bluuebunny/crossref_metadata_2025_split huggingface dataset:
Purification and characterization of endogenous peptides extracted from HLA‐DR isolated from the spleen of a patient with rheumatoid arthritis
Authors: Gordon Robert D. , Young Janice A. , Rayner Stephen , Luke Richard W. A. , Crowther Mandy L. , Wordsworth Paul , Bell John , Hassall Giles , Evans Jonathan , Hinchliffe Sue A. , Culbert Eric J. , Davison Matthew D. 
Published: March 2007

AbstractWe have purified HLA‐DR from the spleen of a patient with rheumatoid arthritis. The patient had Felty's syndrome and was heterozygous for the DR4Dw4 antigen. We have isolated endogenous peptides from purified HLA‐DR molecules. The peptides were purified by reverse phase HPLC and the major peaks were subjected to N‐terminal sequencing. The peptides were derived from a variety of proteins: human serum albumin, human erythroid protein 4.1, 60S ribosomal proteins L31 and L35, VCAM‐1, human immunoglobulin λ chain and cathepsin‐S. A peptide corresponding to the sequence of human serum albumin (HSA) residues 106–120 was synthesized and shown to bind to HLA‐DR4Dw4 (IC50 = 1.41 μM). We have confirmed and refined current ideas about the structural motif for the binding of peptides to HLA‐DR and HLA‐DR4Dw4.
Transforming growth factor‐β1‐induced expression of the mucosa‐related integrin αE on lymphocytes is not associated with mucosa‐specific homing
Authors: Austrup Frank , Rebstock Sabine , Kilshaw Peter J. , Hamann Alf 
Published: March 2007

AbstractThe integrin αE (HML‐1, αIEL, αM290) is largely expressed on lymphocytes in epithelial sites, especially the gut mucosa. We investigated whether αE has any role in homing or delineates a phenotype with distinct migratory behavior. Lymph node T cells were stimulated for 5 days with anti‐CD3 in the presence or absence of transforming growth factor (TGF)‐β1 to generate αE+ or αE− cells, respectively. The two populations were then tested for their homing properties in mice. Both αE+ (TGF‐β‐treated) and αE− (control) cells of either CD4+ or CD8+ subset had a low capacity to enter the gut and showed the same homing behavior with respect to a variety of other organs. The same was true for αE+ and αE− cells that had been briefly stimulated with anti‐CD3 (24 h) and then allowed to return to a resting state before injection, though in this case both populations showed a greater capacity to recirculate through lymphoid tissue than was seen with fully activated cells. The results indicate that αEβ7 does not act as a homing receptor, and that the expression of the site‐specific marker αE does not correlate with a distinct homing behavior.
Lack of L‐selectin expression by cells transferring diabetes in NOD mice: insights into the mechanisms involved in diabetes prevention by Mel‐14 antibody treatment
Authors: Lepault Françoise , Gagnerault Marie‐Claude , Faveeuw Christelle , Bazin Hervé , Boitard Christian 
Published: March 2007

AbstractThe process of mononuclear cell extravasation from the blood into the islets of Langerhans in nonobese diabetic (NOD) mice is dependent on the expression of a set of molecules, most of which remain to be defined. The observation that vascular addressins are expressed in inflamed islets raises the issue of the involvement of one of their ligands, L‐selectin, in the pathogenesis of autoimmune diabetes. Treatment of NOD females with Mel‐14, an antibody specific for L‐selectin, reduced the spontaneous development of both insulitis and diabetes. Pretreatment of diabetic donors with Mel‐14 decreased the capacity of their splenocytes to transfer the disease. However, the treatment of recipients had no effect on the transfer of diabetes by untreated diabetogenic splenocytes. To reconcile these apparently conflicting results, we fractionated spleen T cells from diabetic mice according to L‐selectin expression. Diabetogenic cells were found only in the L‐selectin subpopulation. Thus, diabetogenic cells in adult mice share phenotypic characteristics with activated/memory cells, and enter the pancreas using L‐selectin‐independent migratory pathways.
Uptake of microparticle‐adsorbed protein antigen by bone marrow‐derived dendritic cells results in up‐regulation of interleukin‐1α and interleukin‐12 p40/p35 and triggers prolonged, efficient antigen presentation
Authors: Scheicher Christoph , Mehlig Maria , Dienes Hans‐Peter , Reske Konrad 
Published: March 2007

