bluuebunny/crossref_metadata_2025_split huggingface dataset:
Epitope Specificity of Autoreactive T and B Cells Associated with Experimental Autoimmune Encephalomyelitis and Optic Neuritis Induced by Oligodendrocyte-Specific Protein in SJL/J Mice
Authors: Kaushansky Nathali , Zhong Ming-Chao , Kerlero de Rosbo Nicole , Hoeftberger Romana , Lassmann Hans , Ben-Nun Avraham 
Published: April 2014

Abstract
The encephalitogenic potential of oligodendrocyte-specific protein (OSP) in mice, its specific localization in the intralamellar tight junctions in CNS myelin, and the detection of autoreactivity against OSP in multiple sclerosis (MS) strongly suggest the relevance of autoreactivity against OSP in the pathogenesis of MS. In this study, we have characterized the autoimmune T and B cells that are associated with clinicopathological manifestations of OSP-induced MS-like disease in mice by using recombinant soluble mouse OSP (smOSP) and synthetic overlapping peptides spanning smOSP. SJL/J mice immunized with smOSP developed chronic relapsing clinical experimental autoimmune encephalomyelitis accompanied with intense perivascular and parenchymal inflammatory infiltrates, widespread demyelination, axonal loss, and remarkable optic neuritis. The smOSP-primed lymph node cells reacted predominantly against OSP55–80 and to a lesser extent also to OSP22–46 and OSP179–207. Unexpectedly, in vitro selection with smOSP resulted in pathogenic smOSP-specific CD4+ T cells that reacted equally well against OSP55–80, OSP22–46, OSP45–66, and OSP179–207. Fine analysis of the anti-OSP autoimmunity revealed that the disease is primarily associated with CD4+ T cells directed against the major (OSP55–80) and the minor (OSP179–207) encephalitogenic regions that were further delineated, both in vitro and in vivo, to OSP55–66 and OSP194–207, respectively. In contrast, the OSP-induced Abs were predominantly directed against OSP22–46; these Abs were mostly of IgG1 isotype, but high levels of IgG2a and IgG2b and significant levels of IgE were also observed. The reactivity of pathogenic T cells to two encephalitogenic regions, OSP55–80 and OSP179–207, and their diverse TCRVβ gene repertoire may impose difficulties for epitope-directed or TCR-targeting approaches to immune-specific modulation of OSP-related pathogenesis.
CD4+CD25high T Cells Are Enriched in the Tumor and Peripheral Blood of Prostate Cancer Patients
Authors: Miller Ashley M. , Lundberg Kajsa , Özenci Volkan , Banham Alison H. , Hellström Magnus , Egevad Lars , Pisa Pavel 
Published: April 2014

Abstract
In this study, we investigated whether CD4+CD25high regulatory T cells (Treg) are increased in the tumor tissue and peripheral blood of early-stage prostate cancer patients undergoing prostatectomy. We show that the prevalence of CD4+CD25high T cells inside the prostate was significantly higher in the tumor compared with benign tissue from the same prostate. Furthermore, the frequency of CD4+CD25high T cells in peripheral blood was significantly higher in prostate cancer patients compared with normal donors. A proportion of the CD4+CD25high T cells was also shown to be glucocorticoid-induced TNF receptor, ICOS, and FOXP3 positive. Moreover, CD4+CD25+ T cells from blood and supernatants from cultured prostate tumor tissue samples exhibited immunosuppressive function in vitro. Furthermore, supernatants from cultured prostate tissue samples and prostate cancer ascites fluid induced migration of CD4+CD25+ T cells and were shown to contain the regulatory T cell chemokine CCL22 by ELISA. Our findings indicate that Tregs are an important cellular component of early-stage prostate tumors, and thus new therapeutic strategies aimed at inhibition or depletion of Tregs may improve prostate cancer immunotherapy.
Role of MHC-Linked Genes in Autoantigen Selection and Renal Disease in a Murine Model of Systemic Lupus Erythematosus
Authors: Sekine Hideharu , Graham Kareem L. , Zhao Shenru , Elliott Margaret K. , Ruiz Philip , Utz Paul J. , Gilkeson Gary S. 
Published: April 2014

