bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protease‐modified erythrocytes: CD55 and CD59 deficient PNH‐like cells
Authors: YUAN FANG F. , BRYANT JENNIFER A. , FLETCHER ANNE 
Published: July 2007

SummaryThe increased susceptibility to homologous complement in paroxysmal nocturnal haemoglobinuria (PNH) is known to be associated with the deficiency of the membrane complement inhibitors CD59 and CD55. Proteases have been used in this study to modify normal human RBC to complement sensitive PNH‐like cells. To investigate the protective role of CD59 and CD55, the relationship between the content of CD59 and CD55 and the complement susceptibility of the PNH‐like cells has been determined. The differential resistance of the enzyme‐treated RBC to complement‐mediated injury was measured by acidified serum lysis. Pronase‐treated erythrocytes lacked both CD59 and CD55 and were very susceptible to complement‐mediated lysis. Papain treatment of RBC reduced the CD55 content but did not affect CD59 and induced slight susceptibility to complement‐mediated lysis. Trypsin treatment of RBC destroyed 80% of CD59, had little effect on CD55 (unless incubation was extended) and slightly increased susceptibility to lysis. Thus, partial CD55 and CD59 activity was sufficient to protect cells from complement‐mediated lysis. In the reactive lysis assay, anti‐CD55 and anti‐CD59 induced haemolysis, anti‐CD59 having the more pronounced effect. Lysis was enhanced when RBC were treated by both antibodies simultaneously.
Apoptosis in B lymphocytes: The WEHI‐231 perspective
Authors: GOTTSCHALK ALEXANDER R. , QUINTANS JOSE 
Published: July 2007

SummaryIn this review we summarize recent work on the molecular basis of apoptosis in the murine B cell lymphoma WEHI‐231. WEHI‐231 cells undergo apoptosis in response to antigen receptor cross‐linking with anti‐Ig reagents. Death is specifically triggered via surface IgM (sIgM); cross‐linking sIgD, Ia or FcR has no effect. Apoptosis is preceded by growth arrest in the Go/G1 phase of the cell cycle and may not occur in all currently available WEHI‐231 sublines. The continuous passage of WEHI‐231 cells in different laboratories has yielded variants that differ greatly in their response to anti‐Ig treatment because apoptotic cells tend to be negatively selected in culture. Resistant and susceptible variants undergo growth arrest in response to anti‐Ig but only susceptible cells go on to die by apoptosis. Cells resistant to anti‐Ig have intact apoptotic machinery as indicated by their susceptibility to dexamethasone, irradiation and other treatments. However, anti‐Ig‐resistant cells are also resistant to apoptosis induced by the immunosuppressants cyclosporin A, FK‐506 and rapamycin. We discuss the experimental evidence indicating that the apoptotic machinery in WEHI‐231 cells is pre‐activated but under constant negative regulation by short‐lived protein inhibitors. Inhibition is removed by a mediator released in response to anti‐Ig treatment in susceptible sublines. The mediator of death is the sphingosine derivative, ceramide, presumably produced by membrane sphingomyelinases activated by anti‐Ig. A hypothetical model on how ceramide kills WEHI‐231 is presented.
Productive in vitro infection of human umbilical vein endothelial cells and three colon carcinoma cell lines with HIV‐1
Authors: CORBEIL JACQUES , EVANS LOUISE A. , MCQUEEN PAUL W. , VASAK EVA , EDWARD PAUL D. , RICHMAN DOUGLAS D. , PENNY RONALD , COOPER DAVID A. 
Published: July 2007

SummaryThe objective of this study was to assess the ability of HIV‐1 to establish an in vitro infection of primary human umbilical vein endothelial cells (HUVEC). The HUVEC and colon carcinoma cell lines were inoculated with different isolates of HIV‐1 (HIV‐1SF2, HIV‐1McK and HIV‐1LAI) and productive viral infection was assessed by both the detection of p24 core antigen in the culture supernatants and the presence of specific spliced HIV mRNA. The infection which was detected in the inoculated HUVEC and all the colon carcinoma cell lines could not be blocked using an antibody targeted against the CD4 receptor. Furthermore, the HIV‐inoculated HUVEC secreted elevated levels of IL‐6 and this increase was found to be proportional to the size of the viral inoculum. No changes in the production of IL‐lβ, TNF‐α, IFN‐α and IFN‐γ were detected following HIV infection. The colon carcinoma cells, however, did not secrete increased levels of these cytokines following HIV‐1 inoculation. These results confirm that non‐CD4 expressing cells, such as endothelial cells and certain colon epithelial cells, serve as targets and reservoirs for HIV. Moreover, the production of IL‐6 by HIV‐infected endothelial cells may be a contributing factor to the aberrant immunoregulation associated with HIV infection in vivo.
An analysis, using monoclonal antibodies, of the role of interferon‐γ in ovine immune responses
Authors: EMERY D. L. , DAVEY R. J. 
Published: July 2007

