bluuebunny/crossref_metadata_2025_split huggingface dataset:
The 52 000 MW Ro/SS‐A autoantigen in Sjögren's syndrome/systemic lupus erythematosus (Ro52) is an interferon‐γ inducible tripartite motif protein associated with membrane proximal structures
Authors: Rhodes Davd A. , Ihrke Gudrun , Reinicke Anna T. , Malcherek Georg , Towey Michael , Isenberg David A. , Trowsdale John 
Published: March 2003

SummaryThe 52 000 MW Ro/SS‐A (Ro52) protein is a major target of autoantibodies in autoimmune conditions such as systemic lupus erythematosus and Sjögren's syndrome. Recent genomic and bioinformatic studies have shown that Ro52 belongs to a large family of related RING/Bbox/coiled‐coil (RBCC) tripartite motif proteins sharing overall domain structure and 40–50% identity at the amino acid level. Ro52 also has a B30.2 domain at the C‐terminus. Using the human genome draft sequence, the genomic organization of the Ro52 gene on human chromosome 11p15.5 has been deduced and related to the protein domain structure. We show that the steady‐state levels of Ro52 mRNA are normally very low but are induced by cell activation with interferon‐γ. In transient transfection of HeLa cells, epitope‐tagged Ro52 protein was localized to unidentified membrane proximal rod‐like structures. Using in vitro coupled transcription/translation followed by immunoprecipitation, the autoimmune response to Ro52 protein was investigated and two distinct interactions were resolved. The Ro52 C‐terminal B30.2 domain interacts with human immunoglobulin independently of antibody specificities. Sera derived from patients with Sjögren's syndrome and systemic lupus erythematosus, in addition, contained specific autoantibodies directed towards the rest of the Ro52 molecule. The majority of these autoimmune sera also immunoprecipitated the Ro52‐related molecule RNF15. A possible role for Ro52 protein in alterations of plasma membranes during cellular activation or apoptosis is discussed.
Effects of human interleukin‐18 and interleukin‐12 treatment on human lymphocyte engraftment in NOD‐scid mouse
Authors: Senpuku Hidenobu , Asano Toshihiko , Matin Khairul , Abdus Salam M. , Tsuha YUZO , Horibata Shigeo , Shimazu Yoshihito , Soeno Yuichi , Aoba Takaaki , Sata Tetsutaro , Hanada Nobuhiro , Honda Mitsuo 
Published: March 2003

SummaryNOD/LtSz‐prkdcscid/prkdcscid (non‐obese diabetic‐severe combine immunodeficiency; NOD‐scid) mice grafted with human peripheral blood lymphoid cells have been used as an in vivo humanized mouse model in various studies. However, cytotoxic human T cells are induced in this model during immune responses, which gives misleading results. To assist in grafting of human lymphocytes without the induction of cytotoxic human T cells, we investigated the effects of T helper type 1 (Th1) and Th2 cytokines on human lymphocyte grafting and migration, as well as the production of immunoglobulin deposited in glomeruli and human immunodeficiency virus‐1 (HIV‐1) infection using NOD‐scid mice. Administration of interleukin‐18 (IL‐18) and IL‐12 enhanced the grafting of human CD4+ and CD8+ T cells in the mice, whereas co‐administration prevented grafting due to interferon‐γ‐dependent apoptosis. Immunoglobulin A (IgA) deposits were observed in mice treated with IL‐18 alone, but not in those given phosphate‐buffered saline, IL‐12 alone, or IL‐18 + IL‐12. A high rate of HIV infection was also observed in the IL‐18‐treated group. Together, these results indicate that IL‐18 may be effective for the grafting and migration of CD4+ and CD8+ T cells, except for the induction of apoptosis and regulation of class‐switching IgA. IL‐18‐administered NOD‐scid mice provide a useful small humanized model for the study of HIV infection and IgA nephropathy.
Tryptophan deprivation sensitizes activated T cells to apoptosis prior to cell division
Authors: Lee Geon Kook , Park Hyeon Jin , Macleod Megan , Chandler Phillip , Munn David H. , Mellor Andrew L. 
Published: March 2003

