bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enhancement of Th2 pathways and direct activation of B cells by the gingipains ofPorphyromonas gingivalis
Authors: YUN L W P , DECARLO A A , COLLYER C , HUNTER N 
Published: October 2003

SUMMARYPorphyromonas gingivalis cysteine proteinases (gingipains) have been associated with virulence in destructive periodontitis, a disease process that has been linked with Th2 pathways. Critical in maintaining Th2 activity is the response of B lymphocytes to environmental interleukin (IL)-4, a cytokine that also counteracts Th1-cell differentiation. Here we demonstrate that while the gingipains effectively degrade interleukin (IL)-4 under serum-free conditions, limited hydrolysis was observed in the presence of serum even after prolonged incubation. Gingipains up-regulated CD69 expression directly in purified peripheral blood B cell preparations. Further, the induction of IL-4 receptor expression on B cells by gingipains correlates with B cell activation, which is also manifested by a mitogenic response. These results suggest that the gingipains of P. gingivalis act during the early stage of B-cell growth as a competence signal, whereby sensitized B cells might become more responsive to further challenge in the disease-susceptible individual.
Contrasting activity of cytosin–guanosin dinucleotide oligonucleotides in mice with experimental colitis
Authors: OBERMEIER F , DUNGER N , STRAUCH U G , GRUNWALD N , HERFARTH H , SCHÖLMERICH J , FALK W 
Published: October 2003

SUMMARYIntestinal inflammation in inflammatory bowel disease (IBD) and experimental models of colitis is characterized by a dysregulated intestinal immune response with elevated levels of Th1 cytokines. The luminal flora has been implicated as a major factor contributing to the initiation and perpetuation of inflammation in experimental colitis by mechanisms not known. Bacterial DNA contains unmethylated cytosin–guanosin dinucleotides (CpG) which strongly activate Th1-mediated immune responses. To test whether these CpG-motifs modulate intestinal inflammation we treated mice with dextran sulphate sodium (DSS)-induced colitis with CpG-containing oligodeoxynucleotides (CpG-ODN). CpG-ODN given after the onset of DSS colitis aggravated the disease, as indicated by a significantly increased loss of body weight and a 30% increase of the histological score. Further, we found a severe increase of proinflammatory cytokines (interleukin (IL)-6: 40-fold; interferon (IFN)-γ : 11-fold). In a pretreatment setting CpG-ODN reduced weight loss significantly and reduced intestinal inflammation by 45%. Colonic IFN-γ and IL-6 mRNA levels were reduced by 75%, and IL-10 was elevated by 400% compared to controls. The prophylactic CpG-effect was not imitated by IL-12 because IL-12 pretreatment was not protective. In time-course experiments, CpG-ODN pretreatment over 5 days resulted in a tolerance effect concerning its IFN-γ-inducing quality, and during the following days of colitis induction IL-10 secretion from mesenterial lymph node cells was elevated compared to controls. Therefore, the prophylactic effect of CpG-ODN might be explained by its tolerizing effect and/or the increased ability for IL-10 production during the consecutive intestinal inflammation.
HLA-B27-restricted T cells from patients with ankylosing spondylitis recognize peptides from B*2705 that are similar to bacteria-derived peptides
Authors: Frauendorf E , Von Goessel H , May E , Märker-Hermann E 
Published: October 2003

SUMMARYAnkylosing spondylitis (AS) is an inflammatory systemic disease affecting the spine, sacroiliacal and peripheral joints. Although the aetiology of AS remains unknown, the strong association with the HLA-B27 allele might reflect directly a detrimental effect of the HLA-B27 molecule itself, resulting from its potential capability to present ‘arthritogenic’ peptides to CD8+ T cells. Because some forms of SpA are triggered by enterobacterial infection, such arthritogenic peptides might originate from autologous and/or bacterial proteins triggering cross-reactive CD8+ T cell clones. Intriguingly, two peptides from the second extracellular domain of HLA-B*2705 share sequence homologies with several enterobacterial antigens, exhibit the HLA-B27-binding-motif, and are presented by HLA-B*2705 itself. The objective of this study was to examine the clonal T cell reactivity against these peptides in patients with AS. To this end, we screened peripheral blood lymphocytes (PBL) of 26 patients with AS and 24 healthy donors for TNF-α-producing cells using ELISPOT assays. PBL and synovial fluid-derived lymphocytes (SFL) of peptide-responsive patients were then stimulated and cultured with the relevant peptide and control peptides in vitro. Antigen-specific T cell lines (TCL) were identified by standard chromium release assays. Clonal analysis was performed subsequently applying TCRB-CDR3 spectratyping. Among eight peptides tested, only the HLA-B27 168–176 peptide LRRYLENGK was recognized by PBL from B27+ AS patients but not from B27+ healthy controls (P = 0·001). LRRYLENGK-specific T cell clones used preferentially the TCRBV5S1 and the BV14 segment. These results suggest that an HLA-B27-derived peptide with homology to bacterial peptides may play a role in AS.
The immunosuppressive drug mycophenolate mofetil impairs the adhesion capacity of gastrointestinal tumour cells
Authors: LECKEL K , BEECKEN W-D , JONAS D , OPPERMANN E , COMAN M C , BECK K-F , CINATL J , HAILER N P , AUTH M K H , BECHSTEIN W O , SHIPKOVA M , BLAHETA R A 
Published: October 2003

