bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Functional Role of HLA-G Expression in Human Gliomas: An Alternative Strategy of Immune Escape
Authors: Wiendl Heinz , Mitsdoerffer Meike , Hofmeister Valeska , Wischhusen Jörg , Bornemann Antje , Meyermann Richard , Weiss Elisabeth H. , Melms Arthur , Weller Michael 
Published: April 2014

Abstract
HLA-G is a nonclassical MHC molecule with highly limited tissue distribution that has been attributed chiefly immune regulatory functions. Glioblastoma is paradigmatic for the capability of human cancers to paralyze the immune system. To delineate the potential role of HLA-G in glioblastoma immunobiology, expression patterns and functional relevance of this MHC class Ib molecule were investigated in glioma cells and brain tissues. HLA-G mRNA expression was detected in six of 12 glioma cell lines in the absence of IFN-γ and in 10 of 12 cell lines in the presence of IFN-γ. HLA-G protein was detected in four of 12 cell lines in the absence of IFN-γ and in eight of 12 cell lines in the presence of IFN-γ. Immunohistochemical analysis of human brain tumors revealed expression of HLA-G in four of five tissue samples. Functional studies on the role of HLA-G in glioma cells were conducted with alloreactive PBMCs, NK cells, and T cell subpopulations. Expression of membrane-bound HLA-G1 and soluble HLA-G5 inhibited alloreactive and Ag-specific immune responses. Gene transfer of HLA-G1 or HLA-G5 into HLA-G-negative glioma cells (U87MG) rendered cells highly resistant to direct alloreactive lysis, inhibited the alloproliferative response, and prevented efficient priming of cytotoxic T cells. The inhibitory effects of HLA-G were directed against CD8 and CD4 T cells, but appeared to be NK cell independent. Interestingly, few HLA-G-positive cells within a population of HLA-G-negative tumor cells exerted significant immune inhibitory effects. We conclude that the aberrant expression of HLA-G may contribute to immune escape in human glioblastoma.
Dimethylfumarate Inhibits TNF-Induced Nuclear Entry of NF-κB/p65 in Human Endothelial Cells
Authors: Loewe Robert , Holnthoner Wolfgang , Gröger Marion , Pillinger Manuela , Gruber Florian , Mechtcheriakova Diana , Hofer Erhard , Wolff Klaus , Petzelbauer Peter 
Published: April 2014

Abstract
Fumaric acid esters, mainly dimethylfumarate (DMF), have been successfully used to treat psoriasis. Based on previous observations that DMF inhibited expression of several TNF-induced genes in endothelial cells, we wished to explore the molecular basis of DMF function in greater detail. In first experiments we analyzed DMF effects on tissue factor expression in human endothelial cells in culture, because tissue factor is expressed by two independent sets of transcription factors, by NF-κB via TNF and by early gene response-1 transcription factor via vascular endothelial growth factor (VEGF). We show that DMF inhibits TNF-induced tissue factor mRNA and protein expression as well as TNF-induced DNA binding of NF-κB proteins, but not VEGF-induced tissue factor protein, mRNA expression, or VEGF-induced early gene response-1 transcription factor/DNA binding. To determine where DMF interferes with the TNF/NF-κB signaling cascade, we next analyzed DMF effects on IκB and on the subcellular distribution of NF-κB. DMF does not inhibit TNF-induced IκBα phosphorylation and IκB degradation; thus, NF-κB is properly released from IκB complexes even in the presence of DMF. Importantly, DMF inhibits the TNF-induced nuclear entry of NF-κB proteins, and this effect appears selective for NF-κB after the release from IκB, because the constitutive shuttling of inactive NF-κB/IκB complexes into and out from the nucleus is not blocked by DMF. Moreover, DMF does not block NF-κB/DNA binding. In conclusion, DMF appears to selectively prevent the nuclear entry of activated NF-κB, and this may be the basis of its beneficial effect in psoriasis.
Gene Transfer of Ig-Fusion Proteins Into B Cells Prevents and Treats Autoimmune Diseases
Authors: Melo Marco E. F. , Qian Jiahua , El-Amine Moustapha , Agarwal Rajeev K. , Soukhareva Nadejda , Kang Yubin , Scott David W. 
Published: April 2014

