bluuebunny/crossref_metadata_2025_split huggingface dataset:
Human monocytes are stimulated for nitric oxide release in vitro by some tumor cells but not by cytokines and lipopolysaccharide
Authors: Zembala Marek , Siedlar Maciej , Pryjma Juliusz , Marcinkiewicz Janusz 
Published: March 2007

AbstractNitric oxide (NO) has been recently identified as a potent mediator of tumoricidal activity of activated macrophages. Macrophages can be activated for tumor cell killing by microbial products, including lipopolysaccharide (LPS) and various cytokines. Here we report that in contrast to mouse macrophages, human peripheral blood monocytes stimulated with cytokines or LPS failed to release NO. Also priming of monocytes with interferon‐γ followed by activation with cytokines or LPS did not cause NO secretion. However, monocytes responded with NO production to stimulation with some human cancer cells but not with untransformed cells. NO production by monocytes was inhibited by NG‐monomethyl‐L‐arginine, specific inhibitor of NO synthase and emetine, an irreversible blocker of protein synthesis. This may imply that human monocytes are unique in their restricted capacity to produce NO following interaction with some tumor cells, but not with other stimulators, and in this respect they may be able to distinguish between malignant and normal cells.
B cell emigration directly from the cortex of lymphoid follicles in the bursa of Fabricius
Authors: Paramithiotis Eustache , Michael J. H. Ratcliffe 
Published: March 2007

AbstractIn the peripheral blood (PBL) of juvenile chickens three populations of B cells have previously been distinguished based on life‐span and origin of cells within each population. In this report we show that the largest PBL B cell subset, population 1 B cells, which are short‐lived cells corresponding to about 60% of PBL B cells and the vast majority of bursal emigrants, exit from the bursa directly from the follicular cortex. This conclusion is based on the specific labeling of rapidly dividing cortical lymphocytes with bromodeoxyuridine, followed by their detection in the periphery prior to the appearance of bromodeoxyuridine labeled cells in the bursa medulla. Furthermore, the rate of emigration of cortical lymphocytes, 1.00 ± 0.1% of PBL B cells per hour, is indistinguishable from the emigration rate of B cells from the bursa as a whole. The anatomical organization of the bursa has evolved to focus gut‐derived antigens from the bursal lumen into the lymphoid follicles. The emigration of cortical bursal cells is discussed in relation to the exposure of bursal lymphocytes to extrinsic antigen.
The functional state of follicular dendritic cells in severe combined immunodeficient (SCID) mice: Role of the lymphocytes
Authors: Yoshida Kikuyoshi , Berg Timo K. Van Den , Dijkstra Christine D. 
Published: March 2007

AbstractIn the present study, we have investigated the capacity of follicular dendritic cells (FDC) to trap immune complexes (IC) in the splenic white pulp of severe combined immunodeficient (SCID) mice and the influence of lymphocyte transfer on FDC function. FDC are absent in the splenic white pulp of naive SCID mice as revealed by in vitro IC trapping assay. One week after transfer of syngeneic lymphocytes, functional FDC with complement receptors appeared in the primary follicles coincident with B cell segregation, and IC were trapped on those FDC in a complement‐dependent manner. Next, we immunized the reconstituted SCID mouse to see whether another type of FDC could be induced in the secondary follicle. Antigenic stimulation induced FDC with an additional capacity to capture IC via FcR γ II. As seen in immunocompetent mice, this type of FDC was located only in the light zone of the secondary follicle. The newly generated FDC did not carry H‐2 antigen of transferred lymphocytes from F1 mice. In SCID mice, in which normally no functional FDC are detectable, the microenvironments of the splenic white pulp have a capacity to develop and differentiate normally after transfer of lymphocytes. Apparently, the generation of functional IC‐trapping FDC causes the induction of complement receptor(s) and Fc receptor on meshwork cells, which requires the presence of the lymphocytes.
The use of antibody‐secreting cell probes to reveal tissue‐restricted immune responses during infection
Authors: Meeusen Els , Brandon Malcolm 
Published: March 2007

