bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inosine monophosphate dehydrogenase (IMPDH) inhibitionin vitrosuppresses lymphocyte proliferation and the production of immunoglobulins, autoantibodies and cytokines in splenocytes from MRLlpr/lprmice
Authors: Jonsson C A , Carlsten H 
Published: March 2003

SUMMARYThe aim of this study was to evaluate the effects of the immunomodulating drug mycophenolic acid (MPA) on splenocytes in an animal model of systemic lupus erythematosus (SLE), using MRLlpr/lpr mice. MPA reversibly inhibits inosine 5′-monophosphate dehydrogenase, an enzyme involved in the de novo guanosine synthesis. Splenocytes were treated with MPA (at 1 or 10 µm), and stimulated with either lipopolysaccharide (LPS; 10 µg/ml) or concanavalin A (ConA; 1.25 µg/ml). In blocking experiments, guanosine (100 µm) was added to the cultures to inhibit the effects of MPA. Lymphocyte proliferation, enumeration of immunoglobulin producing cells (using ELISPOT) and quantification of anti-double-stranded (ds) DNA antibodies, IFN-γ and IL-10 (by ELISA) in supernatants were performed. In addition, cell viability was evaluated using propidium iodide and flow cytometry. We found that MPA-treated splenocytes had dramatically decreased mitogen-induced proliferation and number of immunoglobulin producing cells, down-regulated production of IFN-γ, IL-10 and IgM anti-dsDNA antibodies. The viability of MPA-treated cells was also decreased. All of the effect modulated by MPA could be neutralized by the addition of guanosine. We conclude that MPA has potent immunomodulating effects on both B and T lymphocytes, modulating not only proliferation, but also the production of cytokines, immunoglobulins and autoantibodies.
Different proteolytic mechanisms involved in FcγRIIIb shedding from human neutrophils
Authors: Middelhoven P J , Van Buul J D , Hordijk P L , Roos D 
Published: March 2003

SummaryThe Fcγ receptor type IIIb (CD16) is highly expressed on human neutrophils and is found in a soluble form in plasma and in other body fluids. Upon activation of neutrophils in vitro, FcγRIIIb is shed from the cell surface by proteolytic cleavage. We have now investigated the effect of metalloproteinase inhibitors and a serine proteinase inhibitor on the shedding of FcγRIIIb induced by phorbol 12-myristate 13-acetate (PMA) or cytochalasin B (cyto B) + N-formyl-methionyl-leucyl-phenylalanine (fMLP). Metalloproteinase inhibitors blocked to a large extent PMA-induced, but not cyto B + fMLP-induced shedding of FcγRIIIb. Inhibition of members of the ADAM (a disintegrin and metalloproteinase) family appeared most efficient. In contrast, the serine protease inhibitor N-methoxysuccinyl-alanine-alanine-proline-valine-chloromethylketone (MeOsuc-AAPV-CMK) largely blocked cyto B + fMLP-induced, but not PMA-induced shedding of FcγRIIIb. Metalloproteinase inhibitors in combination with the serine proteinase inhibitor resulted in full inhibition of FcγRIIIb shedding induced by either PMA or cyto B + fMLP. The shedding of FcγRIIIb that accompanied apoptosis was inhibited by 60% in the presence of inhibitors of metalloproteinases but was insensitive to inhibition of serine proteinases. These results show that distinct types of proteolytic enzyme are involved in the stimulus-induced shedding of FcγRIIIb from human neutrophils and suggest that these proteinases may become differentially activated under various physiological or pathological conditions.
Glioma-expressed antigen 2 (GLEA2): a novel protein that can elicit immune responses in glioblastoma patients and some controls
Authors: Fischer U , Struss A-K , Hemmer D , Pallasch C P , Steudel W-I , Meese E 
Published: March 2003

