bluuebunny/crossref_metadata_2025_split huggingface dataset:
Festschrift In vitro synthesis of IgE by human peripheral blood leucocytes: VI Seasonal variations in synthesis of rye pollen (Lolium perenne) specific IgE
Authors: Turner KJ , Siemensma NP , Krska KD , Cameron KJ 
Published: July 2007

SummaryFractionation by Percoll density cetrifugation of peripheral blood leucocyte cells, from atopic subjects with seasonal hay fever, unmasked IgE‐B cell populations whose individual capacities to synthesize IgE in vitro were obscured in cultures of unfractionated B cells. B cell cultures from all six subjects in the study released rye pollen‐specific IgE during the 6 days of culture, but actual synthesis was significant only in October, the pollen season. Synthesis in October occurred most frequently in cultures of mature, low density B cells, which generally responded to the addition of autologous T cells with enhanced synthesis (T‐help). T‐help was also found for high density B ceils in the mid‐winter (July) cultures. Total IgE synthesis in vitro demonstrated a less seasonal relationship, although it tended to be maximal for low density B cell cultures in October and for high density B cells in May. All B cell cultures contained preformed total and rye‐specific IgE antibody which persisted throughout the pre‐ and post‐pollen seasons, particularly in the low density B cell fractions, even in the absence of de novo synthesis. Moreover, the intracellular levels of rye pollen‐specific IgE antibody were often higher in the winter than in the peak of the pollen season. The relevance of this preformed IgE remains to be established.
Intracellular pathway of interleukin‐2 receptors studied using immunogold electron microscopy
Authors: McCrae Cameron , Maxwell Lesley , Ceredig Rhodri 
Published: July 2007

SummaryThe fate of internalized interleukin‐2 receptors (IL‐2R) on proliferating T cell blasts and Lyt‐2−/L3T4− thymocytes was studied by immunogold electron microscopy. Immediately following labeling. IL‐2R were found in coated pits and with lime there was sequential appearance of gold particles in smooth vesicles or endosomes, multivesicular bodies and lysosomes. Thus the IL‐2R appears to be a member of cell surface receptors internalized by endocytosis via coated pits.
Murine candidiasis: Strain dependence of host responses after immunization
Authors: Ashman RB , Papadimitriou JM 
Published: July 2007

SummaryAfter recovery from acute infection with live Candida albicans, both CBA/H and BALB/c mice show increased resistance to colonization by the organism. However, the ‘susceptible’ CBA/H mice develop much stronger protective responses than do ‘resistant’ BALB/c mice. This is manifested particularly as a substantial amelioration of the severity of the lesions in the brain, and a very marked reduction in the number of fungal units therein. Analysis of granulocyte function in normal and immune mice of the two strains tended to exclude this as a basis for the different patterns of susceptibility and resistance.
Mg2+‐dependent adenosine triphosphatase: An enzyme marker for ovine T lymphocytes
Authors: Alders RG , Landsverk T , Shelton JN 
Published: July 2007

SummarySheep T lymphocytes showed a cell surface magnesium‐dependent adenosine triphosphatase (Mg2+‐ATPase) reaction, which is reported to be characteristic of human B lymphocytes. In cryostat sections of lymph nodes, spleen and thymus. Mg2+‐ATPase positive regions closely matched those labelled by sheep pan T monoclonal antibodies (Moab). An Mg2+‐ATPase reaction was also found in fibroblastic recticulum cells of T cell regions in lymph nodes. Double labelling of cells from peripheral blood and peripheral lymph for Mg2+‐ATPase and the pan T marker showed that 78% of the lymphocytes were positive for both of these markers. In cell suspensions enriched for B lymphocytes the percentage of cells positively labelled was decreased to 37%. Samples of each cell population which were labelled with a pan T Moab and analysed by flow microfluorometry revealed T cell levels which were not significantly different from those obtained by histochemical or immunohistochemical techniques. Less than 1% of lymphocytes positive for heavy and light chains of immunoglobulin (Ig) G were labelled with Mg2+‐ATPase. Veiled cells in lymph and monocytes showed a cytoplasmic Mg2+‐ATPase reaction.
Electrophoretic and immunoblot analysis of Cryptosporidium oocysts
Authors: Lumb R , Lanser JA , O'Donoghue PJ 
Published: July 2007