Abstract
We previously described a renal protective effect of factor B deficiency in MRL/lpr mice. Factor B is in the MHC cluster; thus, the deficient mice were H2b, the haplotype on which the knockout was derived, whereas the wild-type littermates were H2k, the H2 of MRL/lpr mice. To determine which protective effects were due to H2 vs factor B deficiency, we derived H2b congenic MRL/lpr mice from the 129/Sv (H2b) strain. Autoantibody profiling using autoantigen microarrays revealed that serum anti-Smith and anti-small nuclear ribonucleoprotein complex autoantibodies, while present in the majority of H2k/k MRL/lpr mice, were absent in the H2b/b MRL/lpr mice. Surprisingly, 70% of MRL/lpr H2b/b mice were found to be serum IgG3 deficient (with few to no IgG3-producing B cells). In addition, H2b/b IgG3-deficient MRL/lpr mice had significantly less proteinuria, decreased glomerular immune complex deposition, and absence of glomerular subepithelial deposits compared with MRL/lpr mice of any H2 type with detectable serum IgG3. Despite these differences, total histopathologic renal scores and survival were similar among the groups. These results indicate that genes encoded within or closely linked to the MHC region regulate autoantigen selection and isotype switching to IgG3 but have minimal effect on end-organ damage or survival in MRL/lpr mice.
Defective Th1 Cytokine Gene Transcription in CD4+ and CD8+ T Cells from Wiskott-Aldrich Syndrome Patients
Authors: Trifari Sara , Sitia Giovanni , Aiuti Alessandro , Scaramuzza Samantha , Marangoni Francesco , Guidotti Luca G. , Martino Silvana , Saracco Paola , Notarangelo Luigi D. , Roncarolo Maria-Grazia , Dupré Loïc 
Published: April 2014

Abstract
Wiskott-Aldrich syndrome (WAS) protein (WASP) plays a key role in TCR-mediated activation and immunological synapse formation. However, the effects of WASP deficiency on effector functions of human CD4+ and CD8+ T cells remain to be determined. In this study, we report that TCR/CD28-driven proliferation and secretion of IL-2, IFN-γ, and TNF-α are strongly reduced in CD8+ T cells from WAS patients, compared with healthy donor CD8+ T cells. Furthermore, WAS CD4+ T cells secrete low levels of IL-2 and fail to produce IFN-γ and TNF-α, while the production of IL-4, IL-5, and IL-10 is only minimally affected. Defective IL-2 and IFN-γ production persists after culture of naive WAS CD4+ T cells in Th1-polarizing conditions. The defect in Th1 cytokine production by WAS CD4+ and CD8+ T cells is also present at the transcriptional level, as shown by reduced IL-2 and IFN-γ mRNA transcripts after TCR/CD28 triggering. The reduced transcription of Th1 cytokine genes in WAS CD4+ T cells is associated with a defective induction of T-bet mRNA and a reduction in the early nuclear recruitment of NFAT-1, while the defective activation of WAS CD8+ T cells correlates with reduced nuclear recruitment of both NFAT-1 and NFAT-2. Together, our data indicate that WASP regulates the transcriptional activation of T cells and is required specifically for Th1 cytokine production.
Cutting Edge: Pivotal Function of Ubc13 in Thymocyte TCR Signaling
Authors: Yamamoto Masahiro , Sato Shintaro , Saitoh Tatsuya , Sakurai Hiroaki , Uematsu Satoshi , Kawai Taro , Ishii Ken J. , Takeuchi Osamu , Akira Shizuo 
Published: April 2014