SummaryA mAb (IFN‐9) which neutralizes biologically active ovine and bovine IFN‐γ was used to deplete levels of the cytokine in vivo in sheep and examine the consequences for immune responses to adjuvanted antigen and skin reactivity to Bacillus‐Calmette‐Guerin (BCG). Groups of sheep were immunized with ovalbumin in the adjuvants, Quil A or dextran sulphate (MW 500 000: DXS), both of which elicit production of IFN‐γ. MAb anti‐IFTM‐γ or an isotype control mAb (anti‐carbonic anhydrase positive particles) were inoculated i.v. during primary and/or secondary responses. Reactions monitored in efferent prefemoral lymph indicated that anti‐IFN‐γ effectively depleted levels of IFN‐γ in lymph but had no effects on the magnitude and kinetics of lymphocyte and lymphoblast traffic, or total or isotypic titres of specific Ig. When incubated in vitro with ovalbumin, antigen‐reactive cells from anti‐IFN‐γ treated sheep did not produce IFN‐γ, suggesting an on‐going modification to cytokine production. In contrast, skin reactions to purified‐protein derivative in sheep immunized with BCG were reduced by < 40% by anti‐IFN‐γ. The results indicate that IFN‐γ production may not be obligatory for delayed‐type hypersensitivity reactions or for the adjuvant action of Quil A or DXS, and that specific mAb can alter the profile of cytokines produced by antigen‐reactive cells in sheep.
The effect of IL‐4 on antigen expression: A comparison of fluorescence intensity and antigen density
Authors: MACARDLE PETER J. , WILLIAMS KERYN A. , BRADLEY JOHN , ZOLA HEDDY 
Published: July 2007

SummaryWe have compared the membrane expression of MHC class II antigen and Ig on murine splenic B lymphocytes by two flow cytometric methods. The first method, commonly used, determined the mean immunofluorescence intensity; the second measured antigen density as a ratio of mean fluorescence intensity to cell volume. The data generated by the two methods allow for different interpretations of antigen density in comparison lo antigen expression. By mean fluorescence intensity, activated B lymphocytes expressed more MHC class II antigen and membrane Ig than did resting B cells. However, resting B cells had the same density of MHC class II antigen and membrane Ig as activated B cells. Next we examined the effect of IL‐4 on antigen expression by the two methods. We found that although lL‐4 increased the mean fluorescence intensity and density of MHC class II and membrane Ig on each B cell population, the density of expression of membrane Ig tended to be greater on the resting B cells than on the activated, while the density of MHC class II antigen was essentially the same on each of the IL‐4 treated B cell populations.
SV40‐adenovirus immortalized cell lines derived from mouse lymphoid dendritic cell preparations
Authors: OHNISHI KAZUO , DAIGO MICHIKO , TOKUNAGA TOHRU 
Published: July 2007

SummaryDendritic cells (DC) are antigen‐presenting cells characteristic in their rarity and potent ability to stimulate resting T cells. We established several cell lines from purified mouse spleen DC and Langerhans' cells (LC) by infecting them with recombinant SV40ori− adenovirus. Using this method, cells from these fractions are efficiently transformed at a frequency as high as 5 × 10−6. Some established lines have dendritic morphology, express surface markers specific for DC (defined by mAb 33D1 and NLDC145) and weak substrate adherence. Interestingly, these lines simultaneously express B cell markers (B220 and Ly‐1) and/or macrophage markers (Mac‐l and F4/80). Among the lines, OT6.2 and OT8.3.1 have retained stimulating activity in mixed lymphocyte reactions (MLR) which is attributable to the primary T cell stimulating activity of native DC However, these lines also present soluble antigens to T cell clones, a secondary T cell stimulating activity, characteristic of B cells and macrophages. Although transformation has perturbed the functional discreteness of the DC cell lineage. DC‐specific properties are partially preserved in the cell lines. These cell lines may provide useful experimental systems for the elucidation of molecular mechanisms involved in the MLR and the differentiation of DC.
Absorption and presentation of antigens by epithelial cells of the small intestine: Hypotheses and predictions relating to the pathogenesis of coeliac disease
Authors: MAYRHOFER GRAHAM 
Published: July 2007

