bluuebunny/crossref_metadata_2025 huggingface dataset:
Receptors for Innate Pathogen Defence in Insects are Normal Activation Receptors for Specific Immune Responses in Mammals
Authors: Möller
Published: March 2003

The Toll genes code for activation receptors for innate microbial defence in insects and have recently been found to code for the Lps receptor in murine B lymphocytes. In this study, I will present evidence to show that this family of receptors are responsible for induction of specific thymus‐independent immune responses in mice. T cells do not possess these pattern‐recognizing receptors, but they possess structures capable of delivering activation signals to these receptors on B cells.
Cytokine mRNA Expression in Leprosy: a Possible Role for Interferon‐γ and Interleukin‐12 in Reactions (RR and ENL)
Authors: Moraes  , Sarno  , Almeida  , Saraiva  , Nery  , Martins  , Sampaio
Published: March 2003

Leprosy patients during the natural course of the disease may develop reactional episodes, namely reversal reaction (RR) and erythema nodosum leprosum (ENL). Immunological events described as occurring during RR indicate up‐regulation of the immune response, whereas in ENL the events are not fully understood. The aim of this study was to analyse the in vivo pattern of cytokine gene expression in the reactional states of leprosy. Peripheral blood mononuclear cells (PBMC, n = 14) and tissue samples (n = 17) obtained from patients with ENL and RR were obtained and assayed by RT‐PCR. PBMC obtained from unreactional patients (n = 15) and normal individuals (n = 5) were also assessed. Expression of interferon (IFN)γ, granulocyte‐macrophage colony stimulating factor (GM‐CSF), interleukin (IL)‐2Rp55, perforin and IL‐1β mRNA in PBMC were detected mostly in ENL/RR patients, but not in unreactional patients. Likewise, cytokines such as IL‐6, IL‐8, tumour necrosis factor (TNF)α and TNFβ were also present in reactional and tuberculoid patients as opposed to lepromatous leprosy (BL/LL). Interestingly, the majority of ENL/RR patients showed messages for IL‐6, IL‐10, IL‐12 and TNFα in the skin. IFNγ was detected in 84.6% (ENL) and 100% (RR) of the patients, whereas IL‐4 was detected only in few individuals (38.5 and 25%, respectively). Although mRNA expression and protein levels may be different, the data reported in this study suggest a cytokine mRNA profile that seems to be indistinguishable for RR and ENL. In addition, it shows up‐regulation of immuno‐inflammatory cytokines in the blood and tissue of the same patient examined before and during reaction. Furthermore, it is suggested that this pattern of response results from an immunological reactivation that might lead to an acute inflammatory response in both reactional episodes.
Dysregulated Production of Interferon‐γ, Interleukin‐4 and Interleukin‐6 in Early Tuberculosis Patients in Response to Antigen 85B of Mycobacterium tuberculosis
Authors: Jo  , Kim  , Lim  , Min  , Song  , Song  , Paik  , Suhr  , Park
Published: March 2003

Both interferon‐γ (IFN‐γ) and interleukin (IL)‐4 expression in T cells and IL‐6 expression in cells of the monocyte/macrophage lineage were monitored using antigen 85B (Ag85B) protein and purified protein derivative (PPD) antigen in the early stages of tuberculosis (TB). We showed that the levels of cell‐associated IFN‐γ and IL‐4 (mRNA and intracellular cytokine) in Ag85B‐stimulated T cells were significantly depressed in TB patients compared with those in healthy tuberculin reactors. On the other hand, the capacity of peripheral blood mononuclear cells (PBMC) to produce IL‐6 spontaneously ex vivo was enhanced in patients (P < 0.001), but their corresponding capacities to respond to Ag85B were not significantly different from those of normal donors. After 2 months of antituberculosis therapy, the mean blastogenic responses of Ag85B‐stimulated PBMC from seven TB patients were increased 6.1‐fold (P = 0.011). Furthermore, the proportions of both IFN‐γ‐ (P < 0.01) and IL‐4‐ (P = 0.05) producing T cells were significantly increased. However, those of IL‐6‐producing cells were diminished in response to Ag85B (P = 0.05). Our results suggest that there may be an altered regulation of IFN‐γ, IL‐4 and IL‐6 to Ag85B in the early stages of TB.
Augmented Expression of Daintain/Allograft Inflammatory Factor‐1 is Associated with Clinical Disease: Dynamics of Daintain/Allograft Inflammatory Factor‐1 Expression in Spleen, Peripheral Nerves and Sera during Experimental Autoimmune Neuritis
Authors: Pashenkov  , Efendic  , Zhu  , Zou  , Östenson  , Mustafa
Published: March 2003

Experimental autoimmune neuritis (EAN) is an animal model of Guillain–Barré syndrome, characterized by inflammation and demyelination of the peripheral nervous system (PNS). Daintain/allograft inflammatory factor‐1 (daintain/AIF‐1) is a novel interferon‐γ–inducible protein expressed by macrophages during organ specific autoimmune diseases. To study the involvement of daintain/AIF‐1 in EAN we induced EAN in Lewis rats by immunizing with bovine PNS myelin (BPM) and complete Freund's adjuvant (CFA). The expression of daintain/AIF‐1 was examined in the spleen, peripheral nerves and sera during the course of EAN by immunohistochemistry and radioimunoassay (RIA). The expression of daintain/AIF‐1 in the spleen and in the sciatic nerves peaked at the preclinical stage (day 7 post immunization (p.i.)) and at the height (day 15 p.i.) of clinical EAN, consistent with a disease promoting role for daintain/AIF‐1. Daintain/AIF‐1 expressing cells represented a subset of ED1+ or CD11b/c+ mononuclear cells. A significant increase of daintain/AIF‐1–like immunoreactivity in sera occurred at the preclinical stage of EAN. Taken together, these data indicate that daintain/AIF‐1 may play a proinflammatory role in the pathogenesis of EAN.
Heat‐Aggregated Immunoglobulins Increase In Vivo Immunogenicity of Mouse Hapten (TNP)‐Derivatized Macrophages by Upregulation of Interleukin‐12 Secretion and Expression of B7–1 and B7–2 Costimulatory Molecules
Authors: Ptak  , Bryniarski  , Nowak  , Szczepanik  , Ptak
Published: March 2003