SummaryCells expressing indoleamine 2,3‐dioxygenase (IDO), an enzyme which catabolizes tryptophan, prevent T‐cell proliferation in vitro, suppress maternal antifetal immunity during pregnancy and inhibit T‐cell‐mediated responses to tumour‐associated antigens. To examine the mechanistic basis of these phenomena we activated naïve murine T cells in chemically defined tryptophan‐free media. Under these conditions T cells expressed CD25 and CD69 and progressed through the first 12 hr of G0/G1 phase but did not express CD71, cyclin D3, cdk4, begin DNA synthesis, or differentiate into cytotoxic effector cells. In addition, activated T cells with their growth arrested by tryptophan deprivation exhibited enhanced tendencies to die via apoptosis when exposed to anti‐Fas antibodies. Apoptosis was inhibited by caspase inhibitor and was not observed when T cells originated from Fas‐deficient mice. These findings suggest that T cells activated in the absence of free tryptophan entered the cell cycle but cell cycle progression ceased in mid‐G1 phase and T cells became susceptible to death via apoptosis, in part though Fas‐mediated signalling. Thus, mature antigen‐presenting cells expressing IDO and Fas‐ligand may induce antigen‐specific T‐cell tolerance by blocking T‐cell cycle progression and by rapid induction of T‐cell activation induced cell death in local tissue microenvironments.
Regulation of epithelial cell cytokine responses by the α3β1 integrin
Authors: Lubin Farah D. , Segal Miriam , Mcgee Dennis W. 
Published: March 2003

SummaryEpithelial cells (EC) from various tissues can produce important cytokines and chemokines when stimulated by proinflammatory cytokines. These EC also receive signals from cell surface integrins, like the α3β1 integrin, which is important in cell migration and wound healing of epithelial monolayers. However, little is known of the effect of integrin signals on cytokine responses by EC. Colonic Caco‐2 cells treated with an anti‐α3 integrin antibody prior to stimulation with the proinflammatory cytokine interleukin (IL)‐1 yielded suppressed levels of mRNA and secreted IL‐6, IL‐8 and monocyte chemoattractant protein‐1 as compared to cells treated with normal mouse immunoglobulin G. Lung A549 cells also showed a similar suppression of cytokine secretion. Likewise, treatment of the Caco‐2 cells with the same antibody suppressed tumour necrosis factor‐α‐stimulated IL‐6 secretion. Fab fragments of the anti‐α3 integrin antibody did not induce the suppressive effect but did block the suppressive effect of the whole antibody suggesting that the effect of the antibody required cross‐linking of the integrins. Finally, culture of the Caco‐2 cells on laminin type 5 (the major ligand for this integrin) yielded depressed levels of IL‐1‐induced IL‐6 secretion as compared to cells on laminin type 1. These data are the first indication that the α3β1 integrin may cause a suppression of cytokine responses by EC which may be important in regulating the capacity of EC to respond during inflammation or wound healing.
Neither lymphotoxin α nor lymphotoxin β receptor expression is required for biogenesis of lymphoid aggregates or differentiation of natural killer cells in the pregnant mouse uterus
Authors: Kather Angela , Chantakru Sirirak , He Hong , Minhas Kanwal , Foster Robert , Markert Udo R. , Pfeffer Klaus , Croy B. Anne 
Published: March 2003

