bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dividing cells in bone marrow and spleen incorporate bromodeoxyuridine with high efficiency
Authors: Schittek Birgit , Rajewsky Klaus , Förster Irmgard 
Published: March 2007

AbstractLabeling of dividing cells with the thymidine analogue 5‐bromo‐2′‐deoxyuridine (BrdUrd) has been frequently used to determine the life‐span of cells in various lymphocyte subsets. In this study we address the question of whether administration of BrdUrd in vivo allows labeling of proliferating lymphocytes at early as well as later stages of maturation with high efficiency. For this purpose, the proportion of BrdUrd‐labeled cells among all cells synthesizing DNA was determined in the bone marrow and spleen of mice that had received a single injection of BrdUrd or, alternatively, had been fed with BrdUrd for 1 week. On the average, 87% of bone marrow and 83% of spleen cells in the S phase of the cell cycle, as determined by DNA content, were labeled with BrdUrd 1.5 h following injection of the drug. We conclude from these data that administration of BrdUrd in vivo allows labeling of the vast majority of the dividing cells in both primary and secondary lymphoid organs and thus represents an efficient method to determine the life‐span of lymphoid cells in vivo.
Transcription, translation and secretion of interleukin 1 and tumor necrosis factor: effects of tebufelone, a dual cyclooxygenase/5‐lipoxygenase inhibitor
Authors: Sirko Steven P. , Schindler Ralf , Doyle Matthew J. , Weisman Steven M. , Dinarello Charles A. 
Published: March 2007

AbstractWe examined the effect of tebufelone, a dual cyclooxygenase (CO)/5‐lipoxygen‐ase (LO) inhibitor, on the synthesis, secretion and gene expression of interleukin (IL) 1β and tumor necrosis factor (TNF)‐α by human peripheral blood mono‐nuclear cells (PBMC). Basal concentrations of immunoreactive IL 1β and TNF‐α after 18–24 h, in the absence or presence of tebufelone (≤ 12.5 μM), were near the limit of detection (100 pg/ml). By contrast, preincubation (1 h) of cells, in amounts of tebufelone which decrease the formation of leukotriene (LT) B4, markedly enhanced (up to 500%) the synthesis of IL 1β and TNF‐α following lipopolysaccharide (LPS), heat‐killed Staphylococcus epidermidis or concanavalin A stimulation. Moreover, a disproportionate amount of the overall increase in IL 1(α and β) was secreted in contrast to the amount which remained cell associated, an effect unrelated to cell damage or leakage as tebufelone had no effect on either lactate dehydrogenase release by PBMC, or mitochondrial dehydrogenases of adherent monocytes as detected by enzymatic cleavage of the substrate 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐tetrazolium bromide. There was no inverse correlation between the changes in prostaglandin (PG)E2 levels and TNF‐α or IL 1β synthesis, and when PG formation was maximally inhibited by preincubating the cells in indomethacin, tebufelone, added 1 h before the stimulus, continued to enhance the synthesis of IL 1β although not that of TNF‐α. The addition of the CO/5‐LO inhibitor 2 h after LPS stimulation, however, did not interfere with IL 1β synthesis, suggesting that tebufelone interacts with an early event(s) in the activation of PBMC. For IL 1β and TNF‐α, basal and stimulated (4 h post LPS) mRNA levels were not increased by tebufelone, despite a concomitant increase in the synthesis of IL1β. In conclusion, we have demonstrated that tebufelone enhances IL 1(α and β) and TNF‐α synthesis at concentrations which suppress leukotriene formation. These findings argue against a role of 5‐LO products as necessary intermediates of IL 1(α and β) and TNF‐α synthesis.
Immobilized anti‐CD5 together with prolonged activation of protein kinase C induce interleukin 2‐dependent T cell growth: evidence for signal transduction through CD5
Authors: Vandenberghe Peter , Ceuppens Jan L. 
Published: March 2007