SummaryEffects of the route of antigen absorption and presentation in the small intestine are discussed in relation to outcomes from antigen exposure. It is proposed that antigens presented by epithelial cells to intrinsic T cell populations in the mucosa induce anti‐inflammatory immune responses, while antigens presented to conventional T cells by lamina propria APC predisposes to inflammation. The pathogenesis of coeliac disease is attributed to three factors: a defect in antigen processing by epithelial cells; the intrinsic properties of the gliadins; and the HLA‐D haplotype of the individual. It is suggested that MHC class II molecules play a role in antigen uptake by enterocytes, in addition to their function in antigen presentation to T cells.
Expression of rabbit C‐reactive protein in transgenic mice
Authors: LIN CAROL S , XIA DONGYUAN , YUN JEUNG S , WAGNER THOMAS , MAGNUSON TERRY , MOLD CAROLYN , SAMOLS DAVID 
Published: July 2007

SummaryC‐reactive protein (CRP) is a prototypic acute phase reactant in humans and rabbits whose serum concentration can increase up to 1000‐fold following an acute inflammatory stimulus. CRP binds to many phosphate ester‐containing compounds including phosphorylcholine, nucleotides, chromatin and snRNP. To examine the in vivo function of this protein, we produced transgenic mice capable of significant CRP synthesis. In contrast to most other vertebrates, mice synthesize CRP in only trace amounts. The transgenic animals express rabbit CRP from either the phosphoeno lpyruvate carboxykinase promoter (PEPCK‐CRP) or the mouse metallothionein I promoter (MT‐CRP). Manipulating the diet in one of the PEPCK‐CRP lines led to a rise in serum CRP levels from < 5 μg/mL to 100–200 μg/mL over a period of 2 days. The two MT‐CRP lines examined expressed CRP constitutively which could be further elevated 2–4‐fold following an inflammatory stimulus. Transgenic CRP bound phosphonlcholine was pentameric, had a circulating half‐life of 30–60 min and was capable of activating mouse complement when bound to a ligand. We conclude that these transgenic lines express CRP with many of the properties of authentic rabbit CRP, and that the expression of CRP can be controlled to be dependent or independent of the acute phase response.
Autoimmune diabetes: Caught in the causality trap?
Authors: GAZDA LAWRENCE S , GILCHRIST KIRSTY A , LAFFERTY KEVIN J 
Published: July 2007

SummaryThe lack of concordance between genotype and clinical diabetes has prompted a search for the infectious agent that precipitates this autoimmune disease. However, this approach may be misleading. It assumes that the disease‐prone individuals that do not develop diabetes do not have autoimmunity. In the non‐obese diabetic (NOD) mouse, the genotype is a primary determinant of autoimmunity. Not all animals of the disease‐prone genotype develop clinical disease; however, all have autoimmunity. This is expressed as a destructive or non‐destructive process. Multiple pathways are open to the immune system and whether or not the immune response is destructive and leads to the development of clinical disease, appears to be a random process. If this is the case, the most important questions relating to autoimmune disease are not those concerning the ‘causative’ agents. Instead we should be asking what are the differences between pathways open to the immune system and what factors affect the probability that one or another pathway is finally selected?
Depletion of IFN‐γ, CD8+ or Tcrγδ+ cells in vivo during primary infection with an enteric parasite (Trichostrongylus colubriformis) enhances protective immunity
Authors: McCLURE SJ , DAVEY RJ , LLOYD JB , EMERY DL 
Published: July 2007