Abstract
Based on the tolerogenic properties of IgG carriers and B cell Ag presentation, we developed a retrovirally mediated gene expression approach for treatment of autoimmune conditions. In this study, we show that the IgG-Ag retroviral constructs, expressing myelin basic protein (MBP) or glutamic acid decarboxylase in B cells, can be used for the treatment of murine models for multiple sclerosis and diabetes. Transduction of syngeneic B cells with MBP-IgG leads to the amelioration of ongoing experimental allergic encephalomyelitis induced by the transfer of primed cells from PL×SJL F1 mice with ongoing disease and could be effective even after symptoms appeared. This effect is specific and does not involve bystander suppression because treatment with MBP-IgG does not affect disease induced after immunization with proteolipid protein immunodominant peptide plus MBP. Interestingly, if donor B cells are derived from gld mice (Fas ligand-negative), then tolerance is not induced with a model Ag although there was no evidence for Fas ligand-mediated deletion of target T cells. In spontaneous diabetes in nonobese diabetic mice, we were able to stop the ongoing autoimmune process by treatment at 7–10 wk with glutamic acid decarboxylase-IgG retrovirally transduced B cells, or attenuate it with B cells transduced with an insulin B chain (B9–23) epitope IgG fusion protein. Furthermore, IgG fusion protein gene therapy can also protect primed recipients from Ag-induced anaphylactic shock, and thus does not cause immune deviation. These results demonstrate proof of principle for future efforts to develop this approach in a clinical setting.
Persistent Decreases in Blood Plasmacytoid Dendritic Cell Number and Function Despite Effective Highly Active Antiretroviral Therapy and Increased Blood Myeloid Dendritic Cells in HIV-Infected Individuals
Authors: Chehimi Jihed , Campbell Donald E. , Azzoni Livio , Bacheller Darlene , Papasavvas Emmanouil , Jerandi Ghassen , Mounzer Karam , Kostman Jay , Trinchieri Giorgio , Montaner Luis J. 
Published: April 2014

Abstract
Dendritic cells (DC) have an instrumental role in the activation and function of both innate and adaptive immune responses. In humans, at least two distinct DC subsets have been characterized based on phenotypic markers: the myeloid DC (MDC) and the plasmacytoid DC (PDC). Both subsets are critical producers of cytokines (IL-12 for MDC and type I/II IFNs for PDC) and are functionally different. We show in this study that HIV+ individuals have a significant decrease in the number of the Lin−HLA-DR+CD123+ and BDCA-2+ PDC compared with uninfected donors (p = 0.0001). HIV+ individuals also have a sustained impairment in viral-induced IFN-α production (p &lt; 0.0001). The decrease of the PDC subsets did not correlate with CD4 count or viral load and was not reversed in subjects under virally suppressive treatment, suggesting an irreversible change after infection. By contrast, the absolute number and median frequency of MDC in HIV-infected individuals were similar to those observed in uninfected controls, while a significant decrease was present in subjects with &gt;5000 HIV-1 copies/ml. The inverse association with viral load of the MDC number, but not of IFN-α secretion or the number of PDC, suggests a role for MDC in viral control. Our data suggest that DC subsets are differentially reconstituted during the immune recovery associated with antiviral therapy. The persistent impairment of certain DC subsets may result in a sustained defect in DC-mediated innate immune functions despite an effective treatment regimen.
A ras-Mutated Peptide Targeted by CTL Infiltrating a Human Melanoma Lesion
Authors: Linard Boris , Bézieau Stéphane , Benlalam Houssem , Labarrière Nathalie , Guilloux Yannick , Diez Elisabeth , Jotereau Francine 
Published: April 2014

Abstract
Ags derived from commonly mutated oncogenic proteins seem ideally suited as targets for tumor immunotherapy. Nonetheless, only a few mutated epitopes efficiently presented by human tumors have thus far been identified. We describe here an approach to identify such epitopes. This approach involves: 1) identifying tumors expressing a ras mutation and isolating the tumor-infiltrating lymphocytes (TIL); 2) transfecting COS cells to induce expression of unknown mutated peptides in the context of a patient’s HLA class I molecules; and 3) screening epitope recognition by using TIL from the tumors expressing a ras mutation. By using this approach, there appeared to be a N-ras mutation (a glutamine-to-arginine exchange at residue 61 (Q61R)), detected in a melanoma lesion, which was recognized specifically by the autologous TIL in the HLA-A*0101 context. The ras peptide 55–64Q61R was the epitope of these TIL and was regularly presented by Q61R-mutated HLA-A*0101+ melanoma cell lines. This peptide and its wild-type homolog (55–64wt) bound to HLA-A*0101 with similar affinities. However, only the mutated peptide could induce specific CTL expansion from PBL. All the CTL clones specific to the mutated peptide, failed to recognize the wild-type sequence on both COS and melanoma cells. These data thus show that oncogenic protein mutations can create shared tumor-specific CTL epitopes, efficiently presented by tumor cells, and that screening for oncogene-transfected COS cell recognition by TIL (from tumors containing mutations) is a powerful approach for the identification of these epitopes.
Cutting Edge: IFN-Producing Cells Respond to CXCR3 Ligands in the Presence of CXCL12 and Secrete Inflammatory Chemokines upon Activation
Authors: Krug Anne , Uppaluri Ravindra , Facchetti Fabio , Dorner Brigitte G. , Sheehan Kathleen C. F. , Schreiber Robert D. , Cella Marina , Colonna Marco 
Published: April 2014