Antigen‐antibody complexes (IC) can up or down regulate immune responses by induction of immunoregulatory cells. We have studied the effect of mouse heat‐aggregated immunoglobulin (Ig) (HA) which have many biological activities similar to IC on immunogenicity of TNP‐substituted macrophages (TNP‐Mφ). Our results show that: (1) mouse oil‐induced peritoneal macrophages treated with HA produce in vitro significantly higher levels of interleukin (IL‐1β), tumor necrosis factor (TNF)‐α, IL‐6, IL‐10 and particularly IL‐12 and express more B7–1 and B7–2 and ICAM‐1 cell surface costimulatory molecules than Mφ treated with monomeric Ig (MM); (2) Mφ derivatized with TNP, treated or not with MM, induce in vivo antigen‐specific unresponsiveness. In contrast TNP‐Mφ treated with HA induce significant contact sensitivity reaction even when injected into previously tolerized recipient animals. Treatment of recipients with anti‐IL‐12 Ab prevents immunization by TNP‐Mφ‐HA. These results indicate that bypass of tolerance by treatment of TNP‐Mφ with HA is a result of an increased production of IL‐12 by these cells and an enhanced expression of costimulatory molecules important in T cell–Mφ interactions. We suggest that a similar overcoming of tolerance through the action of IC may be responsible for the generation of autoantibodies of heterologous specificity in pathological conditions in which such complexes are formed.
Multiepitope Vaccines Intensively Increased Levels of Antibodies Recognizing Three Neutralizing Epitopes on Human Immunodeficiency Virus‐1 Envelope Protein
Authors: Lu  , Xiao  , Ding  , Dierich  , Chen
Published: March 2003

A few neutralizing antibodies against human immunodeficiency virus‐1 (HIV‐1) envelope proteins have been shown to be highly effective at neutralizing different strains in vitro, and exist at very low levels in the sera of HIV‐1‐infected individuals. Based on our hypothesis that epitope vaccination may be a novel strategy for inducing high levels of antibodies against HIV‐1, we prepared multiepitope vaccines using three neutralizing epitopes (GPGRAFY, ELDKWA and RILAVERYLKD) on HIV‐1 envelope proteins. The PI [C‐G‐(ELDKWA‐GPGRAFY)2‐K] and PII (CG‐GPGRAFY‐G‐ELDKWA‐G‐RILAVERYLKD) peptides were synthesized and conjugated to a carrier protein, bovine serum albumin (BSA). After vaccination, both the PI‐BSA and PII‐BSA multiepitope vaccines induced high levels of epitope‐specific antibodies to the three neutralizing epitopes (antibody titre: 1 : 12,800–102,400). The recombinant glycoprotein 160 (rgp160) subunit vaccine induced strong antibody responses to rgp160, but only very weak epitope‐specific antibody responses to the three epitopes. The epitope‐specific antibodies were isolated from rabbit sera by single epitope–peptide‐conjugated sepharose columns. A yield of 51 μg of epitope‐specific antibodies/ml of serum (mean value) was obtained and identified to recognize these epitopes, while 0.35 μg of protein was isolated from 1 ml of pooled preserum by C‐(ELDKWAG)4– or C‐(RILAVERYLKD‐G)2‐K– and C‐(GPGRAFY)4–sepharose columns. The levels of these epitope‐specific antibodies induced in rabbits were much greater than 1 μg/ml, a level that is considered to confer long‐term protection against some viruses. Moreover, these antibodies recognized the neutralizing epitopes on peptides and rgp41. Based on the fact that a very low level of ELDKWA epitope‐specific antibodies exist in HIV‐1‐infected individuals, these results suggesting that synthetic epitope vaccines could induce high levels of multiepitope‐specific neutralizing antibodies indicate a new strategy for developing an effective neutralizing antibody‐based epitope/peptide vaccine against HIV‐1.
Modulation of Neutrophil Influx with Cell Adhesion Molecule Specific Antibodies during Nonspecific and Immune Mediated Inflammatory Reactions
Authors: Gonçalves  , Appelberg
Published: March 2003

Neutrophils are essential for the host defence against infection. However, neutrophils may also mediate damage namely during immune mediated pathologies. We therefore tested whether targeting of different cell adhesion molecules with specific monoclonal antibodies might reduce immune mediated neutrophil recruitment but spare the nonspecific accumulation of neutrophils that is essential for the resistance against acute infections. Neutrophil recruitment was induced by either intraperitoneal injection of casein as a nonspecific phlogistic agent or by i.p. injection of antigen in Mycobacterium bovis Bacille Caimette‐Guérin (BCG) immune mice. Similar degrees of inhibition of neutrophil accumulation were observed in both models of inflammation with antibodies directed at CD11a, ICAM‐1 and CD11b with the latter showing the most marked effects. Individual targeting of selectins was without effect in immune mediated responses whereas targeting of L or E selectin inhibited nonspecific recruitment of neutrophils. This was apparently not owing to a dosage effect nor to a kinetic difference. The inhibitory effect of anti‐CD11b antibodies was most likely as a result of activation of circulating neutrophils rather than the blocking of receptor–ligand interactions. We were therefore unable to selectively abrogate immune mediated neutrophil recruitment with the use of the antibodies selected in this study.
Co‐Induction of Mad1 and c‐Myc in Activated Normal B Lymphocytes
Authors: Ertesvåg  , Blomhoff  , Beiske  , Naderi
Published: March 2003