SummaryIn order to examine the role of CD8+ and WCI+ T cells and of IFN‐γ in the development of protective immunity against infection with the enteric nematode parasite Trichostrongylus colubriformis in sheep, mAb were administered during induction of the immune response to deplete or neutralize these components. Protection against the primary and challenge infections were assessed by faecal egg count and total worm count. Prolonged administration of mAb recognizing IFN‐γ and CD8+ resulted in significantly increased protection during the 6‐week primary infection. CD8+ cells were depleted from blood but not intestinal mucosa. After injection of mAb (CC15) recognizing the surface antigen WCI, WCI+ and T cell receptor (Tcr) γδ+ cells were depleted from blood but not from enteric mucosa, and protection against challenge, although variable, was increased by up to 88%. It appears that CD8+ and WCI+/γδ+ cells and IFN‐γ all retard the potential development of naturally‐acquired immunity against the parasite.
Dendritic cells and myeloid leukaemias: plasticity and commitment in cell differentiation
Authors: Rasaiyaah Jane , Yong Kwee , Katz David R. , Kellam Paul , Chain Benjamin M. 
Published: July 2007

SummaryDendritic cells (DCs) are key antigen‐presenting cells (APCs), which link innate and adaptive immunity, ultimately activating antigen‐specific T cells. This review examines the relationship between the acute and chronic myeloid leukaemias and cells with DC properties. DCs are non‐dividing terminally differentiated cells, and ex vivo leukaemic cells or cell lines show little similarity to DCs. However, many leukaemias differentiate further in response to defined stimuli, and retain a degree of lineage plasticity. Therefore, several studies have explored the response of leukaemic cells to the in vitro regimens used to differentiate ex vivo primary DCs. Recent data suggest that the most ‘dendritic‐like’ cells can be derived from more undifferentiated myeloid leukaemias, such as the myelomonocytic Mutz‐3 cell line. These findings have important implications for understanding the developmental origins of DCs, for harnessing the APC properties of this class of tumour to stimulate the therapeutic anti‐tumour immunity, and for developing useful models for the study of human DC physiology and pathology. There is a strong rationale for further exploration of this class of tumour and its relationship to the normal DC.
Distribution of t(14;18)‐positive, putative lymphoma precursor cells among B‐cell subsets in healthy individuals1
Authors: Hirt Carsten , Dölken Gottfried , Janz Siegfried , Rabkin Charles S. 
Published: July 2007

SummaryThe t(14;18)(q32;q21) is the characteristic chromosomal translocation of follicular lymphoma (FL). Highly sensitive polymerase chain reaction (PCR) techniques can also detect t(14;18)‐sequences in the blood and lymphoid tissues of healthy individuals (HI). The aim of this study was to determine the immunophenotypic markers of t(14;18)‐positive cells in HI and to relate these features to lymphocyte maturation. B cells from 10 subjects with t(14;18)‐positive and three subjects with t(14;18)‐negative peripheral blood mononuclear cells (PBMC) were fluorescence‐activated cell sorted for antigen‐naïve (CD27−), immunoglobulin M (IgM) memory (IgM+CD27+) and switched memory (IgM− CD27+) cells. t(14;18)‐recombinations were detected by quantitative PCR. Among PBMC‐positive subjects, t(14;18)‐frequency was significantly higher in IgM memory (median: 380/106) than in antigen‐naïve (median: 16/106) or switched memory (median: 5/106) B cells. All PBMC‐negative subjects nevertheless had detectable t(14;18) in sorted B cells; levels were lower than in PBMC‐positive subjects, but had the same relative predominance. These results suggest that t(14;18) is generated during early B‐cell development in the bone marrow and that affected cells may mature and expand in germinal centres. t(14;18)‐frequency was highest in IgM memory cells, a B‐cell subset that shares immunophenotypic similarities with FL. The significance of these cells as lymphoma precursors or indicators of lymphoma risk remains to be established.
Leucocytosis in polycythaemia vera predicts both inferior survival and leukaemic transformation
Authors: Gangat Naseema , Strand Jacob , Li Chin‐Yang , Wu Wenting , Pardanani Animesh , Tefferi Ayalew 
Published: July 2007

