bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protein tyrosine kinase p59fyn is associated with the T cell receptor‐CD3 complex in functional human lymphocytes
Authors: Gassmann Martin , Guttinger Maria , Amrein Kurt E. , Burn Paul 
Published: March 2007

AbstractThe binding of antigen to the multicomponent T cell antigen receptor (TcR)‐CD3 complex leads to the activation of several signal transduction pathways which result in T lymphocyte proliferation and lymphokine secretion by molecular mechanisms and catalytic molecules as yet poorly defined. One of the earliest events that follows the triggering of the antigen‐specific TcR‐CD3 complex is a rapid tyrosine phosphorylation of several intracellular substrates, suggesting stimulation of at least one protein tyrosine kinase (PTK). Since none of the seven TcR‐CD3 subunits exhibits a recognizable kinase domain, it seems likely that the receptor complex is associated with an intracellular PTK. p59fyn and the T lymphocyte‐specific p56lck are two intracellular, non‐receptor, cell membrane‐associated PTK of the src family expressed in T lymphocytes. Here, we show by double immunofluorescence microscopy a specific co‐distribution of p59fyn, but not p56lck, with antibody‐induced TcR or CD3 caps in intact human T lymphocytes. These findings provide direct evidence for a significant association of p59fyn with the TcR‐CD3 complex under physiologically relevant conditions in functional T lymphocytes. They suggest that p59fyn is a crucial component of the TcR signal transduction machinery and that one of the earliest consequences of antigen recognition by the TcR is p59fyn‐mediated phosphorylation of intracellular substrates on tyrosine residues.
Liposome‐mediated delivery stimulates a class I‐restricted cytotoxic T cell response to soluble antigen
Authors: Lopes Luciene M. , Chain Benjamin M. 
Published: March 2007

AbstractMost soluble protein antigens are poor at priming class I‐restricted cytotoxic cell activity. In this study we show that incorporation of one protein, ovalbumin, into liposomes converts this antigen into an effective stimulator of antigen‐specific cytotoxicity. The mechanisms responsible for this phenomenon are discussed.
H‐2‐linked control of the Yaa gene‐induced acceleration of lupus‐like autoimmune disease in BXSB mice
Authors: Merino Ramón , Fossati Liliane , Lacour Marc , Lemoine Robert , Higaki Megumu , Izui Shozo 
Published: March 2007

AbstractThe accelerated development of lupus‐like autoimmune disease in male BXSB mice (H‐2b, I‐E−) is associated to the presence of a mutant gene, designated Yaa, located on their Ychromosome. To investigate whether the H‐2b haplotype and/or the lack of expression of I‐E molecules play any role in the Yaa‐linked acceleration of autoimmune disease, an I‐E+ BXSB.H‐2d congenic strain was created by backcross procedures. We compared the development of autoimmune disease in the novel BXSB.H‐2d (I‐E+) strain to that of BXSB.H‐2b (I‐E−) and BXSB.H‐2b/d (I‐E+) heterozygous mice. Male BXSB.H‐2d (I‐E+) mice exhibited only a limited production of autoantibodies and a lower incidence of glomerulonephritis with a markedly prolonged survival rate, which were essentially identical to those of female BXSB mice of both‐H‐2b and H‐2d haplotypes. However. BXSB.H‐2b/d (I‐E+) heterozygous males developed an accelerated disease comparable to that of conventional BXSB.H‐2b (I‐E−) male mice. These results indicate that the expression of I‐E molecules and consequent clonal deletion or anergy of I‐E reactive T cells does not appear to be responsible for the prevention of accelerated autoimmune disease in BXSB.H‐2d (I‐E+) male mice. The finding that the Yaa gene‐induced acceleration of lupus‐like autoimmune disease is modulated by gene(s) within or closely linked to the H‐2 complex underlines the crucial role of the major histocompatibility complex and the polygenetic nature of autoimmune disease in BXSB mice.
Anti‐idiotypic immune responses against adjuvant‐free isologous IgM monoclonal antibodies and their augmentation by complex formation between IgM and albumin in bovine serum
Authors: Hannestad Kristian , Andreassen Kjetil , Kristoffersen Gunn 
Published: March 2007