The purpose of the present study was to examine the expression of the Myc network proteins c‐Myc, Mad1 and Max in normal cells under different growth and differentiation conditions. A dominant view has been that Mad1 as a c‐Myc antagonist plays a role in growth inhibition linked to differentiation. Of particular interest to us was therefore to study the regulation of Mad1 in cells undergoing differentiation in the absence of growth cessation. To do so we utilized normal B lymphocytes isolated from peripheral blood. The cells were induced to concomitant proliferation and differentiation by stimulation with a combination of anti‐IgM antibodies (anti‐μ) and the phorbol ester TPA. Thus, by 72 h of stimulation the percentage of plasmablasts increased from 3 to 17%, and the percentage of lymphocytes decreased from 89 to 27%. The most intriguing observation we made using this cell system was a pronounced coinduction of Mad1 and c‐Myc. The levels of c‐Myc and Mad1 mRNAs and proteins increased within 3 h of anti‐μ stimulation, and the levels were further enhanced by TPA. Furthermore, the expressions of both c‐Myc and Mad1 were reduced by forskolin, which also inhibited the anti‐μ + TPA driven growth and differentiation of the B lymphocytes. The level of Max remained virtually unchanged. Taken together, our results indicate that a high level of Mad1 in normal human B cells is linked to differentiation and not to growth inhibition. Furthermore, the results demonstrate that Mad1 and c‐Myc are not necessarily expressed in a reciprocal manner, which underlines an independent role of Mad1 unrelated to its function as a c‐Myc antagonist.
The Amino Acid Sequence of a Monoclonal γ3‐Heavy Chain from a Patient with Articular γ‐Heavy Chain Deposition Disease
Authors: Danevad  , Sletten  , Gaarder  , Mellbye  , Husby
Published: March 2003

Abnormal deposition of proteins, including monoclonal immunoglobulin γ‐heavy chains, may cause tissue damage and organ dysfunction. We here report the amino acid sequence of the free γ‐heavy chains present in serum and urine of the first reported case (patient G. L.) of synovial heavy chain deposition disease. The protein was heavily deleted and consisted of the hinge, in addition to the CH2 and CH3 domains, in a dimeric form, thus lacking its variable domain as well as the CH1 domain. The sequence was consistent with the γ3 subclass (γ3GL). Gm typing revealed the γ3 allotypes G3m(b0) and G3m(b1) in accordance with the residues Pro123, Phe128, Thr171 and Phe268 in γ3GL. Furthermore, the γ3GL molecule was glycosylated at Asn in position 129. Finally, the γ3GL protein was shown to contain a typical binding site for the first complement component, C1q, namely the residues Glu150, Lys152 and Lys154, with the potential of binding and activating complement, causing tissue damage following deposition.
Prevention of Autoimmune Type 1 Diabetes via Mucosal Tolerance: Is Mucosal Autoantigen Administration As Safe and Effective As It Should?
Authors: Hänninen
Published: March 2003

Mucosal immune response to an antigen leads to a state of attenuated systemic response to the same antigen, known as mucosal or oral tolerance. Thus, autoantigen administration via mucosal routes could be useful in the prevention of autoimmune diseases. Although in various models of autoimmune disease it is often effective, in some cases it is ineffective and in other cases even harmful. In these cases it is likely that, concomitantly with tolerance, a productive immune response is induced that exacerbates autoimmunity. Recent evidence suggests that induction of cytotoxic T lymphocytes capable of destroying pancreatic β cells may be an unavoidable consequence of mucosal administration of pancreatic β‐cell associated autoantigen. To improve the safety and efficacy of mucosal tolerance induction in the prevention of type 1 diabetes, further means to control the induction of cytotoxic T lymphocytes and other potentially tissue‐destructive immune effectors may be required.
IgG Subclass Profile of Serum Antigliadin Antibodies and Antibody‐Dependent Cell‐Mediated Cytotoxicity in Young Children with Coeliac Disease
Authors: Saalman R. , Dahlgren U. I. , Fällström S. P. , Hanson L. Å. , Ahlstedt S. , Wold A. E.
Published: March 2003

Recently, sera from children with active coeliac disease were found to efficiently induce antibody‐dependent cell‐mediated cytotoxicity (ADCC) of gliadin‐coated cells. In the present study, the subclass profile of immunoglobulin (Ig)G antigliadin antibodies in sera from young children, with or without coeliac disease, was determined and related to the ADCC‐mediating capacity of the same sera. In addition, IgG subclasses were selectively depleted from sera and the effect on ADCC‐mediating was studied. Children with untreated coeliac disease had high antigliadin antibody activities of all four IgG subclasses. However, they had a particularly high proportion of IgG1 antigliadin antibodies (ratio IgG1/IgG) compared with healthy references or coeliac children in remission. In contrast, children who had high serum antigliadin antibody activity but no histological signs of enteropathy (disease references), showed significantly lower proportions of antigliadin antibodies of the IgG1 as well as the IgG3 subclass compared with healthy references or untreated coeliac children. Regression analysis showed that IgG1 and IgG3 antigliadin antibody activity correlated positively to ADCC‐mediating capacity, and depletion of IgG1 from sera profoundly diminished ADCC. The results suggest that gliadin‐specific antibodies of predominantly the IgG1 subclass mediate tissue‐damaging immune reactions like ADCC, and may, thus, contribute to the disease process of coeliac disease.
Decreasing Ratios of Phosphocreatine to β‐ATP Correlates to Progressive Acute Rejection in a Concordant Mouse Heart to Rat Xenotransplantation Model
Authors: Lukes D. J. , Madhu B. , Kjellström C. , Gustavsson M. L. , Mjörnstedt L. , Olausson M. , Soussi B.
Published: March 2003