SummaryGene ablation studies in mice indicate that lymphotoxin (LT)α, LTβ and LTβR are essential for the genesis of lymph nodes (LN), normal structural development of peripheral lymphoid tissues and the differentiation of natural killer (NK) cells. LTβR binds to the heterotrimeric cytokines LTα1β2 and LIGHT. LTs also regulate stromal cell expression of lymphocyte homing chemokines. Uterine decidualization in normal (+/+) mice is accompanied by the appearance and maturation of large numbers of uterine NK (uNK) cells that differentiate from precursors mobilized to the uterus from secondary lymphoid tissues. uNK cells accumulate in a transient, lymphocyte‐rich region known as the metrial gland or, more recently, the mesometrial lymphoid aggregrate of pregnancy (MLAp). To determine if LTs contribute to development of the MLAp, and to the differentiation and/or localization of uNK cells, a histological study was undertaken of implantation sites from LTα null, LTβR null and gestation day‐matched, normal mice. Implantation sites from the gene‐ablated mice contained abundant numbers of uNK cells that localized appropriately. This indicates that the stromally derived molecules supporting NK cell differentiation in the uterus differ from those used in secondary lymphoid organs.
Detection of cytoplasmic CD antigens within normal human peripheral blood leucocytes
Authors: Sandilands Gavin P. , Hauffe Birgit , Loudon Elizabeth , Marsh Andrew G. , Gondowidjojo Anna , Campbell Carol , Ferrier Roderick K. , Rodie Martina E. 
Published: March 2003

SummaryPolymorphonuclear neutrophils (PMNs) are capable of synthesizing various pro‐inflammatory cytokines which may indirectly influence specific immune responses. PMNs may also have the capacity to present foreign peptides to helper T cells (Th cells). In support of this hypothesis, recent studies have shown that neutrophils, when activated by the correct combination of cytokines, can be induced to express cell surface major histocompatibility complex (MHC) Class II (DR) antigen, CD80 (B7.1) and CD86 (B7.2): molecules required for antigen presentation and subsequent T‐cell activation. In this study we have used normal ‘resting’ human peripheral blood neutrophils and demonstrated, using a mild fixation and permeabilization protocol, significant cytoplasmic ‘stores’ of these molecules known to be important in antigen presentation. Cytoplasmic MHC Class II antigen was found with two out of 20 normal donors tested whereas cytoplasmic CD80 and CD86 were found to a variable extent within all normal donors. Surprisingly, we also found several other neutrophil cytoplasmic CD antigens more commonly associated with B cells, i.e. CD20, CD21 (CR2/EBV‐R) and CD22 (BL‐CAM). All of these antigens were confined to the ‘resting’ cell cytoplasm and were never found to be expressed on the cell surface. To exclude the possibility that these antigens were absorbed from plasma and to provide evidence for active synthesis, we used a novel whole blood in situ hybridization flow cytometry assay method to detect mRNA specific for these antigens within normal PMNs. We also conducted real‐time polymerase chain reactions to confirm these findings using CD22 as a good example of an ‘inappropriately expressed’ CD antigen. These observations therefore provide support for the hypothesis that human PMNs have the potential to express molecules required for antigen presentation and cell signalling.
Oestrogen receptor specificity in oestradiol‐mediated effects on B lymphopoiesis and immunoglobulin production in male mice
Authors: Erlandsson M. C. , Jonsson C. A. , Islander U. , Ohlsson C. , Carlsten H. 
Published: March 2003

