bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of alloreactive T cell subpopulations of aged mice in vivo. CD4+ but not CD8+ T cell‐mediated rejection response declines with advanced age
Authors: Rosenberg Amy S. , Sechler Joan M. G. , Horvath Judith A. , Maniero Tonnie G. , Bloom Eda T. 
Published: March 2007

AbstractThe present investigation explored age‐related alterations in T cell populations mediating allospecific responses in vivo. Healthy aged and young H‐2b and H‐2bxH‐2k mice were engrafted with major histocompatibility complex (MHC) class II‐disparate bm12 skin, rejection of which requires CD4+ T cells, and MHC class I‐disparate bm1 skin, rejection of which requires CD8+ T cells. Aged mice of both genders exhibited prolonged survival of bm12 skin grafts relative to their young counterparts but rejected bm1 skin grafts at a rate equivalent to that of young mice. Consistent with prolonged survival of bm12 skin grafts, markedly diminished levels of Iabm12 CTL activity were elicited from T cells of aged mice in vitro. However, no such decline was observed in the level of Kbm1 CTL from T cells of aged mice. The alterations in Iabm12 allospecific responses were not attributable to quantitative changes in CD4+ T cells of aged mice, and addition of soluble T cell helper factors to response cultures of aged mice did not augment Iabm12 cytotoxic T lymphocytes activity. These data demonstrate that aging fundamentally affects CD4+ T cell‐mediated allospecific responses particularly in vivo, and that deficient generation of soluble T cell helper factors alone cannot explain this deficit.
CD5− dendritic epidermal T cells are derived from CD5+ precursor cells
Authors: Payer Elisabeth , Kutil Raphaela , Stingl Georg 
Published: March 2007

AbstractMurine Thy‐1+, TcR Vγ3/Vδ+ dendritic epidermal T cells (DETC) differ from most other T cell subsets by the absence of CD4 and CD8 antigens as well as the lack of CD5 expression. To see whether negativity for those antigens is an intrinsic feature of a given T cell population or if such triple‐negative T cells go through a maturational stage where they express these antigens, we determined the phenotype of TcR Vγ3+ fetal thymocytes which are the precursor cells of DETC. We found that TcR Vγ3+ fetal thymocytes phenotypically differ from mature DETC in that they are CD5+, mostly CD8+ and partly CD4+. The injection of fetal thymic suspensions containing TcR Vγ3+/CD5+ (but not TcR Vγ3+/CD5−) thymocytes into Thy‐1‐disparate athymic nude mice resulted in the appearance of donor‐type TcR Vγ3+/CD5− dendritic cells in the recipients' epidermis, indicating that TcR Vγ3+ thymocytes are indeed the precursors of CD5− DETC. Tracing CD5 expression on DETC precursors during their intrathymic maturation and their migration to the fetal skin, we found that (i) the earliest DETC precursor cells as defined by TcR Vγ3 expression express high levels of CD5 antigen (day 15 of gestation), (ii) after day 16 of gestation 70% of TcR Vγ3+ thymocytes express high and 30% express intermediate levels of CD5, (iii) TcR Vγ3+ cells in the fetal blood express low levels of CD5, (iv) the first TcR Vγ3+ cells entering the epidermis express very low levels of this antigen and (v) TcR Vγ3+ epidermal cells later than day 19 of gestation are CD5−. A similar down‐regulation of CD5 expression on DETC precursors was also noted when TcR Vγ3+ cells were cultured in vitro. Even the addition of PMA and ionomycin, which up‐regulates CD5 expression on TcR α/β‐bearing thymocytes and lymph node T cells, could not prevent down‐regulation on DETC precursors. The described cell system may serve as a useful tool in further experiments aimed to clarify the function of the CD5 glycoprotein as well as the mechanism(s) regulating its expression.
Negative selection of multireactive B cell clones in normal adult mice
Authors: Grandien Alf , Fucs Rita , Nobrega Alberto , Andersson Jan , Coutinho Antonio 
Published: March 2007