Abstract
The Ubc13 E2 ubiquitin-conjugating enzyme is essential for BCR-, TLR-, and IL-1 receptor (IL-1R)-mediated immune responses. Although Ubc13-deficient mice show defects in BCR-, TLR/IL-1R-, or CD40-mediated activation of mitogen-activated protein kinases, the function of Ubc13 in TCR-mediated signaling and responses remains uncertain. To address this, we here generated T cell-specific conditional Ubc13-deficient mice. The frequency of T lymphocytes was severely reduced in spleens from Ubc13-deficient mice. Moreover, Ubc13-deficient thymocytes displayed defective proliferation in response to anti-CD3/CD28 or PMA/ionophore stimulation. Regarding the signal transduction, although NF-κB activation was modestly affected, PMA/ionophore-induced activation of Jnk and p38 was profoundly impaired in Ubc13-deficient thymocytes. In addition, PMA/ionophore-mediated ubiquitination of NF-κB essential modulator (NEMO)/IκB kinase γ (IKKγ) and phosphorylation of TGF-β-activated kinase 1 (TAK1) were nearly abolished in Ubc13-deficient thymocytes. Thus, Ubc13 plays an important role in thymocyte TCR-mediated signaling and immune responses.
Regulation of Immunity by a Novel Population of Qa-1-Restricted CD8αα+TCRαβ+ T Cells
Authors: Tang Xiaolei , Maricic Igor , Purohit Nikunj , Bakamjian Berge , Reed-Loisel Lisa M. , Beeston Tara , Jensen Peter , Kumar Vipin 
Published: April 2014

Abstract
Regulatory mechanisms involving CD8+ T cells (CD8 regulatory T cells (Tregs)) are important in the maintenance of immune homeostasis. However, the inability to generate functional CD8 Treg clones with defined Ag specificity has precluded a direct demonstration of CD8 Treg-mediated regulation. In the present study, we describe the isolation of functional lines and clones representing a novel population of TCRαβ+ Tregs that control activated Vβ8.2+ CD4 T cells mediating experimental autoimmune encephalomyelitis. They express exclusively the CD8αα homodimer and recognize a peptide from a conserved region of the TCR Vβ8.2 chain in the context of the Qa-1a (CD8αα Tregs). They secrete type 1 cytokines but not IL-2. CD8αα Tregs kill activated Vβ8.2+ but not Vβ8.2− or naive T cells. The CD8αα Tregs prevent autoimmunity upon adoptive transfer or following in vivo activation. These findings reveal an important negative feedback regulatory mechanism targeting activated T cells and have implications in the development of therapeutic strategies for autoimmune diseases and transplantation.
Oncostatin M Enhances CCL21 Expression by Microvascular Endothelial Cells and Increases the Efficiency of Dendritic Cell Trafficking to Lymph Nodes
Authors: Sugaya Makoto , Fang Lei , Cardones Adela R. , Kakinuma Takashi , Jaber Samer H. , Blauvelt Andrew , Hwang Sam T. 
Published: April 2014

Abstract
CCL21, a lymphatic endothelial cell (LEC)-derived chemokine, and its receptor CCR7 regulate dendritic cell (DC) trafficking to lymph nodes (LN), but it is unclear how CCL21 expression is regulated. Oncostatin M (OSM) is an IL-6-like cytokine synthesized by activated DC and other leukocytes. In vitro, OSM (but not TNF-α) stimulated CCL21 mRNA and protein expression by human dermal microvascular EC (DMEC) in an ERK1/2-dependent fashion. Conditioned medium from OSM-treated DMEC stimulated CCL21-dependent chemotaxis of mouse bone marrow-derived DC (BMDC). Cultured BMDC expressed OSM, which was increased with the addition of LPS. Topical application of the contact-sensitizing hapten, trinitrochlorobenzene, resulted in enhanced OSM expression in the skin, whereas cutaneous injection of TNF-α did not. Injection of OSM into the footpad increased CCL21 mRNA expression in the draining LN by ∼10-fold and in mouse skin by ∼4-fold without increasing CCR7 mRNA. In vitro, OSM increased the permeability of DMEC and lung microvascular EC monolayers to FITC-dextran beads, and, in vivo, it enhanced accumulation of Evans blue dye in draining LN by ∼3-fold (p = 0.0291). Of note, OSM increased trafficking of BMDC injected in footpads to draining LN by 2-fold (p = 0.016). In summary, OSM up-regulates CCL21 expression in skin and draining regional LN. We propose that OSM is a regulator of CCL21 expression and endothelial permeability in skin, contributing to efficient migration of DC to regional LN.
Control of Memory CD4 T Cell Recall by the CD28/B7 Costimulatory Pathway
Authors: Ndejembi Modesta P. , Teijaro John R. , Patke Deepa S. , Bingaman Adam W. , Chandok Meena R. , Azimzadeh Agnes , Nadler Steven G. , Farber Donna L. 
Published: April 2014