SummaryOestrogen treatment down‐regulates B lymphopoiesis in the bone marrow of mice. Meanwhile it up‐regulates immunoglobulin production. To understand better the oestrogen action on bone marrow male mice lacking oestrogen receptor α (ERα; ERKO mice), lacking ERβ (BERKO mice), lacking both receptors (DERKO mice) or wild‐type (wt) littermates were castrated and treated for 2·5 weeks with 30 μg/kg 17β‐oestradiol (E2) or vehicle oil as controls. The B lymphopoiesis in the bone marrow was examined by flow cytometry and mature B‐cell function was studied using an ELISPOT assay enumerating the B cells in bone marrow and spleen that were actively producing immunoglobulins. In wt mice the frequency of B‐lymphopoietic (B220+) cells in the bone marrow decreased from 15% to 5% upon E2 treatment. In ERKO and BERKO mice significant reduction was seen but not of the same magnitude. In DERKO mice no reduction of B lymphopoiesis was seen. In addition, our results show that E2 mediated reduction of different steps in B lymphopoiesis require only ERα or both receptors. In wt and BERKO mice E2 treatment resulted in significantly increased levels of B cells actively producing immunoglobulin, while in ERKO and DERKO mice no such change was seen. Similar results were found in both bone marrow and spleen. In conclusion our results clearly show that both ERα and ERβ are required for complete down‐regulation of B lymphopoiesis while only ERα is needed to up‐regulate immunoglobulin production in both bone marrow and spleen.
DNA structures common for chironomid telomeres terminating with complex repeats
Authors: Rosén M. , Edström J.‐E. 
Published: March 2003

AbstractTandem repeats, 340 bp long, have been shown to terminate the chromosomes in Chironomus pallidivittatus and similar DNA may be used for this purpose by related insects. In view of the importance of Chironomus in telomere studies, representing in principle a third system after short repeats and Drosophila telomeric retrotransposons, we have investigated the related Chironomus dilutus, to learn what DNA structures are conserved at the chromosome ends. Interspersed subrepeats in the telomeric repeats, which contain a long palindrome, and a zone of about 100 bp of relatively constant subtelomeric DNA towards the junction to the telomeric DNA, are characteristic for C. dilutus as for previously investigated species. C. dilutus has similar subtelomeric DNA at all chromosome ends, but typical telomeric repeats in only seven of the pairs since the eighth telocentric pair contains centromere‐specific repeats.
Persistence of Anopheles arabiensis during the severe dry season conditions in Senegal: an indirect approach using microsatellite loci
Authors: Simard Frédéric , Lehmann Tovi , Lemasson, Jean‐Jacques , Diatta Mathurin , Fontenille Didier 
Published: March 2003

AbstractVariation at nine microsatellite loci was investigated to understand how Anopheles arabiensis populations survive the dry season in the sahelian region of Senegal. Low estimates of genetic differentiation (FST = 0.012, RST = 0.009) between two populations, 250 km apart, suggested extensive gene flow across this distance. Despite extreme seasonal fluctuation in abundance with dry season minima in which mosquitoes virtually disappeared, allele frequencies remained stable over time in the village of Barkedji from August 1994 to December 1997 (including four rainy seasons and three dry seasons). The effective population size (Ne) was estimated to be 601 with 95% CI (281, 1592), providing strong evidence against annual bottlenecks. Differences in measures of genetic diversity and linkage disequilibrium between the dry and the rainy seasons were not detected. These results suggest that despite extreme minima in local density, An. arabiensis maintains large permanent deme spread out over large area.
The mitochondrial genome of the primary screwworm fly Cochliomyia hominivorax (Diptera: Calliphoridae)
Authors: Lessinger A. C. , Martins Junqueira A. C. , Lemos T. A. , Kemper E. L. , Da Silva F. R. , Vettore A. L. , Arruda P. , L. Azeredo‐Espin A. M. 
Published: March 2003

AbstractThe complete sequence of the mitochondrial genome of the screwworm Cochliomyia hominivorax was determined. This genome is 16 022 bp in size and corresponds to a typical Brachycera mtDNA. A Serine start codon for COI and incomplete termination codons for COII, NADH 5 and NADH 4 genes were described. The nucleotide composition of C. hominivorax mtDNA is 77% AT‐rich, reflected in the predominance of AT‐rich codons in protein‐coding genes. Non‐optimal codon usage was commonly observed in C. hominivorax mitochondrial genes. Phylogenetic analysis distributed the Acalypterate species as a monophyletic group and assembled the C. hominivorax (Calyptratae) and the Acalyptratae in a typical Brachycera cluster. The identification of diagnostic restriction sites on the sequenced mitochondrial genome and the correlation with previous RFLP analysis are discussed.
Wolbachia neither induces nor suppresses transcripts encoding antimicrobial peptides
Authors: Bourtzis K. , Pettigrew M. M. , O’Neill S. L. 
Published: March 2003