SUMMARYImmunosuppression correlates with the development and recurrence of cancer. Mycophenolate mofetil (MMF) has been shown to reduce adhesion molecule expression and leucocyte recruitment into the donor organ. We have hypothesized that MMF might also prevent receptor-dependent tumour dissemination. Therefore, we have investigated the effects of MMF on tumour cell adhesion to human umbilical vein endothelial cells (HUVEC) and compared them with the effects on T cell–endothelial cell interactions. Influence of MMF on cellular adhesion to HUVEC was analysed using isolated CD4+ and CD8+ T cells, or WiDr colon adenocarcinoma cells as the model tumour. HUVEC receptors ICAM-1, VCAM-1, E-selectin and P-selectin were detected by flow cytometry, Western blot or Northern blot analysis. Binding activity of T cells or WiDr cells in the presence of MMF were measured using immobilized receptor globulin chimeras. MMF potently blocked both T cell and WiDr cell binding to endothelium by 80%. Surface expression of the endothelial cell receptors was reduced by MMF in a dose-dependent manner. E-selectin mRNA was concurrently reduced with a maximum effect at 1 µm. Interestingly, MMF acted differently on T cells and WiDr cells. Maximum efficacy of MMF was reached at 10 and 1 µm, respectively. Furthermore, MMF specifically suppressed T cell attachment to ICAM-1, VCAM-1 and P-selectin. In contrast, MMF prevented WiDr cell attachment to E-selectin. In conclusion, our data reveal distinct effects of MMF on both T cell adhesion and tumour cell adhesion to endothelial cells. This suggests that MMF not only interferes with the invasion of alloactivated T cells, but might also be of value in managing post-transplantation malignancy.
Circulating lymphocyte subsets linked to intracellular cytokine profiles in normal humans
Authors: MATSUI M , ARAYA S , WANG H-Y , ONAI N , MATSUSHIMA K , SAIDA T 
Published: October 2003

SUMMARYTo determine whether there is an association between intracellular cytokine profiles and the expression of surface antigens, we performed a simultaneous flow cytometric analysis of these laboratory parameters in 11 healthy volunteers. Peripheral blood lymphocytes were double-stained for CD4 or CD8, as well as CD11a, CD25, CD26, CD29 and CD45RA or the chemokine receptors CCR3, CCR4, CCR5 or CXCR3. Portions of the cell samples were cultured for 4 h in the presence of 1 µm monensin and 20 µg/ml brefeldin A with or without stimulation by phorbol myristate acetate plus ionomycin for the detection of intracellular interferon-γ (IFN-γ), interleukin-2 (IL-2), tumour necrosis factor (TNF)-α, and IL-4. As a result, CD4+CD29high helper inducer T cells were closely associated with IFN-γ and TNF-α producing CD4+ cells, while CD4+CXCR3+ cells showed a negative correlation with IL-4-producing cells, suggesting that both of these CD4+ subsets consist mainly of Th1 cells. In contrast, CD4+CD45RA+ cells were correlated inversely with IFN-γ and TNF-α-producing cells, and CD8+CD11ahigh killer effector and total CCR5+ cells showed an inverse correlation with IL-2 producing cells, suggesting an immunoregulatory role for these three subsets in non-pathological conditions. Therefore, monitoring of lymphocyte subsets that express functional surface antigens could provide additional information concerning immune deviation, as assessed by the production of Th1/Th2 type cytokines. Further, this type of combined study may provide clues for the pathogenesis of immune-mediated disorders.
Effects of streptozotocin on autoimmune diabetes in NOD mice
Authors: KOULMANDA M , QIPO A , AUCHINCLOSS H , SMITH R N 
Published: October 2003