SummaryCryptosporidium oocysts were recovered by density gradient centrifugation from diarrhoeal faeces of four human patients and one goat kid. Goat‐derived oocysts were further treated with excystation medium and the excysted oocyst walls purified by isopycnic ultracentrifugation. Soluble extracts from intact oocysts and the oocyst wall preparation were analysed by SDS‐PAGE. Fifty‐one polypeptide bands were detected in intact oocyst preparations: 48 were in the range 14 000–200 000 molecular weight (MW), two bands were less than 14 000 MW and one band was above 200 000 MW. Twenty‐one bands were detected in the oocyst wall preparation, all within the range 14 000–200 000 MW. Immunoblot analysis of Cryptosporidium polypeptides using acute or convalescent human and goat sera revealed a large number of reactive bands. Varying degrees of heterogeneity were observed within and between the two serum groups. Nine of the 10 human sera and all of the goat kid sera reacted with a 23 000 MW and 32 000 MW antigen. A 15 500 MW antigen was also detected by all the goat and four of the 10 human sera. Both serum groups reacted with various antigens above 40 000 MW. Surface labelling of three human isolates of Cryptosporidium oocysts with 125I was performed using the Bolton and Hunter reagent. The solubilized preparations were separated by SDS‐PAGE on 12% and 18% slab gels and autoradiographed. Common bands were seen at 15 500, 32 000, 47 500, 79 000 and 96 000 MW. Some variation in the molecular weight of polypeptides labelled with 125I was observed among the three isolates. These studies indicate that the 32 000 MW antigen appears to be a suitable candidate for the preparation of an antibody probe because it is common to many isolates and is located on the exterior of the oocyst wall.
Resting (IL‐2 non‐responsive) precursors of human T cell receptor γδ‐positive cells (TCR1 cells) are activated by a two signal process
Authors: Warren Hilary S 
Published: July 2007

SummaryPrecursors of T cells expressing the γδ‐T cell receptor (TCR1 cells) have been identified in a resting (IL‐2 non‐responsive) subpopulation of human peripheral blood mononuclear cells (PBMC). Activation of the TCR1 precursor cells into proliferating and cytotoxic cells requires two signals, viz. IL‐2 and either activated T cells (autologous or allogeneic) or malignant melanoma cells (MM‐170). The activation process is inhibited by 0.1 μg/ml cyclosporine. CD3 expression on TCR1 precursor cells was low, since the precursor cells were not always adequately depleted by OKT3 plus complement. Natural killer cells were generated from the same resting subpopulation of PBMC and by the same set of activation stimuli as were the TCR1 cells, suggesting a common pathway for activation of both cell types.
Changes in cell surface antigen expression during murine bone marrow cell regeneration in vivo and proliferation in vitro
Authors: Bertoncello I , Bartelmez SH , Bradley TR , Hodgson GS 
Published: July 2007

SummaryModulations in surface antigen expression during marrow regeneration in vivo, and proliferation in vitro in response to haemopoietic growth factors, were studied using a panel of monoclonal antibodies recognizing antigenic determinants expressed by primitive multipotential progenitor cells (Thy‐1, Qa‐m7), or lineage antigens restricted to committed progenitors and differentiated cells of the neutrophil/macrophage (7/4) and B lymphocyte (B220) lineages. These two categories of antigen exhibited differing responses to marrow perturbation and proliferation. Following administration of a cytotoxic dose of 5‐fluorouracil, or lethal irradiation and transplantation of normal donor marrow, the levels of Thy‐1 and Qa‐m7 antigen expression rapidly increase, reaching a peak at the onset of regeneration: the nadir of marrow cellularity. Expression of these antigens returns to normal as regeneration proceeds and marrow is reconstituted. 7/4 and B220 antigen expression reflect the presence or absence of maturing cells bearing these markers: antigen expression declining following perturbation, and re‐emerging during the course of regeneration. In vitro, when marrow cells taken from mice 8 days following treatment with 5‐FU are grown in liquid culture in the presence of colony‐stimulating factor‐1 plus bladder cell carcinoma cell line 5637 conditioned medium, marrow cells are stimulated to proliferate and differentiate along the neutrophil/ macrophage lineage. 7/4 antigen expression increases throughout the culture period, and B220 antigen is undetectable after the fifth day of culture. Thy‐1 antigen expression also rises and remains elevated, and Qa‐m7 antigen expression remains stable.
Proteoglycans synthesized by human polymorphonuclear leucocytes in vitro
Authors: Bartold PM , Harkin DG , Bignold LP 
Published: July 2007