AbstractIn previous studies we demonstrated that the hypermutated isologous myeloma protein MOPC 315 (isotype IgA; λ2) is recognized by T helper cells like an ordinary foreign protein antigen. To what extent can an immune system recognize and respond to V domains from the primary (pre‐immune) repertoire? To study this question we made 21 BALB/c hybridoma anti‐2, 4, 6 trinitrophenyl monoclonal antibodies (mAb) of IgM; λ isotype. All mAb purified from supernatants containing fetal bovine serum had formed spontaneous complexes with bovine serum albumin possibly by way of disulfide interchange. Twenty of twenty‐one mAb from this source elicited IgG1 anti‐idiotypic (Id) Ab when given as a single adjuvant‐free dose of 200 μg. For 12 of them even 10 μg was sufficient. This indicated that BSA augmented the anti‐Id responses by a carrier effect. Three of the mAb were therefore purified from ascites fluid and from serum‐free medium. Only one of them then induced humoral anti‐Id responses in BALB/c mice when given as a single adjuvant‐free dose of 100 μg. The other two became immunogenic when emulsified in Freund's complete adjuvant. The results indicate that some IgM mAb exist whose Id determinants alone can elicit substantial anti‐Id responses because they are recognized like ordinary foreign protein antigens. Since albumin in fetal bovine serum forms complexes with IgM and greatly augments its immunogenicity, serum‐free medium should be used for production of human or humanized therapeutic IgM mAb. A possible role for Id of IgM Ab as cardinal autoantigens is discussed.
Seeding of neonatal lymph nodes by T cells and identification of a novel population of CD3−CD4+ cells
Authors: Kelly Katherine A. , Scollay Roland 
Published: March 2007

AbstractMature T cells first appear in the thymus of the mouse a few days before birth, about 7–8 days after the thymus was colonized by stem cells. These mature cells are exported to the peripheral lymphoid organs beginning at about the time of birth, but because the number is very small at this stage, little is known about the phenotype or function of these early emigrants. We have examined the cells that accumulate in the peripheral lymph nodes (LN) during the first week of life to understand better the initial seeding of the periphery by T cells. Our studies showed that a high proportion of neonatal LN cells were CD4+, but that the majority of these were CD3− during the first few days of life. The CD3− population did not increase greatly in number after birth and rapidly diminished in proportion as the number of CD3+ cells increased. These CD3−CD4+CD8− cells were found to be Thy‐1loCD44+ and to lack surface expression of heat‐stable antigen, B220 and Mac‐1. They had lymphoid morphology, did not phagocytose latex, and did not exhibit any precursor activity for cells of hemopoietic lineages. Their origin (intra‐ or extrathymic) as well as their function and physiological role, therefore, remains unknown. CD3+ T cells, both CD4+CD8− and CD4−CD8+, were present in low numbers during the first 1–2 days of life, but at post‐natal day 3, a sharp increase in the accumulation of these cells occurred in both LN and spleen. By day 3 the CD4: CD8 ratio in LN was about 2:1, as in the adult. Crude estimates of the rate of export from the thymus from day 3 onwards gave values around 1% of thymocytes per day, i.e. close to our previous estimates for young adult thymus. We found no evidence of particularly high levels of emigration from the thymus during the first week after birth. Both CD4+CD8− and CD4−CD8+ T cell subsets were present in the LN as early as 1 day post‐natally with CD4−CD8+ predominating among LN T cells, even though CD3+CD4+CD8− cells predominated over CD3+CD4−CD8+ cells in the thymus. By day 3 the ratio had changed to 2:1 (as in the adult). T cells, therefore, appear to emigrate from the thymus from about the time of birth with a dramatic increase around day 3 after birth.
Altered course of visceral leishmaniasis in mice expressing transgenic I‐E molecules
Authors: Kaye Paul M. , Cooke Anne , Lund Torben , Wattie Moira , Blackwell Jenefer M. 
Published: March 2007