AbstractIn the absence of intentional immunizations, normal mice produce natural antibodies that react with a variety of self and foreign antigens. We have now addressed the putative physiological selection of such reactivities and some of their clonal characteristics, by analyzing antibodies produced by B cells at different stages of differentiation. Using an antigen‐specific spot‐enzyme‐linked immunosorbent assay (ELISA) with a panel of self and foreign antigens, we found that newly formed B cells, either from adult bone marrow or from newborn spleen, contain the highest frequencies of IgM antibodies with reactivities towards the panel. Resting peripheral B cells show lower frequencies of such antibodies, that are lowest among naturally activated splenic plasma cells. Analyses of monoclonal IgM antibodies derived from lipopolysaccharide‐stimulated bone marrow and spleen cell hybridomas in normal mice show that the majority of reactivities scored in spot‐ELISA originate from multireactive IgM clones. In Western blots against a large number of self antigens, each multireactive IgM antibody studied shows a unique and specific pattern of reactivity. We conclude that multireactive B cell clones are very frequent in the emergent repertoires of newborns and adults, but are subsequently negatively selected from bone marrow to periphery, and from the available repertoire to that of natural plasma cells. It, thus, seems that multireactivity of natural antibodies is not a positively selected property, but represents the sum of unique multireactive clones that have escaped inactivation or deletion.
Regulation of VH‐gene expression is a lineage‐specific developmental marker
Authors: Viale Anne‐Claire , Freitas Antonio A. , Coutinho Antonio 
Published: March 2007

AbstractWe have previously shown that in IgH congenic mice VH‐gene family usage in neonatal spleen B cells and adult Ig‐secreting cells is entirely determined by the IgH locus, while in adult resting B cells it is regulated by genetic element(s) located outside the IgH locus. Two observations reported here demonstrate that the differential expression of VH genes is an intrinsic property of the respective cell populations, determined by both the IgH locus and by a cis element(s) operating independently in the same animal. First, the study of F1 hybrids between the IgH congenic B6a and CB.20 strains demonstrates that cis elements control VH‐gene family expression. Second, studies in irradiation chimeras showed that the environment in which cell differentiation proceeds is unable to overcome those controls. In chimeras of IgH congenic donors, VH‐gene expression in fetal liver‐derived splenic B cells and Ig‐secreting cells is dictated by the IgH haplotype, while in bone marrow‐derived B cells is entirely determined by the cis element(s). These results show a developmental and cell lineage‐related restriction in VH‐gene expression, and suggest that most adult splenic Ig‐secreting cells may originate from precursors originally present in fetal liver, but which are rare among adult bone marrow precursors and CD5+ B cells.
B lymphocyte and macrophage expression of carcinoembryonic antigen‐related adhesion molecules that serve as receptors for murine coronavirus
Authors: Coutelier Jean‐Paul , Godfraind Catherine , Dveksler Gabriela S. , Wysocka Maria , Cardellichio Christine B. , Noël Henri , Holmes Kathryn V. 
Published: March 2007