Biopsies are difficult to perform in rodent heart transplant models without compromising the graft function and therefore other means to evaluate the grafts repeatedly and noninvasively are warranted. The goal of the present study was to measure changes in ratios of high energy phosphorus containing metabolites detected within vivo31Phosphorous Magnetic Resonance Spectroscopy (31P MRS) in a xenotransplantation model and to investigate if these ratios correlated to histological signs of acute xenograft rejection. Thirty‐five heart transplantations were performed (NMRI‐mice to Lewis (RT11) rats). Thirteen heart transplants underwent repeated dailyin vivo31P MRS measurements and 22 grafts were measured on any of 4 postoperative days and thereafter sacrificed for histology. A modified scoring system based on Billingham's criteria was used to stage the rejection process. The median graft survival was 3.0 ± 0.44 (median ± SD) days (n = 17). Significant differences, both overall and interday, could be calculated for the phosphocreatine (PCr)/β‐adenosine triphosphate (β‐ATP) ratios and for the rejection score. The decreases in PCr/β‐ATP ratios correlated significantly to the progressive acute rejection process in the sacrificed grafts (P = 0.01). Further studies are indicated to establish the potential of31P MRS in immunosuppressed recipients of vascularized xenotransplants with prolonged graft survival.
T‐Cell Enforced Invariance of the Antibody Repertoire in the Immune Response Against a Bacterial Carbohydrate Antigen
Authors: Rademaekers A. , Specht C. , Kölsch E.
Published: March 2003

The humoral response against the bacterial polysaccharide antigen α(1→3) dextran (Dex) is controlled by J558 idiotype‐(Id) specific T cells. These T cells of which the cell clone 178–4 Ts is a representative by all relevant criteria, recognize J558 Id‐bearing B cells in an I‐Ed‐restricted manner. Costimulation via CD28/B7‐1 but not via CD40/CD40L leads to T‐cell activation. These T cells do not only suppress B cells producing the immunoglobulin (Ig)G3 isotype but also support the survival and clonal expansion of J558 Id positive B cells both in vivo and in vitro. This T‐cell mediated dominance of the J558 idiotype limits the appearance of antibodies carrying other more diverse idiotypes which appear in immunized BALB/c nu/nu mice where no regulatory T cells occur. This T‐cell mediated antibody invariance could be a strategy of the immune system responding to highly conserved antigens like polysaccharides, different from those against protein antigens, where diversity is assumed to be the basis for a successful response.
Cytokine Expression in Unstimulated PBMC of Children with Type 1 Diabetes and Subjects Positive for Diabetes‐Associated Autoantibodies
Authors: Halminen M. , Simell O. , Knip M. , Ilonen J.
Published: March 2003

The aim of this study was to evaluate possible changes in the circulating levels of interferon (IFN)‐γ, interleukin (IL)‐4 and transforming growth factor (TGF)‐β in association with the autoimmune process leading to type 1 diabetes. Expression levels of mRNAs specific for each cytokine were determined in peripheral blood mononuclear cells (PBMC) by a multiplex reverse transcription–polymerase chain reaction (RT–PCR) followed by hybridization reactions with lanthanide‐labelled probes and detection by time‐resolved fluorometry. Newly diagnosed diabetic children had lower levels of IFN‐γ, IL‐4 and TGF‐β1 signals compared to their age‐ and sex‐matched controls (P < 0.02, P < 0.005 and P < 0.005, respectively) and also the autoantibody‐positive subjects had significantly lower levels of IL‐4 and TGF‐β1 in comparison with their matched controls (P = 0.0013 and P = 0.012). No significant differences were observed when comparing matched pairs of diabetic children and autoantibody‐positive subjects. Our results suggest a systemic bias towards reduced production of T‐helper cell type 2 cytokines (IL‐4 and TGF‐β1) during the autoimmune process, but there was also a reduced level of IFN‐γ expression in the periphery at the onset of clinical diabetes.
Presence of IL‐4‐Like Molecules in Larval Excretory‐Secretory Products and Crude Extracts from Anisakis simplex
Authors: Cuéllar C. , Jesús Perteguer M. , Rodero M.
Published: March 2003

Acute symptoms of anisakidosis are caused by a type I allergic reaction in the gastrointestinal wall with elevated specific immunoglobulin (Ig)E. The purpose of this study was to investigate the presence of interleukin (IL)‐4 in the larval antigens of Anisakis simplex. We detected concentrations of IL‐4 in pg/ml when larval excretory–secretory products and crude extract from A. simplex were investigated by ELISA. Specific antibodies were obtained by immunization of rabbits with mouse IL‐4 and tested in ELISA against A. simplex antigens obtaining higher values of optical density, that were confirmed by western blot analysis. The absorption of these sera with A. simplex antigen resulted in a 70–80% inhibition of antigen binding when retested in ELISA. We demonstrated that A. simplex antigens react with antibodies raised against vertebrate IL‐4. The results obtained by us support the hypothesis that A. simplex shares several epitopes with IL‐4, important for the Th2 response development in human anisakiasis, where the parasite may modulate the Th1–Th2 dichotomy for its own benefit by mucosal inflammation control in an attempt to avoid the larval expelling.
Characterization of the Human FLICE‐Inhibitory Protein Locus and Comparison of the Anti‐Apoptotic Activity of Four Different FLIP Isoforms
Authors: Djerbi M. , Darreh‐Shori T. , Zhivotovsky B. , Grandien A.
Published: March 2003