SummaryPolymorphonuclear leucocytes (PMN) were assessed in vitro for their ability to synthesize and secrete proteoglycans. The PMN were isolated from human peripheral blood and were found to contain < 5% mononuclear cells. Following 24 h incubation in the presence of (35S)‐sulfate, significant quantities of 35S‐labelled macromolecules were detected both within the culture medium and cells. Although the PMN preparations contained some platelets (approximately five platelets: one PMN), culture of platelets alone did not result in the detection of any 35S‐labelled macromolecules in either the medium or platelets. 35S/3H‐labelled macromolecules from the PMN cultures were identified as proteoglycans on the basis of their degradation by papain, alkaline sodium borohydride, chondroitinase ACII, chondroitinase ABC and nitrous acid. The labelled proteoglycans isolated from the medium and cells eluted from Sepharose CL‐4B with a Kav of 0·63; this indicated a small size compared with many other proteoglycans. The glycosaminoglycans associated with the proteoglycans were identified as heparan sulfate, chondroitin sulfate and dermatan sulfate, with chondroitin sulfate being the principal component. The average molecular weight of the glycosaminoglycans was determined to be 16 000. Therefore, the data from this study demonstrate the ability of human PMN to synthesize and secrete proteoglycans in vitro which appear to differ from those synthesized by mesenchymal cells with respect to molecular size and glycosaminoglycan composition
Ontogeny, morphology and tissue distribution of a unique subset of CD4−CD8− sheep T lymphocytes
Authors: McClure SJ , Hein WR , Yamaguchi K , Dudler L , Beya M‐F , Miyasaka M 
Published: July 2007

SummaryThe morphology, distribution and ontogeny of the 197+ T lymphocyte subpopulation is described. Cells were identified by Immunofluorescent and immunoenzymic staining of cell suspensions and tissue sections. In the circulation, 197+ cells are small and regular, indistinguishable in size from peripheral CD4+ and CD8+ cells, with little cytoplasm and a large amount of condensed chromatin. In the post‐natal animal they are unevenly distributed, being most common in the circulatory pathways, particularly in the blood. In the thymus they chiefly localize in the regions around Hassal's corpuscles and medullary blood vessels. They are totally absent from B cell areas in all tissues. They are the last of the T cells 10 appear in ontogeny, and are first detected in the thymus. Their frequency in blood is age‐dependent with peak levels occurring perinatally. There is a post‐natal decline in the frequency of 197+ cells in ileocaecal but not in prescapular lymph nodes. We conclude that these T cells differ from the more commonly described T cells, not only in their surface expression of the CD4, CD8 and T19 antigens, but also in the time of their first appearance, their age‐related prevalence and their distribution between and within tissues.
Humoral and cell‐mediated immune responses to recombinant vaccinia viruses in mice
Authors: Andrew ME , Coupar BEH , Boyle DB 
Published: July 2007

SummaryIntravenous (i.v.) immunization of mice with recombinant vaccinia viruses stimulated the highest antibody and cytotoxic T lymphocyte (CTL) responses when i.v., intraperitoneal (i.p). intranasal (i.n.), footpad (f.p.) and tail scarification (t.s.) routes were compared. Intraperitoneal immunization of mice resulted in high CTL activity, but low antibody responses. Antibody levels after i.n., f.p., and t.s. immunization were slightly lower than following i.v. immunization. Although very low levels of CTL primary activity were stimulated by i.n. or f.p. inoculation of recombinant vaccinia virus, levels of secondary CTL activity after in vitro restimulation of splenocytes were as high as those seen from i.v. immunized splenocytes. The effect of the thymidine kinase (TK) phenotype of the virus also was examined. Wildtype (TK positive) viruses replicated to a higher titre in vivo and stimulated higher antibody and CTL responses than a TK negative recombinant virus. A recombinant virus that expressed the TK gene from herpes simplex virus at a low level was intermediate between wildtype and TK negative virus, both in virus replication in vivo and in immunogenicity
Production and characterization of murine monoclonal antibody to human α‐lactalbumin
Authors: Thean ET , Toh B‐H 
Published: July 2007