Abstract
Human natural IFN-producing cells (IPC) circulate in the blood and cluster in chronically inflamed lymph nodes around high endothelial venules (HEV). Although L-selectin, CXCR4, and CCR7 are recognized as critical IPC homing mediators, the role of CXCR3 is unclear, since IPC do not respond to CXCR3 ligands in vitro. In this study, we show that migration of murine and human IPC to CXCR3 ligands in vitro requires engagement of CXCR4 by CXCL12. We also demonstrate that CXCL12 is present in human HEV in vivo. Moreover, after interaction with pathogenic stimuli, murine and human IPC secrete high levels of inflammatory chemokines. Thus, IPC migration into inflamed lymph nodes may be initially mediated by L-selectin, CXCL12, and CXCR3 ligands. Upon pathogen encounter, IPC positioning within the lymph node may be further directed by CCR7 and IPC secretion of inflammatory chemokines may attract other IPC, promoting cluster formation in lymph nodes.
The Fate of Effector T Cells In Vivo Is Determined During Activation and Differs for CD4+ and CD8+ Cells
Authors: Bode Ulrike , Sahle Andrea , Sparmann Gisela , Weidner Frauke , Westermann Jürgen 
Published: April 2014

Abstract
Effector T cells generated in the mesenteric lymph nodes (mLN) are known to accumulate in mLN and the tissue drained by them after circulating in the blood. Their accumulation is due less to preferential entry into mLN but more to preferential proliferation within mLN. The factors regulating the proliferation of effector T cells in vivo are unclear, and it is unknown whether they are different for CD4+ and CD8+ effector T cells. Rat T cells from mLN or peripheral lymph nodes (pLN) were stimulated polyclonally via the TCR and CD28 and injected i.v. into congenic recipients. Using three-color flow cytometry and immunohistochemistry, they were identified in mLN, pLN, and blood over time, and proliferation was determined by measuring bromodeoxyuridine incorporation. Only effector mLN T cells showed a significantly increased proliferation rate after entry into mLN compared with that in pLN (2.4 ± 1.8% vs 0.8 ± 0.4%). Proliferation among the injected cells was higher when they had contact with dendritic cells within mLN (9.0 ± 4.3%) than when they did not (4.1 ± 2.1%). Furthermore, effector mLN T cells which were observed 56 days after injection maintained the capacity for preferential proliferation within mLN. Interestingly, CD4+ effector mLN T cells proliferated at a higher rate (4.8 ± 0.7%), remaining in mLN, whereas CD8+ effector mLN T cells proliferated at a lower rate (3.3 ± 1.0%) and were able to leave the mLN into the blood. Elucidating the factors regulating the proliferation of effector T cells in vivo will help to modify their distribution for therapeutic purposes.
Live-Cell Dynamics and the Role of Costimulation in Immunological Synapse Formation
Authors: Wetzel Scott A. , McKeithan Timothy W. , Parker David C. 
Published: April 2014

Abstract
Using transfected fibroblasts expressing both wild-type I-Ek and green fluorescent protein-tagged I-Ek with covalently attached antigenic peptide, we have monitored movement of specific MHC:peptide complexes during CD4+ T cell-APC interactions by live-cell video microscopy. Ag recognition occurs within 30 s of T cell-APC contact, as shown by a sharp increase in cytoplasmic calcium ion concentration. Within 1 min, small MHC:peptide clusters form in the contact zone that coalesce into an immunological synapse over 3–20 min. When T cells conjugated to APC move across the APC surface, they appear to drag the synapse with them. This system was used to examine the role of costimulation in the formation of the immunological synapse. Blocking CD80/CD28 or ICAM-1/LFA-1 interactions alters synapse morphology and reduces the area and density of accumulated complexes. These reductions correlate with reduced T cell proliferation, while CD69 and CD25 expression and TCR down-modulation remain unaffected. Thus, costimulation is essential for normal mature immunological synapse formation.
NK Cell CD94/NKG2A Inhibitory Receptors Are Internalized and Recycle Independently of Inhibitory Signaling Processes
Authors: Borrego Francisco , Kabat Juraj , Sanni Tolib B. , Coligan John E. 
Published: April 2014