Death receptor‐mediated apoptosis is involved in the regulation of immune responses and in the maintenance of immunological tolerance. FLICE‐inhibitory proteins (FLIPs) are important modulators of death receptor‐mediated apoptosis. To date, the FLIP family encompasses multiple members, of which some are reported to be antiapoptotic and others pro‐apoptotic. This led us to investigate the activity of several FLIP proteins in vitro. Concomitant with the cloning of various FLIP isoforms, a new and unexpected member of the FLIP family, denoted FLIPR, was isolated from the human Burkitt lymphoma B‐cell line Raji. During the characterization of FLIPR, the genomic sequence of human FLIP was found in the NCBI GenBank. This enabled us to present the complete exon‐intron constellation of the human FLIP gene and the generation of all known human FLIP isoforms by alternative splicing. We show that the human FLIP gene with a size of approximately 48 kb, consists of at least 14 exons and can give rise to 11 distinct isoforms by alternative splicing. When studying the activity of some of these isoforms, including FLIPR, they all efficiently inhibited Fas‐mediated apoptosis in A20 B lymphoma cells by impeding caspase‐8, ‐3 and ‐7 activity as well as poly(ADP‐ribose) polymerase (PARP) cleavage.
Use of Liposomes as an Immunopotentiating Delivery System: in Perspective of Vaccine Development
Authors: Owais M. , Masood A. K. , Agrewala J. N. , Bisht D. , Gupta C. M.
Published: March 2003

Liposomes have been widely used to deliver antigens to the antigen‐presenting cells (APCs) and also to modify their immunological behaviour in model animals. We recently demonstrated the potential of yeast lipid liposomes to undergo membrane–membrane fusion with cytoplasmic membrane of the target cells. Interestingly, studies in the present report revealed that antigen encapsulated in yeast lipid liposomes could be successfully delivered simultaneously into the cytosolic as well as endosomal processing pathways of APCs, leading to the generation of both CD4+ T helper and CD8+ cytotoxic T cells. In contrast, encapsulation of same antigen in egg phosphatidyl‐choline (PC) liposomes, just like its free form, has inefficient access to the cytosolic pathway of major histocompatibility complex (MHC) I dependent antigen presentation and failed to generate antigen specific CD8+ cytotoxic T‐cell response. However, both egg PC as well as yeast lipid liposomes have elicited strong antigen specific antibody responses in immunized animals. These results imply usage of liposome encapsulated antigen as potential candidate vaccine capable of eliciting both cell mediated as well as humoral immune responses.
Development of Anti‐dsDNA Autoantibodies Prior to Clinical Diagnosis of Systemic Lupus Erythematosus
Authors: Arbuckle M. R. , James J. A. , Kohlhase K. F. , Rubertone M. V. , Dennis G. J. , Harley J. B.
Published: March 2003

Anti‐double stranded (dsDNA) antibodies are of considerable diagnostic value and are thought to be involved in the pathogenesis of systemic lupus erythematosus (SLE). Fluctuations in anti‐dsDNA antibody levels are also used as markers for disease activity and exacerbations. In this study we sought to evaluate the anti‐dsDNA antibody level in serum samples collected before the onset of SLE diagnosis. A total of 130 SLE patients were identified with stored serum samples available prior to diagnosis within the US Department of Defense serum repository. All 633 sera available from these patients were screened for anti‐dsDNA antibodies using an enzyme linked immunosorbant assay (ELISA). Within this cohort 55% of cases had detectable anti‐dsDNA antibodies prior to SLE diagnosis. The onset of anti‐dsDNA antibodies ranged from 9.3 years before to within the same month as diagnosis (with a mean onset 2.7 years before diagnosis). In order to assess for fluctuations in anti‐dsDNA levels relative to diagnosis, cases were selected with at least two positive samples, one within 6 months and a second greater than 6 months prior to diagnosis (n = 26). Seven of these cases also had samples available shortly after diagnosis (≤ 6 months) for comparison. Fifty‐eight percent of the 26 cases developed a significant rise in anti‐dsDNA antibody levels within 6 months of diagnosis. A significant decline in anti‐dsDNA levels ensued after diagnosis (and following treatment with corticosteroids) in all seven cases with samples available. Patients with a significant rise in anti‐dsDNA antibodies at diagnosis were more likely to have renal disease than those who did not (66.7% compared to 27.3%, χ2=3.94, P<0.05). These data suggest that anti‐dsDNA antibodies are present in SLE patient sera much earlier than previously suspected. In addition, the data are consistent with increases in anti‐dsDNA levels contributing to the onset of clinical illness in some patients with SLE.
Binding of the Galanthus nivalis Agglutinin to Thymocytes Reveals Alterations in Surface Glycosylation during T‐Cell Development
Authors: Šinkora J. , Kolínská J. , Řeháková Z. , Černý J. , Doubravská L.
Published: March 2003

Surface binding of the Galanthus nivalis agglutinin (GNA) to thymocyte subsets has been studied in pigs and rodents by multicolour flow cytometry. In all the species examined, analogous staining profiles have been recorded. Counter‐staining with anti‐CD3ε, anti‐CD4 and anti‐CD8 monoclonal antibodies (MoAb) revealed that a significant increase of the GNA targets on the cell surface occurred during early thymocyte differentiation and reached its maximum at the level of the CD3loCD4+CD8+ small cortical thymocyte. This was followed by a decrease in the GNA binding capacity upon terminal maturation to the single positive thymocytes. PAGE analysis has revealed a dominant GNA‐binding glycoprotein (molar mass approx. 90 kDa) present on thymocyte plasma membranes and absent on the surface of splenic lymphocytes, although both the whole cell lysates from both organs contained GNA ligands of the same size. Our findings are in agreement with previous data showing that immature thymocytes differ from their mature counterparts and peripheral T lymphocytes in the surface glycosylation pattern, and support the hypothesis that lectin–glycoprotein interaction plays a significant role in the cell‐to‐cell crosstalk in the thymic cortex.
Chloroquine Enhances the Number of IL‐10 Producing Cells and the Expression of B7‐2 and ICAM‐1 in In Vitro‐Cultured PBMC
Authors: Hugosson E. , Björkman A. , Troye‐Blomberg M.
Published: March 2003