Summary
Glioma constitutes the most frequent brain tumour in man with glioblastoma as the most prevalent and malignant type. The average survival time of less than 16 months underlines the need for improvements in diagnosis and therapy. Here, we report the identification of a novel antigen termed glioma-expressed antigen 2 (GLEA2) causing a frequent immune response in glioma patients. Screening of 450 000 clones from a glioblastoma lambda zap expression library with autologous patient serum revealed a group of five serum-positive clones sharing a high sequence homology. Further sequence analysis showed a sequence homology to a hepatocellular carcinoma associated antigen 58 (HCA58). We localized the novel HCA homologous gene termed glioma-expressed antigen 2 (GLEA2) on chromosome 20 by somatic cell hybrid panel mapping. Using allogenic sera from 39 glioblastoma patients, we found an immune response against GLEA2 in 17 patients (43%). In addition, screening with allogenic sera from other glioma patients revealed GLEA2 directed antibodies in two out of five pilocytic astrocytomas and in one out of two astrocytomas. Unrelated tumour sera revealed no immune response and sera from healthy persons showed an immune response in two out of 14 cases (14%). Northern blot hybridization and RT-PCR showed ubiquitous GLEA2 gene expression in glioma and normal tissues. The novel HCA homologous gene, GLEA2, appears to induce a frequent immune response in glioma. In the light of the lack of useful glioma markers, it appears reasonable to consider GLEA2 as a potential future diagnostic marker.
MHC class I chain-like gene A (MICA) and its associations with inflammatory bowel disease and peripheral arthropathy
Authors: Orchard T R , Dhar A , Simmons J D , Vaughan R , Welsh K I , Jewell D P 
Published: March 2003

Summary
MHC class I chain gene A (MICA) is a non-classical Class I gene which is expressed on the surface of epithelia without β2-microglobulin. The gene is found in the major histocompatibility complex (MHC) in tight linkage disequilibrium with human leucocyte antigen-B (HLA-B). Its precise function is unknown, but it interacts with γδ T cells of the intestinal immune system. This region of the MHC has been implicated in inflammatory bowel disease (IBD) pathogenesis by recent association mapping studies and this study was performed to examine the prevalence of MICA gene polymorphisms in IBD, in particular in type 2 peripheral arthropathy (PeA), which also has a strong HLA–B association. An assessment of the prevalence of MICA polymorphisms in IBD was made. Blood from 50 ulcerative colitis (UC) and 50 Crohn's disease controls was taken and MICA status determined using allele-specific PCR for 16 known alleles of MICA. A further 91 UC patients were recruited to confirm the results of this stage, and then the polymorphisms were studied in 52 type 1 and 45 type 2 PeA patients. The MICA status of these groups was compared with 118 blood and organ donor controls with appropriate correction for multiple comparisons. UC overall was associated with possession of MICA*007 in 32% compared to 11% of controls (Pc = 0·017). This association was confirmed in a second cohort of 91 patients (23% versus 11%, P= 0·02). These were independent of HLA class I status. Type 2 IBD PeA was associated with MICA*008 in 98% compared to 73% of controls (P = 0·0001). MICA*007 is associated with susceptibility to UC in our population and MICA*008 with type 2 IBD PeA. Further work is now required to assess the distribution and expression of MICA throughout the gut in health and disease.
T cell cytokines determine the severity of experimental IgA nephropathy by regulating IgA glycosylation
Authors: Chintalacharuvu S R , Nagy N U , Sigmund N , Nedrud J G , Amm M E L , Emancipator S N 
Published: March 2003

SummaryHyperfunction of Th2 cells and aberrant glycosylation of IgA have been proposed independently as factors in the pathogenesis of IgA nephropathy (IgAN), the most common form of glomerulonephritis. To investigate the relationship between Th2 cytokines and IgA glycosylation in the genesis of IgAN, we induced IgAN in C3HeB and BALB/c mice by oral immunization and intranasal challenge with Sendai virus. Although both strains of mice developed microhaematuria and glomerular IgA immune deposits to similar degrees, only BALB/c mice developed significant renal insufficiency. More profound reductions of terminal galactosylation and sialylation occurred in Sendai virus-specific IgA from BALB/c versus C3HeB mice, and splenocytes from immunized BALB/c mice produced more Th2 and less Th1 cytokines compared to C3HeB mice when stimulated with antigen in vitro. Furthermore, the decreased glycosylation of IgA elicited by Th2 cytokines in vitro was blunted by the addition of IFN-γ. We conclude that increased production of Th2 cytokines can lead to abnormalities in IgA glycosylation, which in turn promote heightened phlogistic responses to IgA immune complexes lodging in the glomerulus. We suggest that a relative or absolute increase in Th2 cytokine production in response to mucosal infection is a significant pathogenic factor in human IgAN.
B7-1 and B7-2 co-stimulatory molecules are required for mercury-induced autoimmunity
Authors: Bagenstose L M , Class R , Salgame P , Monestier M 
Published: March 2003