SummaryHuman α‐lactalbumin (α‐LA), a milk protein normally produced by, and restricted to, functionally differentiated breast epithelial cells has been shown immunohistochemically to be a good marker for breast cancer. Antibodies with specificity only for human α‐LA have not previously been reported. The present study documents the production and characterization of an IgG1 murine monoclonal antibody with specificity restricted only to human α‐LA. This monoclonal antibody, designated ET‐1, was purified by affinity chromatography using human α‐LA. Specificity of ET‐1 for human α‐LA was established by enzyme linked immunosorbent assay (ELISA), absorption studies, immunoprecipitation and by immunoblotting. ET‐1 binds to human α‐LA with a KD of 7·41 × 10‐8 mol/l and does not cross‐react with bovine α‐LA. This unique reactivity of ET‐1, which is not inherently shared by polyclonal antisera, should enable the antibody to be used for the development of a sensitive immunoassay for circulating human α‐LA.
Antipsoriatic effects of avarol‐3′‐thiosalicylate are mediated by inhibition of TNF‐αgeneration and NF‐κB activation in mouse skin
Authors: Amigó M , Payá M , De Rosa S , Terencio M C 
Published: July 2007

Background and purpose:Avarol is a marine sesquiterpenoid hydroquinone with anti‐inflammatory and antipsoriatic properties. The aim of this study was to evaluate thein vitroandin vivopharmacological behaviour of the derivative avarol‐3′‐thiosalicylate (TA) on some inflammatory parameters related to the pathogenesis of psoriasis.Experimental approach:Human neutrophils and monocytes as well as the human keratinocyte cell line HaCaT were used to study the effect of TA on oxidative stress, the arachidonic acid pathway, tumour necrosis factor‐α(TNF‐α) release and nuclear factor‐κB (NF‐κB) activation. All these parameters were also determinedin vivousing the zymosan induced mouse air pouch model and the 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) induced mouse epidermal hyperplasia model.Key results:TA showed antioxidant properties in human neutrophils and in the hypoxanthine/xanthine oxidase assay. This compound reduced, in a concentration‐dependent manner, leukotriene B4, prostaglandin E2and TNF‐αproduction in activated leukocytes. Oral and intrapouch administration of TA in the mouse air pouch model produced a dose‐dependent reduction of all these inflammatory mediators. TA also inhibited secretory phospholipase A2activity and NF‐κB DNA‐binding in HaCaT keratinocytes. In TPA‐induced mouse epidermal hyperplasia, topical administration of TA reduced oedema, leukocyte infiltration, eicosanoid levels and TNF‐αin skin. In addition, interleukin (IL)‐1βand IL‐2 production were also inhibited. Finally, TA was also capable of suppressing NF‐κB nuclear translocationin vivo.Conclusions and implications:TA inhibited several key biomarkers up‐regulated in the inflammatory response of psoriatic skin and this compound could be a promising antipsoriatic agent.British Journal of Pharmacology(2007)152, 353–365; doi:10.1038/sj.bjp.0707394; published online 16 July 2007
Potato spindle tuber viroid: the simplicity paradox resolved?
Authors: OWENS ROBERT A. 
Published: July 2007

SUMMARYTaxonomy:   Potato spindle tuber viroid (PSTVd) is the type species of the genus Posipiviroid, family Pospiviroidae. An absence of hammerhead ribozymes and the presence of a ‘central conserved region’ distinguish PSTVd and related viroids from members of a second viroid family, the Avsunviroidae.Physical properties:   Viroids are small, unencapsidated, circular, single‐stranded RNA molecules which replicate autonomously when inoculated into host plants. Because viroids are non‐protein‐coding RNAs, designation of the more abundant, highly infectious polarity strand as the positive strand is arbitrary. PSTVd assumes a rod‐like, highly structured conformation that is resistant to nuclease degradation in vitro. Naturally occurring sequence variants of PSTVd range in size from 356 to 361 nt.Hosts and symptoms:   The natural host range of PSTVd—cultivated potato, certain other Solanum spp., and avocado—appears to be quite limited. Foliar symptoms in potato are often obscure, and the severity of tuber symptoms (elongation with the appearance of prominent bud scales/eyebrows and growth cracks) depends on both temperature and length of infection. PSTVd has a broad experimental host range, especially among solanaceous species, and strains are classified as mild, intermediate or severe based upon the symptoms observed in sensitive tomato cultivars. These symptoms include shortening of internodes, petioles and mid‐ribs, severe epinasty and wrinkling of the leaves, and necrosis of mid‐ribs, petioles and stems.
MHC class II transactivator represses human IL‐4 gene transcription by interruption of promoter binding with CBP/p300, STAT6 and NFAT1 via histone hypoacetylation
Authors: Zhou Xiaorong , Jiang Yang , Lu Liming , Ding Qing , Jiao Zhijun , Zhou Yun , Xin Lijun , Chou Kuang‐Yen 
Published: July 2007