Chloroquine is prescribed as both an anti‐malarial and an anti‐inflammatory drug. However, its immuno‐modulating effects remain largely unclear. Previous studies have shown that chloroquine inhibits antigen‐induced proliferation, implying immuno‐suppressive effects. In this study, we examined whether the inhibition of the proliferation reflects changes in the surface molecules that are important for T‐cell activation and whether chloroquine affects the balance between pro‐ and anti‐inflammatory cytokines. Chloroquine elevated the expression of the costimulatory and adhesion molecules B7‐2 (CD86) and ICAM‐1 (CD54) in peripheral mononuclear cells (PBMC). An increased percentage of CD14+ cells was also observed, and within this cell population, an increase in ICAM‐1 expression was revealed by double‐staining experiments. Assessment of the frequencies of interleukin (IL)‐10 and interferon (IFN)‐γ‐producing cells in in vitro‐cultivated PBMCs showed that the ratio between pro‐ and anti‐inflammatory cytokines changed after exposure to chloroquine, favouring anti‐inflammatory immune responses. This effect was mainly because of increased frequencies of IL‐10‐producing cells and was seen with or without the presence of stimulating antigens or mitogens. Our findings indicate that chloroquine affects the direction of the lymphocyte stimulation towards an anti‐inflammatory response by affecting the antigen‐presenting cells (APC) and the balance between pro‐ and anti‐inflammatory cytokines, rather than generally inhibiting cytokine production.
CD4+CD25+ T Lymphocytes in Human Tonsils Suppress the Proliferation of CD4+CD25– Tonsil Cells
Authors: Simark‐Mattsson C. , Dahlgren U. , Roos K.
Published: March 2003

Animal studies define CD4+CD25+ T cells as a subset that protect against autoimmune inflammation. We wanted to investigate whether CD4+CD25+ T cells from patients with recurrent tonsillitis could suppress the proliferation of other tonsil cells, in vitro, as this immunological tissue also may serve as a model for chronic inflammation. Tonsil CD4+CD25+ cells markedly suppressed the proliferation of CD4+CD25– T cells in Concanavalin A‐stimulated cocultures compared with cultures containing CD4+CD25– T cells only. The suppression exerted by the CD4+CD25+ cells was abrogated if these cells were irradiated before coculture or if interleukin (IL)‐2 was added to the culture medium. CD4+CD25+ T cells proliferated poorly in response to mitogen, when cultured alone. Substitution with CD4+CD25+ T cells isolated from peripheral blood, enriched by similar methods, did not downregulate the proliferation of CD4+CD25– responder cells from tonsils. The augmented suppressive ability of tonsil CD4+CD25+ T cells compared with cells of this phenotype from blood, on CD4+CD25– responder cells from tonsils, suggests that there may be a functional difference between CD25+ cells from the two locations. In conclusion, CD4+CD25+ T cells from inflamed tonsils distinctly suppressed T‐cell responses to mitogen in vitro, pointing to a regulatory role for CD4+CD25+ cells retrieved from inflammatory reactions in humans.
Expression of the EP4 Prostaglandin E2 Receptor Subtype with Rat Dextran Sodium Sulphate Colitis: Colitis Suppression by a Selective Agonist, ONO‐AE1‐329
Authors: Nitta M. , Hirata I. , Toshina K. , Murano M. , Maemura K. , Hamamoto N. , Sasaki S. , Yamauchi H. , Katsu K.
Published: March 2003

Expression of the EP4 receptor, a prostaglandin (PG)E2 receptor subtype, as well as disease suppression by the administration of a selective EP4 agonist (ONO‐AE1‐329) was investigated in the colorectal mucosa of rats with dextran sodium sulphate (DSS)‐induced colitis. Rats were given drinking water containing 3% DSS for 2 weeks. Expression of EP4 receptor mRNA was barely detectable under normal conditions according to reverse transcription‐polymerase chain reaction (RT‐PCR). By 1 week after the initial administration of DSS, the receptor mRNA was strongly expressed. After ONO‐AE1‐329 was administered intracolonically to rats with DSS colitis for 7 consecutive days, erosion and ulceration decreased. Peripheral white blood cell (WBC) counts became less elevated. Interleukin (IL)‐1β and growth‐regulated gene product/cytokine‐induced neutrophil chemoattractant (GRO/CINC‐1) concentrations in colorectal mucosa were lower than in colitis control group (IL‐1β: 12.8 ± 4.6 and 30.8 ± 6.2 µg/mg protein, P < 0.05; GRO/CINC‐1: 15.5 ± 3.0 and 39.2 ± 5.4 µg/mg protein, P < 0.05), and the expression of the corresponding cytokine mRNA was strongly suppressed. IL‐10 concentration was higher than in control group (14.5 ± 1.7 and 7.9 ± 1.2 µg/mg, P < 0.05), and the mRNA was more strongly expressed. These results suggest that the EP4 receptor is important in colonic inflammation, and that PGE2 suppresses DSS colitis at least partly via the EP4 receptor and the above cytokine changes. Intracolonic administration of selective EP4 agonist might have therapeutic applicability in inflammatory bowel disease such as ulcerative colitis.
Restricted Specificity of Intermolecular Spreading to Endogenous La (SS‐B) and 60 kDa Ro (SS‐A) in Experimental Autoimmunity
Authors: GORDON T. P. , KINOSHITA G. , CAVILL D. , KEECH C. , FARRIS A. D. , KAUFMAN K. , McCLUSKEY J. , PURCELL A. W.
Published: March 2003