AbstractDendritic cells synthesize and express major histocompatibility complex (MHC) class II peptide‐binding elements constitutively and, therefore, belong to the category of professional antigen‐presenting cells. Unlike other cells that show constitutive class II expression, such as B cells and certain T cell clones, dendritic cells possess the unique capacity to activate naive T cells. Using dendritic cells generated in vitro by culture of mouse bone marrow in the presence of low doses of recombinant mouse granulocyte/macrophage colony‐stimulating factor, we found that discrete maturation stages of these cells can be distinguished which were correlated with defined functional capabilities. The striking observation was the presence of a progenitor dendritic cell expressing low levels of class II which, unlike its differentiated counterpart in vitro, possessed pronounced phagocytic activity. Adding protein antigen to dendritic cells in a particle‐adsorbed form, as compared to a soluble form, we demonstrate that phagocytosis of the particle‐adsorbed protein by progenitor dendritic cells involves an activation event. This is evidenced by the de novo synthesis of transcripts of interleukin‐1α and interleukin‐12 p40/p35 as well as transcripts of MHC class II. Most importantly, an augmented and prolonged antigen‐presentation capacity was observed when the antigen was given in particle‐adsorbed instead of soluble form. These findings indicate that progenitor dendritic cells are functionally more flexible and potent than fully differentiated dendritic cells and that they play a crucial role in antigen presentation. It is suggested that these findings will open up new possibilities to devise strategies for vaccine development.
A gut‐homing, oligoclonal CD4+ T cell population in severe‐combined immunodeficient mice expressing a rearranged, transgenic class I‐restricted αβ T cell receptor
Authors: Reimann Jörg , Rudolphi Angelika , Spieß Sibylle , Claesson Mogens H. 
Published: March 2007

AbstractWe studied the peripheral T cell compartment of H‐2b severe combined immunodeficient (scid) mice that express a transgenic (tg) αβ T cell receptor (TcR) specific for the H‐Y (male) epitope presented by the H‐2 class I Db molecule. Large populations of CD3+ NK1.1−TCRβT+ T cells were present in spleen, mesenteric lymph nodes, peritoneal cavity, lamina propria and epithelial layer of the small and large intestine of 6‐ to 10‐month‐old, male and female tg scid mice. Only low numbers of CD3+ T cells were recovered from inguinal, popliteal, or axillary lymph nodes. We studied CD4+ T cells in these tg scid mice. CD4+ T cells were found in the peritoneal cavity, in the mesenteric lymph nodes and in the intraepithelial layer and lamina propria of the gut. All CD4+ T cells were CD44+ (i.e. showed evidence of antigen‐driven differentiation) and expressed the tg Vβ8.2 TcR β‐chain (TcRβT+). Only few CD4+ T cells expressed the tg Vα3+ TcR α‐chain (TcRαT). cDNA was prepared from CD4+ T cells from spleen or mesenteric lymph nodes of individual male and female tg scid mice; sequence analyses of polymerase chain reaction‐amplified, endogenous TcR α‐chain (TcRαE) transcripts indicated that > 90% of the TcRαE‐chain transcripts were in‐frame, that the TcRαE repertoire in CD4+ T cell populations was oligoclonal, and that the TcRαE repertoire was different in individual tg scid mice. Hence, an oligoclonal, leaky CD4+ T cell population is selected in tg scid mice that apparently responds to gut‐derived antigens. No inflammatory bowel disease (IBD) was evident in the small or large intestine of 6‐ to 10‐month old tg scid mice. After adoptive transfer of purified CD4+ T cells (105 cells per mouse) from tg scid mice into non‐tg H‐2b scid mice, CD4+ TcRαT−βT+ cells were found in gut tissues of the immunodeficient host. Transplanted scid mice developed clinical and histological signs of IBD. An oligoclonal, gut‐homing, memory/effector CD4+ CD44+ TcRβT+ TcRαT− T cell subset from leaky tg scid mice thus has a pathogenic potential when released from the control of TcRβT+ TcRαT+ T cells.
Immunoglobulin variable gene analysis of human autoantibodies reveals antigen‐driven immune response to glutamate decarboxylase in type 1 diabetes mellitus
Authors: Richter Wiltrud , Jury Karin M. , Loeffler Daniela , Manfras Burkhard J. , Eiermann Thomas H. , Boehm Bernhard O. 
Published: March 2007