AbstractThe expression of carcinoembryonic antigen (CEA)‐related glycoproteins that have been associated with intercellular adhesion and that serve as receptors for mouse hepatitis virus (MHV) was analyzed in cells from the immune system of BALB/c mice using immunolabeling and RNA polymerase chain reaction amplification of receptor transcripts. These glycoproteins, which are called biliary glycoproteins, were highly expressed in B lymphocytes, including cells of the B‐la (CD5+) lineage, and in macrophages, but were not detectable in resting T lymphocytes. Similarly, murine cell lines of B cell and macrophage origin expressed messenger RNA encoding CEA‐related molecules, while the corresponding mRNA was only slightly detectable in a T cell line. These CEA‐related cell adhesion glycoproteins were also expressed in endothelial cells. Therefore, their specific interaction with their so far unknown ligand may be of functional importance in cellular interactions in the immune response.Monoclonal antibody directed against these glycoproteins blocked MHV‐A59 infection of the B cell‐derived SP20 cell line. Thus, the functional receptors for MHV on B lymphocytes, like those on murine fibroblasts, are isoforms of CEA‐related glycoproteins. Treatment of B cells with anti‐receptor antibody also blocked B cell‐mediated cytotoxicity against MHV‐A59‐infected fibroblasts, indicating that this phenomenon is mediated by interaction of viral attachment protein on the infected target cells with specific CEA‐related receptor glycoproteins on the effector B cells.
Preformed purified peptide/major histocompatibility class I complexes are potent stimulators of class I‐restricted T cell hybridomas
Authors: Stryhn Anette , Pedersen Lars østergaard , Ortiz‐Navarrete Vianney , Buus Søren 
Published: March 2007

AbstractA panel of antigen‐specific, major histocompatibility complex class I‐restricted T cell hybridomas has been generated to examine the capacity of peptide/class I complexes to stimulate T cells at the molecular level. Peptide/class I complexes were generated in detergent solution, purified and quantitated. Latex particles were subsequently coated with known amounts of preformed complexes and used to stimulate the T cell hybridomas. Stimulation was specific, i.e. only the appropriate peptide/class I combination were stimulatory, and quite sensitive, i.e. as little as 300 complexes per bead could be detected by the T cells. Preformed complexes were about 500000 times more potent than free peptide in terms of T cell stimulation, demonstrating the physiological relevancy of the biochemically generated complexes. Surprinsingly, the majority (including the most sensitive of the hybridomas) had lost CD8 expression, suggesting that antigen‐specific stimulation of class I‐restricted T cell hybridomas, as assessed by IL‐2 release, does not depend on CD8.
Peptide transporter‐independent, stress protein‐mediated endosomal processing of endogenous protein antigens for major histocompatibility complex class I presentation
Authors: Schirmbeck Reinhold , Reimann Jörg 
Published: March 2007

AbstractThe peptide transporter‐defective cell line RMA‐S expressing the wild‐type simian virus 40 large T antigen (wtT‐Ag) from a transfected gene did not present two well‐defined, H‐2 class I (Db)‐restricted epitopes of T‐Ag to cytotoxic T lymphocytes (CTL). Hence, “endogenous” processing and presentation of the wtT‐Ag depended on a functional peptide transporter heterodimer. In contrast, both T‐Ag epitopes were efficiently presented to CTL by transfected RMA‐S cells expressing a truncated, cytoplasmic T‐Ag variant (cT‐Ag) or a karyophilic, amino‐terminal 272‐amino acid T‐Ag fragment. Transporter‐independent “endogenous” processing of mutant T‐Ag molecules correlated with their association with the constitutively expressed heat shock protein 73 (hsp 73). Class I‐restricted presentation of both epitopes processed from these hsp73‐associated protein antigens was sensitive to NH4Cl and chloroquine. These data indicate that selected intracellular proteins access an alternative, hsp73‐mediated pathway for class I‐restricted presentation that operates independent of peptide transporters in an endosomal compartment.
Human immunodeficiency virus‐1 reverse transcriptase immunodominant CD4+ T cell epitopes: A peptide‐based multiparametric assessment in the mouse
Authors: Borg Jean‐Paul , Ihlenfeldt Hans‐Georg , Jung Günther , Haas Gaby , Pierres Michel 
Published: March 2007