SummaryIn addition to its property of enhancing major histocompatibility complex (MHC) class II expression, the class II transactivator (CIITA) was recently demonstrated to be involved in T helper type 1/type 2 (Th1/Th2) differentiation by regulating interleukin‐4 (IL‐4) gene transcription. There was however, controversy regarding whether CIITA promotes or suppresses IL‐4 expression in the experiments with transgenic mice. To clarify the discrepancy by using simpler experimental systems, human Jurkat T cells that express IL‐4 but not interferon‐γ, even if stimulated with phorbol 12‐myristate 13‐acetate plus ionomycin, were used for CIITA transfection. Significant suppression of IL‐4 gene expression was demonstrated. Simultaneously, histones H3 and H4 in the IL‐4 promoter were hypoacetylated. The suppression could be totally reversed by the histone deacetylatase inhibitor trichostatin A. Furthermore, the IL‐4 expression was determined in primarily established human Th1/Th2 cells to which CIITA small interference RNA (siRNA) had been introduced. A substantially increased level of IL‐4 was recorded in the CIITA siRNA‐transfected Th1 cells, which was in parallel with significantly enhanced acetylation in histone H3 of the IL‐4 promoter. Chromatin immunoprecipitation analysis indicated that CIITA abrogated the binding of coactivator CBP/p300 and transcription factors STAT6/NFAT1 to IL‐4 promoter in the CIITA‐transfected cells. In conclusion, CIITA was active in the repression of transcription activation of human IL‐4 gene in both the T‐cell line and the primary human CD4 T cells by preventing transcription factors from binding to IL‐4 promoter through histone hypoacetylation. Our data confirm a potential significant role of CIITA in controlling Th1/Th2 differentiation via modulation of IL‐4 gene activation.
Impaired function of CD4+/CD25+ T regulatory lymphocytes characterizes the self‐limited hepatitis A virus infection
Authors: Perrella Alessandro , Vitiello Laura , Atripaldi Luigi , Sbreglia Costanza , Grattacaso Stella , Bellopede Pasquale , Patarino Tommaso , Morelli Giuseppe , Altamura Simona , Racioppi Luigi , Perrella Oreste 
Published: July 2007

AbstractBackground and Aim:  Hepatitis A virus (HAV) causes a transient illness leaving permanent protection against reinfection. Few data are available on the regulatory mechanisms involved in the CD4+ T helper activation. We aimed to investigate the frequency and function of CD3+/CD4+/CD25+ T cells with regulatory function (Tregs) during acute HAV infection.Methods:  We enrolled 35 consecutive patients and 15 healthy donors, enumerated Tregs by flow cytometry assay and evaluated, after immunomagnetical sorting with magnetic beads, their ability to inhibit the proliferation of CD4+/CD25– T lymphocytes at different ratios (1:1, 1:10, 1:20).Results:  All patients had the usual course of infection. Our immunological analysis showed Tregs frequency in these patients (6.5% [range, 5–8.8%]; 36 [range, 10–87] cells) did not have any statistical difference compared with healthy donors (6% [range, 5–8%]; 48 (range, 23–71) cells), while their ability to suppress CD4+/CD25– was drastically reduced at different ratios (Mann–Whitney U‐test; ratio 1:1, 93% vs 72%, z = −3.34, P < 0.0001; ratio 1:10, 86% vs 51%, z = −4.04, P < 0.001; ratio 1:20, 56% vs 30%, z = −3.43, P < 0.0001). After the seroconversion, CD4+/CD25+ frequency and function in HAV‐infected patients did not differ from healthy individuals.Conclusion:  CD4+/CD25+ T cells seem to be impaired in their function during the HAV acute infection. This evidence might help to determine an optimal T helper cell immune network that is a predisposing factor for a self‐limiting disease.