AbstractMonoclonal antibodies (mAb) identifying the CD5 antigen were used to stimulate human peripheral blood T lymphocytes. Three out of three anti‐CD5 mAb, 10.2, OKT1 and anti‐Leu‐1 induced vigorous proliferation of purified T cells in the presence of 1.6 nM phorbol 12‐myristate 13‐acetate (PMA). Immobilization of anti‐CD5 mAb on a solid support was necessary for the induction of a proliferative response. Neither 1.6 nM PMA, nor immobilized anti‐CD5 mAb were mitogenic as a sole stimulus. mAb identifying CD4, CD7, CD11a, CD18, and major histocompatibility complex class I molecules were not comitogenic with PMA. Anti‐CD5/PMA‐induced cell proliferation proceeded by an interleukin 2 (IL2)‐dependent mechanism, as was demonstrated by the cell surface expression of the p55 chain of the IL2 receptor (IL 2R), the production of IL2 and the inhibition of the proliferative response by anti‐IL2R mAb anti‐Tac. There was no strict requirement for detectable numbers of monocytes, although cell proliferation could be enhanced by the monocyte‐derived cytokines IL 1 and IL6. Phorbol 12, 13‐dibutyrate and mezerein could substitute for PMA in this activation pathway, but synthetic diacylglycerols and phorbol esters that do not activate protein kinase C (PKC) could not, indicating a need for prolonged activation of PKC. T cells activated by anti‐CD5/PMA are sensitive to inhibition by cyclosporin A (CsA) and by prostaglandin E2 (PGE2). This contrasts with anti‐CD28/PMA‐induced Tcell proliferation, which is resistant to CsA and PGE2. Cell surface expression of CD5 was strongly up‐regulated by PMA, whereas CD3 expression was down‐regulated. We conclude that T cell activation can be triggered by engagement of CD5 by immobilized anti‐CD5 mAb, combined with prolonged activation of PKC. These data support a role for CD5 as an independent signal transducing molecule.
Ilal Peyer's patch emigrants are predominantly B cells and travel to all lymphoid tissues in sheep
Authors: Reynolds John D. , Kennedy Laurie , Peppard Jane , Pabst Reinhard 
Published: March 2007

AbstractThe ileal Peyer's patch (PP) was selectively labeled with fluorescein isothiocyanate by extracorporeal perfusion in 7–12 week‐old lambs and the lymphocyte linege and fate of the emigrants was determined by fluorescence microscopy and flow cytometry. PP emigrants were found in all tissues examined, accounting for 10%–15% of ileal mesenteric lymph node (MLN), 1%–2% of jejunal MLN, jejunal PP, prescapular lymph node (PLN) and 3%–4% of spleen cells. All ileal PP emigrants enter the ileal MLN on their way to the circulation. Removal of the MLN prior to perfusion enabled emigrants to go directly to the circulation and extravasate in distant tissues faster than in intact animals. The ileal MLN might provide an additional level of regulation for ileal PP emigrants. The perfused ileal PP contained about 25 times more B cells than T cells. The emigrant cells found in different tissues included both T and B cells but came to reflect, although to a lesser degree, the B cell composition of the tissue from which they were derived. One day after perfusion the composition of PP emigrants was similar to that of the tissue within which they were found; the spleen was the exception with a bias towards B cells. By day 3 the ratio of B to T cells in the PP emigrants was 1 for jejunal MLN and PLN, 1.5 for ileal MLN and jejunal PP, and 4–5 for the spleen and blood. It was concluded that the PP‐derived T cells were recirculating T cells that were in the ileal PP at the time of perfusion. These cells emigrated rapidly and equilibrated such that they accounted for about 1.5% of the T cell pool in various tissues. Most PP‐derived B cells were probably produced in the PP. The greatest contribution (24.4%) that ileal PP emigrants made to the B cell pool of a tissue was with the ileal MLN through which they are obliged to pass. The contribution was lower but still very significant in blood (8.9%), spleen (6.8%), PLN (3.9%), jejunal MLN (3.5%) and jejunal PP (1.8%). There was no evidence that ileal PP emigrants made a greater relative contribution to either T or B cell populations in MLN or jejunal PP than to non‐gut‐associated sites. The B cells were distributed throughout the immune system, which is in accordance with the proposal that the ileal PP is a site of primary B cell genesis in sheep.
The accessory function of B lymphocytes is resistant to the adverse effects of UV radiation
Authors: Hertl Michael , Kaplan David R. , Fayen John D. , Panuska James R. , Ellner Jerrold J. , Elmets Craig A. 
Published: March 2007