AbstractWe previously identified an immunodominant CD4+ T cell determinant in the carboxy‐terminal region of HIV‐1 reverse transcriptase (RT528–543). The present study aimed at enumerating all the potential sites of HIV‐1 RT recognized by Th cells in the BALB/c (H‐2d) mouse model. To achieve this we used a panel of 62 overlapping 15‐mer synthetic peptides covering the whole RT sequence to assay the following parameters: (i) immunogenicity in naive BALB/c mice injected either with peptides pools or individual peptides; (ii) antigenicity, as detected by their ability to restimulate in vitro T cells from BALB/c mice primed with native RT: (iii) MHC class II (Ad)‐binding capacity as measured by the inhibition of the antigen‐specific, Ad‐restricted presentation of unfolded apamin (4‐Acm) by fixed antigen‐presenting cells to Ad/4‐Acm‐specific, interleukin‐2‐producing T hybridoma cells; and (iv) the presence of typical or degenerate consensus Ad‐binding motifs. The results in this study permitted identification of three novel immunodominant RT mouse CD4+ T cell sites (RT276–290), RT375–389 and RT411–425) located in regions of limited polymorphism among RT from several HIV isolates. Some of these RT segments were found to be in the vicinity of B cell or H‐2Kk‐ or HLA‐A2‐restricted cytotoxic T lymphocyte epitopes. Finally, the approach used in this study was found to be very efficient for enumerating most T cell recognition sites in a complex protein, a result that would have not been achieved by a single parameter‐based analysis.
Naive T cells can mediate delayed‐type hypersensitivity response in T cell receptor transgenic mice
Authors: Sato Takehito , Sasahara Takeshi , Nakamura Yukitsugu , Osaki Takako , Hasegawa Takanori , Tadakuma Takushi , Arata Yoji , Kumagai Yoshihiro , Katsuki Motoya , Habu Sonoko 
Published: March 2007

AbstractWe produced transgenic mice expressing Tcell receptor‐αβ chain genes, derived from the chicken ovalbumin (OVA)‐specific I‐Ad‐restricted CD4+CD8− T helper cell clone 7–3–7. In transgenic mice with H‐2d genetic background (Tg‐d mice), delayed‐type hypersensitivity (DTH) was induced in the hind footpad by one inoculation with OVA without any previous sensitization, suggesting that naive T cells have the potential to be involved in DTH response. Spleen cells from nonimmunized Tg‐d mice showed a strong T cell proliferative response to in vitro stimulation with OVA. Furthermore, these spleen cells produce cytokines including interleukin(IL)‐2, IL‐3, interferon‐γ, granulocyte/macrophage colony‐stimulating factor, macrophage inflammatory protein (MIP)‐1α and MIP‐1β, which may play an important role in the attraction of mononuclear cells to an antigen‐challenging site.
Identification and characterization of membrane cofactor protein (CD46) in the human kidneys
Authors: Nakanishi Isao , Moutabarrik Abdelhakim , Hara Tomoko , Hatanaka Michiyo , Hayashi Terumasa , Syouji Tatsuya , Okada Noriyuki , Kitamura Eisaku , Tsubakihara Yoshiharu , Matsumoto Misako , Seya Tsukasa 
Published: March 2007

