one of the main pathological features of Alzheimer's disease. Within these deposits, the βA4 (Aß) polypeptide represents a major component with the C-terminal 39–43 amino acid variants being most abundant. Using a mouse IgG1 MoAb produced by hybridoma βA4[35–43]-95.2 3B9, which reacts with the epitope is defined by the amino acid residues βA438[GVV]40, this study has identified a unique conformation within the carboxyl terminus of human βA4[1–42]. Although the βA438[GVV]40 sequence is present within the C-termini of human βA4[1–40] and βA4[1–43] and the βA4-containing region of human APP, the βA4[35–43]-95.2 3B9 MoAb (designated MoAb 3B9) does not bind these polypeptides, demonstrating a high degree of specificity for the βA438[GVV]40 epitope as presented within the βA4[1–42] sequence. The βA4[1–42] epitope bound by MoAb 3B9 is sensitive to heating (100°C for 5 min) and is denatured by SDS but not by oxidative radio-iodination of βA4 or by adsorption to plastic surfaces or nitrocellulose. The recognition of βA4 plaque deposits and ACA by MoAb 3B9 within formalin-fixed sections of human AD brain demonstrates the potential of these antibodies for investigating the role of the unique βA4[1–42] conformation in the development of Alzheimer's disease.
Anti-CD3-induced and anti-Fas-induced apoptosis in systemic lupus erythematosus (SLE)
Authors: Bijl M , Horst G , Limburg P C , Kallenberg C G M
Published: March 2003

Disturbances in apoptosis or in the clearance of apoptotic material might result in increased presentation of autoantigens which could be relevant to the pathogenesis of SLE. Data concerning defects in apoptosis in SLE are conflicting. To determine whether intrinsic defects in apoptosis induction occur in SLE irrespective of disease activity, we examined anti-CD3 and anti-Fas-induced apoptosis in vitro in SLE patients with inactive disease. Isolated peripheral blood lymphocytes (PBL) from 13 SLE patients and 14 healthy controls were incubated with anti-CD3, and, subsequently, after up-regulation of membrane Fas following anti-CD3 incubation, with anti-Fas. Expression of Fas and levels of apoptosis as detected by annexin V and propidium iodide staining were assessed by flow cytometry before and after the respective incubations. Fas expression on freshly isolated lymphocytes of SLE patients was increased whereas levels of circulating apoptotic cells were comparable between patients and controls. Stimulation with anti-CD3 resulted in up-regulation of membrane Fas in patients and in controls. In vitro induction of apoptosis by anti-CD3 as well as by anti-Fas occurred both in SLE patients and controls, and was higher in SLE patients after incubation with anti-CD3 as well as with anti-Fas. We conclude that Fas expression and in vitro induction of apoptosis are increased in SLE even in the absence of disease activity.
Monocyte-derived dendritic cells: a potential target for therapy inmultiple sclerosis (MS)
Authors: Duddy M E , Dickson G , Hawkins S A , Armstrong M A
Published: March 2003

Monocytes can differentiate into dendritic cells (DC), cells with a pivotal role in both protective immunity and tolerance. Defects in the maturation or function of DC may be important in the development of autoimmune disease. We sought to establish if there were differences in the cytokine (granulocyte-macrophage colony-stimulating factor and IL-4)-driven maturation of monocytes to DC in patients with MS and whether drugs used to treat MS affected this process in vitro. We have demonstrated that there is no defect in the ability of magnetic activated cell sorting (MACS)-purified monocytes from patients with MS to differentiate to DC, but equally they show no tendency to acquire a DC phenotype without exogenous cytokines. Interferon-beta1a prevents the acquisition of a full DC phenotype as determined by light and electron microscopy and by flow cytometry. Methylprednisolone not only prevents the development of monocyte-derived DC but totally redirects monocyte differentiation towards a macrophage phenotype. Evidence is evolving for a role for DC in central nervous system immunity, either within the brain or in cervical lymph nodes. The demonstrated effect of both drugs on monocyte differentiation may represent an important site for immune therapy in MS.
Lack of evidence of a specific role for C4A gene deficiency in determining disease susceptibility among C4-deficient patients with systemic lupus erythematosus (SLE)
Authors: Dragon-Durey M-A , Rougier N , Clauvel J-P , Caillat-Zucman S , Remy P , Guillevin L , Liote F , Blouin J , Ariey F , Lambert B U , Kazatchkine M D , Weiss L
Published: March 2003

The aim of the present study was to investigate the prevalence of C4 and C2 deficiencies and to characterize genomic alterations in C4 genes in a large cohort of 125 unselected patients with SLE. We determined the protein concentration and functional activity of C2 and C4, as well as the C4 phenotype. C4 genotyping included Taq 1 restricted fragment lengh polymorphism (RFLP) analysis and polymerase chain reaction using sequence-specific primers (SSP-PCR). Type I C2 deficiency was diagnosed by PCR. Overall, 79·2% of the patients exhibited abnormalities of the C4 genes including deletion, non-expression, gene conversion and duplication. Among C4-deficient patients (n = 66, 52·8% prevalence), 41·0% of the patients exhibited a C4A deficiency and 59·0% a C4B deficiency. Half of the C4 deficiencies were due to a gene deletion. There was a strong association between C4A and C4B gene deletion and the presence of the DRB1*03 allele. Among the silent C4A genes, only two cases were related to a 2-bp insertion in exon 29 of the C4A gene. A gene conversion was demonstrated in eight patients (6·4%). One patient had a homozygous C4A deficiency. Three (2·4%) patients presented with a heterozygous type I C2 deficiency and none with homozygous deficiency. Our results argue against a specific role for C4A gene deficiency in determining disease susceptibility among patients with SLE that are C4-deficient.
Effect of deworming on human T cell responses to mycobacterial antigens in helminth-exposed individuals before and after bacille Calmette–Guérin (BCG) vaccination
Authors: Elias D , Wolday D , Akuffo H , Petros B , Bronner U , Britton S
Published: March 2003