AbstractPrevious studies had shown that the outcome of infection with Leishmania donovani was exquisitely sensitive to the influence of the major histocompatibility complex. In this study, we have examined the course of infection in non‐obese diabetic (NOD) and NOD‐E‐3 mice, the latter expressing an I‐E molecule as a result of transgenic introduction of the wild‐type Edα gene. Introduction of this transgene significantly altered the course of infection allowing for enhanced parasite multiplication in the viscera from day 14 to day 28. This was associated with both a delayed and reduced tissue granulomatous response in NOD‐E‐3 mice. In vitro, spleen cells from these mice produced equivalent levels of interferon (IFN)‐γ during the early phase of infection but this originated from populations having a different balance of T cells subsets. In NOD mice CD8+ T cells contribute substantially to the total levels of IFN‐γ produced, but in transgenic mice the contribution from this subset is significantly decreased. This is reflected in a reduction in the proportion of Leishmania‐specific CD8+ T cells, which could only partially be accounted for by deletion of Vβ5‐ and Vβ3‐expressing CD8+ T cells in NOD‐E‐3 mice. This study highlights the impact of the introduction of a class II gene product on disease outcome and unexpectedly on the functional potential of CD8+ T cells.
Alloantigen‐specific regulation of cytotoxic T cell responses is mediated through the induction of clonal anergy of CD8+ T cells
Authors: Schutze Marie‐Paule , Langlade‐Demoyen Pierre , Leclerc Claude 
Published: March 2007

AbstractPriming mice with an alloantigen before immunization with this same alloantigen presented in association with a second one on an F1 stimulator cell inhibits the induction of cytotoxic response directed against the second alloantigen. This inhibition is associated with the induction of a strong cytotoxic T lymphocyte (CTL) response against the first priming alloantigen. For example, a specific suppression of anti‐H‐2b CTL responses could be induced in C3H/He mice (H‐2k) by priming them with H‐2d spleen cells before immunization with F1 (H‐2dxb) spleen cells. In the present study, we have analyzed the mechanisms underlying this specific suppression of CTL responses. We have demonstrated that the reduction of H‐2b‐specific CTL responses is reflected by a decrease in the frequency of effector cells specific for H‐2b antigen. However, there was no difference in the frequencies of precursor CTL in control and suppressed mice excluding clonal deletion as the mechanism maintaining low responsiveness. Co‐culture experiments have shown that the suppression of anti‐H‐2b CTL responses was not due to suppressor cells but to the failure of CD8+ T cells of suppressed mice to collaborate with normal helper CD4+ T cells. The suppression was therefore ascribed to a functional impairment (clonal anergy) of the CD8+ T cell subset.
Human endothelial cells transfected by SV40 T antigens: characterization and potential use as a source of normal endothelial factors
Authors: Lassalle Philippe , Lagrou Christian , Delneste Yves , Sanceau Josiane , Coll Jean , Torpier Gérard , Wietzerbin Jeanne , Stehelin Dominique , Tonnel André‐Bernard , Capron André 
Published: March 2007

AbstractA putative role for the vascular endothelium as target for autoantibodies has been suggested in several autoimmune disorders and connective‐tissue diseases. However, there are some difficulties linked to the use of cultured endothelial cells (EC) that limit considerably the extensive studies on the nature of endothelial target antigens involved. To overcome this problem, human EC, derived from umbilical veins, were transfected with recombinant plasmid pSV1 which contained the early genes of simian virus SV40. These transfected cells, called EC‐pSV1, are able to grow without EC growth supplement and demonstrate a population doubling time of about 50 h. Among the EC properties, EC‐pSV1 retain intracellular content of angiotensin‐converting enzyme activity, exhibit constitutive production of interleukin 6 and of a growth‐promoting activity on early passage EV, express intercellular adhesion molecule 1 (ICAM‐1) and its up‐regulation by tumor necrosis factor α, but have lost the expression of factor VIII‐related antigen. Moreover, EC‐pSV1 express a 55‐kDa antigen found on EC and human platelets, and presumably acting as an antibody target in some cases of non‐allergic asthma. However, at the 50–55th generation, morphological changes and altered growth behavior were visible. This work demonstrates that transfection of EC with SV40 T antigens may be of interest, particularly in areas of research including the study of EC targets involved in different human diseases.
Catalase inhibits nitric oxide synthesis and the killing of intracellular Leishmania major in murine macrophages
Authors: Li Yun , Severn Alison , Rogers Mark V. , Palmer Richard M. J. , Moncada Salvador , Liew Foo Y. 
Published: March 2007