AbstractInsulin‐dependent (type 1) diabetes mellitus is an organ‐specific autoimmune disease frequently associated with an islet‐specific humoral autoimmune response. The role of islet cell autoantibodies in the disease process is unclear; in particular, it is not known whether they are a non‐specific side effect of islet cell destruction or play a role in the autoimmune network leading to type 1 diabetes. Here we report the immunoglobulin gene usage and somatic mutation rates of a panel of seven human monoclonal islet cell autoantibodies (MICA 1–7) directed towards the major islet cell autoantigen glutamate decarboxylase (GAD). These autoantibodies were produced from cells from two patients with newly diagnosed type 1 diabetes. VH1, VH4 and Vλ2 gene segments were frequently used in the MICA, but no correlation between V gene usage and epitope recognition was found. The nonrandom ratio of replacement versus silent mutations in the variable gene region, an accumulation of replacement mutations in the complementarity determining regions, which confer antigen binding, and the high relative avidity for GAD observed for MICA 1, 3, 4, and 6, suggested that the immune response to GAD is driven by the antigen. In contrast, MICA 2, 5, and 7, revealing a lower affinity for antigen, have accumulated a large number of silent mutations. These latter antibodies may, therefore, be characteristic for later stages of the chronic autoimmune disease. Our results argue in favor of an antigen‐driven autoantibody response to islets in human type 1 diabetes. They suggest that GAD is an important target of autoimmunity associated with type 1 diabetes.
Repression of the immunoglobulin heavy chain 3′ enhancer by helix‐loop‐helix protein Id3 via a functionally important E47/E12 binding site: implications for developmental control of enhancer function
Authors: Meyer Kerstin B. , Skogberg Michaela , Margenfeld Cecilia , Ireland John , Pettersson Sven 
Published: March 2007

AbstractThe activity of the immunoglobulin 3′ enhancer is restricted to the late stages of B lymphoid development. Here we further examine the molecular basis for the temporally restricted activity of the B‐lymphoid IgH 3′ enhancer. We demonstrate that a binding site (E5 site) for the E47 and/or E12 proteins is functionally important for enhancer activity. The multimerized E5 site acts as a B cell‐specific enhancer and, when assayed in COS cells, can be transactivated by E47/E12 proteins. This transactivation in COS cells, as well as the activity of the full length 3′ enhancer in plasma cells, can be repressed by overexpression of the dominant negative nuclear regulator Id3. When examining the tissue distribution of Id3 in murine cell lines, we find that Id3 is expressed throughout the pre‐B and B cell stages, but is down‐regulated at the plasma cell stage. Thus, Id3 may contribute to the temporal regulation of the IgH 3′ enhancer.
The type I interleukin‐1 receptor acts in series with tumor necrosis factor (TNF) to induce arthritis in TNF‐transgenic mice
Authors: Probert Lesley , Plows David , Kontogeorgos George , Kollias George 
Published: March 2007