Abstract
The CD28/B7 costimulatory pathway is generally considered dispensable for memory T cell responses, largely based on in vitro studies demonstrating memory T cell activation in the absence of CD28 engagement by B7 ligands. However, the susceptibility of memory CD4 T cells, including central (CD62Lhigh) and effector memory (TEM; CD62Llow) subsets, to inhibition of CD28-derived costimulation has not been closely examined. In this study, we demonstrate that inhibition of CD28/B7 costimulation with the B7-binding fusion molecule CTLA4Ig has profound and specific effects on secondary responses mediated by memory CD4 T cells generated by priming with Ag or infection with influenza virus. In vitro, CTLA4Ig substantially inhibits IL-2, but not IFN-γ production from heterogeneous memory CD4 T cells specific for influenza hemagglutinin or OVA in response to peptide challenge. Moreover, IL-2 production from polyclonal influenza-specific memory CD4 T cells in response to virus challenge was completely abrogated by CTLA4Ig with IFN-γ production partially inhibited. When administered in vivo, CTLA4Ig significantly blocks Ag-driven memory CD4 T cell proliferation and expansion, without affecting early recall and activation. Importantly, CTLA4Ig treatment in vivo induced a striking shift in the phenotype of the responding population from predominantly TEM in control-treated mice to predominantly central memory T cells in CTLA4Ig-treated mice, suggesting biased effects of CTLA4Ig on TEM responses. Our results identify a novel role for CD28/B7 as a regulator of memory T cell responses, and have important clinical implications for using CTLA4Ig to abrogate the pathologic consequences of TEM cells in autoimmunity and chronic disease.
Expression of Integrin β3 Is Correlated to the Properties of Quiescent Hemopoietic Stem Cells Possessing the Side Population Phenotype
Authors: Umemoto Terumasa , Yamato Masayuki , Shiratsuchi Yoshiko , Terasawa Masao , Yang Joseph , Nishida Kohji , Kobayashi Yoshiro , Okano Teruo 
Published: April 2014

Abstract
With significant attention paid to the field of tissue-specific stem cells, the identification of stem cell-specific markers is of considerable importance. Previously, the side population (SP) phenotype, with the capacity to efflux the DNA-binding dye Hoechst 33342, has been recognized as a common feature of adult tissue-specific stem cells. In this study, we show that high expression of integrin β3 (CD61) is an attribute of SP cells isolated from mouse bone marrow. Additionally, we confirmed that the expression of integrin β3 is correlated with properties of quiescent hemopoietic stem cells (HSCs) including the strength of the SP phenotype, cell cycle arrest, expression of HSC markers, and long-term hemopoiesis. Importantly, Lineage− (Lin−)/integrin β3high (β3high) SP cells have as strong a capacity for long-term hemopoiesis as c-Kit+/Sca-1+/Lin− SP cells, which are regarded as one of the most highly enriched HSC populations. Finally, the integrin β3 subunit that is present in SP cells having the properties of HSCs, is associated with integrin αv (CD51). Therefore, our results demonstrate that high expression of integrin β3 is correlated to the properties of quiescent HSCs and suggest that the integrin β3 subunit is available as a common surface marker of tissue-specific stem cells.
TLR2/TLR4-Independent Neutrophil Activation and Recruitment upon Endocytosis of Nucleosomes Reveals a New Pathway of Innate Immunity in Systemic Lupus Erythematosus
Authors: Rönnefarth Viktoria M. , Erbacher Annika I. M. , Lamkemeyer Tobias , Madlung Johannes , Nordheim Alfred , Rammensee Hans-Georg , Decker Patrice 
Published: April 2014