Abstract Wolbachia are intracellular maternally inherited microorganisms that are associated with reproductive abnormalities such as cytoplasmic incompatibility (CI), feminization and parthenogenesis in the various arthropod species they infect. Surveys indicate that these bacteria infect more than 16% of all insect species as well as isopods, mites and nematodes, making Wolbachia one of the most ubiquitous parasites yet described. However, nothing is known about the interactions of this bacterium with the host’s immune system. We studied the expression of inducible antimicrobial markers in the adults of two Wolbachia infected insect species, Drosophila simulans and Aedes albopictus. The lack of available immune markers in the mosquito species led us to clone part of the defensin gene from this species, which was found to be very similar to the other mosquito defensins cloned from Anopheles gambiae and Aedes aegypti. Comparisons of the expression pattern of the antibacterial markers between Wolbachia‐infected and cured lines, and also between bacteria‐challenged and unchallenged adults indicated that Wolbachia does not either constitutively induce or suppress the transcription of these antibacterial genes. In addition, no difference in the transcription of these genes was found between double and single Wolbachia‐infected strains or between strains in which Wolbachia has different tissue tropisms.
Molecular characterization of two serine proteases expressed in gut tissue of the African trypanosome vector, Glossina morsitans morsitans
Authors: Yan Jian , Cheng Qiuying , Li Chang‐Ben , Aksoy Serap 
Published: March 2003

AbstractSerine proteases are major insect gut enzymes involved in digestion of dietary proteins, and in addition they have been implicated in the process of pathogen establishment in several vector insects. The medically important vector, tsetse fly (Diptera:Glossinidiae), is involved in the transmission of African trypanosomes, which cause devastating diseases in animals and humans. Both the male and female tsetse can transmit trypanosomes and both are strict bloodfeeders throughout all stages of their development. Here, we describe the characterization of two putative serine protease‐encoding genes, Glossina serine protease‐1 (Gsp1) and Glossina serine protease‐2 (Gsp2) from gut tissue. Both putative cDNA products represent prepro peptides with hydrophobic signal peptide sequences associated with their 5′‐end terminus. The Gsp1 cDNA encodes a putative mature protein of 245 amino acids with a molecular mass of 26 428 Da, while the predicted size of the 228 amino acid mature peptide encoded by Gsp2 cDNA is 24 573 Da. Both deduced peptides contain the Asp/His/Ser catalytic triad and the conserved residues surrounding it which are characteristic of serine proteases. In addition, both proteins have the six‐conserved cysteine residues to form the three‐cysteine bonds typically present in invertebrate serine proteases. Based on the presence of substrate specific residues, the Gsp1 gene encodes a chymotrypsin‐like protease while Gsp2 gene encodes for a protein with trypsin‐like activity. Both proteins are encoded by few loci in tsetse genome, being present in one or two copies only. The mRNA expression levels for the genes do not vary extensively throughout the digestive cycle, and high levels of mRNAs can be readily detected in the gut tissue of newly emerged flies. The levels of trypsin and chymotrypsin activities in the gut lumen increase following blood feeding and change significantly in the gut cells throughout the digestion cycle. Hence, the regulation of expression for trypsin and chymotrypsin occurs at the post‐transcriptional level in tsetse. Both the coding sequences and patterns of expression of Gsp1 and Gsp2 genes are similar to the serine proteases that have been reported from the bloodfeeding insect Stomoxys calcitrans.
Inhibition of the lepidopteran amino acid co‐transporter KAAT1 by phenylglyoxal: role of arginine 76
Authors: Castagna Michela , Vincenti Sergio , Marciani Paola , Sacchi V. Franca 
Published: March 2003