AbstractThe pro‐inflammatory cytokines tumor necrosis factor (TNF) and interleukin‐1 (IL‐1) have been shown to be primary mediators in the pathogenesis of chronic inflammatory joint diseases. However, the relative contributions of these molecules to the development and progression of disease is not known. In the present study, we have investigated the involvement of the type I IL‐1 receptor in the development and progression of chronic arthritis in a previously described TNF‐transgenic mouse model of this disease. A neutralizing monoclonal antibody to the murine type I IL‐1 receptor was injected intraperitoneally three times a week from birth to 9 weeks of age. In the positive control group of untreated transgenic mice the incidence of arthritis was 100% after 9 weeks of age. The injection of normal hamster IgG did not influence the incidence or development of arthritis. In contrast, the injection of antibody to the type I IL‐1 receptor completely prevented the development of arthritis. Clinical evaluation of disease was confirmed histologically, anti‐receptor antibody‐treated mice showed no sign of arthritic change. Moreover, the analysis of sera taken at the end of the study period showed that the neutralization of arthritis by IL‐1 receptor antibody treatment was accompanied by significantly lower levels of circulating human TNF compared to the control groups and to untreated transgenic mice prior to disease onset. Taken together, these results show that IL‐1 signaling blockade exerts a direct negative feedback effect on TNF production. Our results show that in TNF‐transgenic mice the IL‐1 receptor accepts the whole pathogenic load of TNF, thereby acting as a potent downstream mediator in the pathogenesis of chronic arthritis.
Induction of the increased Fyn kinase activity in anergic T helper type 1 clones requires calcium and protein synthesis and is sensitive to cyclosporin A
Authors: Gajewski Thomas F. , Fields Patrick , Fitch Frank W. 
Published: March 2007

AbstractSeveral alterations in T cell receptor‐associated signal transduction have been observed following induction of anergy of T helper type 1 (Th1) clones, including a modified intracellular free calcium ([Ca2+]i) response and increased kinase activity associated with the protein tyrosine kinase p59fyn. In the current study, we demonstrate that, although the kinetics of acquisition of both of these signaling alterations correlated with the generation of anergy, a normal calcium response returned within 48 h after removal from the anergizing stimulus, whereas the increased p59fyn activity persisted and the cells remained hyporesponsive. Generation of both the anergic state and the increased p59fyn activity was prevented in the presence of calcium‐free medium, cycloheximide (CHX), or cyclosporin A (CsA), and could be mimicked by the calcium ionophore ionomycin. In contrast, the altered calcium response was inhibited by stimulation in the presence of calcium‐free medium or CsA, but not CHX. Thus, surprisingly, these data suggest that a chronic elevation of [Ca2+]i is proximal to and necessary for the increase in p59fyn‐associated kinase activity observed in anergic Th1 clones. Increased p59fyn activity, but not the altered calcium response, correlates with maintenance of the anergic state.
Apoptosis of ileal Peyer's patch B cells is increased by glucocorticoids or anti‐immunoglobulin antibodies
Authors: Motyka Bruce , Bhogal Hardeep S. , Reynolds John D. 
Published: March 2007

AbstractThe ileal Peyer's patch (PP) in sheep plays a central role in the development and production of B cells. Associated with a tremendous amount of B cell proliferation in this site is the extensive diversification of the Ig repertoire by somatic hypermutation. Very few (<5%) of the B cells produced in the ileal PP differentiate and emigrate; instead, the vast majority of these cells soon die, and we have previously shown that death is associated with apoptosis. When placed in culture, ileal PP B cells die rapidly by apoptosis, such that after 24h, 60 ± 1 % of DNA is fragmented. Here, we show that the extent of this spontaneous B cell apoptosis in culture, as quantitated by DNA fragmentation, was significantly increased in a dose‐dependent manner by the glucocorticoids hydrocortisone or dexamethasone. Furthermore, treatment of lambs with 2–2.5 mg/kg of dexamethasone resulted in a marked increase in the number of apoptotic cells in the ileal PP and an increase in ileal PP B cell DNA fragmentation to 20 ± 6%, compared with 2.4 ± 0.1 % in untreated lambs. Anti‐immunoglobulin (Ig) antibodies also increased the extent of DNA fragmentation in cultured ileal PP B cells. After 24 or 48 h of culture with anti‐Ig (PIg47A), DNA fragmentation was 74 ± 2 % and 75 ± 3 %, respectively. Ileal PP B cells are rescued from apoptosis by agents that activate protein kinase C and increase cytosolic Ca2+, and here we show that this treatment also results in apoptotic rescue in the presence of dexamethasone or anti‐Ig. We speculate that the apoptosis of ileal PP B cells in situ may be modulated by glucocorticoids and by the cross‐linking of surface Ig. Apoptosis, induced by a signal through surface Ig, may be an important mechanism in the deletion of self‐reactive B cells during the expansion of the Ig repertoire in the ileal PP.
Hyaluronan binding by CD44 is regulated by a phosphorylation‐independent mechanism
Authors: Uff Caroline R. , Neame Stephen J. , Isacke Clare M. 
Published: March 2007