Abstract
The nucleosome is a major autoantigen in systemic lupus erythematosus (SLE); it can be detected as a circulating complex in the serum, and nucleosomes have been suggested to play a key role in disease development. In the present study, we show for the first time that physiological concentrations of purified nucleosomes trigger innate immunity. The nucleosomes are endocytosed and induce the direct activation of human neutrophils (polymorphonuclear leukocytes (PMN)) as revealed by CD11b/CD66b up-regulation, IL-8 secretion, and increased phagocytic activity. IL-8 is a neutrophil chemoattractant detected in high concentrations in the sera of patients, and IL-8 secretion might thus result in enhanced inflammation, as observed in lupus patients, via an amplification loop. Nucleosomes act as free complexes requiring no immune complex formation and independently of the presence of unmethylated CpG DNA motifs. Both normal and lupus neutrophils are sensitive to nucleosome-induced activation, and activation is not due to endotoxin or high-mobility group box 1 contamination. In mice, i.p. injection of purified nucleosomes induces neutrophil activation and recruitment in a TLR2/TLR4-independent manner. Importantly, neutrophils have been suggested to link innate and adaptive immunity. Thus, nucleosomes trigger a previously unknown pathway of innate immunity, which may partially explain why peripheral tolerance is broken in SLE patients.
Generation and Growth of CD28nullCD8+ Memory T Cells Mediated by IL-15 and Its Induced Cytokines
Authors: Chiu Wai Kan , Fann Monchou , Weng Nan-ping 
Published: April 2014

Abstract
Accumulation of CD28nullCD8+ T cells and the defects of these cells in response to antigenic stimulation are the hallmarks of age-associated decline of T cell function. However, the mechanism of these age-associated changes is not fully understood. In this study, we report an analysis of the growth of human CD28null and CD28+CD8+ memory T cells in response to homeostatic cytokine IL-15 in vitro. We showed that 1) there was no proliferative defect of CD28nullCD8+ memory T cells in response to IL-15 compared with their CD28+ counterparts; 2) stable loss of CD28 expression occurred in those actively dividing CD28+CD8+ memory T cells responding to IL-15; 3) the loss of CD28 was in part mediated by TNF-α that was induced by IL-15; and 4) CCL4 (MIP-1β), also induced by IL-15, had a significant inhibitory effect on the growth of CD28null cells, which in turn down-regulated their expression of CCL4 receptor CCR5. Together, these findings demonstrate that CD28nullCD8+ memory T cells proliferate normally in response to IL-15 and that IL-15 and its induced cytokines regulate the generation and growth of CD28nullCD8+ T cells, suggesting a possible role of IL-15 in the increase in CD28nullCD8+ T cells that occurs with aging.
Heat Shock Protein 70 Is Secreted from Tumor Cells by a Nonclassical Pathway Involving Lysosomal Endosomes
Authors: Mambula Salamatu S. , Calderwood Stuart K. 
Published: April 2014