SummaryB7-1 (CD80) and B7-2 (CD86) molecules on antigen presenting cells play important roles in providing co-stimulatory signals required for activation and expansion of autoreactive T cells. Moreover, some reports have suggested that these molecules may have distinct functions in the differentiation of Th1 and Th2 cells. Mercury-induced autoimmunity in H-2s mice is characterized by lymphoproliferation of T and B cells, serum increases in IgG1 and IgE and production of antinucleolar antibodies (ANoA). The mechanisms responsible for the various manifestations of this syndrome have yet to be elucidated. To examine the contributions of B7 co-stimulatory molecules to this model, susceptible mice were treated with antibodies to B7-1, B7-2, or both during the development of mercury-induced autoimmunity. The combination of anti-B7-1 and anti-B7-2 antibodies prevented Hg-induced disease in H-2s mice. Additionally, single anti-B7-1 antibody treatment was sufficient to prevent Hg-induced ANoA production, but not IgG1 and IgE hypergammaglobulinaemia. Further, single antibody treatment with anti-B7-2 resulted in a partial reduction of ANoA titres but had no significant effect on total serum IgG1 and IgE levels. Taken together, these results indicate that B7-1 and B7-2 molecules are critical for the development of Hg-induced autoimmunity and suggest that the different manifestations of the syndrome are regulated by independent mechanisms.
Extra-articular cartilage affected in collagen-induced, but not pristane-induced, arthritis models
Authors: Hansson A-S , Lu S , Holmdahl R 
Published: March 2003

SummaryRheumatoid arthritis (RA) is a chronic inflammatory disease primarily affecting cartilaginous joints but also extra-articular tissues such as the nose and upper respiratory tract. We have investigated extra-articular cartilage involvement in two commonly used animal models for RA, collagen-induced and pristane-induced arthritis, by immunizing rats with different susceptibility to disease (LEW.1 A, LEW.1F and DA rats). We found that nasal and tracheolaryngeal cartilage is affected in LEW.1 A and DA rats to varying degrees in collagen-induced arthritis but not in any strain in the pristane-induced model. Antibodies to matrilin-1, a cartilage-specific protein expressed mainly in tracheolaryngeal and nasal cartilage but not in joints, were positively associated with the presence of inflammation in nasal cartilage. In contrast, no antibody response to matrilin-1 could be detected in pristane-induced arthritis. In addition, nasal vaccination with collagen type II prior to immunization in DA rats significantly decreased the antibody response to matrilin-1 at day 56, but not at earlier time points, indicating a late protective effect on extra-articular cartilage. We conclude that pristane-induced arthritis is a joint-specific model whereas collagen-induced arthritis affect joints as well as extra-articular cartilage. Furthermore, collagen immunization induces an antibody response to matrilin-1.
Placentally derived prostaglandin E2 acts via the EP4 receptor to inhibit IL-2-dependent proliferation of CTLL-2 T cells
Authors: KVIRKVELIA N , VOJNOVIC I , WARNER T D , ATHIE-MORALES V , FREE P , RAYMENT N , CHAIN B M , RADEMACHER T W , LUND T , ROITT I M , DELVES P J 
Published: March 2003

SummaryA number of immunomodulatory molecules are present in the placenta, including cytokines, prostaglandins, progesterone and indoleamine 2,3-dioxygenase. An undefined factor capable of down-regulating T-cell activity has recently been reported [1] as being produced by short-term cultures of placental fragments. By careful repetition of these studies we have confirmed that chorionic villi isolated from term placenta produce a low molecular weight, heat stable factor capable of inhibiting the IL-2-dependent proliferation of mouse CTLL-2 cells. This activity was not due, however, to a previously unknown immunosuppressive molecule, but rather to prostaglandin E2 (PGE2). Expression of cyclooxygenase (COX)-2 was detected in the syncytiotrophoblast of chorionic villi explants using immunohistochemistry. Culture of the explants in the presence of the COX-1/COX–2 inhibitors indomethacin and diclofenac, or with the COX-2-selective inhibitor DFP, blocked the production of the immunosuppressive factor. The immunosuppressive activity was restored by adding PGE2 to the supernatants obtained from diclofenac-inhibited explants. A number of different receptors are involved in mediating the biological effects of prostaglandins. By utilizing selective antagonists of individual receptors, we have established that the immunosuppressive effect of PGE2 on CTLL-2 cells is exerted via the EP4 receptor. Thus, addition of an EP4-selective antagonist, but not of EP1 or EP3 antagonists, abolished the immunosuppressive effect of PGE2 on CTLL-2 cells. This may have implications for attempts to selectively manipulate T-cell responses.
Thein vivoeffects of tumour necrosis factor blockade on the early cell mediated immune events and syndrome expression in rat adjuvant arthritis
Authors: BUSH K A , KIRKHAM B W , WALKER J S 
Published: March 2003