AbstractAntibody secreting cell probes (ASC‐probes) were generated from the hepatic lymph node (HLN), mesenteric lymph node (MLN) and spleen of rats after infection with the liver fluke, Fasciola hepatica, and used to probe Western blots of parasite antigens. In chronic primary infections, parasite‐specific antibodies were only detected in ASC‐probes derived from HLN. Seven days after a secondary infection, a restricted response was detected in ASC‐probes from the MLN, directed predominantly against an antigen specific to the newly excysted juvenile (NEJ) stage. This NEJ‐specific antigen was only recognized by HLN if the second infection was not rejected and the challenge flukes reached the liver. Measurement of the immunoglobulin levels present in the ASC‐probes showed significant elevation only in lymph nodes draining sites of recent infection. In addition, when the isotype profiles were determined in ASC‐probes derived from different lymph nodes, it was observed that they showed different isotype preferences, in particular IgA for the MLN, IgE for HLN and IgM for spleen. These results show that discrete and independent immune responses occur in different body compartments of a rat against different stages of a parasite.
Interleukin‐2 (IL‐2) receptor γ chain mutations in X‐linked severe combined immunodeficiency disease result in the loss of high‐affinity IL‐2 receptor binding
Authors: Disanto James P. , Certain Stéphanie , Fischer Alain , Basile Geneviève De Saint , Dautry‐Varsat Alice 
Published: March 2007

AbstractInteractions of interleukin‐2 (IL‐2) with its high‐affinity, heterotrimeric receptor (IL‐2Rαβγ) play a pivotal role in the autocrine pathway of T lymphocyte expansion required in an immune response. Mutations in the IL‐2Rγ chain‐encoding gene have been found in SCIDX1, a primary immunodeficiency characterized by the absence of T cell and NK cell development. We have investigated six unrelated SCIDX1 patients for molecular abnormalities of the IL‐2Rγ gene. A variety of defects were identified, including the absence of transcripts, frame‐shift deletions and point mutations within canonical cytokine receptor motifs (conserved cysteines and the “WS” box). The ability of these mutated IL‐2Rγ chains to participate in the function of a high‐affinity IL‐2R complex was examined by radiolabeled IL‐2 binding studies using Epstein‐Barr virus‐transformed B lymphoblastoid cell lines (B‐LCL) derived from SCIDX1 patients. Although normal control B‐LCL express high‐affinity IL‐2 binding sites (Kd = 60 pM, 150 sites/cell), B‐LCL derived from SCIDX1 patients failed to bind IL‐2 under high‐affinity conditions. These SCIDX1 mutations confirm the critical role of the IL‐2Rγ chain in T cell and NK cell development. In addition, these data provide insight into the structure/function relationship of the IL‐2Rγ chain by identifying residues required for the formation of a high‐affinity IL‐2R complex.
Vβ gene repertoires in T cells expanded in local self‐healing and lethal systemic murine cutaneous leishmaniasis
Authors: Lohoff Michael , Steinert Meike , Weiss Angela , Röllinghoff Martin , Balderas Robert S. , Theofilopoulos Argyrios N. 
Published: March 2007

AbstractInbred mice infected with Leishmania major promastigotes display two different courses of leishmaniasis: resistant strains develop self‐healing local sores, while susceptible strains show progressive systemic disease with lethal outcome. Resistance predominantly correlates with the production of T helper type 1 (TH1) lymphokines and susceptibility with production of TH2‐type lymphokines. Here, we analyzed whether this TH phenotype difference correlates with expression of particular T cell receptor Vβ chains. Our results show that T cells expand strongly during infection in all groups of mice and invariantly express the same Vβ gene families as prior to infection. Our data indicate that TH1 and TH2 cells use similar Vβ gene families, and argue against the engagement of a restricted set of Vβ by dominant determinants associated with L. major.
Selective expansion of activated Vδ4+ cells during experimental infection of mice with Leishmania major
Authors: Rosat Jean‐Pierre , Louis Jacques A. , Schreyer Magali , Ohteki Toshiaki , Waanders Gary A. , MacDonald H. Robson 
Published: March 2007