Abstract
Human CD94/NKG2A is an inhibitory receptor that recognizes HLA-E and is expressed by NK cells and a subset of T cells. We have analyzed the cellular trafficking of the CD94/NKG2A receptor using the NKL cell line and peripheral blood NK cells. Flow cytometric, confocal microscopic, and biochemical analyses show that CD94/NKG2A continuously recycles in an active process that requires the cytoskeleton between the cell surface and intracellular compartments that are distinguishable from recycling compartments used by well-characterized receptors, such as transferrin receptor (CD71). CD94/NKG2A, an inhibitory receptor, traffics differently from the closely related CD94/NKG2C molecule, an activating receptor. Using transfection/expression analyses of wild-type and mutant CD94/NKG2A molecules in the HLA-E negative rat basophilic cell line RBL-2H3, we demonstrate that CD94/NKG2A internalization is independent of ligand cross-linking or the presence of functional immunoreceptor tyrosine-based inhibition motifs. Thus, the mechanisms that control cell surface homeostasis of CD94/NKG2A are independent of functional signaling.
Bacterial-Reactive T Regulatory Cells Inhibit Pathogenic Immune Responses to the Enteric Flora
Authors: Cong Yingzi , Weaver Casey T. , Lazenby Audrey , Elson Charles O. 
Published: April 2014

Abstract
We showed previously that cecal bacterial Ag (CBA)-specific CD4+ T cells induce colitis when transferred into SCID mice. The purpose of this study was to generate and characterize CBA-specific regulatory T cells in C3H/HeJBir (Bir) mice. CD4+ T cells were stimulated with CBA-pulsed APC in the presence of IL-10 every 10–14 days. After four or more cycles, these T cells produced high levels of IL-10, low levels of IL-4 and IFN-γ, and no IL-2, consistent with the phenotype of T regulatory-1 (Tr1) cells. Bir Tr1 cells proliferated poorly, but their proliferation was dependent on CD28-B7 interactions and was MHC class II-restricted. Transfer of Bir Tr1 cells into SCID mice did not result in colitis, and cotransfer of Bir Tr1 T cells with pathogenic Bir CD4+ Th1 cells prevented colitis. Bir Tr1 cells inhibited proliferation and IFN-γ production of a CBA-specific Th1 cell line in vitro. Such inhibition was partly due to IL-10 and TGFβ1, but cognate interactions with either APCs or Th1 cells were also involved. Normal intestinal lamina propria CD4+ T cells had Tr1-like activity when stimulated with CBA-pulsed APCs. We conclude that CD4+ T cells with the properties of Tr1 cells are present in the intestinal lamina propria and hypothesize that these cells maintain intestinal immune homeostasis to the enteric flora.
Determinants of Autoantibody Induction by Conjugated Papillomavirus Virus-Like Particles
Authors: Chackerian Bryce , Lenz Petra , Lowy Douglas R. , Schiller John T. 
Published: April 2014

AbstractImmunization of mice with self-Ag arrayed on the surface of papillomavirus-like particles induces long-lasting high-titer IgG production by autoreactive B cells. In contrast, immunization with disorganized self-Ag linked to foreign Th epitopes induces weak autoantibody responses that are predominantly of the IgM isotype. In this study, we evaluated the structural correlates of autoantibody induction to determine the basis of these disparate observations, using a system in which mice were vaccinated with a fusion protein containing self (TNF-α) and foreign (streptavidin) components, conjugated to biotinylated virus-like particles (VLPs). Similar titers of autoantibodies to TNF-α were elicited using conjugated polyomavirus VLPs and papillomavirus VLPs, indicating that acute activation of dendritic cells by the Ag is not required. Strong autoantibody responses were also induced by conjugated papillomavirus capsid pentamers, indicating that a higher order particulate structure is also not required. However, a reduction of self-Ag density on VLP surfaces dramatically reduced the efficiency of IgG autoantibody induction. In contrast, the negative effects of reductions in foreign Ag density were limited and could be overcome by dosage and adjuvant. These data suggest that the immune system has evolved to differentially recognize closely spaced repetitive Ags and that the signals generated upon interactions with high-density self-Ags can overwhelm the normal mechanisms for B cell tolerance.
Age-Associated Augmentation of the Synthetic Ligand- Mediated Function of Mouse NK1.1 Ag+ T Cells: Their Cytokine Production and Hepatotoxicity In Vivo and In Vitro
Authors: Inui Takuo , Nakagawa Ryusuke , Ohkura Shuri , Habu Yoshiko , Koike Yuji , Motoki Kazuhiro , Kuranaga Noritsugu , Fukasawa Masashi , Shinomiya Nariyoshi , Seki Shuhji 
Published: April 2014