SUMMARYAnti-TNF therapy is effective in rheumatoid arthritis (RA); however, its mechanisms of action are incompletely understood. T cell-driven mechanisms are thought to play an important role in RA and the effects of TNF blockade on these mechanisms are unclear. Adjuvant arthritis (AA) is a T cell dependent model of inflammatory arthritis. The aims of this study were to investigate the effects of TNF blockade on in vivo T cell cytokine expression and to clarify the role of TNF in the inguinal lymph nodes (ILN) in early arthritis. AA was induced in male DA rats. Rats received either 3 mg/kg or 10 mg/kg PEG sTNF-RI at days 0, 2 and 4 postinduction or 10 mg/kg anti-TNF antibody on day of arthritis induction. Control rats received either saline or normal sheep serum. Paw volume was assessed every 3–4 days. Rats were sacrificed on days 0, 6, 13 and 21 postinduction. Ankles were removed for quantitative radiology and histology. Synovium and ILN were removed for cell culture and to determine mRNA expression of cytokines using semiquantitative RT-PCR. TNF and IFN-γ protein production was measured using a bioassay and an ELISA. TNF blockade did not suppress mRNA expression of T cell cytokines in the ILN of rats in the early phase of AA, suggesting ongoing T cell activity. TNF protein production by ILN cells in culture was reduced in PEG sTNF-RI treated rats, although mRNA expression was increased in the ILN prior to culture. Early administration of PEG sTNF-RI did not attenuate AA, in contrast to an anti-TNF antibody, which suppressed disease. A shorter half-life for the PEG sTNF-RI compared with the anti-TNF antibody or the development of anti-PEG sTNF-RI antibodies may account for these results.
Age-dependent preference in human antibody responses toStreptococcus pneumoniaepolypeptide antigens
Authors: LIFSHITZ S , DAGAN R , SHANI-SEKLER M , GROSSMAN N , FLEMINGER G , FRIGER M , NEBENZAHL Y MIZRACHI 
Published: March 2003

SummaryVulnerability to Streptococcus pneumoniae is most pronounced in children. The microbial virulence factors and the features of the host immune response contributing to this phenomenon are not completely understood. In the current study, the humoral immune response to separated Strep. pneumoniae surface proteins and the ability to interfere with Strep. pneumoniae adhesion to cultured epithelial cells were analysed in adults and in children. Sera collected from healthy adults recognized Strep. pneumoniae separated lectin and nonlectin surface proteins in Western blot analysis and inhibited on average 80% of Strep. pneumoniae adhesion to epithelial cells in a concentration-dependent manner. However, sera longitudinally collected from healthy children attending day care centres from 18 months of age and over the course of the following 2 years revealed: (a) development of antibodies to previously unrecognized Strep. pneumoniae surface proteins with age; (b) a quantitative increase in antibody responses, measured by densitometry, towards separated Strep. pneumoniae surface proteins with age; and (c) inhibition of Strep. pneumoniae adhesion to epithelial cells, which was 50% on average at 18 months of age, increased significantly to an average level of 80% inhibition at 42 months of age equalling adult sera inhibitory values. The results obtained in the current study, from the longitudinally collected sera from healthy children with documented repeated Strep. pneumoniae colonization, show that repeated exposures are insufficient to elicit an immune response to Strep. pneumoniae proteins at 18 months of age. This inability to recognize Strep. pneumoniae surface proteins may stem from the inefficiency of T-cell-dependent B-cell responses at this age and/or from the low immunogenicity of the proteins.
CD40 on salivary gland epithelial cells: high constitutive expression by cultured cells from Sjögren’s syndrome patients indicating their intrinsic activation
Authors: DIMITRIOU I D , KAPSOGEORGOU E K , MOUTSOPOULOS H M , MANOUSSAKIS M N 
Published: March 2003