SUMMARYNon-obese diabetic (NOD) mice develop autoimmunity that destroys their native beta cells causing diabetes. Their autoimmunity will also destroy syngeneic transplanted islets and transfer both autoimmunity and diabetes via spleen cells to non-diabetic mice. In this report, we studied the effects of streptozotocin (STZ) on the autoimmune diabetes in NOD mice. We transplanted NOD.SCID islets into three groups of NOD mice: (1) spontaneously diabetic NOD mice (NOD-sp.); (2) prediabetic NOD mice made diabetic by streptozotocin (NOD-stz); and (3) diabetic NOD mice also treated with streptozotocin (NOD-sp./stz). In the first group, the transplants were rejected within 3 weeks. In the second and third groups, the transplants survived indefinitely. Alloxan, a drug similar to streptozotocin, did not have the same effect as streptozotocin. The ability of streptozotocin to prevent diabetes in young NOD mice was reversed by anti-CD8 antibody treatment but not by anti-CD4 treatment. Streptozotocin also made spleen cells from diabetic NOD mice less effective transferring diabetes. These results indicate that streptozotocin treatment both prevents and reverses the islet destructive autoimmunity in NOD mice. We postulate that the effects of streptozotocin treatment may be mediated in part by regulatory T cells.
Role of IFN-α/βand IL-12 in the activation of natural killer cells and interferon-γproduction during experimental infection withTrypanosoma cruzi
Authors: UNE C , ANDERSSON J , ÖRN A 
Published: October 2003

SUMMARYControl of Trypanosoma cruzi infection depends largely upon the production of interferon (IFN)-γ. During experimental infection this cytokine is produced early, mainly by natural killer (NK) cells and later by T cells. As NK cells have been reported to participate in defence against T. cruzi, it is of importance to study the regulation of NK cell functions during infection with the parasite. Several innate cytokines regulate NK cell activity, among them being interferon (IFN)-α and IFN-β (type 1 IFNs) and interleukin (IL)-12, which have all been reported to be involved in protection against T. cruzi. The role of these cytokines in regulation of NK cell functions and disease outcome were studied by infection of mutant mice lacking the IFN-α/β receptor (IFNα/βR–/–) or IL-12 (IL-12–/–) with T. cruzi. IFNα/βR–/– mice were unable to activate the cytotoxic response but produced IFN-γ, and were not more susceptible than controls. IL-12–/– mice were extremely susceptible and failed to produce T cell-derived IFN-γ and nitric oxide (NO), although NK cytotoxicity was induced. The results indicate that IL-12 protects against T. cruzi by initiating T cell-mediated production of IFN-γ, but that endogenous IFN-α/β and NK cell cytotoxicity are not of major importance in defence.
Increased serum transforming growth factor-β1 in human colorectal cancer correlates with reduced circulating dendritic cells and increased colonic Langerhans cell infiltration
Authors: HUANG A , GILMOUR J W , IMAMI N , AMJADI P , HENDERSON D C , ALLEN-MERSH T G 
Published: October 2003

SUMMARYCancer-related cytokines may interfere with the differentiation and migration of dendritic cells (DCs) and with the associated up-regulation of co-stimulatory molecules in vitro. We determined whether cytokines affected the distribution and activation of DCs in patients with colorectal cancer by measuring the levels of serum cytokines [transforming growth factor (TGF)-β1 and vascular endothelial growth factor (VEGF)], DC numbers and phenotype from peripheral blood and mesenteric lymph nodes draining the cancer, and the infiltration of DCs into colorectal cancer. A significant increase in the serum level of TGF-β1 correlated with a significant reduction in the level of circulating DCs in cancer patients that was associated with an increased infiltration of Langerhans cells into colorectal mucosa. The prevalence but not intensity of co-stimulatory molecule expression in circulating and mesenteric lymph node DCs was reduced in patients with colorectal cancer compared to patients with inflammatory bowel conditions. There was no correlation between co-stimulatory molecule expression and serum TGF-β1. Thus the circulating DC depletion in colorectal cancer could be explained by a TGF-β1-related DC redistribution from the circulation into the colorectal cancer and adjacent mucosa where DC levels were increased. There was an impairment of DC activation within colorectal cancer that was not related to serum level of cytokines.
Avidity progression of dietary antibodies in healthy and coeliac children
Authors: SAALMAN R , DAHLGREN U I , FÄLLSTRÖM S P , HANSON L Å , AHLSTEDT S , WOLD A E 
Published: October 2003