AbstractHeat shock protein (HSP)70 can be released from tumor cells and stimulate a potent antitumor immune response. However, HSP70 does not contain a consensus secretory signal and thus cannot traverse the plasma membrane by conventional mechanisms. We have observed HSP70 release from intact human prostate carcinoma cell lines (PC-3 and LNCaP) by a mechanism independent of de novo HSP70 synthesis or cell death. This pathway is similar to one used by the leaderless protein IL-1β. Our studies show that HSP70 release involves transit though an endolysosomal compartment and is inhibited by lysosomotropic compounds. In addition, the rate of HSP70 secretion correlates well with the appearance of the lysosomal marker LAMP1 on the cell surface, further suggesting the role for endolysosomes. The entry of HSP70 into this secretory compartment appears to involve the ABC family transporter proteins and ABC transporter inhibitor glibenclamide antagonizes secretion. Although the cell signals involved in triggering stress induced HSP70 release though this lysosomal pathway are largely unknown, our experiments suggest a regulatory role for extracellular ATP. These mechanisms appear to be shared by IL-1β secretion. Following release, we observed the binding of extracellular HSP70 to the cell surface of the prostate carcinoma cells. These findings suggest that secreted HSP70 can take part in paracrine or autocrine interactions with adjacent cell surfaces. Our experiments therefore suggest a mechanism for HSP70 secretion and binding to the surface of other cells that may be involved in recognition of the tumor cells by the immune system.
Microarrays Reveal Distinct Gene Signatures in the Thymus of Seropositive and Seronegative Myasthenia Gravis Patients and the Role of CC Chemokine Ligand 21 in Thymic Hyperplasia
Authors: Le Panse Rozen , Cizeron-Clairac Géraldine , Bismuth Jacky , Berrih-Aknin Sonia 
Published: April 2014

AbstractMyasthenia gravis (MG) is an autoimmune disease mainly caused by antiacetylcholine receptor autoantibodies (seropositive (SP) disease) or by Abs against unknown autoantigenic target(s) (seronegative (SN) disease). Thymectomy is usually beneficial although thymic hyperplasia with ectopic germinal centers is mainly observed in SP MG. To understand the role of thymus in the disease process, we compared the thymic transcriptome of non-MG adults to those of SP patients with a low or high degree of hyperplasia or SN patients. Surprisingly, an overexpression of MHC class II, Ig, and B cell marker genes is observed in SP but also SN MG patients. Moreover, we demonstrate an overexpression of CXCL13 in all MG thymuses leading probably to the generalized B cell infiltration. However, we find different chemotactic properties for MG subgroups and, especially, a specific overexpression of CCL21 in hyperplastic thymuses triggering most likely ectopic germinal center development. Besides, SN patients present a peculiar signature with an abnormal expression of genes involved in muscle development and synaptic transmission, but also genes implicated in host response, suggesting that viral infection might be related to SN MG. Altogether, these results underline differential pathogenic mechanisms in the thymus of SP and SN MG and propose new research areas.
Analysis of the Individual Contributions of Igα (CD79a)- and Igβ (CD79b)-Mediated Tonic Signaling for Bone Marrow B Cell Development and Peripheral B Cell Maturation
Authors: Fuentes-Pananá Ezequiel M. , Bannish Gregory , Karnell Fredrick G. , Treml John F. , Monroe John G. 
Published: April 2014

Abstract
The individual contribution of Igα and Igβ for BCR-triggered fates is unclear. Prior evidence supports conflicting ideas concerning unique as well as redundant functions for these proteins in the context of BCR/pre-BCR signaling. Part of this ambiguity may reflect the recent appreciation that Igα and Igβ participate in both Ag-independent (tonic) and Ag-dependent signaling. The present study undertook defining the individual requirement for Igα and Igβ under conditions where only ligand-independent tonic signaling was operative. In this regard, we have constructed chimeric proteins containing one or two copies of the cytoplasmic domains of either Igα or Igβ and Igα/Igβ heterodimers with targeted Tyr→Phe modifications. The ability of these proteins to act as surrogate receptors and trigger early bone marrow and peripheral B cell maturation was tested in RAG2−/− primary pro-B cell lines and in gene transfer experiments in the μMT mouse model. We considered that the threshold for a functional activity mediated by the pre-BCR/BCR might only be reached when two functional copies of the Igα/Igβ ITAM domain are expressed together, and therefore the specificity conferred by these proteins can only be observed in these conditions. We found that the ligand-independent tonic signal is sufficient to drive development into mature follicular B cells and both Igα and Igβ chains supported formation of this population. In contrast, neither marginal zone nor B1 mature B cell subsets develop from bone marrow precursors under conditions where only tonic signals are generated.