AbstractPrevious work from this laboratory has revealed that infection of mice with Leishmania major leads to an expansion of γδ+ T cells in the spleen. Further examination of the γδ+ T cells expanding in infected mice has shown that the majority of these cells in the spleen, lymph nodes, blood and liver expressed the Vβ4 gene segment.Cell cycle analysis, using propidium iodide incorporation, demonstrated that while only 1% of αβ+ T cells in the spleen were in either S + G2/M phase, up to 10% of the γδ+ T cells were in cycling phase 8 weeks after infection. Comparison of the state of activation of the two populations in different organs after infection, confirmed that γδ+ T cells are actively dividing in lymph nodes, liver and blood, but not in the thymus or among intraepithelial lymphocytes. Examination of the expression of different activation markers on the surface of γδ+ T cells in the spleen of both normal and chronically infected BALB/c mice by FACS analysis, revealed increased expression of LFA‐1, CD25, CD44, 4F2, CD28 and the heat‐stable antigen, whereas Thy‐1 and CD5 decreased. Collectively, these results suggest an oligoclonal expansion and activation of γδ+ T cells in response to L. major infection.
Leishmania major parasites share an epitope with the murine CD3‐T cell receptor complex
Authors: Zimmermann Stefan , Becker‐Perez Inge , Beuscher Horst‐Ulrich , Kroczek Richard A. , Röllinghoff Martin , Solbach Werner 
Published: March 2007

AbstractAfter immunization of BALB/c mice with a low molecular mass fraction (FrD; ≦ 31 kDa) isolated from a soluble extract of Leishmania major promastigotes, a panel of monoclonal antibodies (mAb) was obtained. One of these antibodies (mAb 9C) recognized a cytosol‐associated antigen from L. major of approximately 21 kDa as shown by Western blot and immunoprecipitation. In addition, mAb 9C reacted with surface structures of murine splenic T cells and T cell clones. Reactivity was confined to murine cells, but was not strain restricted. Immunoprecipitation studies and surface‐labeling experiments with CD4+ T cell clones and the T cell receptor (TCR)−CD3− T cell line TG40 transfected with V α/β chains from human TCR and concomitant co‐expression of murine CD3 suggested that mAb 9C binds to an epitope located within the murine CD3‐TCR complex. In addition, mAb 9C induced strong T cell proliferation. We conclude that L. major parasites share an epitope with the murine CD3‐TCR complex which is functionally important for T cell activation.
C3a activates reactive oxygen radical species production and intracellular calcium transients in human eosinophils
Authors: Elsner Jörn , Oppermann Martin , Czech Wolfgang , Dobos Gustav , Schöpf Erwin , Norgauer Johannes , Kapp Alexander 
Published: March 2007

AbstractWhereas C5a is a well‐established potent activator of eosinophils, the functional role of C3a in the activation of eosinophils is, so far, poorly understood, Here, the activation of human eosinophils stimulated with C3a was analyzed and compared to C5a activation. Flow‐cytometrical measurements revealed that stimulation of eosinophils by C3a resulted in a transient elevation of the intracellular calcium concentration ([Ca2+]i) in a dose‐dependent manner. In addition, the production of reactive oxygen radical species (ROS) of eosinophils after C3a and C5a stimulation was measured by lucigenin‐dependent chemiluminescence and quantified by superoxide dimutase‐inhibitable reduction of ferricytochrom C. Half maximal and maximal ROS production in response to C3a was observed at 50 ng/ml and 1000 ng/ml, respectively, whereas C3a‐desArg was inactive. To ensure that C3a stimulation was not caused by contamination with C5a, monoclonal antibodies were used to demonstrate the specificity of C3a. The effect of C3a was completely abolished in the presence of monovalent antigen‐binding fragments of a functionally blocking anti‐C3a monoclonal antibody. In addition, blockade of the C5a receptor by the monoclonal anti‐C5a receptor antibody S5/1 totally inhibited the C5a‐evoked ROS production, whereas the C3a response in the presence of S5/1 was unaffected. Finally, desensitization experiments revealed a homologous desensitization of C3a after restimulation with C3a. In contrast, no cross‐desensitization was observed upon stimulation with C5a. Furthermore, the C3a‐ and C5a‐induced production of ROS of eosinophils was totally inhibited by pertussis toxin, indicating the involvement of guanine nucleotide‐binding proteins (Gi‐proteins). In summary, these results demonstrate that C3a is a potent activator for eosinophils initiating transient [Ca2+]i changes and production of reactive oxygen species. C3a therefore may play a part in the pathophysiology of diseases with eosinophil and complement activation.
Failure of correlation between B7 expression and activation of interleukin‐2‐secreting T cells
Authors: Lombardi Giovanna , Sidhu Sid , Dodi Tony , Batchelor Richard , Lechler Robert 
Published: March 2007