SUMMARYIn most individuals minute amounts of food proteins pass undegraded across the intestinal mucosa and trigger antibody formation. Children with coeliac disease have enhanced antibody production against gliadin as well as other dietary antigens, e.g. β-lactoglobulin, in cow's milk. Antibody avidity, i.e. the binding strength between antibody and antigen, often increases during antibody responses and may be related to the biological effectiveness of antibodies. The aim of the present study was to determine the avidity of serum IgG antibodies against β-lactoglobulin and gliadin in healthy children during early childhood and compare these avidities to those found in children with coeliac disease. The average antibody avidity was analysed using a thiocyanate elution assay, whereas the antibody activity of the corresponding sera was assayed by ELISA. The avidity of serum IgG antibodies against β-lactoglobulin as well as gliadin increased with age in healthy children, even in the face of falling antibody titres to the same antigens. Children with untreated coeliac disease had IgG anti-β-lactoglobulin antibodies of significantly higher avidity than healthy children of the same age, and the same trend was observed for IgG antigliadin antibodies. The present data suggest that the avidities of antibodies against dietary antigens increase progressively during early childhood, and that this process seems to be accelerated during active coeliac disease.
Transendothelial migration confers a survival advantage to activated T lymphocytes: role of LFA-1/ICAM-1 interactions
Authors: BORTHWICK N J , AKBAR A A , BUCKLEY C , PILLING D , SALMON M , JEWELL A P , YONG K L 
Published: October 2003

SUMMARYThe clearance of activated T lymphocytes by apoptosis is an essential component in the resolution of the immune response; however, certain signals received within inflamed tissue may result in the persistence of activated T cells. Our previous work has shown that, when compared with resting cells, effector cells migrate more efficiently across endothelium, thus such cells may be selectively recruited to sites of inflammation. We hypothesized that transmigration of T cells across endothelium might influence cell survival. We have generated T cell lines by culturing in IL-2 following PHA activation. These T cell lines die rapidly by apoptosis when deprived of IL-2 (53·7 ± 4·0% survival after 24 h). In contrast, cells that have migrated across human umbilical vein endothelial cells (HUVEC) survived significantly better than control cells (80·3 ± 3·6%, n= 18, P &lt; 0·001). Endothelial cell conditioned medium was also able to reduce apoptosis, but this effect was small when compared with the protective effect of transmigration. Culture of T lymphocytes on fibronectin, or RGD peptides, or in suspension with a range of chemokines active on T cells, including RANTES and lymphotactin had no effect on survival. In contrast, blocking LFA-l/ICAM-l interactions reduced the protective effect of transmigration (42·3 ± 6·7% reduction). Culture of activated T cells on immobilized ICAM-l alone also increased survival. These results indicate that signals received by activated T cells during extravasation can influence their subsequent survival within tissue, and implicates the involvement of LF A-l/ICAM-l interactions.
Immune response measured in human volunteers vaccinated with autoclavedLeishmania majorvaccine mixed with low dose of BCG
Authors: MAHMOODI M , KHAMESIPOUR A , DOWLATI Y , RAFATI S , MOMENI A Z , EMAMJOMEH M , HEJAZI H , MODABBER F 
Published: October 2003

SUMMARYThe immune responses induced against Leishmania antigens in volunteers who were vaccinated in a double-blind, randomized field efficacy trial of a preparation of autoclaved Leishmania major (ALM) mixed with a low dose of Bacille Calmette–Guerin vaccine (BCG) who developed either a cutaneous leishmaniasis (CL) lesion due to exposure to infected sandfly bite(s) or did not develop a lesion during the course of the trial were studied and compared with those of non-vaccinated controls. Blood samples were also assayed from different groups including volunteers with history of CL and volunteers with previous positive or negative leishmanin skin test (LST) without a history of CL. The vaccinated volunteers had received a single dose of either ALM mixed with a low dose of BCG or the same dose of BCG alone. The LST and in vitro proliferative response (stimulation index, SI), interferon gamma (IFN-γ) production and, in a few cases, interleukin (IL)-4 production of peripheral blood mononuclear cells to soluble Leishmania antigens were measured. The results indicated that volunteers who developed CL in the vaccine arm showed a slightly higher SI than cases who received BCG alone. Volunteers with history of CL and volunteers with positive LST demonstrated the strongest proliferation indices and IFN-γ production. The data suggest that a single dose of ALM + BCG induces a weak Th1 response in vaccinated volunteers that is far lower than that in volunteers with prior subclinical infection or volunteers with history of CL, who are presumed to be immune.
The bi-specific CD3 × NCAM antibody: a model to preactivate T cells prior to tumour cell lysis
Authors: JENSEN M , ERNESTUS K , KEMSHEAD J , KLEHR M , VON BERGWELT-BAILDON M S , SCHINKÖTHE T , SCHULTZE J L , BERTHOLD F 
Published: October 2003