Intermolecular spreading of humoral autoimmunity to different components of the Ro (SS‐A) and La (SS‐B) ribonucleoprotein (RNP) complex has been reported following immunization with a single component of the complex. Although the immune response to the immunizing antigen is polyclonal and diversified, little is known about the specificity of the recruited autoimmune responses to the endogenous Ro and La antigens which drive B‐cell spreading. To determine the specificity of intermolecular spreading to La, we examined sera from 52 kDa Ro (Ro52)‐ and 60 kDa Ro (Ro60)‐immunized C3H/HeJ mice for reactivity with recombinant fragments spanning endogenous mouse (m)La by enzyme‐linked immunosorbent assay (ELISA) and immunoblotting. Sera from mice primed and boosted with recombinant Ro52 and Ro60 showed reactivity restricted to the COOH‐terminal fragment of mLa (aa361–415). The recruited anti‐La response was species‐specific, cross‐reacting weakly with the corresponding region on the human La molecule, and was abrogated by the preabsorption of the Ro‐immune sera with mLa 361–415. Analogous experiments using recombinant mRo60 fragments spanning the mRo60 molecule revealed a similar pattern of oligoclonality in the specificity of anti‐Ro60 autoimmunity following active immunization with La and Ro52. These results suggest that intermolecular–intrastructural T–B help is limiting in this model, and reveal unsuspected immunodominance of selected Ro–La epitopes in the spreading of the autoantibody response to these structures. The focusing of the recruited autoantibody response to these COOH‐terminal regions of the Ro and La polypeptides may also reflect the surface accessibility of these regions in La–Ro RNP.
Treatment of an Immortalized APC Cell Line with Both Cytokines and LPS Ensures Effective T‐Cell Activation In Vitro
Authors: Jørgensen T. N. , Haase C. , Michelsen B. K.
Published: March 2003

Antigen‐presenting cells (APCs) are crucial for the generation of a functional immune response to pathogens. Furthermore, there is abundant evidence for their importance in primary T‐cell activation, B‐cell maturation and maintenance of an ongoing immune response. In the present study, we have analysed phenotypic characteristics and functionality of a p53‐deficient APC cell line (JawsII) derived from mouse bone marrow culture. We show that unstimulated JawsII cells express low surface levels of major histocompatibility complex (MHC) and costimulatory molecules, both of which can be upregulated upon treatment with cytokines in vitro. Cytokine stimulation also leads to an enhanced T‐cell activation capacity but has only little effect on cytokine release by the JawsII cells themselves. On the contrary, stimulation of the JawsII cells with lipopolysaccharide (LPS) leads to the production and secretion of high amounts of interleukin‐1 (IL‐1), IL‐6 and tumour necrosis factor‐α (TNF‐α) but no increase in the surface levels of MHC and costimulatory molecules, and has only little effect on the T‐cell activation capacity. Our data suggest that the effects observed upon treatment with cytokines or LPSs are complementary, and that both stimuli are needed for mediating a strong and efficient JawsII cell‐dependent T‐cell activation.
Facies architecture and sedimentology of a meandering fluvial system: a Palaeogene example from the Weisselster Basin, Germany
Authors: Halfar Jochen , Riegel Walter , Walther Harald
Published: March 2003

The Schleenhain open pit coal mine, located 30 km south of Leipzig, Germany, exposes Upper Eocene and Oligocene non‐marine strata representing fluvial deposition in the centre of the Weisselster Basin. Active mining and successive cuts provided the rare opportunity to obtain a three‐dimensional perspective of laterally extensive surface outcrops. These were used to construct a detailed fence diagram, which provided the basis for recognition of key architectural elements in the weakly consolidated meandering stream deposits. In addition to the eight basic architectural elements of Miall (1985), the element SL (shallow lake deposits) was newly defined and the element CH (channel) was subdivided into CHg (palaeo‐river system) and CHk (small channel). The profiles contain parts of two fining‐upward cycles, which are separated by an unconformity spanning the Early Oligocene. Deposits of the first cycle begin with transverse sand bars (downstream accretion deposits‐DA) and point bars (lateral accretion deposits‐LA). The upper part of the cycle is represented by overbank fines (OF) and the element SL, which consists of laterally discontinuous lenses of dark, plant‐bearing, kaolinite‐rich clays, that were deposited in shallow lakes adjacent to the active channel. Coal seams interlayered with palaeosols are the main constituents of element OF. Sheetlike bodies of medium to fine gravels (gravel bars and bedforms‐GB) on an erosive coal surface mark the beginning of the second cycle. Dissolution of underlying Permian salts and sulphates prior to, during, and after the deposition of the Palaeogene strata caused the development of two synclines within the outcrop. Coal seams and clay horizons which thicken and dip towards the centre of the synclines, provide evidence for their chronological development.
Firmgrounds – key surfaces in the recognition of parasequences in the Aptian Lower Greensand Group, Isle of Wight (southern England)
Authors: Ruffell Alastair , Wach Grant
Published: March 2003