AbstractIt is well established that triggering interleukin‐2 (IL‐2) secretion by helper T cells requires the T cell to receive at least two discrete signals. One signal is transduced by the CD3 complex, usually as the result of T cell receptor (TcR) occupancy, the second, or co‐stimulatory, signal involves a non‐cognate interaction between cell surface accessory molecules on the antigen‐presenting cell (APC) and the T cell. A molecular interaction that has been implicated in the provision of co‐stimulatory signals is that between B7/BB1 on the APC and its ligands, CD28 and CTL‐A4 on the T cell.We have studied the ability of HLA‐class II antigen‐positive human T cells and a population of DR1‐expressing transfected human fibroblasts to stimulate a proliferative response by human T cell clones, and by freshly isolated peripheral blood T cells. Despite their high levels of B7 expression, the T cell clones, were unable to induce proliferation or IL‐2 secretion by DR‐restricted, antigen‐specific T cells. In contrast, the DR1‐expressing transfectants, that were B7 negative, induced a strong proliferative response. When these two populations of DR‐expressing cells were used to stimulate a primary alloresponse the results were reversed, in that the T cell clones induced a strong alloresponse but the transfected fibroblasts induced no proliferation.These results suggest that the expression of B7 may be necessary for co‐stimulation of unprimed T cells, but not of established T cell clones. Furthermore the data show that the expression of B7 by an APC does not necessarily lead to IL‐2 production or protection from the induction of tolerance. The mechanisms responsible for the inability of these T cells to provide full activation signals when used as APC is currently under investigation.
Identifying amino acid residues that influence plasma clearance of murine IgG1 fragments by site‐directed mutagenesis
Authors: Kim Jin‐Kyoo , Tsen May‐Fang , Ghetie Victor , Sally Ward E. 
Published: March 2007

AbstractSite‐directed mutagenesis has been used to change amino acid residues of a recombinant Fc‐hinge fragment derived from the murine immunoglobulin (Ig)G1 molecule, and the effects of these mutations on the pharmacokinetics of the Fc‐hinge fragment have been determined. Specifically, Ile‐253, His‐310 and Gln‐311 of the CH2 domain and His‐433 and Asn‐434 of the CH3 domain have been changed. In the three dimensional structure of an antibody, these amino acids are in close proximity to each other at the CH2‐CH3 domain interface. The mutated Fc‐hinge fragments have been purified from recombinant Escherichia coli cells and their pharmacokinetic parameters determined in mice and compared with those of the wild‐type Fc‐hinge fragment. The results show that the site of the IgG1 molecule that controls the catabolic rate (the ‘catabolic site’) is located at the CH2‐CH3 domain interface and overlaps with the Staphylococcal protein A binding site.
Two distinct non‐T helper type 2 interleukin‐4 cell subsets in mice as revealed by single‐cell cytokine analysis
Authors: Kariv Ilona , Hardy Richard R. , Hayakawa Kyoko 
Published: March 2007

AbstractWe have previously defined four murine CD4+ peripheral T cell subsets, fractions (Fr.) I – IV, based on expression of the 6C10 and 3G11 determinants (Hayakawa, K. and Hardy, R. R., J. Exp. Med. 1988. 168: 1825). These subsets also show distinctive levels of other cell surface markers: the two minor subsets, Fr. III and Fr. IV, are both CD45RBlow/‐, L‐selectin (Mel‐14)− and CD44hi, characteristic of secondary T cells. The patterns and levels of cytokine production by individual cells in each subset were determined by bioassay for interleukin (IL)‐2/IL‐4 or IL‐4/interferon (IFN)‐γ production after anti‐CD3 stimulation. Our data revealed that these four phenotypically defined subsets largely coincide with clusters of cells showing uniform distinctive cytokine profiles, i.e. IL‐2+/IFN‐γ−/IL‐4− (Fr. I and Fr. II, L‐selectin+), IL‐2+/IFN‐γ+/IL‐4+ (Fr. III, L‐selectin−), and IL‐2−/IFN‐γlow/‐/IL‐4+ (Fr. IV, L‐selectin−). Besides these subsets, an L‐selectin‐negative cell subfraction within Fr. II appears to represent a transitional population between the IL‐2+/IFN‐γ−/IL‐4− stage and the IL‐2+/IFN‐γ+/IL‐4+ stage. Taken together, these results demonstrate the presence of two IL‐4+ secondary T cell subsets with distinct cytokine production patterns, and show that the majority of IL‐4+ cells found in healthy adult laboratory mice co‐produce IFN‐γ, and thus are not typical T helper type 2 cells.
Reversal of hyporesponsiveness in lpr CD4−CD8− T cells is achieved by induction of cell cycling and normalization of CD2 and p59fyn expression
Authors: Clements James L. , Wolfe Julie , Cooper Sheldon M. , Budd Ralph C. 
Published: March 2007