Abstract
We recently reported that the direct antitumor effectors in the liver induced by α-galactosylceramide (α-GalCer) are NK cells that are activated by the IFN-γ produced from NK1.1 Ag+ T cells (NKT cells) specifically stimulated with α-GalCer, whereas NKT cells cause hepatocyte injury through the Fas-Fas ligand pathway. In the present study, we investigated how mouse age affects the α-GalCer-induced effect using young (6-wk-old), middle-aged (30-wk-old), and old (75-wk-old) mice. The serum IFN-γ and IL-4 concentrations as well as alanine aminotransferase levels after the α-GalCer injection increased in an age-dependent manner. An α-GalCer injection also induced an age-dependent increase in the Fas ligand expression on liver NKT cells. Under the stimulus of α-GalCer in vitro, the liver mononuclear cells from old and middle-aged mice showed vigorous proliferation, remarkable antitumor cytotoxicity, and enhanced production of both IFN-γ and IL-4 in comparison to those of young mice, all of which were mediated mainly by NK1.1+ cells. Furthermore, liver mononuclear cells from old mice stimulated with α-GalCer showed a more potent Fas-Fas ligand-mediated cytotoxicity against primary cultured hepatocytes than did those from young mice. Most α-GalCer-injected old mice, but no young mice, died, while anti-IFN-γ Ab pretreatment completely inhibited mouse mortality. However, α-GalCer-induced hepatic injury did not improve at all by anti-IFN-γ Ab treatment, and the Fas-ligand expression of liver NKT cells did not change. Taken together, the synthetic ligand-mediated function of NKT cells is age-dependently up-regulated, and the produced IFN-γ is responsible for α-GalCer-induced antitumor immunity and the mouse mortality, while hepatic injury was unexpectedly found to be independent of IFN-γ.
Multilineage Engraftment with Minimal Graft-Versus-Host Disease Following In Utero Transplantation of S-59 Psoralen/Ultraviolet A Light-Treated, Sensitized T Cells and Adult T Cell-Depleted Bone Marrow in Fetal Mice
Authors: Bhattacharyya Swati , Chawla Anjulika , Smith Kristofer , Zhou Yungui , Talib Sohel , Wardwell Brian , Cowan Morton J. 
Published: April 2014

Abstract
Although engraftment following in utero stem cell transplantation can readily be achieved, a major limitation is the low level of donor chimerism. We hypothesized that a lack of space for donor cells in the recipient marrow was one of the primary reasons for failure to achieve significant engraftment, and that donor T cells could make space in an allogeneic mismatched setting. We found that 3 × 105 C57BL/6 (B6) naive CD3+ cells coinjected with B6 T cell-depleted bone marrow (TCDBM) into 14- to 15-day-old BALB/c fetuses resulted in multilineage engraftment (median, 68.3%) associated with severe graft-vs-host disease (GvHD; 62 vs 0% with TCDBM alone). When 1.5 × 105 CD4+ or CD8+ cells were used, low levels of engraftment were seen vs recipients of 1.5 × 105 CD3+ cells (2.4 ± 1.1 and 6.6 ± 3.9 vs 20.4 ± 10.4%, respectively). To test the hypothesis that proliferation of T cells in response to alloantigen resulted in GvHD and increased engraftment, we pretreated naive T cells with photochemical therapy (PCT) using S-59 psoralen and UVA light to prevent proliferation. GvHD was reduced (60–0%), but was also associated with a significant reduction in engrafted donor cells (53.4 ± 4.2 to 1.7 ± 0.5%). However, when B6 T cells were sensitized to BALB/c splenocytes, treated with PCT, and coinjected with TCDBM, there was a partial restoration of engraftment (13.3 ± 2.4% H2Kb+ cells) with only one of nine animals developing mild to moderate GvHD. In this study we have shown that PCT-treated T cells that are cytotoxic but nonproliferative can provide an engraftment advantage to donor cells, presumably by destroying host hemopoietic cells without causing GvHD.