Aptian Lower Greensand Group exposures in the cliffs of the Isle of Wight (southern England) display a consistent coarsening‐up cyclicity on the scale of centimetres to tens of metres that reflects the bed, bed‐set, parasequence, parasequence set and sequence hierarchy. These coarsening‐up cycles are most commonly recognized at the scale of parasequences (20 cm to 10 m thick), genetically related groups of which form parasequence sets. Both parasequences and parasequence sets contain the succession of biofacies that culminate in firmground development. Numerous episodes of erosion, deposition and colonization are recorded, reflecting multiple erosion/bypass events. The increase in mean grain‐size through each cycle is reflected by changes in physical sedimentary structures; ichnofauna or bioturbational fabric; fossil fauna and diagenesis. Interbedded mudstones, siltstones and sandstones in the lower beds of each cycle display a variety of structures ranging from low‐angle, hummocky, or tabular cross‐strata, sandstone‐filled erosional gutters and planar lamination. The cleaner sandstones found in the upper parts to each cycle are often completely bioturbated with only rare stratification and pebble/plant debris‐filled scours preserved. Bioturbational fabrics change upward through each cycle from small, subhorizontal, mud‐ or sandstone‐filled burrows to large, branching, clay‐filled or cemented burrow systems. The top surface of each cycle is marked by a fossil epifauna indicative of firm to hard substrate conditions. Concentrations of bivalves, brachiopods, bryozoa, crinoids and corals are preferentially cemented by iron oxide, carbonate or phosphate. Such cements were early and thus utilized by firm or hard substrate dwellers. This fossiliferous, cemented sandstone is overlain by a flooding surface marked by the mudstone and silt‐rich sandstones at the base of the next cycle. Together, the fauna and ichnofauna in each cycle represent the gradual development of firm substrate conditions, culminating in the diverse firmground fauna preserved at the top of each cycle. The fauna and changing substrate conditions reflect the hiatuses developed during successive episodes of marine flooding. High species diversity is matched by complex patterns of taphonomic feedback in the mature firmground faunas that mark major flooding surfaces. Increasing faunal maturity allows recognition of a hierarchy of hiatuses. This hierarchy is analogous to the parasequence–parasequence set division. The stratigraphic condensation of firmgrounds can be used to empirically define the condensed section, the thickness of sediment between firmgrounds being a function of sediment supply and water depth (accommodation space).
Micro‐environmental controls on biomineralization: superficial processes of apatite and calcite precipitation in Quaternary soils, Roussillon, France
Authors: Schmittner Karl‐Erich , Giresse Pierre
Published: March 2003

Calcium hydroxyapatite and calcite precipitates around bacteria were observed in 2‐week‐old alluvial topsoil (Roussillon area, SE France). This observation prompted a laboratory study of Ca2+ and PO43− incorporation into hydroxyapatite and Ca2+ into calcite mediated by bacteria using similar topsoil material, but free from apatite and calcite. Subsamples were prepared using three different grain sizes, and experiments were undertaken using sucrose and different contents of Ca2+ and PO43−. Mineralization experiments proceeded over 5 days. Calcium and PO43− sorption onto clay influenced the Ca/P ratio in the solutions. Hydroxyapatite and calcite precipitation only occurred in unsterilized samples. The presence of clay minerals promoted biomineralization.
Levee morphology and sedimentology along the lower Tuross River, south‐eastern Australia
Authors: Ferguson Rob J. , Brierley Gary J.
Published: March 2003

Levees on the lower Tuross River in south‐eastern Australia reflect a complex interplay between depositional and erosional processes. Stream power, conditioned primarily by valley width, is the key determinant of levee morphology and sedimentology in this confined valley setting. Three styles of levee are described. The Rewlee levee is functionally linked to a flood channel in narrow valley settings (< 250 m). These levees contain a diverse facies assemblage characterized by various scales of erosion surfaces. Vertical accretion on levees has produced conditions under which stream power values exceed the threshold for catastrophic floodplain stripping. The levee at the Mortfield site is associated with less confined settings (valley width 500–600 m), which present lower flood stage and stream power conditions. This levee hosts a wide range of facies, but erosion surfaces are seldom observed. In the more open valley setting at the Central site (valley width 700–1000 m), levees comprise uniform, fine‐grained deposits, which grade to pronounced distal floodplains with backswamps. As levees reflect a combination of within‐channel and overbank processes, both depositional and erosional, these geomorphic features influence the character and sedimentology of adjacent landforms and the associated alluvial architecture of the basin.
Microbial signatures in peritidal siliciclastic sediments: a catalogue
Authors: Gerdes Gisela , Klenke Thomas , Noffke Nora
Published: March 2003

A catalogue of microbial structural signatures is presented, based upon the coupling of fundamental biogeochemical–microbial processes and local morphogenetic determinants. It summarizes a collection of sedimentary structures obtained from two modern siliciclastic peritidal environments in different climatic zones (temperate humid: Mellum Island, southern North Sea; subtropical arid: coast of southern Tunisia). Textural geometries reveal a high structural diversity, but their determinants are primarily based upon six major parameters: (1) intrinsic biofactors: structural diversification of sedimentary microbial films and mats inherent in the organisms, i.e. their construction morphology, growth, taxis and behaviour, and local abundance of specific morphotypes. Most prominent are the ensheathed filamentous cyanobacteria Microcoleus chthonoplastes and Lyngbya aestuarii, and the sheathless filamentous cyanobacterium Oscillatoria limosa. (2) Biological response to physical disturbances: sediment supply, erosion and fracturing of surface layers resulting from desiccation cause growth responses of biofilms and microbial mats. (3) Trapping/binding effects: physicobiological processes give rise to grain orientations and wavy to lenticular lamina, lamina‐specific grain arrangements and ‘sucrose’ calcium carbonate accumulations. (4) Secondary physical deformation of biogenic build‐ups: mechanical stresses acting upon sediments overgrown and biostabilized by biofilms and mats produce erosional and overthrust structures. (5) Post‐burial processes: textural fabrics that evolve from mechanical effects of gas formation from decaying mats, and features related to the formation of authigenic minerals (calcium carbonates, calcium sulphates, pyrite). (6) Bioturbation and grazing: post‐depositional structures, such as Skolithos‐type dwellings, traces of burrowing insects, gastropod grazing traces and faecal pellets. In synopsis, the catalogue firstly comprises a sound set of ubiquitous signatures. This uniformity in architectural characteristics is attributed to the presence and local dominance of certain microbes throughout the different settings. The catalogue secondly documents signatures that are extremely sensitive to tidal position, hydrodynamic regime and overall climatic conditions. These kinds of signature indicate narrow facies zones, which often coincide with the activity or dominance zones of certain organisms. An overview of structures of microbial origin from the fossil record underlines the potential of many of the signatures included in this catalogue to become fossilized and provide strong indicators of former siliciclastic tidal settings.