SummaryCD40 has been identified in an expanding list of haematopoietic and non-haematopoietic cells and has received an increased interest based on its role in a variety of cell-mediated responses and its potential to participate in the pathogenesis of chronic inflammatory disorders. Sjögren’s syndrome (SS) is an autoimmune exocrinopathy, which is characterized by chronic lymphocytic infiltration of exocrine glands and aberrant activation of epithelial tissues. We studied the expression of CD40 protein in cultured non-neoplastic salivary gland epithelial cell (SGEC) lines as well as in minor SG biopsies obtained from 17 SS patients and 12 controls. Immunocytochemical and flow cytometric analyses had revealed the occurrence of constitutively expressed CD40 molecules on the surface of long-term cultured SGEC lines, which could be further induced by interferon-gamma (IFN-γ) and IL-1β cytokines, but not tumour necrosis factor-alpha (TNF-α), IL-4, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF) or IFN-α. Triggering of SGEC through CD40 enhanced the surface expression of the adhesion molecule intercellular adhesion molecule-1 (ICAM-1)/CD54, but not MHC class I and class II (HLA-DR) molecules. Spontaneous CD40 expression was significantly higher in SGEC lines derived from SS patients, compared with controls (P &lt; 0·001), which is suggestive of their intrinsically activated status. In SG biopsies, CD40 was constitutively expressed by lymphocytes, ductal epithelial cells and endothelial cells but not by other glandular cell types, such as acinar cells, myoepithelial cells and fibroblasts. In addition, CD40L staining was also detected in 30–50% of the infiltrating lymphocytes in the biopsies of SS patients. Our findings indicate the immunoregulatory potential of SGEC and lend further support to a model of intrinsic activation in salivary epithelia in SS, whereby these cells actively participate in the induction and maintenance of lymphocytic infiltrates of patients.
Intravenous immunoglobulin (IVIG) preparations induce apoptosis in TNF-α-stimulated endothelial cells via a mitochondria-dependent pathway
Authors: NAKATANI K , TAKESHITA S , TSUJIMOTO H , SEKINE I 
Published: March 2003

SUMMARYEndothelial cells (ECs) are a target in inflammation, and the death of EC is regulated by various factors. Although intravenous immunoglobulin (IVIG) preparations are known to be beneficial therapeutic agents for the treatment of autoimmune diseases and systemic inflammatory disorders, their mechanism of action have not yet been completely elucidated. The aim of the present study is to investigate the possible role of IVIG in EC apoptosis. We demonstrate herein that IVIG induced the apoptosis of human umbilical vein ECs (HUVECs) prestimulated by TNF-αin vitro, but not in unstimulated HUVECs, in a dose- and time-dependent manner, using a proportion of cells with hypodiploid DNA, DNA ladder formation and morphological changes. Anti-Fas MoAbs had no effect on the IVIG-induced apoptosis in the TNF-α-stimulated HUVECs. IVIG decreased the intracellular expression of anti-apoptotic proteins of the Bcl-2 family (A1 and Bcl-XL) while IVIG increased the intracellular expression of pro-apoptotic proteins (Bax and Bcl-XS) in the TNF-α-stimulated HUVECs. Furthermore, IVIG increased the intracellular production of reactive oxygen species and decreased the mitochondrial membrane potential (Δψm). Caspase-inhibitors inhibited the IVIG-induced apoptosis of the TNF-α-stimulated HUVECs. The present results show a novel action in which IVIG can induce the apoptosis of TNF-α-stimulated HUVECs through a mitochondrial apoptotic signalling pathway. These observations suggest that the clinical use of IVIG preparations may thereby regulate the cell death of activated ECs in inflammation.
Inflammatory cytokines in small intestinal mucosa of patients with potential coeliac disease
Authors: WESTERHOLM-ORMIO M , GARIOCH J , KETOLA I , SAVILAHTI E 
Published: March 2003

SUMMARY
T helper cell type 1 (Th1) response to gluten has been implicated in the pathogenesis of coeliac disease (CD). To characterize immunological activation and mild inflammations leading to overt CD in potential coeliac patients, jejunal biopsies were obtained from family members of patients with CD or dermatitis herpetiformis (DH). Nine family members and one latent CD, eight CD patients and eight normal controls furnished jejunal biopsy specimens. Immunohistochemical staining of sections for interleukin-1α (IL-1α), IL-2, IL-4, interferon-γ (IFN-γ), tumour necrosis factor α (TNF-α), CD3, γδ-T cell receptor (γδ-TCR), and αβ-TCR was carried out with monoclonal antibodies. Further, expression of IL-4 and IFN-γ messenger RNA was detected by radioactive in situ hybridization in these same samples. In lamina propria, CD patients and potential CD patients had higher densities of IL-2 (P = 0·028, P = 0·043), IL-4 (P = 0·021, P = 0·034) and IFN-γ positive cells (P = 0·000, P = 0·009) than did controls. Moreover, CD patients showed a higher density of TNF-α positive cells (P = 0·012, P = 0·001) than the other two groups, and expression of IFN-γ mRNA (P = 0·035) was higher in them than in the other two study groups. Additionally, higher densities of TNF-α and IFN-γ positive cells occurred in potential CD patients with high γδ-TCR+ intraepithelial lymphocytes (IELs). Our findings support the hypothesis that lamina propria T cells and macrophages, through their secretion of cytokines, play a central role in the pathogenesis of coeliac disease. The inflammatory cytokines found in potential CD specimens strongly suggest that these inflammatory markers can be identified long before visible villous changes have occurred.