AbstractThe effect of UV radiation on the accessory activities of B lymphoblastoid cell lines (B‐LCL) was investigated in three types of in vitro T lymphocyte proliferation assay, each of which differed in its accessory requirements. In contrast to monocytes whose accessory function was universally sensitive to UV radiation, B‐LCL were resistant to UV in oxidative mitogenesis and staphylococcal enterotoxin B assays, in which stimulus processing was not a requirement. Expression of membrane interleukin (IL) 1 and HLA‐DR antigens by B‐LCL and monocytes was not affected by UV, nor was surface membrane expression of intercellular adhesion molecule‐1 (ICAM‐1) on B‐LCL. These results were in marked contrast to monocytes in which there was a >65% reduction in ICAM‐1 expression. When UV‐irradiated B‐LCL were employed as antigen‐presenting cells for tetanus toxoid‐dependent T cell stimulation, a reduction in antigen‐presenting function was observed. However, pulsing of B‐LCL with tetanus toxoid prior to UV irradiation preserved their antigen‐ presenting capacity in this system also. These findings indicate that there is differential UV sensitivity among accessory cells which may be explained by different effects of UV radiation on antigen processing and adhesion molecule expression.
Fibronectin associated with infiltrating T lymphocytes. Evidence for in situ localization in biopsies and synthesis in vitro
Authors: Sundqvist Karl‐Gösta , Wanger Lena , Heimdahl Anders , Lönnqvist Berit , Hauzenberger Dan 
Published: March 2007

AbstractDermal and mucosal lymphocyte infiltrates in patients with lichen ruber planus and chronic graft‐vs.‐host disease exhibited reactivity with anti‐fibronectin antibodies. This reactivity was associated with the lymphocytes and localized pericellularly. In contrast, biopsy areas outside lymphocyte accumulations were relatively devoid of reactivity with anti‐fibronectin antibodies. Furthermore, the corresponding biopsies from healthy individuals or patients without lymphocyte infiltration showed negligible reactivity with anti‐fibronectin antibodies. The fibronectin associated with infiltrating lymphocytes in biopsies may be exogenous of non‐lymphoid origin. However, another possibility suggested by in vitro experiments is that this fibronectin is lymphocyte derived. Thus, during cultivation in vitro lymphocytes appear to synthesize a component with fibronectin‐like properties. Furthermore, a prerequisite for detection of this synthesis was that the cells were cultured in the presence of serum depleted of fibronectin. These results point to the possibility that fibronectin may play a role for lymphocyte interactions with tissues during infiltrative processes.
Evidence for regulation of naturally activated autoreactive B cells
Authors: Zöller Margot , Achtnich Martin 
Published: March 2007

AbstractA large fraction of naturally activated B cells in the neonate displays degenerate specificity, including reactivity with autoantigens. Transgenic mouse models of autoreactive B cells are mainly concerned with monospecific B cells of high avidity, and the fate of naturally activated autoreactive B cells is still a matter of debate. To pursue this question further, we chose an IgM autoantibody with a recurrent idiotype (Id), i.e. Sp6, because transgenic mice expressing this IgM also were available. In a first approach monoclonal antibodies (mAb) derived from untreated, antigenically stimulated and transgenic mice were used to test whether there were indications for deletion or for Id regulation of naturally activated autoreactive B cells.Over 90% of thymus and spleen cell derived hybridomas from 6‐day‐old Sp6‐transgenic mice were trinitrophenyl (TNP) reactive, carried the Sp6‐Id and bound to a panel of self antigens, including mouse albumin. We failed to obtain B cell hybridomas from the thymus of 28‐day‐old Sp6‐transgenic mice. Furthermore, we could not detect any mAb carrying an anti‐Sp6 Id, but Sp6 did weakly bind to itself. About 25% of mAb derived from control mice displayed degenerate specificity, the majority of them also were TNP reactive. The Sp6 Id was found at a low frequency and a comparable number of mAb carried an anti‐Sp6 Id. Prenatal manipulation at the antigen level (trinitrobenzenesulfonic acid treatment) led to a transient expansion of TNP‐ and autoreactive mAb. The number of mAb carrying the Sp6 Id was not increased, but mAb carrying an anti‐Sp6 Id were observed at high frequency. Those mAb also displayed degenerate specificity.Since Sp6‐transgenic mice were perfectly healthy, it is concluded that this particular autoreactive antibody of degenerate specificity cannot be harmful for the developing organism, which may possibly be due to its self‐binding capacity. Furthermore, some process of down‐regulation was indicated by the absence of B cells expressing the transgene in the thymus of young adult mice. Autoreactivity of untreated and prenatally antigen‐treated mice was, in addition, regulated at the Id level. In particular, mAb recognizing the Id of Sp6 were significantly expanded in antigenically stimulated mice. The data were interpreted in the sense that autoreactive B cells appearing early during ontogeny were rather strictly controlled either by (functional) clonal deletion or by idiotypic connectivity.
T cell activation in the absence of interleukin 2 (IL 2) results in the induction of high‐affinity IL 2 receptor unable to transmit a proliferative signal
Authors: Proust Jacques J. , Shaper Nancy L. , Buchholz Meredith A. , Nordin Albert A. 
Published: March 2007