AbstractMouse peritoneal macrophages activated with interferon‐γ (IFN‐γ) and lipopolysaccharide produce substantial amounts of nitric oxide (NO), which correlates with the elimination of the intracellular protozoan parasite Leishmania major. Both the production of NO and the leishmanicidal function of the activated macrophages can be significantly inhibited by catalase in a dose‐ and time‐dependent manner. These results could not be interpreted by the reduction of H2O2 by catalase since the removal of H2O2 by the addition of glutathione peroxidase had no effect on the NO synthesis or the leishmanicidal function of activated macrophages. Furthermore, catalase did not affect the induction of NO synthase in IFN‐γ‐activated macrophages. In contrast, the inhibition of NO synthesis and leishmanicidal activity by catalase was reversed in a dose‐dependent manner by the addition of tetrahydrobiopterin, a cofactor of NO synthase. Taken together, these results not only further support the central role of NO as the cytotoxic moiety, but also suggest that hydrogen peroxide may interfere with NO production by affecting the levels of cofactor needed for its synthesis.
T cell receptor activation of a ribosomal S6 kinase activity
Authors: Calvo Victor , Bierer Barbara E. , Vik Terry A. 
Published: March 2007

AbstractStimulation of the T cell receptor‐CD3 complex activates multiple signal transduction pathways, including serine/threonine and tyrosine protein kinases. Stimulation of the human T cell line Jurkat via the T cell receptor‐CD3 complex with anti‐CD3 monoclonal antibody or incubation with the tumor promoter phorbol 12‐myristate 13‐acetate caused increases in S6 kinase and microtubule‐associated protein 2 (MAP) kinase activities. An S6 kinase activity that was able to phosphorylate exogenous 40S ribosomal S6 protein was recovered in immunoprecipitates obtained using a 90‐kDa ribosomal S6 kinase‐specific antiserum and thus represents activation of a member of the 90‐kDa ribosomal S6 kinase family. Stimulation of the S6 kinase activity correlated with an increase in a kinase activity able to phosphorylate exogenous 90‐kDa ribosomal S6 kinase (rsk) attributed to a MAP kinase activity. These increases in S6 and MAP kinase activities further correlated with the appearance of a 42‐kDa phosphoprotein detected by anti‐phosphotyrosine immunoblotting. However, while the tyrosine phosphorylation of the 42‐kDa protein and the MAP kinase activity are dependent on protein kinase C activity, residual S6 kinase activity can be detected following protein kinase C depletion and subsequent anti‐CD3 stimulation. Thus, T cell activation through the T cell receptor‐CD3 complex results in activation of a member of the 90‐kDa S6 kinase family which correlates with, but can be independent of, MAP kinase activation.
Mouse autoreactive γ/δ T cells I. Functional properties of autoreactive T cell hybridomas
Authors: Wilde David B. , Roberts Kewan , Sturmhöfel Knut , Kikuchi Gary , Coligan John E. , Shevach Ethan M. 
Published: March 2007

AbstractA minor population of dendritic epidermal T cells (DETC) express the Vγ1. 1Cγ4Vδ6 T cell receptor and T cell clones and hybridomas derived from this subset constitutively secrete cytokines in culture secondary to recognition of an autoantigen. Activation of these autoreactive cells requires the use of the vitronection receptor (VNR) as an accessory molecule which interacts with the Arg‐Gly‐Asp‐Ser (RGDS) sequence of extracellular matrix (ECM) proteins. We have compared the functional properties of Cγ4+ hybridomas derived from newborn thymocytes and from adult spleen with the DETC hybridomas/lines in terms of their ability to secrete cytokines spontaneously and for the use of the VNR as an accessory molecule. Almost all of the Cγ4+ thymocyte hybridomas secreted cytokines spontaneously and in the majority of lines the most prominent cytokine secreted was granulocyte‐monocyte colony‐stimulating factor. In contrast, none of the four splenic Cγ4+ hybridomas secreted cytokines spontaneously although all were capable of cytokine production following activation via the T cell receptor. Although the thymocyte hybridomas did not grow as adherent cell lines in culture, constitutive cytokine production required engagement of the VNR by its ligand in ECM proteins. In all cases, cytokine production could be inhibited by an anti‐VNR monoclonal antibody as well as by soluble RGDS. The strong correlation of functional and molecular properties (see accompanying report) between thymocyte Cγ4+ hybridomas and Cγ4+ DETC suggests that the Cγ4+ DETC may be of thymic origin and that cells with potential for autoreactivity residing in the thymus at birth may populate other peripheral locations in the mouse. The data also support the concept that the VNR, and possibly other integrins, play a role as accessory elements for autoreactive cells and may be essential for the regulation of such activity.
Transgenic T cell receptor interactions in the lymphoproliferative and autoimmune syndromes of lpr and gld mutant mice
Authors: Sidman Charles L. , Marshall Jan D. , von Boehmer Harald 
Published: March 2007