AbstractMembrane cofactor protein (MCP, CD46) is an integral protein that serves as a cofactor for factor I in inactivating C3b/C4b deposited on the same cell‐membrane as C3bi/C4c+C4d. This C3b/C4b inactivation is closely associated with self‐protection of host cells from autologous complement attack. We have studied the distribution and properties of MCP in the normal human kidney by immunohistochemical and immunoblotting methods using monoclonal antibodies against MCP. MCP was predominantly expressed on the juxtaglomerular apparatus. Glomerular capillary walls, mesangial areas, and tubulus were also MCP positive. Glomerulus MCP was composed of two major bands of 45–65 kDa, which were similar to those of lymphocyte MCP. The proportion of the high and low molecular weight components in glomerulus MCP, however, was considerably different from that of lymphocyte MCP among the individual samples tested. Glomerular epithelial cells and mesangial cells from an individual having equal amounts of high and low molecular weight components in the lymphocytes were cultured seperately and the properties of their MCP investigated. MCP in the mesangial cells and glomerular epithelial cells showed profiles in which the upper band was predominant. The results may explain the unique distribution of the high and low molecular weight forms in the glomerulus. These forms of MCP together with factor I were all capable of inactivating C3b to C3bi. Message analysis suggested that glomerular epithelial cells and mesangial cells synthesized a single species of mRNA of 4.2 kb from which the polymorphic MCP species were generated. Flow cytometric analysis suggested that MCP was minimal in mesangial cells. These results, taken together with the previous reports on the distribution of other complement regulatory proteins, infer that the distribution profile of MCP is rather similar to that of DAF but differs from those of CD59 and CR1 in the normal human kidney; this may reflect the differences between their roles or functional properties in renal tissue.
Fine antigen specificity of human γδ T cell lines (Vγ9+) established by repetitive stimulation with a serotype (KTH‐1) of a gram‐positive bacterium, Streptococcus sanguis
Authors: Mochizuki Mitsuru , Suzuki Noboru , Takeno Mitsuhiro , Nagafuchi Hiroko , Harada Tatsuhiro , Kaneoka Hidetoshi , Yamashita Naomi , Hirayama Kenji , Nakajima Toshiharu , Mizushima Yutaka , Yamamoto Shoso , Sakane Tsuyoshi 
Published: March 2007

AbstractWe have established human γδ T cell lines specific for Streptococcus sanguis (S. sanguis) KTH‐1 present in normal oral cavity flora. The CD4−CD8− CD3+Vγ9+Vδ1−CD45RO+ CD25+ T cell lines showed a proliferative response to the streptococcal antigen (Ag) in the presence of autologous antigen‐presenting cells without apparent evidence of HLA restriction. The proliferative response of the γδ T cell lines was completely blocked by anti‐TcRγδ monoclonal antibody (mAb) and anti‐HLA class I mAb (W6/32), whereas anti‐HLA classical class Ia mAb (B‐H9; anti‐HLA‐A,B,C), anti‐HLA class II mAb (anti‐DR, anti‐DQ, and anti‐DP) and anti‐CD4 mAb did not have any inhibitory effects. Surprisingly, the γδ T cell lines showed the proliferative response against the original bacterial Ag KTH‐1 exclusively, and exhibited no cross‐reactivity with nominal Ag such as purified protein derivative of tuberculin, tetanus toxoid and Mycobacterium tuberculosis, or the same species but different strain of S. sanguis, American Type Culture Collection (ATCC) standard strain (10556), or even with the same strain but different serotype of S. sanguis, KTH‐3. Moreover, cytokine production of the γδ T cell lines was similar to the Th1 pattern [interferon‐γ, tumor necrosis factor (TNF)‐α and TNF‐β]. They also produced interleukin‐8 that functions as one of chemoattractants for polymorphonuclear cells. Using direct sequencing technique of the polymerase chain reaction products, we found that junctional diversity of the T cell receptor (TcR) used by the parental KTH‐1 specific γδ T cell line and its subclones is rather limited. It is suggested that γδ T cells with canonical TcR could preferentially respond to KTH‐1 Ag. Thus, in addition to a broad or cross‐reactivity of γδ T cells against phylogenetically conserved stress/heat‐shock protein, which is well characterized by others, some peripheral blood γδ T cells could recognize and kill exogenous agents with fine antigenic specificity to protect the body against them.
Characterization of the B cell‐macrophage lineage transition in 70Z/3 cells
Authors: Tanaka Tetsuji , Wu Gillian E. , Paige Christopher J. 
Published: March 2007