AbstractT cells freshly isolated from the peripheral lymph nodes of autoimmune MRL lpr/lpr (lpr) mice contain a large proportion of functionally non‐mature T cell receptor (TcR)‐αβ+CD3+CD2−CD4−CD8− T cells displaying the B cell isoform of CD45, B220. These cells are hyporesponsive as defined by minimal interleukin‐2 (IL‐2) production and proliferation in response to stimulation. However, increased levels of inositol phosphates and a rapid mobilization of Ca2+ do occur upon stimulation of the TcR/CD3 complex. Furthermore, lpr CD4−CD8− T cells contain high levels of transcripts for the src‐family tyrosine kinase p59fyn, and express a constitutively tyrosine‐phosphorylated CD3‐ζ chain. These features bear a certain resemblance to anergized T cells. These similarities are extended to show that culturing of lpr CD4−CD8− T cells in the presence of IL‐2 in combination with phorbol 12‐myristate 13‐acetate and ionomycin initiates cell cycling and results in the gain of function; re‐stimulation now yields IL‐2‐dependent proliferation in the absence of exogenous IL‐2. In parallel with this gain in function, the population of cells obtained after 1 week in culture retains the TcR‐αβ+CD4−CD8− phenotype, yet displays increased levels of CD2, decreased surface B220, and normal amounts of p59fyn‐specific transcripts. These findings show that cell cycling is associated with the recovery of functional capabilities by lpr CD4−CD8− T cells and is closely allied with surface CD2 expression. Thus, the hyporesponsiveness of lpr T cells is not a fixed state.
Binding of adenosine deaminase to the lymphocyte surface via CD26
Authors: De Meester Ingrid , Vanham Guido , Kestens Luc , Vanhoof Greet , Bosmans Eugène , Gigase Paul , Scharpé Simon 
Published: March 2007

AbstractThe relationship between CD26/dipeptidyl peptidase IV, an ectopeptidase involved in T cell activation, and the binding protein for adenosine deaminase (ADAbp) was studied. Monoclonal antibodies (mAb) against CD26 and ADAbp, respectively, showed a similar binding profile on various lymphocyte subsets from the peripheral blood. The adenosine deaminase (ADA) itself blocked the binding of a specific set of anti‐CD26 mAb (among these the anti‐TA5.9 mAb) on lymphocytic CD26; ADA also hindered the binding of soluble CD26 to the same immobilized anti‐CD26 mAb. In addition, the interaction between immobilized ADA and purified CD26/DPP IV was inhibited by the anti‐TA5.9 mAb. ADA did not inhibit the specific peptidase activity of CD26. Neither soluble nor immobilized ADA was able to down‐modulate CD26 on the lymphocyte surface. Our data thus confirm the identity between ADAbp and CD26 and identify some epitopes, crucial in the binding of ADA to CD26.
T cell receptor γ cDNA in human fetal liver and thymus: Variable regions of γ chains are restricted to VγI or V9, due to the absence of splicing of the V10 and V11 leader intron
Authors: Zhang Xiao‐Min , Tonnelle Cécile , Lefranc Marie‐Paule , Huck Sylvie 
Published: March 2007

AbstractAlthough complete in‐frame transcripts of the human T cell receptor γ V10 and V11 genes have been described, the corresponding γ chains have never been found in γδ T cell receptors. In this study, we show that the leader intron of all V10 and V11 cDNA isolated from fetal thymus, fetal liver and adult peripheral blood lymphocytes are unspliced. We demonstrate that, due to the absence of splicing, V10 and V11 are pseudogenes and cannot be expressed in γ chains. They are the first pseudogenes of this type described in a rearranging T cell receptor/immunoglobulin locus. Therefore the γ repertoire at the protein level is limited to subgroup VγI and to V9. By analysis of the γ polymerase chain reaction products from total cDNA, we find that the γ locus is active in early ontogeny (8 weeks), as shown by the presence of rearranged V9 and V10 gene transcripts in the liver. At 13 weeks, the VγI genes as well as V9 and V10 have undergone productive rearrangements in the liver, and in the thymus. Most rearrangements, if not all, involve the T cell receptor γ C1 region (JP1, JP, J1 segments) in both tissues, confirming the accessibility of the C1 region in early stages of development.