The protective efficacy of BCG vaccination against pulmonary tuberculosis (TB) is highly variable in different populations. The reason remains to be elucidated. This study aims to investigate the possible effect of intestinal helminths on the immune response to PPD in naturally immunized or BCG-vaccinated humans. The study population was assessed for helminthic infection and those found to be positive were randomly assigned to either an albendazole treatment group or a control group who received a placebo. The immune response to PPD was compared between the two groups. In addition, subjects who were tuberculin skin test-negative in both groups were BCG vaccinated and later on tested for PPD-specific responses. Albendazole induced elimination/or reduction in intestinal worms resulting in a significant improvement in T cell proliferation and in interferon-gamma production by peripheral blood mononuclear cells (PBMC) stimulated with PPD. Moreover, BCG vaccination significantly improved PPD-specific immune responses in the treated group but not in the placebo group. The differences in the in vivo skin test responses were not significant. The data show that cellular immune responses to PPD are reduced in persons with concurrent helminthic infections, perhaps reflecting a lowered resistance to mycobacterial infections. This could explain, at least in part, the reduced efficacy of BCG against TB in helminth-endemic areas of the world.
Impaired degradation of serum amyloid A (SAA) protein by cytokine-stimulated monocytes
Authors: Migita K , Yamasaki S , Shibatomi K , Ida H , Kita M , Kawakami A , Eguchi K
Published: March 2003

Secondary amyloidosis (AA amyloidosis) is a systemic disease characterized by the extracellular tissue deposition of insoluble amyloid A (AA) protein. Aberrant metabolism of serum amyloid A (SAA) by macrophages is only one of many putative mechanisms which may be important in AA amyloidogenesis. In this study, we investigated the effects of cytokines on human monocyte-mediated SAA proteolysis. Human peripheral blood mononuclear cells (PBMC) or CD14+ monocytes were cultured with SAA, and the culture supernatants were then subjected to anti-SAA immunoblot. CD14+ monocytes degraded SAA completely. Whereas, when CD14+ monocytes were pretreated with IL-1β or IFN-γ, increasing amounts of SAA-related derivatives were detected in culture supernatants. These findings suggest that activation of monocytes by IL-1β or IFN-γ hampers the proteolysis of a precursor protein and leads to a partial degradation of SAA. This down-regulated proteolysis of SAA protein by cytokine-stimulated monocytes may play a role in the mechanism of AA amyloid formation as well as its removal.
Early immune responses accompanying human asymptomatic Ebola infections
Authors: Leroy E M , Baize S , Debre P , Lansoud-Soukate J , Mavoungou E
Published: March 2003

In a recent study we identified certain asymptomatic individuals infected by Ebola virus (EBOV) who mounted specific IgG and early and strong inflammatory responses. Here, we further characterized the primary immune response to EBOV during the course of asymptomatic infection in humans. Inflammatory responses occurred in temporal association with anti-inflammatory phase composed by soluble antagonist IL-1RA, circulating TNF receptors, IL-10 and cortisol. At the end of the inflammatory process, mRNA expression of T-cell cytokines (IL-2 and IL-4) and activation markers (CD28, CD40L and CTLA4) was up-regulated, strongly suggesting T-cell activation. This T-cell activation was followed by EBOV-specific IgG responses (mainly IgG3 ang IgG1), and by marked and sustained up-regulation of IFNγ, FasL and perforin mRNA expression, suggesting activation of cytotoxic cells. The terminal down-regulation of these latter markers coincided with the release of the apoptotic marker 41/7 NMP in blood and with the disappearance of viral RNA from PBMC, suggesting that infected cells are eliminated by cytotoxic mechanisms. Finally, RT-PCR analysis of TCR-Vβ repertoire usage showed that TCR-Vβ12 mRNA was never expressed during the infection. Taken together, these findings improve our understanding about immune response during human asymptomatic Ebola infection, and throw new light on protection against Ebola virus.
Melatonin provides signal 3 to unprimed CD4+ T cells but failed to stimulate LPS primed B cells
Authors: Raghavendra V , Singh V , Shaji A V , Vohra H , Kulkarni S K , Agrewala J N
Published: March 2003

Growing evidence has supported the conclusion that melatonin, a pineal hormone, modulates the immune function. In our previous study, we evaluated in vivo the potential role of melatonin in the regulation of the antigen specific T and B cells. In the present study, we observe that melatonin down-regulated the expression of the co-stimulatory molecule B7-1 but not B7-2 on macrophages. Further, melatonin encouraged the proliferation of anti-CD3 antibody activated CD4+ T cells only in the presence of antigen-presenting cells and promoted the production of Th2-like cytokines. Furthermore, it failed to influence the activity of B cells in a T-independent manner. Melatonin suppressed the release of TNF-α by LPS or IFN-γ activated macrophages but failed to inhibit nitric oxide (NO) release. Thus the study shows that melatonin can engineer the growth of unprimed CD4+ T cells if both the signals are provided by antigen-presenting cells. However, it could not regulate the function of B cells.