SummaryLeucocytosis (leucocyte count >15 × 109/l) was recently associated with thrombosis in polycythaemia vera (PV). This study sought the prognostic relevance of leucocytosis for survival and leukaemic or fibrotic transformation. Amongst 459 patients with PV seen at our institution in recent years (median age, 60 years; 56% males), 146 deaths and 88 leukaemic (n = 34) or fibrotic (n = 54) transformations were documented. Arterial or venous thrombosis occurred in 14% and 9% of patients at diagnosis and in 25% and 15% during follow‐up, respectively. Multivariate analysis identified the advanced age (P < 0·0001), leucocytosis (leucocyte count ≥15 × 109/l; P = 0·0006) and arterial thrombosis at diagnosis (P = 0·01) as independent predictors of inferior survival. In the absence of the first two risk factors, median survival was projected at 272 months as opposed to 108 months in the presence of both risk factors (P < 0·0001). Leucocytosis was also identified as an independent predictor of both leukaemic transformation and venous thrombosis during follow‐up. Time‐to‐event analysis did not disclose a significant association between single or multiple cytotoxic drug exposure and either leukaemic or fibrotic transformation. The current study highlighted the prognostic relevance of leucocytosis on various aspects of the disease in PV.
Centrosome aberrations after nilotinib and imatinib treatment in vitro are associated with mitotic spindle defects and genetic instability
Authors: Fabarius Alice , Giehl Michelle , Frank Oliver , Spiess Birgit , Zheng Chun , Müller Martin C. , Weiss Christel , Duesberg Peter , Hehlmann Rüdiger , Hochhaus Andreas , Seifarth Wolfgang 
Published: July 2007

SummaryCentrosomes play fundamental roles in mitotic spindle organisation, chromosome segregation and maintenance of genetic stability. Recently, we have demonstrated that the tyrosine kinase inhibitor imatinib induces centrosome and chromosome aberrations in vitro. Here, we comparatively investigated the effects of imatinib and the more potent successor drug nilotinib on centrosome, mitotic spindle and karyotype status in primary human fibroblasts. Therapeutic doses of imatinib and/or nilotinib administered separately, consecutively or in combination similarly induced centrosome, mitotic spindle, and karyotype aberrations. Our data suggest that distinct tyrosine kinases likewise targeted by both drugs are essential actuators in maintenance of centrosome and karyotype integrity.
Identification of novel allergens of Aspergillus fumigatus using immunoproteomics approach
Authors: Gautam P. , Sundaram C. S. , Madan T. , Gade W. N. , Shah A. , Sirdeshmukh R. , Sarma P. U. 
Published: July 2007

SummaryBackground
Approximately 20% of the world's asthmatics are suffering from Aspergillus fumigatus (Afu)‐induced allergies. The characterization of specific IgE‐inducing allergens in allergic aspergillosis patients is fundamental for clinical diagnosis and for immunotherapy.Methods
Immunoproteomics combined with mass spectrometric analysis was used to identify proteins of third‐week culture filtrate (3wcf) potentially responsible for Afu‐specific IgE immunoreactivity, using pooled sera from Afu‐sensitized asthmatics. Their allergenic potential was also tested against patients with allergic bronchopulmonary aspergillosis (ABPA), by two‐dimensional (2‐D) gel electrophoresis immunoblotting of 3wcf proteins with individual sera from such patients. This helped us to establish a set of candidate allergens, which could be explored further for diagnostic application in allergic aspergillosis asthmatics including ABPA.Results
Peptide mass fingerprint using matrix‐assisted laser desorption/ionization‐time of flight‐mass spectrometry (MALDI‐TOF‐MS) and/or de novo sequencing by MS/MS analysis of the protein spots from 2‐D gels led to the identification of a total of 16 allergens of Afu. Eleven of them are being reported as allergens for the first time and five had been reported earlier. Putative isoforms of the proteins Asp f 13 and chitosanase have been observed for the first time. When studied for reactivity of these proteins among patients with ABPA using their individual sera, these patients exhibited sensitization although the pattern was varying. Taken together, these proteins could thus be considered as potential allergens even among patients with ABPA. Three of these proteins viz. the hypothetical protein (# spot no. 5), extracellular arabinase (# spot no. 6) and chitosanase (# spot no. 11) could be major allergens with specific IgE immunoreactivity with six out of eight patients' sera.Conclusions
The immunoproteomic approach applied to the analysis of culture filtrate proteins resulted in the identification of several candidate allergens, many of them novel, contributing to the catalogue of Afu allergenic proteins, which would facilitate improved serodiagnosis for allergic aspergillosis. In addition, the immunoreactivity of these proteins observed among the patients with ABPA may be potentially useful for its serodiagnosis and opens up further opportunities for the development of personalized immunotherapeutics for patients with ABPA.