AbstractPhenylglyoxal (PGO), an arginine‐modifying reagent, is an irreversible inhibitor of KAAT1‐mediated leucine transport, expressed in Xenopus oocytes. The PGO effect was dose‐dependent and 5 mm PGO determined a Vmax reduction to 24% of the control, consistent with the covalent binding to transporter arginine residues not located in the leucine binding site. The use of labelled [14C]PGO confirmed that the inhibitor binds KAAT1. The protein membrane domain contains seven arginine residues one of which, arginine 76, is conserved in the family of GABA transporters. Using site‐directed mutagenesis we showed that only arginine 76 is crucial for KAAT1 activity and is involved in PGO binding.
Differentially expressed midgut transcripts inCulicoides sonorensis(Diptera: Ceratopogonidae) following Orbivirus (Reoviridae) oral feeding
Authors: Campbell C. L. , Wilson W. C. 
Published: March 2003

AbstractUnderstanding the vector insect's gene expression response to a virus infection may aid design of control measures for arbovirus diseases.Culicoides sonorensisis a vector of several agriculturally important pathogens, such as epizootic haemorrhagic disease virus (EHDV) that causes disease in ruminants. Two approaches, differential display and suppression subtractive hybridization, were used to identify 400+Culicoidestranscripts that were more abundant in midguts 1 day following an oral meal containing EHDV. Of these, quantitative PCR confirmed seven to be more abundant in virus‐fed midguts than controls. One such transcript encodes a putative RNA editase, CsRED1, induced by dsRNA. Transcripts encoding putative receptors involved in cell differentiation included CsLAR, a protein tyrosine phosphatase, and CsFZ2, homologous to thewinglessreceptor inD. melanogaster. Transcripts encoding putative translation machinery components included CseIF3, CseIF5A and CsRPS6. Overall, the cDNA fragments identified in this study increased in the midgut at one day postfeeding; by 2 days postfeeding, increases in transcript levels shifted from the midgut to the remainder of the infected midge.
Bacterial eradication from root dentine by ultrasonic irrigation with sodium hypochlorite
Authors: Huque  , Kota  , Yamaga  , Iwaku  , Hoshino  
Published: March 2003

The study aimed to evaluate intracanal irrigation procedures in eradicating bacteria from surface, shallow and deep layers of root dentine using extracted human teeth. Artificial bacterial smear layer was successfully produced by rubbing a mixture of dental plaque and artificially decalcified dentine or carious dentine on root canal walls. The reservoir holes were 3.5 mm in depth, 1 mm in diameter prepared 1.5 mm apart and parallel to the root canals on the decrowned planes, in which five separate bacterial species were placed (Actinomyces israelii, Fusobacterium nucleatum, Propionibacterium acnes, Streptococcus mutans and Streptococcus sanguis). Bacterial eradication after irrigation of the prepared canals was determined by bacterial recovery (i) from the root canal surfaces and shallow layers where bacteria were smeared artificially and (ii) from deeper layers of root canal dentine reservoir holes.Ultrasonic irrigation with 5.5% and 12% NaOCl eradicated bacteria from artificial smear layer (P<0.0001), whilst 12% NaOCl irrigation with a syringe was insufficient. Ultrasonic irrigation with water or 15% EDTA failed to eradicate bacteria from smeared surfaces. Ultrasonic irrigation with 12% NaOCl killed A. israelii, F. nucleatum, P. acnes, S. mutans, and S. sanguis placed in reservoir channels, although for F. nucleatum, a very small number of bacteria remained in five samples out of 12. Ultrasonic irrigation with less concentrated NaOCl failed to eliminate bacteria completely from reservoir channels in most samples. Ultrasonic irrigation with 12% NaOCl appeared to eliminate bacteria efficiently from surface, shallow and deep layers of root dentine.