AbstractTo investigate the role of T cell receptor (TcR) expression and interactions in development of lymphoproliferation and autoimmunity in lpr and gld mutant mice, and to determine whether these autoimmune mutations affect T cell selection and repertoire formation, we generated mice homozygous for either the gld or the lpr mutation and containing TcR α/β transgenes (Von Boehmer, H., Annu. Rev. Immunol. 1990. 8: 531) specific for the male (H‐Y) antigen in the context of H‐2Db. Four main results emerged from analysis of these mice. First, expression of transgenic TcR had no effect on disease incidence and progression. Second, the accumulating T cells reflected normal processes of positive and negative selection. Third, cells expressing the transgenic TcR participated equally in lymphoproliferation regardless of whether their antigenic peptide and/or presenting major histocompatibility complex molecules were present or not. Fourth, expression of the TcR transgenes markedly altered the phenotype of the major accumulating lymphocyte subset. Thus, in these models of lymphoproliferation and autoimmunity, T cell repertoire formation proceeds normally, specific T cell recognition of antigen has no effect on the participation of individual clones, and the phenotype of the cells accumulating is sensitive to either the timing or the amount of TcR expression. These results are discussed in the context of the primary cause vs. secondary manifestations of autoimmunity in these models.
Different expression of the recombination activity gene RAG‐1 in various populations of thymocytes, peripheral T cells and gut thymus‐independent intraepithelial lymphocytes suggests two pathways of T cell receptor rearrangement
Authors: Guy‐Grand Delphine , Broecke Catherine Vanden , Briottet Chantal , Malassis‐Seris Michèle , Selz Françoise , Vassalli Pierre 
Published: March 2007

AbstractThe presence of transcripts of the recombination activating gene RAG‐1 was studied by in situ hybridization on selected populations of murine thymocytes, peripheral lymphocytes and gut intraepithelial lymphocytes (IEL), obtained by cell sorting. RAG‐1 mRNA was found in a majority of “double‐positive” (DP) thymocytes, but was absent in “single‐positive” thymocytes and peripheral T lymphocytes. The only other T lineages in which about 10%–20% of the cells contained RAG‐1 mRNA, and in smaller amounts, were “double‐negative” (DN), T cell receptor (TcR) γδ‐ cortical thymocytes and gut CD3− IEL. These observations suggest that (a) the high expression of RAG‐1 transcripts in DP thymocytes is related to the process of expansion‐selection of these cells, probably accompanied by repeated TcR rearrangements, and that (b) in contrast. CD3− IEL from the gut (which are thymus independent) as well as some DN thymocytes undergo limited TcR rearrangement giving rise locally to TcR+ T cells without prior extensive process of local expansion‐selection. A small percentage of peripheral B cells also contained RAG‐1 mRNA, raising the possibility that this protein may also be involved in immunoglobulin class switching.
Accumulation of somatic mutants in the B cell compartment after primary immunization with a T cell‐dependent antigen
Authors: Weiss Ursula , Zoebelein Rele , Rajewsky Klaus 
Published: March 2007

AbstractThe accumulation of somatic mutants in splenic B lymphocytes early after primary immunization with the hapten (4‐hydroxy‐3‐nitro‐phenyl)acetyl (NP) coupled to chicken gamma globulin (CG) was determined. Rearranged V186.2 heavy chain genes were amplified by the polymerase chain reaction from genomic DNA and subjected to nucleotide sequence analysis. Somatic antibody mutants become detectable on day 6 after immunization, and most of the somatic mutations accumulating in the memory compartment are introduced until day 14. At this time strong selection for mutants expressing high binding affinity for NP is apparent. Extrapolation from the mutation frequency increases between day 6 and day 14 to the previously determined mutation frequency at week 6 (Weiss, U. and Rajewsky, K., J. Exp. Med. 1990. 172: 1681) leads to the prediction that the process of mutant generation ceases to operate around day 22 after primary immunization.