AbstractAlthough interleukin 2 (IL2) clearly up‐regulates the expression of the p55 chain of the IL 2 receptor (IL 2R) little is known about its role in the induction of the high‐affinity IL 2R. Resting T lymphocytes were induced to express IL 2R under experimental conditions in which IL 2 production was not induced or was prevented. Under these conditions high‐ and low‐affinity IL 2R were easily demonstrated by Scatchard analysis. Northern blot analysis confirmed the accumulation of p55 specific mRNA and the absence of the IL 2 transcript. High‐affinity IL 2R induced in the complete absence of IL 2 were unable to transmit a proliferative response unless exposed to extremely high concentrations of IL 2. The addition of picomolar amounts of recombinant IL 2 or the initiation of endogenous IL 2 production during the induction period restored the functionality of high‐affinity IL 2R. Also, T cells induced to generate IL 2 displayed functional high‐affinity IL 2R even in the presence of monoclonal antibodies blocking extracellular IL 2 and IL 2R. These results indicate that the presence of IL 2 during the early phase of T cell activation is an absolute requirement for the induction of fully operational high‐affinity IL 2R and that low amounts of intracellular IL 2 are sufficient to confer functional properties to these receptors. The data also suggest that an intracellular as well as an extracellular high‐affinity structure, expressed as a consequence of cell activation, is responsible for conferring competence to the high‐affinity IL 2R involved in IL 2‐dependent proliferation.
The effect of interleukin 3 upon IgE‐dependent and IgE‐independent basophil degranulation and leukotriene generation
Authors: Kurimoto Yoshiyuki , de Weck Alan L. , Dahinden Clemens A. 
Published: March 2007

AbstractRecent investigations have shown that the hematopoietic growth factor interleukin 3 (IL3) enhances histamine release of mature human basophils. Furthermore, basophils exposed to IL3 generate large amounts of leukotriene C4 in response to C5a, a basophil agonist which by itself is unable to promote lipid mediator formation. Also IL 3 renders the cells responsive to factors which do not otherwise induce basophil mediator release. Here we show in more detail how IL 3 affects the release of preformed and newly synthesized inflammatory mediators by basophils in response to antigen, anti‐IgE, N‐formyl‐methionyl‐leucyl‐phenylalanine (FMLP) and C5a. In cells triggered by maximally effective concentrations of these agonists, IL 3 enhances histamine release, although it more profoundly affects leukotriene generation, in particular in response to stimuli which by themselves are inefficient or poor inducers of lipid mediator formation. This change in the mediator‐release reaction occurs at low IL 3 concentrations, over the same concentration range of IL 3 of 0.01–1.0 U/ml regardless of which triggering agent is used as a second signal. Pretreatment of basophils with IL 3 results in a left shift of the dose‐response curves for mediator release of both IgE‐dependent and IgE‐independent agonists by approximately one order of magnitude. IL 3 affects only the extent and not the time course of IgE‐independent peptide‐induced basophil degranulation. By contrast, histamine and leukotrienes are released more rapidly in response to IgE‐dependent stimulation after IL 3 priming. IL 3 also shortens the lag time and increases the rate of leukotriene generation in basophils triggered by FMLP. The priming process induced by IL 3 does not require extracellular calcium. Basophils exposed to IL 3 release significant amount of mediators in response to C5a, even in EDTA buffers without addition of Ca2+/Mg2+, indicating that in the presence of IL 3 the Ca2+‐dependent mediator release induced by C5a becomes partially Ca2+ independent. Thus, we find that IL 3 strongly affects the mediator profile, the amounts of mediators released, the dose‐response curves and the kinetic of the release reaction in basophils stimulated with diverse agonists. The data further support the hypothesis that IL 3 plays an important role in inflammatory processes, in particular in hypersensitivity reactions.
A new superfamily of lymphoid and melanoma cell proteins with extensive homology to Schistosoma mansoni antigen Sm23
Authors: Gaugitsch Helmut W. , Hofer Erhard , Huber Nathalie E. , Schnabl Eva , Baumruker Thomas 
Published: March 2007