AbstractCD44 is an adhesion receptor for which the major characterized ligand is the extracellular matrix glycosaminoglycan, hyaluronan. This interaction underlies CD44‐mediated cell attachment, cell migration, and matrix remodelling during development and wound healing. Truncation of the CD44 cytoplasmic domain does not prevent cell surface expression of this hyaluronan receptor but it dramatically impairs ligand binding. In this study we have examined the role of phosphorylation in regulating this function by mutating the target serine residues to either neutral amino acids with the aim of creating a phosphorylation‐incompetent molecule, or to acidic residues to mimic a fully phosphorylated CD44. In transfected AKR1 cells the behavior of both the neutral and acidic mutants was indistinguishable from wild‐type CD44, indicating that there is a phosphorylation‐independent mechanism involved in regulating hyaluronan binding.
Comparative analysis of B7‐1 and B7‐2 expression in Langerhans cells: differential regulation by T helper type 1 and T helper type 2 cytokines
Authors: Kawamura Tatsuyoshi , Furue Masutaka 
Published: March 2007

AbstractEpidermal Langerhans cells (LC) are Ia‐bearing potent antigen‐presenting cells (APC) of dendritic cell lineage that play a crucial role in primary and secondary T cell‐dependent immune responses. LC express several costimulatory molecules such as B7, which has been implicated as one of the important determinants of professional APC. Recently, B7 antigens have been shown to include three distinct molecules termed B7‐1, B7‐2, and B7‐3, and the expression of B7‐1 and B7‐2 in LC has been already confirmed. However, little is known of the regulation of B7‐1 and B7‐2 expression in LC. We demonstrated that LC do not express B7‐1 and B7‐2 in situ; however, the expression of both molecules is rapidly induced during the first 3 days of culture, and high levels of expression are maintained at least until day 6. We show that the expression of B7‐2 in LC is much higher than that of B7‐1 in each experiment, and that B7‐1 and B7‐2 expression is reproducibly augmented by interleukin (IL)‐4 in a dose‐dependent manner; however, IL‐2 affected expression very little. Finally, B7‐1 expression is significantly and dose‐dependently down‐regulated by interferon (IFN)‐γ or IL‐10, and B7‐2 expression is consistently inhibited by IL‐10, but not by IFN‐γ. The effects of these cytokines are active only in the induction phase (during first 3 days of culture) of B7 expression: the modulatory effects of cytokines are hardly detected in the plateau phase (days 4 to 6 of culture) of B7 expression in LC. These findings suggest that B7‐1 and B7‐2 expression are indeed selectively and differentially regulated by these T cell‐derived cytokines, and that the cytokines may modulate the synthesis of B7 molecules rather than the degradation of already‐expressed B7 molecules.
Spontaneous apoptosis of dendritic cells is efficiently inhibited by TRAP (CD40‐ligand) and TNF‐α, but strongly enhanced by interleukin‐10
Authors: Ludewig Burkhard , Graf Daniel , Gelderblom Hans R. , Becker Yechiel , Kroczek Richard A. , Pauli Georg 
Published: March 2007