AbstractThe 70Z/3 cell line is able to undergo lineage conversion from a pre‐B to macrophage phenotype. Data presented here show that the transition from pre‐B to macrophage follows a reproducible pathway via a stable intermediate stage. The cells in the intermediate stage are adherent and have lost the ability to respond to lipopolysaccharide or interferon‐γ by induction of immunoglobulin χ light chains. However, these cells do not yet display the full range of macrophage‐specific properties such as receptors for macrophage‐colony stimulating factor or the β2 integrin CD11b/CD18. Subcloning experiments with the intermediate cells revealed that they retain the options of either persisting along the macrophage line of differentiation, acquiring additional macrophage traits, or reverting to the pre‐B phenotype. Further differentiation to the macrophage stage is accompanied by the apparent loss of the ability to revert. Thus, these studies define relationships among lineage‐specific traits, and begin to reveal critical stages in lineage commitment.
CD4 engagement induces Fas antigen‐dependent apoptosis of T cells in vivo
Authors: Wang Zhi‐Qin , Dudhane Anita , Orlikowsky Thorsten , Clarke Karen , Li Xun , Darzynkiewicz Zbigniew , Hoffmann Michael K. 
Published: March 2007

AbstractCD4 is a T lymphocyte receptor for major histocompatibility complex class II antigens. It is referred to as coreceptor because it synergizes with the T cell receptor for antigen when both receptors become engaged simultaneously. We show here in mice that when engaged by antibody independently of the T cell antigen receptor, CD4 induces T cells to undergo apoptosis. Several features of this process were identified. The expression of an intact Fas protein is a requirement for CD4‐mediated T cell death. Mice homozygous for the lpr mutation which are defective in the expression of Fas and in their ability to delete lymphocytes apoptotically fail to delete anti‐CD4‐reactive T cells. Sessile anti‐CD4‐reactive T cells leave their homing environment in lymphoid organs and modulate their cell surface molecules, e.g. CD2, CD3, CD4. A massive influx of lymphoid cells with null‐cell phenotype occurs in the blood where they begin to reexpress cell surface markers. With their arrival in the circulation, anti‐CD4‐reactive T cells develop features of DNA degradation typical of apoptosis. More than one third of the circulating lymphoid cells show apoptotic features 7–8 h after anti‐CD4 injection. Their frequency declines subsequently presumably due to their physical disintegration via shedding of apoptotic bodies and phagocytosis. Our data show that when not obliged to the activation process by the antigen receptor, CD4 can mediate deletion signals. Thus, besides functioning as coreceptor with the antigen receptor, CD4 has a function of its own in facilitating the induction of apoptosis.
The degradation product of the C5a anaphylatoxin C5adesarg retains basophil‐activating properties
Authors: Bürgi Béatrice , Brunner Thomas , Dahinden Clemens A. 
Published: March 2007

AbstractThe complement cleavage product C5a is a potent agonist of different leukocyte types and also has anaphylatoxic properties through the release of mediators by basophils and tissue mast cells. C5a is very rapidly degraded by serum carboxypeptidase N which cleaves the functionally important carboxy‐terminal arginine, generating C5adesarg, a chemotactic agonist with little mast cell‐activating ability. Here we show that natural human C5adesarg is still a trigger for basophil mediator release superior to other endogenous IgE‐independent agonists such as monocyte chemotactic protein (MCP)‐1, interleukin (IL)‐8, C3a and platelet‐activating factor. On a molar basis C5adesarg is only one order of magnitude less potent and about half as efficacious as C5a at inducing basophil degranulation. Priming of basophils with either IL‐3, IL‐5, granulocyte‐macrophage‐colony‐stimulating factor (GM‐CSF) or nerve growth factor (NGF) (with comparable efficacies, but different potencies: IL‐3>NGF>IL‐5>GM‐CSF) enhanced histamine release and conditioned the cells to produce large amounts of leukotriene C4 (LTC4), which is not generated by basophils exposed to C5adesarg alone. The efficacy of C5a and C5adesarg at inducing histamine and LTC4 release by primed basophils was similar. Thus, C5adesarg is a stable inducer of release of inflammatory mediators by human basophils, particularly in primed cells, and complement may, therefore, play a role in immediate‐type hypersensitivity diseases in allergic late‐phase reactions.