AbstractA novel cDNA clone termed R2 was isolated by subtractive hybridization of a cDNA library of phytohemagglutinin (PHA)/phorbol myristate acetate‐stimulated Jurkat cells and by rescreening a cDNA library of PHA‐stimulated peripheral blood lymphocytes. It hybridizes to a single mRNA species of about 2.2 kb, which is inducible in lymphoid cells and codes for a protein of 267 amino acids which contains four potential transmembrane domains. A computer‐aided comparison showed strong homology to four other membrane proteins, the pan B cell marker CD37, the pan leukocyte marker CD53, the melanoma antigen ME491 and surprisingly, the Schistosoma mansoni antigen Sm23. The four human proteins share a number of additional similarities in their overall structure. These include identical spacing of the transmembrane domains, similar hydro‐phobicity plots, possible N‐linked glycosylation sites of similar number and position as well as similar distribution of the cysteine residues. The majority of these characteristics are still conserved in the evolutionary most distant member of this family, the Schistosoma mansoni antigen Sm23. Here we introduce this new protein superfamily and characterize the inducible, lymphoid‐specific member R2.
Growth of Mycobacterium avium in human monocytes: identification of cytokines which reduce and enhance intracellular microbial growth
Authors: Denis Michel 
Published: March 2007

AbstractHuman monocytes were isolated by standard procedures and their ability to harbor growth of two virulent strains of Mycobacterium avium, TMC724 and TMC7479, was assessed in the absence or presence of cytokines. Both strains of mycobacteria, especially the M. avium TMC7479, grew progressively in untreated human monocytes. Inclusion of certain macrophage‐activating cytokines, such as interferon‐γ in the presence of indomethacin or 1,25(OH2)‐vitamin D3 (calcitriol) led to significant reductions in bacterial growth at 7 days post‐infection. Conversely, treatment of human monocytes with interleukin‐(IL) 1, macrophage‐colony stimulating factor or IL 3 led to an increased permissiveness of these cells for M. avium. Moreover, these cytokines were shown to increase dramatically extracellular M. avium growth in vitro in tissue culture medium. Further, inclusion of antibodies against IL 1β and IL6 in untreated infected monocytes monolayers led to a reduced growth of M. avium, suggesting that infected monocytes produce factors which enhance their susceptibility to M. avium. Overall, my findings suggest that cytokines may play a bidirectional role in atypical mycobacterial infections, by either increasing or decreasing resistance of the monocyte.
Avian CD4 and CD8 interact with a cellular tyrosine protein kinase homologous to mammalian p56lck
Authors: Veillette André , Ratcliffe Michael J. H. 
Published: March 2007

AbstractFunctional as well as immunochemical studies have indicated that chicken T lymphocytes express surface antigens homologous to mammalian CD4 and CD8. The results presented in this report demonstrate that the avian CD4 and CD8 homologs are physically associated with a cellular tyrosine protein kinase related to mammalian p56lck. Furthermore, they show that engagement of either avian CD4 or CD8 is associated with a rapid intracellular tyrosine phosphorylation signal, suggesting that the function of these surface molecules may be mediated through alterations of the associated tyrosine protein kinase. Taken together, these findings demonstrate that the associations of CD4 and CD8 with an intracellular tyrosine protein kinase are evolutionarily conserved, further enhancing the likelihood that they are critical for normal immune functions.
Mapping of the duplicated rabbit immunoglobulin χ light chain locus
Authors: Hole Nichola J. K. , Young‐Cooper Glendowlyn O. , Mage Rose G. 
Published: March 2007

AbstractThe rabbit has two isotypic forms of the immunoglobulin χ light chain, K1 and K2, which probably arose by duplication. In the normal rabbit, only traces of K2 light chains are produced. However, K2 levels are elevated in allotype‐suppressed rabbits and in the Basilea strain which does not produce K1 because of a K1 mRNA splice site mutation. Previous cloning and sequencing showed that each isotype has its own set of Jχ genes but it was not known whether the two isotypes utilize shared or separate sets of Vχ genes. In addition, although genetic linkage of allotypes associated with the K1 and K2 genes has been demonstrated, physical linkage had not been previously demonstrated by overlapping cosmid or phage clones. We used pulsed field and transverse alternating field electrophoresis to obtain megabase maps and to estimate the size of the duplication of the rabbit χ light chain locus. We found that the two Cχ genes are about 1 megabase apart. One explanation for the poor expression of K2, could be great physical distance from Vχ genes. However, we found that there are Vχ, Jχ and Cχ2 genes within a ∼ 105‐kb fragment. Thus, physical distance of Vχ from Cχ2 may not be the basis for poor K2 expression.