AbstractIn the lymphoid tissues, adaptive immune responses are initiated by the interaction of interdigitating dendritic cells (IDC) with naive T cells. To understand this interplay better, we used mature Langerhans cells (mLC), migrating from human epidermis, as the correlate of IDC ex vivo to evaluate the different effects of tumor necrosis factor (TNF)‐α, TNF‐related activation protein (TRAP; CD40‐ligand) and interleukin‐10 (IL‐10) on induction or prevention of apoptotic cell death in these cells. Spontaneous decrease of mLC viability in culture was due to apoptosis, as determined by the appearance of typical morphological changes such as dilatation of the endoplasmic reticulum (ER), chromatin condensation and membrane blebbing. IL‐10 strongly reduced mLC viability, whereas TRAP and TNF‐α facilitated the survival of mLC. Spontaneous DNA fragmentation was detectable after 24 h in culture. IL‐10 led to an earlier onset of DNA fragmentation, whereas TRAP and TNF‐α delayed internucleosomal DNA cleavage. We found that IL‐10‐treated mLC were readily ingested and removed by macrophages. TNF‐α and TRAP, in contrast, reduced engulfment of mLC by macrophages. Interestingly, IL‐10, even at low concentrations, reverted the effects of TNF‐α and TRAP in inhibiting mLC apoptosis. Furthermore, IL‐10 led to the down‐regulation of various surface antigens, especially of CD86 and CD54, whereas TNF‐α and TRAP enhanced the expression of MHC class I and II antigens and of the accessory molecules CD40, CD54, CD80 and CD86. Taken together, these results show that mLC spontaneously undergo apoptosis in culture and that the progression of mLC to apoptosis is inhibited by TRAP and TNF‐α, but accelerated by IL‐10.
Early appearance of T cell receptor αβ+ CD4− CD8− T cells with a skewed variable region repertoire after infection with Listeria monocytogenes
Authors: Matsuzaki Goro , Li Xiao‐Yan , Kadena Tsutomu , Song Fei , Hiromatsu Kenji , Yoshida Hiroki , Nomoto Kikuo 
Published: March 2007

AbstractWe found that the number of T cell receptor (TCR)αβ+ CD4− CD8− T cells increased in the peritoneal cavity on day 5 after an intraperitoneal infection with Listeria monocytogenes strain EGD together with TCRγδ+ CD4− CD8− T cells. Thereafter, the TCRαβ+ CD4− CD8− T cells decreased to a normal level by day 14. The TCRαβ+ CD4− CD8− T cells showed an activated T cell phenotype (L‐selectin‐CD44+) and expressed CD45/B220 and interleukin‐2 receptor β, but did not express heat stable antigen, which is expressed by the immature CD4− CD8− thymocytes. Furthermore, 20–30% of the TCRαβ+ CD4− CD8− T cells expressed the NK1.1 natural killer cell marker. Analyses of the TCR V region repertoire of the TCRαβ+ CD4− CD8− T cells induced by L. monocytogenes infection showed that more than 80% of the TCRαβ+ CD4− CD8− T cells expressed TCR Vβ8 detected by anti‐TCR Vβ8.1 and 8.2 mAb, and a reverse transcription‐polymerase chain reaction analysis of Vα14 relative to Vα11 expression revealed that the TCRαβ+ CD4− CD8− T cells expressed a higher level of Vα14, which was reported to be preferentially expressed by TCRαβ+ CD4− CD8− thymocytes rather than conventional CD4+ T cells. The TCRαβ+ CD4− CD8− T cells showed a proliferative response to anti‐TCRαβ mAb stimulation. In contrast, they showed no response to stimulation with either Listeria antigen or 65‐kDa heat shock protein of Mycobacterium bovis, which do stimulate the Listeria‐specific TCRαβ+ CD4+ CD8− T cells and the Listeria‐induced TCR γδ+ T cells, respectively. These results suggest that the TCRαβ+ CD4− CD8− T cells may recognize a restricted set of self antigens induced by L. monocytogenes infection, and that they contribute to host protection at an early stage of the infection.