SUMMARYTo target the neural cell adhesion molecule (NCAM, CD56) on neuroblastoma by T cell-based immunotherapy we have generated a bi-specific CD3 × NCAM antibody (OE-1). This antibody can be used to redirect T cells to NCAM+ cells. Expectedly, the antibody binds specifically to NCAM+ neuroblastoma cells and CD3+ T cells. OE-1 induces T cell activation, expansion and effector function in peripheral blood mononuclear cell (PBMC)-derived CD4+ and CD8+ T cells. T cell activation was shown to depend on the presence of normal natural killer (NK) cells in the culture. Interestingly, while PBMC- derived T cells were activated by OE-1, NK cells were almost completely depleted, suggesting that T cells activated by OE-1 deleted the NK cells. Activated CD4+ and CD8+ T cells differentiate into a larger CCR7+ central memory and a smaller CCR7– effector memory cell population. Most importantly, preactivated T cells were highly cytotoxic for neuroblastoma cells. In eight of 11 experiments tumour-directed cytotoxicity was enhanced when NK cells were present during preactivation with OE-1. These data strongly support a bi-phasic therapeutic concept of primarily stimulating T cells with the bi-specific antibody in the presence of normal NCAM+ cells to induce T cell activation, migratory capacity and finally tumour cell lysis.
Effects of deviating the Th2-response in murine mercury-induced autoimmunity towards a Th1-response
Authors: HÄGGQVIST B , HULTMAN P 
Published: October 2003

SUMMARYT-helper cells type 1 (Th1) and type 2 (Th2) play an important role in the pathogenesis of autoimmune diseases. In many Th1-dependent autoimmune models, treatment with recombinant interleukin-12 (rIL-12) accelerates the autoimmune response. Mercury-induced autoimmunity (HgIA) in mice is an H-2 regulated condition with antinucleolar antibodies targeting fibrillarin (ANoA), systemic immune-complex (IC) deposits and transient polyclonal B-cell activation (PBA). HgIA has many characteristics of a Th2 type of reaction, including a strong increase of IgE, but disease induction is critically dependent on the Th1 cytokine IFN-γ. The aim of this study was to investigate if a strong deviation of the immune response in HgIA towards Th1 would aggravate HgIA. Injections of both rIL-12 and anti-IL-4 monoclonal antibody (α-IL-4) reduced the HgCl2-(Hg-)induced concentration of the Th2-dependent serum IgE and IgG1, but increased the Th1-dependent serum IgG2a. The IgG-ANoA developed earlier and attained a higher titre after combined treatment, and the ANoA titre of the IgG1 isotype decreased while the ANoA titre of the Th1-associated IgG2a, IgG2b and IgG3-ANoA isotypes increased. Treatment with rIL-12 alone increased the Hg-induced IgG2a and IgG3 ANoA titres, the PBA, and the IC deposits in renal and splenic vessel walls, while treatment with α-IL-4 + Hg inhibited renal but not splenic vessel wall IC deposits. We conclude that manipulating the cytokine status, by altering the Th1/Th2 balance, will influence autoimmune disease manifestations. This might be an important way of modulating human autoimmune diseases.
The effects of fruit juices on drug disposition: a new model for drug interactions
Authors: Dresser G. K. , Bailey D. G. 
Published: October 2003

AbstractGrapefruit juice produces mechanism‐based inhibition of intestinal drug metabolism when consumed in normal quantities. This can produce clinically important increases in oral drug bioavailability when coadministered with substrates of cytochrome P450 3A4 (CYP3A4) that undergo high presystemic metabolism. Furanocoumarins such as bergamottin and 6′,7′‐dihydroxybergamottin have been identified as probable active constituents. Grapefruit juice may also inhibit intestinal P‐glycoprotein‐mediated efflux transport of drugs such as cyclosporine to increase its oral bioavailability. However, grapefruit juice does not enhance the absorption of digoxin, a prototypical P‐glycoprotein substrate, likely because it has high inherent oral bioavailability. Grapefruit and other fruit juices have recently been shown to be potent in vitro inhibitors of a number of organic anion‐transporting polypeptides (OATPs). These juices were also found to decrease the absorption of the nonmetabolized OATP substrate, fexofenadine. Taken together, the data support inhibition of intestinal uptake transporters by fruit juices to decrease drug bioavailability. This would represent a new mechanism for food–drug interactions. These findings with grapefruit and other fruit juices continue to enhance our understanding of the complex nature of food–drug interactions, and their possible influence on the clinical effects of medications.